/* Common target dependent code for GDB on ARM systems.
Copyright (C) 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998, 1999, 2000,
- 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
-#include <ctype.h> /* XXX for isupper () */
+#include <ctype.h> /* XXX for isupper (). */
#include "defs.h"
#include "frame.h"
#include "gdbcmd.h"
#include "gdbcore.h"
#include "gdb_string.h"
-#include "dis-asm.h" /* For register styles. */
+#include "dis-asm.h" /* For register styles. */
#include "regcache.h"
+#include "reggroups.h"
#include "doublest.h"
#include "value.h"
#include "arch-utils.h"
#include "prologue-value.h"
#include "target-descriptions.h"
#include "user-regs.h"
+#include "observer.h"
#include "arm-tdep.h"
#include "gdb/sim-arm.h"
#include "gdb_assert.h"
#include "vec.h"
+#include "features/arm-with-m.c"
+
static int arm_debug;
/* Macros for setting and testing a bit in a minimal symbol that marks
MSYMBOL_SET_SPECIAL Actually sets the "special" bit.
MSYMBOL_IS_SPECIAL Tests the "special" bit in a minimal symbol. */
-#define MSYMBOL_SET_SPECIAL(msym) \
+#define MSYMBOL_SET_SPECIAL(msym) \
MSYMBOL_TARGET_FLAG_1 (msym) = 1
#define MSYMBOL_IS_SPECIAL(msym) \
{
"auto",
"arm",
- "thumb"
+ "thumb",
+ NULL
};
static const char *arm_fallback_mode_string = "auto";
/* Number of different reg name sets (options). */
static int num_disassembly_options;
-/* The standard register names, and all the valid aliases for them. */
+/* The standard register names, and all the valid aliases for them. Note
+ that `fp', `sp' and `pc' are not added in this alias list, because they
+ have been added as builtin user registers in
+ std-regs.c:_initialize_frame_reg. */
static const struct
{
const char *name;
{ "tr", 9 },
/* Special names. */
{ "ip", 12 },
- { "sp", 13 },
{ "lr", 14 },
- { "pc", 15 },
/* Names used by GCC (not listed in the ARM EABI). */
{ "sl", 10 },
- { "fp", 11 },
/* A special name from the older ATPCS. */
{ "wr", 7 },
};
struct trad_frame_saved_reg *saved_regs;
};
+static CORE_ADDR arm_analyze_prologue (struct gdbarch *gdbarch,
+ CORE_ADDR prologue_start,
+ CORE_ADDR prologue_end,
+ struct arm_prologue_cache *cache);
+
/* Architecture version for displaced stepping. This effects the behaviour of
certain instructions, and really should not be hard-wired. */
int arm_apcs_32 = 1;
+/* Return the bit mask in ARM_PS_REGNUM that indicates Thumb mode. */
+
+int
+arm_psr_thumb_bit (struct gdbarch *gdbarch)
+{
+ if (gdbarch_tdep (gdbarch)->is_m)
+ return XPSR_T;
+ else
+ return CPSR_T;
+}
+
/* Determine if FRAME is executing in Thumb mode. */
-static int
+int
arm_frame_is_thumb (struct frame_info *frame)
{
CORE_ADDR cpsr;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_frame_arch (frame));
/* Every ARM frame unwinder can unwind the T bit of the CPSR, either
directly (from a signal frame or dummy frame) or by interpreting
trust the unwinders. */
cpsr = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
- return (cpsr & CPSR_T) != 0;
+ return (cpsr & t_bit) != 0;
}
/* Callback for VEC_lower_bound. */
function. This function should be called for addresses unrelated to
any executing frame; otherwise, prefer arm_frame_is_thumb. */
-static int
-arm_pc_is_thumb (CORE_ADDR memaddr)
+int
+arm_pc_is_thumb (struct gdbarch *gdbarch, CORE_ADDR memaddr)
{
struct obj_section *sec;
struct minimal_symbol *sym;
char type;
+ struct displaced_step_closure* dsc
+ = get_displaced_step_closure_by_addr(memaddr);
+
+ /* If checking the mode of displaced instruction in copy area, the mode
+ should be determined by instruction on the original address. */
+ if (dsc)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: check mode of %.8lx instead of %.8lx\n",
+ (unsigned long) dsc->insn_addr,
+ (unsigned long) memaddr);
+ memaddr = dsc->insn_addr;
+ }
/* If bit 0 of the address is set, assume this is a Thumb address. */
if (IS_THUMB_ADDR (memaddr))
if (strcmp (arm_force_mode_string, "thumb") == 0)
return 1;
+ /* ARM v6-M and v7-M are always in Thumb mode. */
+ if (gdbarch_tdep (gdbarch)->is_m)
+ return 1;
+
/* If there are mapping symbols, consult them. */
type = arm_find_mapping_symbol (memaddr, NULL);
if (type)
return val & ~1;
}
+/* Return 1 if PC is the start of a compiler helper function which
+ can be safely ignored during prologue skipping. IS_THUMB is true
+ if the function is known to be a Thumb function due to the way it
+ is being called. */
+static int
+skip_prologue_function (struct gdbarch *gdbarch, CORE_ADDR pc, int is_thumb)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ struct minimal_symbol *msym;
+
+ msym = lookup_minimal_symbol_by_pc (pc);
+ if (msym != NULL
+ && SYMBOL_VALUE_ADDRESS (msym) == pc
+ && SYMBOL_LINKAGE_NAME (msym) != NULL)
+ {
+ const char *name = SYMBOL_LINKAGE_NAME (msym);
+
+ /* The GNU linker's Thumb call stub to foo is named
+ __foo_from_thumb. */
+ if (strstr (name, "_from_thumb") != NULL)
+ name += 2;
+
+ /* On soft-float targets, __truncdfsf2 is called to convert promoted
+ arguments to their argument types in non-prototyped
+ functions. */
+ if (strncmp (name, "__truncdfsf2", strlen ("__truncdfsf2")) == 0)
+ return 1;
+ if (strncmp (name, "__aeabi_d2f", strlen ("__aeabi_d2f")) == 0)
+ return 1;
+
+ /* Internal functions related to thread-local storage. */
+ if (strncmp (name, "__tls_get_addr", strlen ("__tls_get_addr")) == 0)
+ return 1;
+ if (strncmp (name, "__aeabi_read_tp", strlen ("__aeabi_read_tp")) == 0)
+ return 1;
+ }
+ else
+ {
+ /* If we run against a stripped glibc, we may be unable to identify
+ special functions by name. Check for one important case,
+ __aeabi_read_tp, by comparing the *code* against the default
+ implementation (this is hand-written ARM assembler in glibc). */
+
+ if (!is_thumb
+ && read_memory_unsigned_integer (pc, 4, byte_order_for_code)
+ == 0xe3e00a0f /* mov r0, #0xffff0fff */
+ && read_memory_unsigned_integer (pc + 4, 4, byte_order_for_code)
+ == 0xe240f01f) /* sub pc, r0, #31 */
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Support routines for instruction parsing. */
+#define submask(x) ((1L << ((x) + 1)) - 1)
+#define bit(obj,st) (((obj) >> (st)) & 1)
+#define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st)))
+#define sbits(obj,st,fn) \
+ ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st))))
+#define BranchDest(addr,instr) \
+ ((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2)))
+
+/* Extract the immediate from instruction movw/movt of encoding T. INSN1 is
+ the first 16-bit of instruction, and INSN2 is the second 16-bit of
+ instruction. */
+#define EXTRACT_MOVW_MOVT_IMM_T(insn1, insn2) \
+ ((bits ((insn1), 0, 3) << 12) \
+ | (bits ((insn1), 10, 10) << 11) \
+ | (bits ((insn2), 12, 14) << 8) \
+ | bits ((insn2), 0, 7))
+
+/* Extract the immediate from instruction movw/movt of encoding A. INSN is
+ the 32-bit instruction. */
+#define EXTRACT_MOVW_MOVT_IMM_A(insn) \
+ ((bits ((insn), 16, 19) << 12) \
+ | bits ((insn), 0, 11))
+
+/* Decode immediate value; implements ThumbExpandImmediate pseudo-op. */
+
+static unsigned int
+thumb_expand_immediate (unsigned int imm)
+{
+ unsigned int count = imm >> 7;
+
+ if (count < 8)
+ switch (count / 2)
+ {
+ case 0:
+ return imm & 0xff;
+ case 1:
+ return (imm & 0xff) | ((imm & 0xff) << 16);
+ case 2:
+ return ((imm & 0xff) << 8) | ((imm & 0xff) << 24);
+ case 3:
+ return (imm & 0xff) | ((imm & 0xff) << 8)
+ | ((imm & 0xff) << 16) | ((imm & 0xff) << 24);
+ }
+
+ return (0x80 | (imm & 0x7f)) << (32 - count);
+}
+
+/* Return 1 if the 16-bit Thumb instruction INST might change
+ control flow, 0 otherwise. */
+
+static int
+thumb_instruction_changes_pc (unsigned short inst)
+{
+ if ((inst & 0xff00) == 0xbd00) /* pop {rlist, pc} */
+ return 1;
+
+ if ((inst & 0xf000) == 0xd000) /* conditional branch */
+ return 1;
+
+ if ((inst & 0xf800) == 0xe000) /* unconditional branch */
+ return 1;
+
+ if ((inst & 0xff00) == 0x4700) /* bx REG, blx REG */
+ return 1;
+
+ if ((inst & 0xff87) == 0x4687) /* mov pc, REG */
+ return 1;
+
+ if ((inst & 0xf500) == 0xb100) /* CBNZ or CBZ. */
+ return 1;
+
+ return 0;
+}
+
+/* Return 1 if the 32-bit Thumb instruction in INST1 and INST2
+ might change control flow, 0 otherwise. */
+
+static int
+thumb2_instruction_changes_pc (unsigned short inst1, unsigned short inst2)
+{
+ if ((inst1 & 0xf800) == 0xf000 && (inst2 & 0x8000) == 0x8000)
+ {
+ /* Branches and miscellaneous control instructions. */
+
+ if ((inst2 & 0x1000) != 0 || (inst2 & 0xd001) == 0xc000)
+ {
+ /* B, BL, BLX. */
+ return 1;
+ }
+ else if (inst1 == 0xf3de && (inst2 & 0xff00) == 0x3f00)
+ {
+ /* SUBS PC, LR, #imm8. */
+ return 1;
+ }
+ else if ((inst2 & 0xd000) == 0x8000 && (inst1 & 0x0380) != 0x0380)
+ {
+ /* Conditional branch. */
+ return 1;
+ }
+
+ return 0;
+ }
+
+ if ((inst1 & 0xfe50) == 0xe810)
+ {
+ /* Load multiple or RFE. */
+
+ if (bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* LDMIA or POP */
+ if (bit (inst2, 15))
+ return 1;
+ }
+ else if (!bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* LDMDB */
+ if (bit (inst2, 15))
+ return 1;
+ }
+ else if (bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* RFEIA */
+ return 1;
+ }
+ else if (!bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* RFEDB */
+ return 1;
+ }
+
+ return 0;
+ }
+
+ if ((inst1 & 0xffef) == 0xea4f && (inst2 & 0xfff0) == 0x0f00)
+ {
+ /* MOV PC or MOVS PC. */
+ return 1;
+ }
+
+ if ((inst1 & 0xff70) == 0xf850 && (inst2 & 0xf000) == 0xf000)
+ {
+ /* LDR PC. */
+ if (bits (inst1, 0, 3) == 15)
+ return 1;
+ if (bit (inst1, 7))
+ return 1;
+ if (bit (inst2, 11))
+ return 1;
+ if ((inst2 & 0x0fc0) == 0x0000)
+ return 1;
+
+ return 0;
+ }
+
+ if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
+ {
+ /* TBB. */
+ return 1;
+ }
+
+ if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf010)
+ {
+ /* TBH. */
+ return 1;
+ }
+
+ return 0;
+}
+
/* Analyze a Thumb prologue, looking for a recognizable stack frame
and frame pointer. Scan until we encounter a store that could
- clobber the stack frame unexpectedly, or an unknown instruction. */
+ clobber the stack frame unexpectedly, or an unknown instruction.
+ Return the last address which is definitely safe to skip for an
+ initial breakpoint. */
static CORE_ADDR
thumb_analyze_prologue (struct gdbarch *gdbarch,
CORE_ADDR start, CORE_ADDR limit,
struct arm_prologue_cache *cache)
{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
int i;
pv_t regs[16];
struct pv_area *stack;
struct cleanup *back_to;
CORE_ADDR offset;
+ CORE_ADDR unrecognized_pc = 0;
for (i = 0; i < 16; i++)
regs[i] = pv_register (i, 0);
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
offset);
}
- else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
- regs[THUMB_FP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
- (insn & 0xff) << 2);
+ else if ((insn & 0xf800) == 0xa800) /* add Rd, sp, #imm */
+ regs[bits (insn, 8, 10)] = pv_add_constant (regs[ARM_SP_REGNUM],
+ (insn & 0xff) << 2);
+ else if ((insn & 0xfe00) == 0x1c00 /* add Rd, Rn, #imm */
+ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM))
+ regs[bits (insn, 0, 2)] = pv_add_constant (regs[bits (insn, 3, 5)],
+ bits (insn, 6, 8));
+ else if ((insn & 0xf800) == 0x3000 /* add Rd, #imm */
+ && pv_is_register (regs[bits (insn, 8, 10)], ARM_SP_REGNUM))
+ regs[bits (insn, 8, 10)] = pv_add_constant (regs[bits (insn, 8, 10)],
+ bits (insn, 0, 7));
+ else if ((insn & 0xfe00) == 0x1800 /* add Rd, Rn, Rm */
+ && pv_is_register (regs[bits (insn, 6, 8)], ARM_SP_REGNUM)
+ && pv_is_constant (regs[bits (insn, 3, 5)]))
+ regs[bits (insn, 0, 2)] = pv_add (regs[bits (insn, 3, 5)],
+ regs[bits (insn, 6, 8)]);
+ else if ((insn & 0xff00) == 0x4400 /* add Rd, Rm */
+ && pv_is_constant (regs[bits (insn, 3, 6)]))
+ {
+ int rd = (bit (insn, 7) << 3) + bits (insn, 0, 2);
+ int rm = bits (insn, 3, 6);
+ regs[rd] = pv_add (regs[rd], regs[rm]);
+ }
else if ((insn & 0xff00) == 0x4600) /* mov hi, lo or mov lo, hi */
{
int dst_reg = (insn & 0x7) + ((insn & 0x80) >> 4);
pv_area_store (stack, addr, 4, regs[regno]);
}
- else
+ else if ((insn & 0xf800) == 0x6000) /* str rd, [rn, #off] */
+ {
+ int rd = bits (insn, 0, 2);
+ int rn = bits (insn, 3, 5);
+ pv_t addr;
+
+ offset = bits (insn, 6, 10) << 2;
+ addr = pv_add_constant (regs[rn], offset);
+
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ pv_area_store (stack, addr, 4, regs[rd]);
+ }
+ else if (((insn & 0xf800) == 0x7000 /* strb Rd, [Rn, #off] */
+ || (insn & 0xf800) == 0x8000) /* strh Rd, [Rn, #off] */
+ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM))
+ /* Ignore stores of argument registers to the stack. */
+ ;
+ else if ((insn & 0xf800) == 0xc800 /* ldmia Rn!, { registers } */
+ && pv_is_register (regs[bits (insn, 8, 10)], ARM_SP_REGNUM))
+ /* Ignore block loads from the stack, potentially copying
+ parameters from memory. */
+ ;
+ else if ((insn & 0xf800) == 0x9800 /* ldr Rd, [Rn, #immed] */
+ || ((insn & 0xf800) == 0x6800 /* ldr Rd, [sp, #immed] */
+ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM)))
+ /* Similarly ignore single loads from the stack. */
+ ;
+ else if ((insn & 0xffc0) == 0x0000 /* lsls Rd, Rm, #0 */
+ || (insn & 0xffc0) == 0x1c00) /* add Rd, Rn, #0 */
+ /* Skip register copies, i.e. saves to another register
+ instead of the stack. */
+ ;
+ else if ((insn & 0xf800) == 0x2000) /* movs Rd, #imm */
+ /* Recognize constant loads; even with small stacks these are necessary
+ on Thumb. */
+ regs[bits (insn, 8, 10)] = pv_constant (bits (insn, 0, 7));
+ else if ((insn & 0xf800) == 0x4800) /* ldr Rd, [pc, #imm] */
+ {
+ /* Constant pool loads, for the same reason. */
+ unsigned int constant;
+ CORE_ADDR loc;
+
+ loc = start + 4 + bits (insn, 0, 7) * 4;
+ constant = read_memory_unsigned_integer (loc, 4, byte_order);
+ regs[bits (insn, 8, 10)] = pv_constant (constant);
+ }
+ else if ((insn & 0xe000) == 0xe000)
+ {
+ unsigned short inst2;
+
+ inst2 = read_memory_unsigned_integer (start + 2, 2,
+ byte_order_for_code);
+
+ if ((insn & 0xf800) == 0xf000 && (inst2 & 0xe800) == 0xe800)
+ {
+ /* BL, BLX. Allow some special function calls when
+ skipping the prologue; GCC generates these before
+ storing arguments to the stack. */
+ CORE_ADDR nextpc;
+ int j1, j2, imm1, imm2;
+
+ imm1 = sbits (insn, 0, 10);
+ imm2 = bits (inst2, 0, 10);
+ j1 = bit (inst2, 13);
+ j2 = bit (inst2, 11);
+
+ offset = ((imm1 << 12) + (imm2 << 1));
+ offset ^= ((!j2) << 22) | ((!j1) << 23);
+
+ nextpc = start + 4 + offset;
+ /* For BLX make sure to clear the low bits. */
+ if (bit (inst2, 12) == 0)
+ nextpc = nextpc & 0xfffffffc;
+
+ if (!skip_prologue_function (gdbarch, nextpc,
+ bit (inst2, 12) != 0))
+ break;
+ }
+
+ else if ((insn & 0xffd0) == 0xe900 /* stmdb Rn{!},
+ { registers } */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ pv_t addr = regs[bits (insn, 0, 3)];
+ int regno;
+
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ /* Calculate offsets of saved registers. */
+ for (regno = ARM_LR_REGNUM; regno >= 0; regno--)
+ if (inst2 & (1 << regno))
+ {
+ addr = pv_add_constant (addr, -4);
+ pv_area_store (stack, addr, 4, regs[regno]);
+ }
+
+ if (insn & 0x0020)
+ regs[bits (insn, 0, 3)] = addr;
+ }
+
+ else if ((insn & 0xff50) == 0xe940 /* strd Rt, Rt2,
+ [Rn, #+/-imm]{!} */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ int regno1 = bits (inst2, 12, 15);
+ int regno2 = bits (inst2, 8, 11);
+ pv_t addr = regs[bits (insn, 0, 3)];
+
+ offset = inst2 & 0xff;
+ if (insn & 0x0080)
+ addr = pv_add_constant (addr, offset);
+ else
+ addr = pv_add_constant (addr, -offset);
+
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ pv_area_store (stack, addr, 4, regs[regno1]);
+ pv_area_store (stack, pv_add_constant (addr, 4),
+ 4, regs[regno2]);
+
+ if (insn & 0x0020)
+ regs[bits (insn, 0, 3)] = addr;
+ }
+
+ else if ((insn & 0xfff0) == 0xf8c0 /* str Rt,[Rn,+/-#imm]{!} */
+ && (inst2 & 0x0c00) == 0x0c00
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ int regno = bits (inst2, 12, 15);
+ pv_t addr = regs[bits (insn, 0, 3)];
+
+ offset = inst2 & 0xff;
+ if (inst2 & 0x0200)
+ addr = pv_add_constant (addr, offset);
+ else
+ addr = pv_add_constant (addr, -offset);
+
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ pv_area_store (stack, addr, 4, regs[regno]);
+
+ if (inst2 & 0x0100)
+ regs[bits (insn, 0, 3)] = addr;
+ }
+
+ else if ((insn & 0xfff0) == 0xf8c0 /* str.w Rt,[Rn,#imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ int regno = bits (inst2, 12, 15);
+ pv_t addr;
+
+ offset = inst2 & 0xfff;
+ addr = pv_add_constant (regs[bits (insn, 0, 3)], offset);
+
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ pv_area_store (stack, addr, 4, regs[regno]);
+ }
+
+ else if ((insn & 0xffd0) == 0xf880 /* str{bh}.w Rt,[Rn,#imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Ignore stores of argument registers to the stack. */
+ ;
+
+ else if ((insn & 0xffd0) == 0xf800 /* str{bh} Rt,[Rn,#+/-imm] */
+ && (inst2 & 0x0d00) == 0x0c00
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Ignore stores of argument registers to the stack. */
+ ;
+
+ else if ((insn & 0xffd0) == 0xe890 /* ldmia Rn[!],
+ { registers } */
+ && (inst2 & 0x8000) == 0x0000
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Ignore block loads from the stack, potentially copying
+ parameters from memory. */
+ ;
+
+ else if ((insn & 0xffb0) == 0xe950 /* ldrd Rt, Rt2,
+ [Rn, #+/-imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Similarly ignore dual loads from the stack. */
+ ;
+
+ else if ((insn & 0xfff0) == 0xf850 /* ldr Rt,[Rn,#+/-imm] */
+ && (inst2 & 0x0d00) == 0x0c00
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Similarly ignore single loads from the stack. */
+ ;
+
+ else if ((insn & 0xfff0) == 0xf8d0 /* ldr.w Rt,[Rn,#imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Similarly ignore single loads from the stack. */
+ ;
+
+ else if ((insn & 0xfbf0) == 0xf100 /* add.w Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)],
+ thumb_expand_immediate (imm));
+ }
+
+ else if ((insn & 0xfbf0) == 0xf200 /* addw Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)], imm);
+ }
+
+ else if ((insn & 0xfbf0) == 0xf1a0 /* sub.w Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)],
+ - (CORE_ADDR) thumb_expand_immediate (imm));
+ }
+
+ else if ((insn & 0xfbf0) == 0xf2a0 /* subw Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)], - (CORE_ADDR) imm);
+ }
+
+ else if ((insn & 0xfbff) == 0xf04f) /* mov.w Rd, #const */
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_constant (thumb_expand_immediate (imm));
+ }
+
+ else if ((insn & 0xfbf0) == 0xf240) /* movw Rd, #const */
+ {
+ unsigned int imm
+ = EXTRACT_MOVW_MOVT_IMM_T (insn, inst2);
+
+ regs[bits (inst2, 8, 11)] = pv_constant (imm);
+ }
+
+ else if (insn == 0xea5f /* mov.w Rd,Rm */
+ && (inst2 & 0xf0f0) == 0)
+ {
+ int dst_reg = (inst2 & 0x0f00) >> 8;
+ int src_reg = inst2 & 0xf;
+ regs[dst_reg] = regs[src_reg];
+ }
+
+ else if ((insn & 0xff7f) == 0xf85f) /* ldr.w Rt,<label> */
+ {
+ /* Constant pool loads. */
+ unsigned int constant;
+ CORE_ADDR loc;
+
+ offset = bits (insn, 0, 11);
+ if (insn & 0x0080)
+ loc = start + 4 + offset;
+ else
+ loc = start + 4 - offset;
+
+ constant = read_memory_unsigned_integer (loc, 4, byte_order);
+ regs[bits (inst2, 12, 15)] = pv_constant (constant);
+ }
+
+ else if ((insn & 0xff7f) == 0xe95f) /* ldrd Rt,Rt2,<label> */
+ {
+ /* Constant pool loads. */
+ unsigned int constant;
+ CORE_ADDR loc;
+
+ offset = bits (insn, 0, 7) << 2;
+ if (insn & 0x0080)
+ loc = start + 4 + offset;
+ else
+ loc = start + 4 - offset;
+
+ constant = read_memory_unsigned_integer (loc, 4, byte_order);
+ regs[bits (inst2, 12, 15)] = pv_constant (constant);
+
+ constant = read_memory_unsigned_integer (loc + 4, 4, byte_order);
+ regs[bits (inst2, 8, 11)] = pv_constant (constant);
+ }
+
+ else if (thumb2_instruction_changes_pc (insn, inst2))
+ {
+ /* Don't scan past anything that might change control flow. */
+ break;
+ }
+ else
+ {
+ /* The optimizer might shove anything into the prologue,
+ so we just skip what we don't recognize. */
+ unrecognized_pc = start;
+ }
+
+ start += 2;
+ }
+ else if (thumb_instruction_changes_pc (insn))
{
- /* We don't know what this instruction is. We're finished
- scanning. NOTE: Recognizing more safe-to-ignore
- instructions here will improve support for optimized
- code. */
+ /* Don't scan past anything that might change control flow. */
break;
}
+ else
+ {
+ /* The optimizer might shove anything into the prologue,
+ so we just skip what we don't recognize. */
+ unrecognized_pc = start;
+ }
start += 2;
}
+ if (arm_debug)
+ fprintf_unfiltered (gdb_stdlog, "Prologue scan stopped at %s\n",
+ paddress (gdbarch, start));
+
+ if (unrecognized_pc == 0)
+ unrecognized_pc = start;
+
if (cache == NULL)
{
do_cleanups (back_to);
- return start;
+ return unrecognized_pc;
}
if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
cache->saved_regs[i].addr = offset;
do_cleanups (back_to);
- return start;
+ return unrecognized_pc;
}
-/* Advance the PC across any function entry prologue instructions to
+
+/* Try to analyze the instructions starting from PC, which load symbol
+ __stack_chk_guard. Return the address of instruction after loading this
+ symbol, set the dest register number to *BASEREG, and set the size of
+ instructions for loading symbol in OFFSET. Return 0 if instructions are
+ not recognized. */
+
+static CORE_ADDR
+arm_analyze_load_stack_chk_guard(CORE_ADDR pc, struct gdbarch *gdbarch,
+ unsigned int *destreg, int *offset)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ int is_thumb = arm_pc_is_thumb (gdbarch, pc);
+ unsigned int low, high, address;
+
+ address = 0;
+ if (is_thumb)
+ {
+ unsigned short insn1
+ = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+
+ if ((insn1 & 0xf800) == 0x4800) /* ldr Rd, #immed */
+ {
+ *destreg = bits (insn1, 8, 10);
+ *offset = 2;
+ address = bits (insn1, 0, 7);
+ }
+ else if ((insn1 & 0xfbf0) == 0xf240) /* movw Rd, #const */
+ {
+ unsigned short insn2
+ = read_memory_unsigned_integer (pc + 2, 2, byte_order_for_code);
+
+ low = EXTRACT_MOVW_MOVT_IMM_T (insn1, insn2);
+
+ insn1
+ = read_memory_unsigned_integer (pc + 4, 2, byte_order_for_code);
+ insn2
+ = read_memory_unsigned_integer (pc + 6, 2, byte_order_for_code);
+
+ /* movt Rd, #const */
+ if ((insn1 & 0xfbc0) == 0xf2c0)
+ {
+ high = EXTRACT_MOVW_MOVT_IMM_T (insn1, insn2);
+ *destreg = bits (insn2, 8, 11);
+ *offset = 8;
+ address = (high << 16 | low);
+ }
+ }
+ }
+ else
+ {
+ unsigned int insn
+ = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
+
+ if ((insn & 0x0e5f0000) == 0x041f0000) /* ldr Rd, #immed */
+ {
+ address = bits (insn, 0, 11);
+ *destreg = bits (insn, 12, 15);
+ *offset = 4;
+ }
+ else if ((insn & 0x0ff00000) == 0x03000000) /* movw Rd, #const */
+ {
+ low = EXTRACT_MOVW_MOVT_IMM_A (insn);
+
+ insn
+ = read_memory_unsigned_integer (pc + 4, 4, byte_order_for_code);
+
+ if ((insn & 0x0ff00000) == 0x03400000) /* movt Rd, #const */
+ {
+ high = EXTRACT_MOVW_MOVT_IMM_A (insn);
+ *destreg = bits (insn, 12, 15);
+ *offset = 8;
+ address = (high << 16 | low);
+ }
+ }
+ }
+
+ return address;
+}
+
+/* Try to skip a sequence of instructions used for stack protector. If PC
+ points to the first instruction of this sequence, return the address of
+ first instruction after this sequence, otherwise, return original PC.
+
+ On arm, this sequence of instructions is composed of mainly three steps,
+ Step 1: load symbol __stack_chk_guard,
+ Step 2: load from address of __stack_chk_guard,
+ Step 3: store it to somewhere else.
+
+ Usually, instructions on step 2 and step 3 are the same on various ARM
+ architectures. On step 2, it is one instruction 'ldr Rx, [Rn, #0]', and
+ on step 3, it is also one instruction 'str Rx, [r7, #immd]'. However,
+ instructions in step 1 vary from different ARM architectures. On ARMv7,
+ they are,
+
+ movw Rn, #:lower16:__stack_chk_guard
+ movt Rn, #:upper16:__stack_chk_guard
+
+ On ARMv5t, it is,
+
+ ldr Rn, .Label
+ ....
+ .Lable:
+ .word __stack_chk_guard
+
+ Since ldr/str is a very popular instruction, we can't use them as
+ 'fingerprint' or 'signature' of stack protector sequence. Here we choose
+ sequence {movw/movt, ldr}/ldr/str plus symbol __stack_chk_guard, if not
+ stripped, as the 'fingerprint' of a stack protector cdoe sequence. */
+
+static CORE_ADDR
+arm_skip_stack_protector(CORE_ADDR pc, struct gdbarch *gdbarch)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned int address, basereg;
+ struct minimal_symbol *stack_chk_guard;
+ int offset;
+ int is_thumb = arm_pc_is_thumb (gdbarch, pc);
+ CORE_ADDR addr;
+
+ /* Try to parse the instructions in Step 1. */
+ addr = arm_analyze_load_stack_chk_guard (pc, gdbarch,
+ &basereg, &offset);
+ if (!addr)
+ return pc;
+
+ stack_chk_guard = lookup_minimal_symbol_by_pc (addr);
+ /* If name of symbol doesn't start with '__stack_chk_guard', this
+ instruction sequence is not for stack protector. If symbol is
+ removed, we conservatively think this sequence is for stack protector. */
+ if (stack_chk_guard
+ && strncmp (SYMBOL_LINKAGE_NAME (stack_chk_guard), "__stack_chk_guard",
+ strlen ("__stack_chk_guard")) != 0)
+ return pc;
+
+ if (is_thumb)
+ {
+ unsigned int destreg;
+ unsigned short insn
+ = read_memory_unsigned_integer (pc + offset, 2, byte_order_for_code);
+
+ /* Step 2: ldr Rd, [Rn, #immed], encoding T1. */
+ if ((insn & 0xf800) != 0x6800)
+ return pc;
+ if (bits (insn, 3, 5) != basereg)
+ return pc;
+ destreg = bits (insn, 0, 2);
+
+ insn = read_memory_unsigned_integer (pc + offset + 2, 2,
+ byte_order_for_code);
+ /* Step 3: str Rd, [Rn, #immed], encoding T1. */
+ if ((insn & 0xf800) != 0x6000)
+ return pc;
+ if (destreg != bits (insn, 0, 2))
+ return pc;
+ }
+ else
+ {
+ unsigned int destreg;
+ unsigned int insn
+ = read_memory_unsigned_integer (pc + offset, 4, byte_order_for_code);
+
+ /* Step 2: ldr Rd, [Rn, #immed], encoding A1. */
+ if ((insn & 0x0e500000) != 0x04100000)
+ return pc;
+ if (bits (insn, 16, 19) != basereg)
+ return pc;
+ destreg = bits (insn, 12, 15);
+ /* Step 3: str Rd, [Rn, #immed], encoding A1. */
+ insn = read_memory_unsigned_integer (pc + offset + 4,
+ 4, byte_order_for_code);
+ if ((insn & 0x0e500000) != 0x04000000)
+ return pc;
+ if (bits (insn, 12, 15) != destreg)
+ return pc;
+ }
+ /* The size of total two instructions ldr/str is 4 on Thumb-2, while 8
+ on arm. */
+ if (is_thumb)
+ return pc + offset + 4;
+ else
+ return pc + offset + 8;
+}
+
+/* Advance the PC across any function entry prologue instructions to
reach some "real" code.
The APCS (ARM Procedure Call Standard) defines the following
[stfe f6, [sp, #-12]!]
[stfe f5, [sp, #-12]!]
[stfe f4, [sp, #-12]!]
- sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn */
+ sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn. */
static CORE_ADDR
arm_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
CORE_ADDR func_addr, limit_pc;
struct symtab_and_line sal;
- /* If we're in a dummy frame, don't even try to skip the prologue. */
- if (deprecated_pc_in_call_dummy (gdbarch, pc))
- return pc;
-
/* See if we can determine the end of the prologue via the symbol table.
If so, then return either PC, or the PC after the prologue, whichever
is greater. */
{
CORE_ADDR post_prologue_pc
= skip_prologue_using_sal (gdbarch, func_addr);
+ struct symtab *s = find_pc_symtab (func_addr);
+
+ if (post_prologue_pc)
+ post_prologue_pc
+ = arm_skip_stack_protector (post_prologue_pc, gdbarch);
+
+
+ /* GCC always emits a line note before the prologue and another
+ one after, even if the two are at the same address or on the
+ same line. Take advantage of this so that we do not need to
+ know every instruction that might appear in the prologue. We
+ will have producer information for most binaries; if it is
+ missing (e.g. for -gstabs), assuming the GNU tools. */
+ if (post_prologue_pc
+ && (s == NULL
+ || s->producer == NULL
+ || strncmp (s->producer, "GNU ", sizeof ("GNU ") - 1) == 0))
+ return post_prologue_pc;
+
if (post_prologue_pc != 0)
- return max (pc, post_prologue_pc);
+ {
+ CORE_ADDR analyzed_limit;
+
+ /* For non-GCC compilers, make sure the entire line is an
+ acceptable prologue; GDB will round this function's
+ return value up to the end of the following line so we
+ can not skip just part of a line (and we do not want to).
+
+ RealView does not treat the prologue specially, but does
+ associate prologue code with the opening brace; so this
+ lets us skip the first line if we think it is the opening
+ brace. */
+ if (arm_pc_is_thumb (gdbarch, func_addr))
+ analyzed_limit = thumb_analyze_prologue (gdbarch, func_addr,
+ post_prologue_pc, NULL);
+ else
+ analyzed_limit = arm_analyze_prologue (gdbarch, func_addr,
+ post_prologue_pc, NULL);
+
+ if (analyzed_limit != post_prologue_pc)
+ return func_addr;
+
+ return post_prologue_pc;
+ }
}
/* Can't determine prologue from the symbol table, need to examine
/* Find an upper limit on the function prologue using the debug
information. If the debug information could not be used to provide
that bound, then use an arbitrary large number as the upper bound. */
- /* Like arm_scan_prologue, stop no later than pc + 64. */
+ /* Like arm_scan_prologue, stop no later than pc + 64. */
limit_pc = skip_prologue_using_sal (gdbarch, pc);
if (limit_pc == 0)
limit_pc = pc + 64; /* Magic. */
/* Check if this is Thumb code. */
- if (arm_pc_is_thumb (pc))
+ if (arm_pc_is_thumb (gdbarch, pc))
return thumb_analyze_prologue (gdbarch, pc, limit_pc, NULL);
for (skip_pc = pc; skip_pc < limit_pc; skip_pc += 4)
break;
}
- return skip_pc; /* End of prologue */
+ return skip_pc; /* End of prologue. */
}
/* *INDENT-OFF* */
R7 -> 0 local variables (16 bytes)
SP -> -12 additional stack space (12 bytes)
The frame size would thus be 36 bytes, and the frame offset would be
- 12 bytes. The frame register is R7.
+ 12 bytes. The frame register is R7.
The comments for thumb_skip_prolog() describe the algorithm we use
to detect the end of the prolog. */
if (find_pc_partial_function (block_addr, NULL, &prologue_start,
&prologue_end))
{
- struct symtab_and_line sal = find_pc_line (prologue_start, 0);
-
- if (sal.line == 0) /* no line info, use current PC */
- prologue_end = prev_pc;
- else if (sal.end < prologue_end) /* next line begins after fn end */
- prologue_end = sal.end; /* (probably means no prologue) */
+ /* See comment in arm_scan_prologue for an explanation of
+ this heuristics. */
+ if (prologue_end > prologue_start + 64)
+ {
+ prologue_end = prologue_start + 64;
+ }
}
else
/* We're in the boondocks: we have no idea where the start of the
thumb_analyze_prologue (gdbarch, prologue_start, prologue_end, cache);
}
-/* This function decodes an ARM function prologue to determine:
- 1) the size of the stack frame
- 2) which registers are saved on it
- 3) the offsets of saved regs
- 4) the offset from the stack pointer to the frame pointer
- This information is stored in the "extra" fields of the frame_info.
-
- There are two basic forms for the ARM prologue. The fixed argument
- function call will look like:
-
- mov ip, sp
- stmfd sp!, {fp, ip, lr, pc}
- sub fp, ip, #4
- [sub sp, sp, #4]
-
- Which would create this stack frame (offsets relative to FP):
- IP -> 4 (caller's stack)
- FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
- -4 LR (return address in caller)
- -8 IP (copy of caller's SP)
- -12 FP (caller's FP)
- SP -> -28 Local variables
-
- The frame size would thus be 32 bytes, and the frame offset would be
- 28 bytes. The stmfd call can also save any of the vN registers it
- plans to use, which increases the frame size accordingly.
-
- Note: The stored PC is 8 off of the STMFD instruction that stored it
- because the ARM Store instructions always store PC + 8 when you read
- the PC register.
-
- A variable argument function call will look like:
-
- mov ip, sp
- stmfd sp!, {a1, a2, a3, a4}
- stmfd sp!, {fp, ip, lr, pc}
- sub fp, ip, #20
-
- Which would create this stack frame (offsets relative to FP):
- IP -> 20 (caller's stack)
- 16 A4
- 12 A3
- 8 A2
- 4 A1
- FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
- -4 LR (return address in caller)
- -8 IP (copy of caller's SP)
- -12 FP (caller's FP)
- SP -> -28 Local variables
-
- The frame size would thus be 48 bytes, and the frame offset would be
- 28 bytes.
-
- There is another potential complication, which is that the optimizer
- will try to separate the store of fp in the "stmfd" instruction from
- the "sub fp, ip, #NN" instruction. Almost anything can be there, so
- we just key on the stmfd, and then scan for the "sub fp, ip, #NN"...
-
- Also, note, the original version of the ARM toolchain claimed that there
- should be an
-
- instruction at the end of the prologue. I have never seen GCC produce
- this, and the ARM docs don't mention it. We still test for it below in
- case it happens...
-
- */
+/* Return 1 if THIS_INSTR might change control flow, 0 otherwise. */
-static void
-arm_scan_prologue (struct frame_info *this_frame,
- struct arm_prologue_cache *cache)
+static int
+arm_instruction_changes_pc (uint32_t this_instr)
{
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- int regno;
- CORE_ADDR prologue_start, prologue_end, current_pc;
- CORE_ADDR prev_pc = get_frame_pc (this_frame);
- CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
- pv_t regs[ARM_FPS_REGNUM];
- struct pv_area *stack;
- struct cleanup *back_to;
- CORE_ADDR offset;
+ if (bits (this_instr, 28, 31) == INST_NV)
+ /* Unconditional instructions. */
+ switch (bits (this_instr, 24, 27))
+ {
+ case 0xa:
+ case 0xb:
+ /* Branch with Link and change to Thumb. */
+ return 1;
+ case 0xc:
+ case 0xd:
+ case 0xe:
+ /* Coprocessor register transfer. */
+ if (bits (this_instr, 12, 15) == 15)
+ error (_("Invalid update to pc in instruction"));
+ return 0;
+ default:
+ return 0;
+ }
+ else
+ switch (bits (this_instr, 25, 27))
+ {
+ case 0x0:
+ if (bits (this_instr, 23, 24) == 2 && bit (this_instr, 20) == 0)
+ {
+ /* Multiplies and extra load/stores. */
+ if (bit (this_instr, 4) == 1 && bit (this_instr, 7) == 1)
+ /* Neither multiplies nor extension load/stores are allowed
+ to modify PC. */
+ return 0;
- /* Assume there is no frame until proven otherwise. */
- cache->framereg = ARM_SP_REGNUM;
- cache->framesize = 0;
+ /* Otherwise, miscellaneous instructions. */
- /* Check for Thumb prologue. */
- if (arm_frame_is_thumb (this_frame))
- {
- thumb_scan_prologue (gdbarch, prev_pc, block_addr, cache);
- return;
- }
+ /* BX <reg>, BXJ <reg>, BLX <reg> */
+ if (bits (this_instr, 4, 27) == 0x12fff1
+ || bits (this_instr, 4, 27) == 0x12fff2
+ || bits (this_instr, 4, 27) == 0x12fff3)
+ return 1;
- /* Find the function prologue. If we can't find the function in
- the symbol table, peek in the stack frame to find the PC. */
- if (find_pc_partial_function (block_addr, NULL, &prologue_start,
- &prologue_end))
- {
- /* One way to find the end of the prologue (which works well
- for unoptimized code) is to do the following:
+ /* Other miscellaneous instructions are unpredictable if they
+ modify PC. */
+ return 0;
+ }
+ /* Data processing instruction. Fall through. */
- struct symtab_and_line sal = find_pc_line (prologue_start, 0);
+ case 0x1:
+ if (bits (this_instr, 12, 15) == 15)
+ return 1;
+ else
+ return 0;
- if (sal.line == 0)
- prologue_end = prev_pc;
- else if (sal.end < prologue_end)
- prologue_end = sal.end;
+ case 0x2:
+ case 0x3:
+ /* Media instructions and architecturally undefined instructions. */
+ if (bits (this_instr, 25, 27) == 3 && bit (this_instr, 4) == 1)
+ return 0;
- This mechanism is very accurate so long as the optimizer
- doesn't move any instructions from the function body into the
- prologue. If this happens, sal.end will be the last
- instruction in the first hunk of prologue code just before
- the first instruction that the scheduler has moved from
- the body to the prologue.
+ /* Stores. */
+ if (bit (this_instr, 20) == 0)
+ return 0;
- In order to make sure that we scan all of the prologue
- instructions, we use a slightly less accurate mechanism which
- may scan more than necessary. To help compensate for this
- lack of accuracy, the prologue scanning loop below contains
- several clauses which'll cause the loop to terminate early if
- an implausible prologue instruction is encountered.
-
- The expression
-
- prologue_start + 64
-
- is a suitable endpoint since it accounts for the largest
- possible prologue plus up to five instructions inserted by
- the scheduler. */
-
- if (prologue_end > prologue_start + 64)
- {
- prologue_end = prologue_start + 64; /* See above. */
- }
- }
- else
- {
- /* We have no symbol information. Our only option is to assume this
- function has a standard stack frame and the normal frame register.
- Then, we can find the value of our frame pointer on entrance to
- the callee (or at the present moment if this is the innermost frame).
- The value stored there should be the address of the stmfd + 8. */
- CORE_ADDR frame_loc;
- LONGEST return_value;
+ /* Loads. */
+ if (bits (this_instr, 12, 15) == ARM_PC_REGNUM)
+ return 1;
+ else
+ return 0;
- frame_loc = get_frame_register_unsigned (this_frame, ARM_FP_REGNUM);
- if (!safe_read_memory_integer (frame_loc, 4, byte_order, &return_value))
- return;
- else
- {
- prologue_start = gdbarch_addr_bits_remove
- (gdbarch, return_value) - 8;
- prologue_end = prologue_start + 64; /* See above. */
- }
- }
+ case 0x4:
+ /* Load/store multiple. */
+ if (bit (this_instr, 20) == 1 && bit (this_instr, 15) == 1)
+ return 1;
+ else
+ return 0;
- if (prev_pc < prologue_end)
- prologue_end = prev_pc;
+ case 0x5:
+ /* Branch and branch with link. */
+ return 1;
+
+ case 0x6:
+ case 0x7:
+ /* Coprocessor transfers or SWIs can not affect PC. */
+ return 0;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("bad value in switch"));
+ }
+}
+
+/* Analyze an ARM mode prologue starting at PROLOGUE_START and
+ continuing no further than PROLOGUE_END. If CACHE is non-NULL,
+ fill it in. Return the first address not recognized as a prologue
+ instruction.
+
+ We recognize all the instructions typically found in ARM prologues,
+ plus harmless instructions which can be skipped (either for analysis
+ purposes, or a more restrictive set that can be skipped when finding
+ the end of the prologue). */
+
+static CORE_ADDR
+arm_analyze_prologue (struct gdbarch *gdbarch,
+ CORE_ADDR prologue_start, CORE_ADDR prologue_end,
+ struct arm_prologue_cache *cache)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ int regno;
+ CORE_ADDR offset, current_pc;
+ pv_t regs[ARM_FPS_REGNUM];
+ struct pv_area *stack;
+ struct cleanup *back_to;
+ int framereg, framesize;
+ CORE_ADDR unrecognized_pc = 0;
- /* Now search the prologue looking for instructions that set up the
+ /* Search the prologue looking for instructions that set up the
frame pointer, adjust the stack pointer, and save registers.
Be careful, however, and if it doesn't look like a prologue,
begins with stmfd sp!, then we will tell ourselves there is
a frame, which will confuse stack traceback, as well as "finish"
and other operations that rely on a knowledge of the stack
- traceback.
-
- In the APCS, the prologue should start with "mov ip, sp" so
- if we don't see this as the first insn, we will stop.
-
- [Note: This doesn't seem to be true any longer, so it's now an
- optional part of the prologue. - Kevin Buettner, 2001-11-20]
-
- [Note further: The "mov ip,sp" only seems to be missing in
- frameless functions at optimization level "-O2" or above,
- in which case it is often (but not always) replaced by
- "str lr, [sp, #-4]!". - Michael Snyder, 2002-04-23] */
+ traceback. */
for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
regs[regno] = pv_register (regno, 0);
regs[ARM_IP_REGNUM] = regs[ARM_SP_REGNUM];
continue;
}
- else if ((insn & 0xfffff000) == 0xe28dc000) /* add ip, sp #n */
+ else if ((insn & 0xfff00000) == 0xe2800000 /* add Rd, Rn, #n */
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
+ int rd = bits (insn, 12, 15);
imm = (imm >> rot) | (imm << (32 - rot));
- regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], imm);
+ regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], imm);
continue;
}
- else if ((insn & 0xfffff000) == 0xe24dc000) /* sub ip, sp #n */
+ else if ((insn & 0xfff00000) == 0xe2400000 /* sub Rd, Rn, #n */
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
+ int rd = bits (insn, 12, 15);
imm = (imm >> rot) | (imm << (32 - rot));
- regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
+ regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], -imm);
continue;
}
- else if (insn == 0xe52de004) /* str lr, [sp, #-4]! */
+ else if ((insn & 0xffff0fff) == 0xe52d0004) /* str Rd,
+ [sp, #-4]! */
{
if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
break;
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4);
- pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[ARM_LR_REGNUM]);
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 4,
+ regs[bits (insn, 12, 15)]);
continue;
}
else if ((insn & 0xffff0000) == 0xe92d0000)
for (regno = ARM_PC_REGNUM; regno >= 0; regno--)
if (mask & (1 << regno))
{
- regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4);
+ regs[ARM_SP_REGNUM]
+ = pv_add_constant (regs[ARM_SP_REGNUM], -4);
pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[regno]);
}
}
- else if ((insn & 0xffffc000) == 0xe54b0000 /* strb rx,[r11,#-n] */
- || (insn & 0xffffc0f0) == 0xe14b00b0 /* strh rx,[r11,#-n] */
+ else if ((insn & 0xffff0000) == 0xe54b0000 /* strb rx,[r11,#-n] */
+ || (insn & 0xffff00f0) == 0xe14b00b0 /* strh rx,[r11,#-n] */
|| (insn & 0xffffc000) == 0xe50b0000) /* str rx,[r11,#-n] */
{
/* No need to add this to saved_regs -- it's just an arg reg. */
continue;
}
- else if ((insn & 0xffffc000) == 0xe5cd0000 /* strb rx,[sp,#n] */
- || (insn & 0xffffc0f0) == 0xe1cd00b0 /* strh rx,[sp,#n] */
+ else if ((insn & 0xffff0000) == 0xe5cd0000 /* strb rx,[sp,#n] */
+ || (insn & 0xffff00f0) == 0xe1cd00b0 /* strh rx,[sp,#n] */
|| (insn & 0xffffc000) == 0xe58d0000) /* str rx,[sp,#n] */
{
/* No need to add this to saved_regs -- it's just an arg reg. */
continue;
}
+ else if ((insn & 0xfff00000) == 0xe8800000 /* stm Rn,
+ { registers } */
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ {
+ /* No need to add this to saved_regs -- it's just arg regs. */
+ continue;
+ }
else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */
{
unsigned imm = insn & 0xff; /* immediate value */
imm = (imm >> rot) | (imm << (32 - rot));
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
}
- else if ((insn & 0xffff7fff) == 0xed6d0103 /* stfe f?, [sp, -#c]! */
- && gdbarch_tdep (gdbarch)->have_fpa_registers)
+ else if ((insn & 0xffff7fff) == 0xed6d0103 /* stfe f?,
+ [sp, -#c]! */
+ && gdbarch_tdep (gdbarch)->have_fpa_registers)
+ {
+ if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
+ break;
+
+ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
+ regno = ARM_F0_REGNUM + ((insn >> 12) & 0x07);
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 12, regs[regno]);
+ }
+ else if ((insn & 0xffbf0fff) == 0xec2d0200 /* sfmfd f0, 4,
+ [sp!] */
+ && gdbarch_tdep (gdbarch)->have_fpa_registers)
+ {
+ int n_saved_fp_regs;
+ unsigned int fp_start_reg, fp_bound_reg;
+
+ if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
+ break;
+
+ if ((insn & 0x800) == 0x800) /* N0 is set */
+ {
+ if ((insn & 0x40000) == 0x40000) /* N1 is set */
+ n_saved_fp_regs = 3;
+ else
+ n_saved_fp_regs = 1;
+ }
+ else
+ {
+ if ((insn & 0x40000) == 0x40000) /* N1 is set */
+ n_saved_fp_regs = 2;
+ else
+ n_saved_fp_regs = 4;
+ }
+
+ fp_start_reg = ARM_F0_REGNUM + ((insn >> 12) & 0x7);
+ fp_bound_reg = fp_start_reg + n_saved_fp_regs;
+ for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
+ {
+ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 12,
+ regs[fp_start_reg++]);
+ }
+ }
+ else if ((insn & 0xff000000) == 0xeb000000 && cache == NULL) /* bl */
+ {
+ /* Allow some special function calls when skipping the
+ prologue; GCC generates these before storing arguments to
+ the stack. */
+ CORE_ADDR dest = BranchDest (current_pc, insn);
+
+ if (skip_prologue_function (gdbarch, dest, 0))
+ continue;
+ else
+ break;
+ }
+ else if ((insn & 0xf0000000) != 0xe0000000)
+ break; /* Condition not true, exit early. */
+ else if (arm_instruction_changes_pc (insn))
+ /* Don't scan past anything that might change control flow. */
+ break;
+ else if ((insn & 0xfe500000) == 0xe8100000) /* ldm */
+ {
+ /* Ignore block loads from the stack, potentially copying
+ parameters from memory. */
+ if (pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ continue;
+ else
+ break;
+ }
+ else if ((insn & 0xfc500000) == 0xe4100000)
+ {
+ /* Similarly ignore single loads from the stack. */
+ if (pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ continue;
+ else
+ break;
+ }
+ else if ((insn & 0xffff0ff0) == 0xe1a00000)
+ /* MOV Rd, Rm. Skip register copies, i.e. saves to another
+ register instead of the stack. */
+ continue;
+ else
+ {
+ /* The optimizer might shove anything into the prologue,
+ so we just skip what we don't recognize. */
+ unrecognized_pc = current_pc;
+ continue;
+ }
+ }
+
+ if (unrecognized_pc == 0)
+ unrecognized_pc = current_pc;
+
+ /* The frame size is just the distance from the frame register
+ to the original stack pointer. */
+ if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
+ {
+ /* Frame pointer is fp. */
+ framereg = ARM_FP_REGNUM;
+ framesize = -regs[ARM_FP_REGNUM].k;
+ }
+ else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
+ {
+ /* Try the stack pointer... this is a bit desperate. */
+ framereg = ARM_SP_REGNUM;
+ framesize = -regs[ARM_SP_REGNUM].k;
+ }
+ else
+ {
+ /* We're just out of luck. We don't know where the frame is. */
+ framereg = -1;
+ framesize = 0;
+ }
+
+ if (cache)
+ {
+ cache->framereg = framereg;
+ cache->framesize = framesize;
+
+ for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
+ if (pv_area_find_reg (stack, gdbarch, regno, &offset))
+ cache->saved_regs[regno].addr = offset;
+ }
+
+ if (arm_debug)
+ fprintf_unfiltered (gdb_stdlog, "Prologue scan stopped at %s\n",
+ paddress (gdbarch, unrecognized_pc));
+
+ do_cleanups (back_to);
+ return unrecognized_pc;
+}
+
+static void
+arm_scan_prologue (struct frame_info *this_frame,
+ struct arm_prologue_cache *cache)
+{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ int regno;
+ CORE_ADDR prologue_start, prologue_end, current_pc;
+ CORE_ADDR prev_pc = get_frame_pc (this_frame);
+ CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
+ pv_t regs[ARM_FPS_REGNUM];
+ struct pv_area *stack;
+ struct cleanup *back_to;
+ CORE_ADDR offset;
+
+ /* Assume there is no frame until proven otherwise. */
+ cache->framereg = ARM_SP_REGNUM;
+ cache->framesize = 0;
+
+ /* Check for Thumb prologue. */
+ if (arm_frame_is_thumb (this_frame))
+ {
+ thumb_scan_prologue (gdbarch, prev_pc, block_addr, cache);
+ return;
+ }
+
+ /* Find the function prologue. If we can't find the function in
+ the symbol table, peek in the stack frame to find the PC. */
+ if (find_pc_partial_function (block_addr, NULL, &prologue_start,
+ &prologue_end))
+ {
+ /* One way to find the end of the prologue (which works well
+ for unoptimized code) is to do the following:
+
+ struct symtab_and_line sal = find_pc_line (prologue_start, 0);
+
+ if (sal.line == 0)
+ prologue_end = prev_pc;
+ else if (sal.end < prologue_end)
+ prologue_end = sal.end;
+
+ This mechanism is very accurate so long as the optimizer
+ doesn't move any instructions from the function body into the
+ prologue. If this happens, sal.end will be the last
+ instruction in the first hunk of prologue code just before
+ the first instruction that the scheduler has moved from
+ the body to the prologue.
+
+ In order to make sure that we scan all of the prologue
+ instructions, we use a slightly less accurate mechanism which
+ may scan more than necessary. To help compensate for this
+ lack of accuracy, the prologue scanning loop below contains
+ several clauses which'll cause the loop to terminate early if
+ an implausible prologue instruction is encountered.
+
+ The expression
+
+ prologue_start + 64
+
+ is a suitable endpoint since it accounts for the largest
+ possible prologue plus up to five instructions inserted by
+ the scheduler. */
+
+ if (prologue_end > prologue_start + 64)
+ {
+ prologue_end = prologue_start + 64; /* See above. */
+ }
+ }
+ else
+ {
+ /* We have no symbol information. Our only option is to assume this
+ function has a standard stack frame and the normal frame register.
+ Then, we can find the value of our frame pointer on entrance to
+ the callee (or at the present moment if this is the innermost frame).
+ The value stored there should be the address of the stmfd + 8. */
+ CORE_ADDR frame_loc;
+ LONGEST return_value;
+
+ frame_loc = get_frame_register_unsigned (this_frame, ARM_FP_REGNUM);
+ if (!safe_read_memory_integer (frame_loc, 4, byte_order, &return_value))
+ return;
+ else
+ {
+ prologue_start = gdbarch_addr_bits_remove
+ (gdbarch, return_value) - 8;
+ prologue_end = prologue_start + 64; /* See above. */
+ }
+ }
+
+ if (prev_pc < prologue_end)
+ prologue_end = prev_pc;
+
+ arm_analyze_prologue (gdbarch, prologue_start, prologue_end, cache);
+}
+
+static struct arm_prologue_cache *
+arm_make_prologue_cache (struct frame_info *this_frame)
+{
+ int reg;
+ struct arm_prologue_cache *cache;
+ CORE_ADDR unwound_fp;
+
+ cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
+ cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
+
+ arm_scan_prologue (this_frame, cache);
+
+ unwound_fp = get_frame_register_unsigned (this_frame, cache->framereg);
+ if (unwound_fp == 0)
+ return cache;
+
+ cache->prev_sp = unwound_fp + cache->framesize;
+
+ /* Calculate actual addresses of saved registers using offsets
+ determined by arm_scan_prologue. */
+ for (reg = 0; reg < gdbarch_num_regs (get_frame_arch (this_frame)); reg++)
+ if (trad_frame_addr_p (cache->saved_regs, reg))
+ cache->saved_regs[reg].addr += cache->prev_sp;
+
+ return cache;
+}
+
+/* Our frame ID for a normal frame is the current function's starting PC
+ and the caller's SP when we were called. */
+
+static void
+arm_prologue_this_id (struct frame_info *this_frame,
+ void **this_cache,
+ struct frame_id *this_id)
+{
+ struct arm_prologue_cache *cache;
+ struct frame_id id;
+ CORE_ADDR pc, func;
+
+ if (*this_cache == NULL)
+ *this_cache = arm_make_prologue_cache (this_frame);
+ cache = *this_cache;
+
+ /* This is meant to halt the backtrace at "_start". */
+ pc = get_frame_pc (this_frame);
+ if (pc <= gdbarch_tdep (get_frame_arch (this_frame))->lowest_pc)
+ return;
+
+ /* If we've hit a wall, stop. */
+ if (cache->prev_sp == 0)
+ return;
+
+ /* Use function start address as part of the frame ID. If we cannot
+ identify the start address (due to missing symbol information),
+ fall back to just using the current PC. */
+ func = get_frame_func (this_frame);
+ if (!func)
+ func = pc;
+
+ id = frame_id_build (cache->prev_sp, func);
+ *this_id = id;
+}
+
+static struct value *
+arm_prologue_prev_register (struct frame_info *this_frame,
+ void **this_cache,
+ int prev_regnum)
+{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct arm_prologue_cache *cache;
+
+ if (*this_cache == NULL)
+ *this_cache = arm_make_prologue_cache (this_frame);
+ cache = *this_cache;
+
+ /* If we are asked to unwind the PC, then we need to return the LR
+ instead. The prologue may save PC, but it will point into this
+ frame's prologue, not the next frame's resume location. Also
+ strip the saved T bit. A valid LR may have the low bit set, but
+ a valid PC never does. */
+ if (prev_regnum == ARM_PC_REGNUM)
+ {
+ CORE_ADDR lr;
+
+ lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
+ return frame_unwind_got_constant (this_frame, prev_regnum,
+ arm_addr_bits_remove (gdbarch, lr));
+ }
+
+ /* SP is generally not saved to the stack, but this frame is
+ identified by the next frame's stack pointer at the time of the call.
+ The value was already reconstructed into PREV_SP. */
+ if (prev_regnum == ARM_SP_REGNUM)
+ return frame_unwind_got_constant (this_frame, prev_regnum, cache->prev_sp);
+
+ /* The CPSR may have been changed by the call instruction and by the
+ called function. The only bit we can reconstruct is the T bit,
+ by checking the low bit of LR as of the call. This is a reliable
+ indicator of Thumb-ness except for some ARM v4T pre-interworking
+ Thumb code, which could get away with a clear low bit as long as
+ the called function did not use bx. Guess that all other
+ bits are unchanged; the condition flags are presumably lost,
+ but the processor status is likely valid. */
+ if (prev_regnum == ARM_PS_REGNUM)
+ {
+ CORE_ADDR lr, cpsr;
+ ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
+
+ cpsr = get_frame_register_unsigned (this_frame, prev_regnum);
+ lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
+ if (IS_THUMB_ADDR (lr))
+ cpsr |= t_bit;
+ else
+ cpsr &= ~t_bit;
+ return frame_unwind_got_constant (this_frame, prev_regnum, cpsr);
+ }
+
+ return trad_frame_get_prev_register (this_frame, cache->saved_regs,
+ prev_regnum);
+}
+
+struct frame_unwind arm_prologue_unwind = {
+ NORMAL_FRAME,
+ arm_prologue_this_id,
+ arm_prologue_prev_register,
+ NULL,
+ default_frame_sniffer
+};
+
+/* Maintain a list of ARM exception table entries per objfile, similar to the
+ list of mapping symbols. We only cache entries for standard ARM-defined
+ personality routines; the cache will contain only the frame unwinding
+ instructions associated with the entry (not the descriptors). */
+
+static const struct objfile_data *arm_exidx_data_key;
+
+struct arm_exidx_entry
+{
+ bfd_vma addr;
+ gdb_byte *entry;
+};
+typedef struct arm_exidx_entry arm_exidx_entry_s;
+DEF_VEC_O(arm_exidx_entry_s);
+
+struct arm_exidx_data
+{
+ VEC(arm_exidx_entry_s) **section_maps;
+};
+
+static void
+arm_exidx_data_free (struct objfile *objfile, void *arg)
+{
+ struct arm_exidx_data *data = arg;
+ unsigned int i;
+
+ for (i = 0; i < objfile->obfd->section_count; i++)
+ VEC_free (arm_exidx_entry_s, data->section_maps[i]);
+}
+
+static inline int
+arm_compare_exidx_entries (const struct arm_exidx_entry *lhs,
+ const struct arm_exidx_entry *rhs)
+{
+ return lhs->addr < rhs->addr;
+}
+
+static struct obj_section *
+arm_obj_section_from_vma (struct objfile *objfile, bfd_vma vma)
+{
+ struct obj_section *osect;
+
+ ALL_OBJFILE_OSECTIONS (objfile, osect)
+ if (bfd_get_section_flags (objfile->obfd,
+ osect->the_bfd_section) & SEC_ALLOC)
+ {
+ bfd_vma start, size;
+ start = bfd_get_section_vma (objfile->obfd, osect->the_bfd_section);
+ size = bfd_get_section_size (osect->the_bfd_section);
+
+ if (start <= vma && vma < start + size)
+ return osect;
+ }
+
+ return NULL;
+}
+
+/* Parse contents of exception table and exception index sections
+ of OBJFILE, and fill in the exception table entry cache.
+
+ For each entry that refers to a standard ARM-defined personality
+ routine, extract the frame unwinding instructions (from either
+ the index or the table section). The unwinding instructions
+ are normalized by:
+ - extracting them from the rest of the table data
+ - converting to host endianness
+ - appending the implicit 0xb0 ("Finish") code
+
+ The extracted and normalized instructions are stored for later
+ retrieval by the arm_find_exidx_entry routine. */
+
+static void
+arm_exidx_new_objfile (struct objfile *objfile)
+{
+ struct cleanup *cleanups = make_cleanup (null_cleanup, NULL);
+ struct arm_exidx_data *data;
+ asection *exidx, *extab;
+ bfd_vma exidx_vma = 0, extab_vma = 0;
+ bfd_size_type exidx_size = 0, extab_size = 0;
+ gdb_byte *exidx_data = NULL, *extab_data = NULL;
+ LONGEST i;
+
+ /* If we've already touched this file, do nothing. */
+ if (!objfile || objfile_data (objfile, arm_exidx_data_key) != NULL)
+ return;
+
+ /* Read contents of exception table and index. */
+ exidx = bfd_get_section_by_name (objfile->obfd, ".ARM.exidx");
+ if (exidx)
+ {
+ exidx_vma = bfd_section_vma (objfile->obfd, exidx);
+ exidx_size = bfd_get_section_size (exidx);
+ exidx_data = xmalloc (exidx_size);
+ make_cleanup (xfree, exidx_data);
+
+ if (!bfd_get_section_contents (objfile->obfd, exidx,
+ exidx_data, 0, exidx_size))
+ {
+ do_cleanups (cleanups);
+ return;
+ }
+ }
+
+ extab = bfd_get_section_by_name (objfile->obfd, ".ARM.extab");
+ if (extab)
+ {
+ extab_vma = bfd_section_vma (objfile->obfd, extab);
+ extab_size = bfd_get_section_size (extab);
+ extab_data = xmalloc (extab_size);
+ make_cleanup (xfree, extab_data);
+
+ if (!bfd_get_section_contents (objfile->obfd, extab,
+ extab_data, 0, extab_size))
+ {
+ do_cleanups (cleanups);
+ return;
+ }
+ }
+
+ /* Allocate exception table data structure. */
+ data = OBSTACK_ZALLOC (&objfile->objfile_obstack, struct arm_exidx_data);
+ set_objfile_data (objfile, arm_exidx_data_key, data);
+ data->section_maps = OBSTACK_CALLOC (&objfile->objfile_obstack,
+ objfile->obfd->section_count,
+ VEC(arm_exidx_entry_s) *);
+
+ /* Fill in exception table. */
+ for (i = 0; i < exidx_size / 8; i++)
+ {
+ struct arm_exidx_entry new_exidx_entry;
+ bfd_vma idx = bfd_h_get_32 (objfile->obfd, exidx_data + i * 8);
+ bfd_vma val = bfd_h_get_32 (objfile->obfd, exidx_data + i * 8 + 4);
+ bfd_vma addr = 0, word = 0;
+ int n_bytes = 0, n_words = 0;
+ struct obj_section *sec;
+ gdb_byte *entry = NULL;
+
+ /* Extract address of start of function. */
+ idx = ((idx & 0x7fffffff) ^ 0x40000000) - 0x40000000;
+ idx += exidx_vma + i * 8;
+
+ /* Find section containing function and compute section offset. */
+ sec = arm_obj_section_from_vma (objfile, idx);
+ if (sec == NULL)
+ continue;
+ idx -= bfd_get_section_vma (objfile->obfd, sec->the_bfd_section);
+
+ /* Determine address of exception table entry. */
+ if (val == 1)
+ {
+ /* EXIDX_CANTUNWIND -- no exception table entry present. */
+ }
+ else if ((val & 0xff000000) == 0x80000000)
+ {
+ /* Exception table entry embedded in .ARM.exidx
+ -- must be short form. */
+ word = val;
+ n_bytes = 3;
+ }
+ else if (!(val & 0x80000000))
+ {
+ /* Exception table entry in .ARM.extab. */
+ addr = ((val & 0x7fffffff) ^ 0x40000000) - 0x40000000;
+ addr += exidx_vma + i * 8 + 4;
+
+ if (addr >= extab_vma && addr + 4 <= extab_vma + extab_size)
+ {
+ word = bfd_h_get_32 (objfile->obfd,
+ extab_data + addr - extab_vma);
+ addr += 4;
+
+ if ((word & 0xff000000) == 0x80000000)
+ {
+ /* Short form. */
+ n_bytes = 3;
+ }
+ else if ((word & 0xff000000) == 0x81000000
+ || (word & 0xff000000) == 0x82000000)
+ {
+ /* Long form. */
+ n_bytes = 2;
+ n_words = ((word >> 16) & 0xff);
+ }
+ else if (!(word & 0x80000000))
+ {
+ bfd_vma pers;
+ struct obj_section *pers_sec;
+ int gnu_personality = 0;
+
+ /* Custom personality routine. */
+ pers = ((word & 0x7fffffff) ^ 0x40000000) - 0x40000000;
+ pers = UNMAKE_THUMB_ADDR (pers + addr - 4);
+
+ /* Check whether we've got one of the variants of the
+ GNU personality routines. */
+ pers_sec = arm_obj_section_from_vma (objfile, pers);
+ if (pers_sec)
+ {
+ static const char *personality[] =
+ {
+ "__gcc_personality_v0",
+ "__gxx_personality_v0",
+ "__gcj_personality_v0",
+ "__gnu_objc_personality_v0",
+ NULL
+ };
+
+ CORE_ADDR pc = pers + obj_section_offset (pers_sec);
+ int k;
+
+ for (k = 0; personality[k]; k++)
+ if (lookup_minimal_symbol_by_pc_name
+ (pc, personality[k], objfile))
+ {
+ gnu_personality = 1;
+ break;
+ }
+ }
+
+ /* If so, the next word contains a word count in the high
+ byte, followed by the same unwind instructions as the
+ pre-defined forms. */
+ if (gnu_personality
+ && addr + 4 <= extab_vma + extab_size)
+ {
+ word = bfd_h_get_32 (objfile->obfd,
+ extab_data + addr - extab_vma);
+ addr += 4;
+ n_bytes = 3;
+ n_words = ((word >> 24) & 0xff);
+ }
+ }
+ }
+ }
+
+ /* Sanity check address. */
+ if (n_words)
+ if (addr < extab_vma || addr + 4 * n_words > extab_vma + extab_size)
+ n_words = n_bytes = 0;
+
+ /* The unwind instructions reside in WORD (only the N_BYTES least
+ significant bytes are valid), followed by N_WORDS words in the
+ extab section starting at ADDR. */
+ if (n_bytes || n_words)
+ {
+ gdb_byte *p = entry = obstack_alloc (&objfile->objfile_obstack,
+ n_bytes + n_words * 4 + 1);
+
+ while (n_bytes--)
+ *p++ = (gdb_byte) ((word >> (8 * n_bytes)) & 0xff);
+
+ while (n_words--)
+ {
+ word = bfd_h_get_32 (objfile->obfd,
+ extab_data + addr - extab_vma);
+ addr += 4;
+
+ *p++ = (gdb_byte) ((word >> 24) & 0xff);
+ *p++ = (gdb_byte) ((word >> 16) & 0xff);
+ *p++ = (gdb_byte) ((word >> 8) & 0xff);
+ *p++ = (gdb_byte) (word & 0xff);
+ }
+
+ /* Implied "Finish" to terminate the list. */
+ *p++ = 0xb0;
+ }
+
+ /* Push entry onto vector. They are guaranteed to always
+ appear in order of increasing addresses. */
+ new_exidx_entry.addr = idx;
+ new_exidx_entry.entry = entry;
+ VEC_safe_push (arm_exidx_entry_s,
+ data->section_maps[sec->the_bfd_section->index],
+ &new_exidx_entry);
+ }
+
+ do_cleanups (cleanups);
+}
+
+/* Search for the exception table entry covering MEMADDR. If one is found,
+ return a pointer to its data. Otherwise, return 0. If START is non-NULL,
+ set *START to the start of the region covered by this entry. */
+
+static gdb_byte *
+arm_find_exidx_entry (CORE_ADDR memaddr, CORE_ADDR *start)
+{
+ struct obj_section *sec;
+
+ sec = find_pc_section (memaddr);
+ if (sec != NULL)
+ {
+ struct arm_exidx_data *data;
+ VEC(arm_exidx_entry_s) *map;
+ struct arm_exidx_entry map_key = { memaddr - obj_section_addr (sec), 0 };
+ unsigned int idx;
+
+ data = objfile_data (sec->objfile, arm_exidx_data_key);
+ if (data != NULL)
+ {
+ map = data->section_maps[sec->the_bfd_section->index];
+ if (!VEC_empty (arm_exidx_entry_s, map))
+ {
+ struct arm_exidx_entry *map_sym;
+
+ idx = VEC_lower_bound (arm_exidx_entry_s, map, &map_key,
+ arm_compare_exidx_entries);
+
+ /* VEC_lower_bound finds the earliest ordered insertion
+ point. If the following symbol starts at this exact
+ address, we use that; otherwise, the preceding
+ exception table entry covers this address. */
+ if (idx < VEC_length (arm_exidx_entry_s, map))
+ {
+ map_sym = VEC_index (arm_exidx_entry_s, map, idx);
+ if (map_sym->addr == map_key.addr)
+ {
+ if (start)
+ *start = map_sym->addr + obj_section_addr (sec);
+ return map_sym->entry;
+ }
+ }
+
+ if (idx > 0)
+ {
+ map_sym = VEC_index (arm_exidx_entry_s, map, idx - 1);
+ if (start)
+ *start = map_sym->addr + obj_section_addr (sec);
+ return map_sym->entry;
+ }
+ }
+ }
+ }
+
+ return NULL;
+}
+
+/* Given the current frame THIS_FRAME, and its associated frame unwinding
+ instruction list from the ARM exception table entry ENTRY, allocate and
+ return a prologue cache structure describing how to unwind this frame.
+
+ Return NULL if the unwinding instruction list contains a "spare",
+ "reserved" or "refuse to unwind" instruction as defined in section
+ "9.3 Frame unwinding instructions" of the "Exception Handling ABI
+ for the ARM Architecture" document. */
+
+static struct arm_prologue_cache *
+arm_exidx_fill_cache (struct frame_info *this_frame, gdb_byte *entry)
+{
+ CORE_ADDR vsp = 0;
+ int vsp_valid = 0;
+
+ struct arm_prologue_cache *cache;
+ cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
+ cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
+
+ for (;;)
+ {
+ gdb_byte insn;
+
+ /* Whenever we reload SP, we actually have to retrieve its
+ actual value in the current frame. */
+ if (!vsp_valid)
+ {
+ if (trad_frame_realreg_p (cache->saved_regs, ARM_SP_REGNUM))
+ {
+ int reg = cache->saved_regs[ARM_SP_REGNUM].realreg;
+ vsp = get_frame_register_unsigned (this_frame, reg);
+ }
+ else
+ {
+ CORE_ADDR addr = cache->saved_regs[ARM_SP_REGNUM].addr;
+ vsp = get_frame_memory_unsigned (this_frame, addr, 4);
+ }
+
+ vsp_valid = 1;
+ }
+
+ /* Decode next unwind instruction. */
+ insn = *entry++;
+
+ if ((insn & 0xc0) == 0)
+ {
+ int offset = insn & 0x3f;
+ vsp += (offset << 2) + 4;
+ }
+ else if ((insn & 0xc0) == 0x40)
+ {
+ int offset = insn & 0x3f;
+ vsp -= (offset << 2) + 4;
+ }
+ else if ((insn & 0xf0) == 0x80)
+ {
+ int mask = ((insn & 0xf) << 8) | *entry++;
+ int i;
+
+ /* The special case of an all-zero mask identifies
+ "Refuse to unwind". We return NULL to fall back
+ to the prologue analyzer. */
+ if (mask == 0)
+ return NULL;
+
+ /* Pop registers r4..r15 under mask. */
+ for (i = 0; i < 12; i++)
+ if (mask & (1 << i))
+ {
+ cache->saved_regs[4 + i].addr = vsp;
+ vsp += 4;
+ }
+
+ /* Special-case popping SP -- we need to reload vsp. */
+ if (mask & (1 << (ARM_SP_REGNUM - 4)))
+ vsp_valid = 0;
+ }
+ else if ((insn & 0xf0) == 0x90)
+ {
+ int reg = insn & 0xf;
+
+ /* Reserved cases. */
+ if (reg == ARM_SP_REGNUM || reg == ARM_PC_REGNUM)
+ return NULL;
+
+ /* Set SP from another register and mark VSP for reload. */
+ cache->saved_regs[ARM_SP_REGNUM] = cache->saved_regs[reg];
+ vsp_valid = 0;
+ }
+ else if ((insn & 0xf0) == 0xa0)
+ {
+ int count = insn & 0x7;
+ int pop_lr = (insn & 0x8) != 0;
+ int i;
+
+ /* Pop r4..r[4+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[4 + i].addr = vsp;
+ vsp += 4;
+ }
+
+ /* If indicated by flag, pop LR as well. */
+ if (pop_lr)
+ {
+ cache->saved_regs[ARM_LR_REGNUM].addr = vsp;
+ vsp += 4;
+ }
+ }
+ else if (insn == 0xb0)
+ {
+ /* We could only have updated PC by popping into it; if so, it
+ will show up as address. Otherwise, copy LR into PC. */
+ if (!trad_frame_addr_p (cache->saved_regs, ARM_PC_REGNUM))
+ cache->saved_regs[ARM_PC_REGNUM]
+ = cache->saved_regs[ARM_LR_REGNUM];
+
+ /* We're done. */
+ break;
+ }
+ else if (insn == 0xb1)
+ {
+ int mask = *entry++;
+ int i;
+
+ /* All-zero mask and mask >= 16 is "spare". */
+ if (mask == 0 || mask >= 16)
+ return NULL;
+
+ /* Pop r0..r3 under mask. */
+ for (i = 0; i < 4; i++)
+ if (mask & (1 << i))
+ {
+ cache->saved_regs[i].addr = vsp;
+ vsp += 4;
+ }
+ }
+ else if (insn == 0xb2)
+ {
+ ULONGEST offset = 0;
+ unsigned shift = 0;
+
+ do
+ {
+ offset |= (*entry & 0x7f) << shift;
+ shift += 7;
+ }
+ while (*entry++ & 0x80);
+
+ vsp += 0x204 + (offset << 2);
+ }
+ else if (insn == 0xb3)
+ {
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
+
+ /* Only registers D0..D15 are valid here. */
+ if (start + count >= 16)
+ return NULL;
+
+ /* Pop VFP double-precision registers D[start]..D[start+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_D0_REGNUM + start + i].addr = vsp;
+ vsp += 8;
+ }
+
+ /* Add an extra 4 bytes for FSTMFDX-style stack. */
+ vsp += 4;
+ }
+ else if ((insn & 0xf8) == 0xb8)
+ {
+ int count = insn & 0x7;
+ int i;
+
+ /* Pop VFP double-precision registers D[8]..D[8+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_D0_REGNUM + 8 + i].addr = vsp;
+ vsp += 8;
+ }
+
+ /* Add an extra 4 bytes for FSTMFDX-style stack. */
+ vsp += 4;
+ }
+ else if (insn == 0xc6)
+ {
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
+
+ /* Only registers WR0..WR15 are valid. */
+ if (start + count >= 16)
+ return NULL;
+
+ /* Pop iwmmx registers WR[start]..WR[start+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_WR0_REGNUM + start + i].addr = vsp;
+ vsp += 8;
+ }
+ }
+ else if (insn == 0xc7)
+ {
+ int mask = *entry++;
+ int i;
+
+ /* All-zero mask and mask >= 16 is "spare". */
+ if (mask == 0 || mask >= 16)
+ return NULL;
+
+ /* Pop iwmmx general-purpose registers WCGR0..WCGR3 under mask. */
+ for (i = 0; i < 4; i++)
+ if (mask & (1 << i))
+ {
+ cache->saved_regs[ARM_WCGR0_REGNUM + i].addr = vsp;
+ vsp += 4;
+ }
+ }
+ else if ((insn & 0xf8) == 0xc0)
{
- if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
- break;
+ int count = insn & 0x7;
+ int i;
- regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
- regno = ARM_F0_REGNUM + ((insn >> 12) & 0x07);
- pv_area_store (stack, regs[ARM_SP_REGNUM], 12, regs[regno]);
+ /* Pop iwmmx registers WR[10]..WR[10+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_WR0_REGNUM + 10 + i].addr = vsp;
+ vsp += 8;
+ }
}
- else if ((insn & 0xffbf0fff) == 0xec2d0200 /* sfmfd f0, 4, [sp!] */
- && gdbarch_tdep (gdbarch)->have_fpa_registers)
+ else if (insn == 0xc8)
{
- int n_saved_fp_regs;
- unsigned int fp_start_reg, fp_bound_reg;
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
- if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
- break;
+ /* Only registers D0..D31 are valid. */
+ if (start + count >= 16)
+ return NULL;
- if ((insn & 0x800) == 0x800) /* N0 is set */
+ /* Pop VFP double-precision registers
+ D[16+start]..D[16+start+count]. */
+ for (i = 0; i <= count; i++)
{
- if ((insn & 0x40000) == 0x40000) /* N1 is set */
- n_saved_fp_regs = 3;
- else
- n_saved_fp_regs = 1;
+ cache->saved_regs[ARM_D0_REGNUM + 16 + start + i].addr = vsp;
+ vsp += 8;
}
- else
+ }
+ else if (insn == 0xc9)
+ {
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
+
+ /* Pop VFP double-precision registers D[start]..D[start+count]. */
+ for (i = 0; i <= count; i++)
{
- if ((insn & 0x40000) == 0x40000) /* N1 is set */
- n_saved_fp_regs = 2;
- else
- n_saved_fp_regs = 4;
+ cache->saved_regs[ARM_D0_REGNUM + start + i].addr = vsp;
+ vsp += 8;
}
+ }
+ else if ((insn & 0xf8) == 0xd0)
+ {
+ int count = insn & 0x7;
+ int i;
- fp_start_reg = ARM_F0_REGNUM + ((insn >> 12) & 0x7);
- fp_bound_reg = fp_start_reg + n_saved_fp_regs;
- for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
+ /* Pop VFP double-precision registers D[8]..D[8+count]. */
+ for (i = 0; i <= count; i++)
{
- regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
- pv_area_store (stack, regs[ARM_SP_REGNUM], 12,
- regs[fp_start_reg++]);
+ cache->saved_regs[ARM_D0_REGNUM + 8 + i].addr = vsp;
+ vsp += 8;
}
}
- else if ((insn & 0xf0000000) != 0xe0000000)
- break; /* Condition not true, exit early */
- else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */
- break; /* Don't scan past a block load */
else
- /* The optimizer might shove anything into the prologue,
- so we just skip what we don't recognize. */
- continue;
+ {
+ /* Everything else is "spare". */
+ return NULL;
+ }
}
- /* The frame size is just the distance from the frame register
- to the original stack pointer. */
- if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
- {
- /* Frame pointer is fp. */
- cache->framereg = ARM_FP_REGNUM;
- cache->framesize = -regs[ARM_FP_REGNUM].k;
- }
- else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
- {
- /* Try the stack pointer... this is a bit desperate. */
- cache->framereg = ARM_SP_REGNUM;
- cache->framesize = -regs[ARM_SP_REGNUM].k;
- }
+ /* If we restore SP from a register, assume this was the frame register.
+ Otherwise just fall back to SP as frame register. */
+ if (trad_frame_realreg_p (cache->saved_regs, ARM_SP_REGNUM))
+ cache->framereg = cache->saved_regs[ARM_SP_REGNUM].realreg;
else
- {
- /* We're just out of luck. We don't know where the frame is. */
- cache->framereg = -1;
- cache->framesize = 0;
- }
-
- for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
- if (pv_area_find_reg (stack, gdbarch, regno, &offset))
- cache->saved_regs[regno].addr = offset;
-
- do_cleanups (back_to);
-}
+ cache->framereg = ARM_SP_REGNUM;
-static struct arm_prologue_cache *
-arm_make_prologue_cache (struct frame_info *this_frame)
-{
- int reg;
- struct arm_prologue_cache *cache;
- CORE_ADDR unwound_fp;
-
- cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
- cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
-
- arm_scan_prologue (this_frame, cache);
-
- unwound_fp = get_frame_register_unsigned (this_frame, cache->framereg);
- if (unwound_fp == 0)
- return cache;
-
- cache->prev_sp = unwound_fp + cache->framesize;
+ /* Determine offset to previous frame. */
+ cache->framesize
+ = vsp - get_frame_register_unsigned (this_frame, cache->framereg);
- /* Calculate actual addresses of saved registers using offsets
- determined by arm_scan_prologue. */
- for (reg = 0; reg < gdbarch_num_regs (get_frame_arch (this_frame)); reg++)
- if (trad_frame_addr_p (cache->saved_regs, reg))
- cache->saved_regs[reg].addr += cache->prev_sp;
+ /* We already got the previous SP. */
+ cache->prev_sp = vsp;
return cache;
}
-/* Our frame ID for a normal frame is the current function's starting PC
- and the caller's SP when we were called. */
-
-static void
-arm_prologue_this_id (struct frame_info *this_frame,
- void **this_cache,
- struct frame_id *this_id)
-{
- struct arm_prologue_cache *cache;
- struct frame_id id;
- CORE_ADDR pc, func;
-
- if (*this_cache == NULL)
- *this_cache = arm_make_prologue_cache (this_frame);
- cache = *this_cache;
-
- /* This is meant to halt the backtrace at "_start". */
- pc = get_frame_pc (this_frame);
- if (pc <= gdbarch_tdep (get_frame_arch (this_frame))->lowest_pc)
- return;
-
- /* If we've hit a wall, stop. */
- if (cache->prev_sp == 0)
- return;
-
- func = get_frame_func (this_frame);
- id = frame_id_build (cache->prev_sp, func);
- *this_id = id;
-}
+/* Unwinding via ARM exception table entries. Note that the sniffer
+ already computes a filled-in prologue cache, which is then used
+ with the same arm_prologue_this_id and arm_prologue_prev_register
+ routines also used for prologue-parsing based unwinding. */
-static struct value *
-arm_prologue_prev_register (struct frame_info *this_frame,
- void **this_cache,
- int prev_regnum)
+static int
+arm_exidx_unwind_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame,
+ void **this_prologue_cache)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ CORE_ADDR addr_in_block, exidx_region, func_start;
struct arm_prologue_cache *cache;
+ gdb_byte *entry;
- if (*this_cache == NULL)
- *this_cache = arm_make_prologue_cache (this_frame);
- cache = *this_cache;
+ /* See if we have an ARM exception table entry covering this address. */
+ addr_in_block = get_frame_address_in_block (this_frame);
+ entry = arm_find_exidx_entry (addr_in_block, &exidx_region);
+ if (!entry)
+ return 0;
- /* If we are asked to unwind the PC, then we need to return the LR
- instead. The prologue may save PC, but it will point into this
- frame's prologue, not the next frame's resume location. Also
- strip the saved T bit. A valid LR may have the low bit set, but
- a valid PC never does. */
- if (prev_regnum == ARM_PC_REGNUM)
+ /* The ARM exception table does not describe unwind information
+ for arbitrary PC values, but is guaranteed to be correct only
+ at call sites. We have to decide here whether we want to use
+ ARM exception table information for this frame, or fall back
+ to using prologue parsing. (Note that if we have DWARF CFI,
+ this sniffer isn't even called -- CFI is always preferred.)
+
+ Before we make this decision, however, we check whether we
+ actually have *symbol* information for the current frame.
+ If not, prologue parsing would not work anyway, so we might
+ as well use the exception table and hope for the best. */
+ if (find_pc_partial_function (addr_in_block, NULL, &func_start, NULL))
{
- CORE_ADDR lr;
-
- lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
- return frame_unwind_got_constant (this_frame, prev_regnum,
- arm_addr_bits_remove (gdbarch, lr));
- }
+ int exc_valid = 0;
+
+ /* If the next frame is "normal", we are at a call site in this
+ frame, so exception information is guaranteed to be valid. */
+ if (get_next_frame (this_frame)
+ && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME)
+ exc_valid = 1;
+
+ /* We also assume exception information is valid if we're currently
+ blocked in a system call. The system library is supposed to
+ ensure this, so that e.g. pthread cancellation works. */
+ if (arm_frame_is_thumb (this_frame))
+ {
+ LONGEST insn;
- /* SP is generally not saved to the stack, but this frame is
- identified by the next frame's stack pointer at the time of the call.
- The value was already reconstructed into PREV_SP. */
- if (prev_regnum == ARM_SP_REGNUM)
- return frame_unwind_got_constant (this_frame, prev_regnum, cache->prev_sp);
+ if (safe_read_memory_integer (get_frame_pc (this_frame) - 2, 2,
+ byte_order_for_code, &insn)
+ && (insn & 0xff00) == 0xdf00 /* svc */)
+ exc_valid = 1;
+ }
+ else
+ {
+ LONGEST insn;
- /* The CPSR may have been changed by the call instruction and by the
- called function. The only bit we can reconstruct is the T bit,
- by checking the low bit of LR as of the call. This is a reliable
- indicator of Thumb-ness except for some ARM v4T pre-interworking
- Thumb code, which could get away with a clear low bit as long as
- the called function did not use bx. Guess that all other
- bits are unchanged; the condition flags are presumably lost,
- but the processor status is likely valid. */
- if (prev_regnum == ARM_PS_REGNUM)
- {
- CORE_ADDR lr, cpsr;
+ if (safe_read_memory_integer (get_frame_pc (this_frame) - 4, 4,
+ byte_order_for_code, &insn)
+ && (insn & 0x0f000000) == 0x0f000000 /* svc */)
+ exc_valid = 1;
+ }
+
+ /* Bail out if we don't know that exception information is valid. */
+ if (!exc_valid)
+ return 0;
- cpsr = get_frame_register_unsigned (this_frame, prev_regnum);
- lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
- if (IS_THUMB_ADDR (lr))
- cpsr |= CPSR_T;
- else
- cpsr &= ~CPSR_T;
- return frame_unwind_got_constant (this_frame, prev_regnum, cpsr);
+ /* The ARM exception index does not mark the *end* of the region
+ covered by the entry, and some functions will not have any entry.
+ To correctly recognize the end of the covered region, the linker
+ should have inserted dummy records with a CANTUNWIND marker.
+
+ Unfortunately, current versions of GNU ld do not reliably do
+ this, and thus we may have found an incorrect entry above.
+ As a (temporary) sanity check, we only use the entry if it
+ lies *within* the bounds of the function. Note that this check
+ might reject perfectly valid entries that just happen to cover
+ multiple functions; therefore this check ought to be removed
+ once the linker is fixed. */
+ if (func_start > exidx_region)
+ return 0;
}
- return trad_frame_get_prev_register (this_frame, cache->saved_regs,
- prev_regnum);
+ /* Decode the list of unwinding instructions into a prologue cache.
+ Note that this may fail due to e.g. a "refuse to unwind" code. */
+ cache = arm_exidx_fill_cache (this_frame, entry);
+ if (!cache)
+ return 0;
+
+ *this_prologue_cache = cache;
+ return 1;
}
-struct frame_unwind arm_prologue_unwind = {
+struct frame_unwind arm_exidx_unwind = {
NORMAL_FRAME,
arm_prologue_this_id,
arm_prologue_prev_register,
NULL,
- default_frame_sniffer
+ arm_exidx_unwind_sniffer
};
static struct arm_prologue_cache *
arm_make_stub_cache (struct frame_info *this_frame)
{
- int reg;
struct arm_prologue_cache *cache;
- CORE_ADDR unwound_fp;
cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
addr_in_block = get_frame_address_in_block (this_frame);
if (in_plt_section (addr_in_block, NULL)
+ /* We also use the stub winder if the target memory is unreadable
+ to avoid having the prologue unwinder trying to read it. */
|| target_read_memory (get_frame_pc (this_frame), dummy, 4) != 0)
return 1;
static struct frame_id
arm_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
- return frame_id_build (get_frame_register_unsigned (this_frame, ARM_SP_REGNUM),
+ return frame_id_build (get_frame_register_unsigned (this_frame,
+ ARM_SP_REGNUM),
get_frame_pc (this_frame));
}
{
struct gdbarch * gdbarch = get_frame_arch (this_frame);
CORE_ADDR lr, cpsr;
+ ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
switch (regnum)
{
cpsr = get_frame_register_unsigned (this_frame, regnum);
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
if (IS_THUMB_ADDR (lr))
- cpsr |= CPSR_T;
+ cpsr |= t_bit;
else
- cpsr &= ~CPSR_T;
+ cpsr &= ~t_bit;
return frame_unwind_got_constant (this_frame, regnum, cpsr);
default:
}
}
+/* Return true if we are in the function's epilogue, i.e. after the
+ instruction that destroyed the function's stack frame. */
+
+static int
+thumb_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned int insn, insn2;
+ int found_return = 0, found_stack_adjust = 0;
+ CORE_ADDR func_start, func_end;
+ CORE_ADDR scan_pc;
+ gdb_byte buf[4];
+
+ if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
+ return 0;
+
+ /* The epilogue is a sequence of instructions along the following lines:
+
+ - add stack frame size to SP or FP
+ - [if frame pointer used] restore SP from FP
+ - restore registers from SP [may include PC]
+ - a return-type instruction [if PC wasn't already restored]
+
+ In a first pass, we scan forward from the current PC and verify the
+ instructions we find as compatible with this sequence, ending in a
+ return instruction.
+
+ However, this is not sufficient to distinguish indirect function calls
+ within a function from indirect tail calls in the epilogue in some cases.
+ Therefore, if we didn't already find any SP-changing instruction during
+ forward scan, we add a backward scanning heuristic to ensure we actually
+ are in the epilogue. */
+
+ scan_pc = pc;
+ while (scan_pc < func_end && !found_return)
+ {
+ if (target_read_memory (scan_pc, buf, 2))
+ break;
+
+ scan_pc += 2;
+ insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
+
+ if ((insn & 0xff80) == 0x4700) /* bx <Rm> */
+ found_return = 1;
+ else if (insn == 0x46f7) /* mov pc, lr */
+ found_return = 1;
+ else if (insn == 0x46bd) /* mov sp, r7 */
+ found_stack_adjust = 1;
+ else if ((insn & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
+ found_stack_adjust = 1;
+ else if ((insn & 0xfe00) == 0xbc00) /* pop <registers> */
+ {
+ found_stack_adjust = 1;
+ if (insn & 0x0100) /* <registers> include PC. */
+ found_return = 1;
+ }
+ else if ((insn & 0xe000) == 0xe000) /* 32-bit Thumb-2 instruction */
+ {
+ if (target_read_memory (scan_pc, buf, 2))
+ break;
+
+ scan_pc += 2;
+ insn2 = extract_unsigned_integer (buf, 2, byte_order_for_code);
+
+ if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
+ {
+ found_stack_adjust = 1;
+ if (insn2 & 0x8000) /* <registers> include PC. */
+ found_return = 1;
+ }
+ else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
+ && (insn2 & 0x0fff) == 0x0b04)
+ {
+ found_stack_adjust = 1;
+ if ((insn2 & 0xf000) == 0xf000) /* <Rt> is PC. */
+ found_return = 1;
+ }
+ else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
+ && (insn2 & 0x0e00) == 0x0a00)
+ found_stack_adjust = 1;
+ else
+ break;
+ }
+ else
+ break;
+ }
+
+ if (!found_return)
+ return 0;
+
+ /* Since any instruction in the epilogue sequence, with the possible
+ exception of return itself, updates the stack pointer, we need to
+ scan backwards for at most one instruction. Try either a 16-bit or
+ a 32-bit instruction. This is just a heuristic, so we do not worry
+ too much about false positives. */
+
+ if (!found_stack_adjust)
+ {
+ if (pc - 4 < func_start)
+ return 0;
+ if (target_read_memory (pc - 4, buf, 4))
+ return 0;
+
+ insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
+ insn2 = extract_unsigned_integer (buf + 2, 2, byte_order_for_code);
+
+ if (insn2 == 0x46bd) /* mov sp, r7 */
+ found_stack_adjust = 1;
+ else if ((insn2 & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
+ found_stack_adjust = 1;
+ else if ((insn2 & 0xff00) == 0xbc00) /* pop <registers> without PC */
+ found_stack_adjust = 1;
+ else if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
+ found_stack_adjust = 1;
+ else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
+ && (insn2 & 0x0fff) == 0x0b04)
+ found_stack_adjust = 1;
+ else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
+ && (insn2 & 0x0e00) == 0x0a00)
+ found_stack_adjust = 1;
+ }
+
+ return found_stack_adjust;
+}
+
+/* Return true if we are in the function's epilogue, i.e. after the
+ instruction that destroyed the function's stack frame. */
+
+static int
+arm_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned int insn;
+ int found_return, found_stack_adjust;
+ CORE_ADDR func_start, func_end;
+
+ if (arm_pc_is_thumb (gdbarch, pc))
+ return thumb_in_function_epilogue_p (gdbarch, pc);
+
+ if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
+ return 0;
+
+ /* We are in the epilogue if the previous instruction was a stack
+ adjustment and the next instruction is a possible return (bx, mov
+ pc, or pop). We could have to scan backwards to find the stack
+ adjustment, or forwards to find the return, but this is a decent
+ approximation. First scan forwards. */
+
+ found_return = 0;
+ insn = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
+ if (bits (insn, 28, 31) != INST_NV)
+ {
+ if ((insn & 0x0ffffff0) == 0x012fff10)
+ /* BX. */
+ found_return = 1;
+ else if ((insn & 0x0ffffff0) == 0x01a0f000)
+ /* MOV PC. */
+ found_return = 1;
+ else if ((insn & 0x0fff0000) == 0x08bd0000
+ && (insn & 0x0000c000) != 0)
+ /* POP (LDMIA), including PC or LR. */
+ found_return = 1;
+ }
+
+ if (!found_return)
+ return 0;
+
+ /* Scan backwards. This is just a heuristic, so do not worry about
+ false positives from mode changes. */
+
+ if (pc < func_start + 4)
+ return 0;
+
+ found_stack_adjust = 0;
+ insn = read_memory_unsigned_integer (pc - 4, 4, byte_order_for_code);
+ if (bits (insn, 28, 31) != INST_NV)
+ {
+ if ((insn & 0x0df0f000) == 0x0080d000)
+ /* ADD SP (register or immediate). */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0df0f000) == 0x0040d000)
+ /* SUB SP (register or immediate). */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0ffffff0) == 0x01a0d000)
+ /* MOV SP. */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0fff0000) == 0x08bd0000)
+ /* POP (LDMIA). */
+ found_stack_adjust = 1;
+ }
+
+ if (found_stack_adjust)
+ return 1;
+
+ return 0;
+}
+
+
/* When arguments must be pushed onto the stack, they go on in reverse
order. The code below implements a FILO (stack) to do this. */
};
static struct stack_item *
-push_stack_item (struct stack_item *prev, void *contents, int len)
+push_stack_item (struct stack_item *prev, const void *contents, int len)
{
struct stack_item *si;
si = xmalloc (sizeof (struct stack_item));
/* Set the return address. For the ARM, the return breakpoint is
always at BP_ADDR. */
- if (arm_pc_is_thumb (bp_addr))
+ if (arm_pc_is_thumb (gdbarch, bp_addr))
bp_addr |= 1;
regcache_cooked_write_unsigned (regcache, ARM_LR_REGNUM, bp_addr);
struct type *arg_type;
struct type *target_type;
enum type_code typecode;
- bfd_byte *val;
+ const bfd_byte *val;
int align;
enum arm_vfp_cprc_base_type vfp_base_type;
int vfp_base_count;
len = TYPE_LENGTH (arg_type);
target_type = TYPE_TARGET_TYPE (arg_type);
typecode = TYPE_CODE (arg_type);
- val = value_contents_writeable (args[argnum]);
+ val = value_contents (args[argnum]);
align = arm_type_align (arg_type);
/* Round alignment up to a whole number of words. */
the THUMB bit in it. */
if (TYPE_CODE_PTR == typecode
&& target_type != NULL
- && TYPE_CODE_FUNC == TYPE_CODE (target_type))
+ && TYPE_CODE_FUNC == TYPE_CODE (check_typedef (target_type)))
{
CORE_ADDR regval = extract_unsigned_integer (val, len, byte_order);
- if (arm_pc_is_thumb (regval))
+ if (arm_pc_is_thumb (gdbarch, regval))
{
- val = alloca (len);
- store_unsigned_integer (val, len, byte_order,
+ bfd_byte *copy = alloca (len);
+ store_unsigned_integer (copy, len, byte_order,
MAKE_THUMB_ADDR (regval));
+ val = copy;
}
}
return 1;
}
-/* Support routines for single stepping. Calculate the next PC value. */
-#define submask(x) ((1L << ((x) + 1)) - 1)
-#define bit(obj,st) (((obj) >> (st)) & 1)
-#define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st)))
-#define sbits(obj,st,fn) \
- ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st))))
-#define BranchDest(addr,instr) \
- ((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2)))
-#define ARM_PC_32 1
-
static unsigned long
shifted_reg_val (struct frame_info *frame, unsigned long inst, int carry,
unsigned long pc_val, unsigned long status_reg)
else
shift = bits (inst, 7, 11);
- res = (rm == 15
- ? ((pc_val | (ARM_PC_32 ? 0 : status_reg))
- + (bit (inst, 4) ? 12 : 8))
+ res = (rm == ARM_PC_REGNUM
+ ? (pc_val + (bit (inst, 4) ? 12 : 8))
: get_frame_register_unsigned (frame, rm));
switch (shifttype)
{
int nbits;
for (nbits = 0; val != 0; nbits++)
- val &= val - 1; /* delete rightmost 1-bit in val */
+ val &= val - 1; /* Delete rightmost 1-bit in val. */
return nbits;
}
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
unsigned short inst1;
- CORE_ADDR nextpc = pc + 2; /* default is next instruction */
+ CORE_ADDR nextpc = pc + 2; /* Default is next instruction. */
unsigned long offset;
ULONGEST status, itstate;
while (itstate != 0 && ! condition_true (itstate >> 4, status))
{
- inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ inst1 = read_memory_unsigned_integer (pc, 2,
+ byte_order_for_code);
pc += thumb_insn_size (inst1);
itstate = thumb_advance_itstate (itstate);
}
while (itstate != 0 && ! condition_true (itstate >> 4, status))
{
- inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ inst1 = read_memory_unsigned_integer (pc, 2,
+ byte_order_for_code);
pc += thumb_insn_size (inst1);
itstate = thumb_advance_itstate (itstate);
}
the instruction after the IT block. */
do
{
- inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ inst1 = read_memory_unsigned_integer (pc, 2,
+ byte_order_for_code);
pc += thumb_insn_size (inst1);
itstate = thumb_advance_itstate (itstate);
}
else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
{
unsigned long cond = bits (inst1, 8, 11);
- if (cond != 0x0f && condition_true (cond, status)) /* 0x0f = SWI */
+ if (cond == 0x0f) /* 0x0f = SWI */
+ {
+ struct gdbarch_tdep *tdep;
+ tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->syscall_next_pc != NULL)
+ nextpc = tdep->syscall_next_pc (frame);
+
+ }
+ else if (cond != 0x0f && condition_true (cond, status))
nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
}
else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */
rn = bits (inst1, 0, 3);
base = get_frame_register_unsigned (frame, rn);
- if (rn == 15)
+ if (rn == ARM_PC_REGNUM)
{
base = (base + 4) & ~(CORE_ADDR) 0x3;
if (bit (inst1, 7))
else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
{
/* TBB. */
- CORE_ADDR table, offset, length;
+ CORE_ADDR tbl_reg, table, offset, length;
+
+ tbl_reg = bits (inst1, 0, 3);
+ if (tbl_reg == 0x0f)
+ table = pc + 4; /* Regcache copy of PC isn't right yet. */
+ else
+ table = get_frame_register_unsigned (frame, tbl_reg);
- table = get_frame_register_unsigned (frame, bits (inst1, 0, 3));
offset = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
length = 2 * get_frame_memory_unsigned (frame, table + offset, 1);
nextpc = pc_val + length;
}
- else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
+ else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf010)
{
/* TBH. */
- CORE_ADDR table, offset, length;
+ CORE_ADDR tbl_reg, table, offset, length;
+
+ tbl_reg = bits (inst1, 0, 3);
+ if (tbl_reg == 0x0f)
+ table = pc + 4; /* Regcache copy of PC isn't right yet. */
+ else
+ table = get_frame_register_unsigned (frame, tbl_reg);
- table = get_frame_register_unsigned (frame, bits (inst1, 0, 3));
offset = 2 * get_frame_register_unsigned (frame, bits (inst2, 0, 3));
length = 2 * get_frame_memory_unsigned (frame, table + offset, 2);
nextpc = pc_val + length;
else
nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
}
+ else if ((inst1 & 0xff87) == 0x4687) /* mov pc, REG */
+ {
+ if (bits (inst1, 3, 6) == 0x0f)
+ nextpc = pc_val;
+ else
+ nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
+
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ }
else if ((inst1 & 0xf500) == 0xb100)
{
/* CBNZ or CBZ. */
The value returned has the execution state of the next instruction
encoded in it. Use IS_THUMB_ADDR () to see whether the instruction is
in Thumb-State, and gdbarch_addr_bits_remove () to get the plain memory
- address.
-*/
+ address. */
+
static CORE_ADDR
arm_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc, int insert_bkpt)
{
|| bits (this_instr, 4, 27) == 0x12fff3)
{
rn = bits (this_instr, 0, 3);
- nextpc = (rn == 15) ? pc_val + 8
- : get_frame_register_unsigned (frame, rn);
+ nextpc = ((rn == ARM_PC_REGNUM)
+ ? (pc_val + 8)
+ : get_frame_register_unsigned (frame, rn));
+
return nextpc;
}
- /* Multiply into PC */
+ /* Multiply into PC. */
c = (status & FLAG_C) ? 1 : 0;
rn = bits (this_instr, 16, 19);
- operand1 = (rn == 15) ? pc_val + 8
- : get_frame_register_unsigned (frame, rn);
+ operand1 = ((rn == ARM_PC_REGNUM)
+ ? (pc_val + 8)
+ : get_frame_register_unsigned (frame, rn));
if (bit (this_instr, 25))
{
operand2 = ((immval >> rotate) | (immval << (32 - rotate)))
& 0xffffffff;
}
- else /* operand 2 is a shifted register */
- operand2 = shifted_reg_val (frame, this_instr, c, pc_val, status);
+ else /* operand 2 is a shifted register. */
+ operand2 = shifted_reg_val (frame, this_instr, c,
+ pc_val, status);
switch (bits (this_instr, 21, 24))
{
/* byte write to PC */
rn = bits (this_instr, 16, 19);
- base = (rn == 15) ? pc_val + 8
- : get_frame_register_unsigned (frame, rn);
+ base = ((rn == ARM_PC_REGNUM)
+ ? (pc_val + 8)
+ : get_frame_register_unsigned (frame, rn));
+
if (bit (this_instr, 24))
{
/* pre-indexed */
case 0xc:
case 0xd:
case 0xe: /* coproc ops */
+ break;
case 0xf: /* SWI */
+ {
+ struct gdbarch_tdep *tdep;
+ tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->syscall_next_pc != NULL)
+ nextpc = tdep->syscall_next_pc (frame);
+
+ }
break;
default:
return bpaddr;
/* ARM mode does not have this problem. */
- if (!arm_pc_is_thumb (bpaddr))
+ if (!arm_pc_is_thumb (gdbarch, bpaddr))
return bpaddr;
/* We are setting a breakpoint in Thumb code that could potentially
known boundary. */
if (! definite)
{
- buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary);
+ buf = extend_buffer_earlier (buf, bpaddr, buf_len,
+ bpaddr - boundary);
if (buf == NULL)
return bpaddr;
buf_len = bpaddr - boundary;
arm_process_displaced_insn (called from arm_displaced_step_copy_insn).
Depending on the type of instruction, it is then copied to a scratch
location, possibly in a modified form. The copy_* set of functions
- performs such modification, as necessary. A breakpoint is placed after
+ performs such modification, as necessary. A breakpoint is placed after
the modified instruction in the scratch space to return control to GDB.
Note in particular that instructions which modify the PC will no longer
do so after modification.
location. */
ULONGEST
-displaced_read_reg (struct regcache *regs, CORE_ADDR from, int regno)
+displaced_read_reg (struct regcache *regs, struct displaced_step_closure *dsc,
+ int regno)
{
ULONGEST ret;
+ CORE_ADDR from = dsc->insn_addr;
- if (regno == 15)
+ if (regno == ARM_PC_REGNUM)
{
+ /* Compute pipeline offset:
+ - When executing an ARM instruction, PC reads as the address of the
+ current instruction plus 8.
+ - When executing a Thumb instruction, PC reads as the address of the
+ current instruction plus 4. */
+
+ if (!dsc->is_thumb)
+ from += 8;
+ else
+ from += 4;
+
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: read pc value %.8lx\n",
- (unsigned long) from + 8);
- return (ULONGEST) from + 8; /* Pipeline offset. */
+ (unsigned long) from);
+ return (ULONGEST) from;
}
else
{
displaced_in_arm_mode (struct regcache *regs)
{
ULONGEST ps;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
- return (ps & CPSR_T) == 0;
+ return (ps & t_bit) == 0;
}
/* Write to the PC as from a branch instruction. */
static void
-branch_write_pc (struct regcache *regs, ULONGEST val)
+branch_write_pc (struct regcache *regs, struct displaced_step_closure *dsc,
+ ULONGEST val)
{
- if (displaced_in_arm_mode (regs))
+ if (!dsc->is_thumb)
/* Note: If bits 0/1 are set, this branch would be unpredictable for
architecture versions < 6. */
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x3);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
+ val & ~(ULONGEST) 0x3);
else
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x1);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
+ val & ~(ULONGEST) 0x1);
}
/* Write to the PC as from a branch-exchange instruction. */
bx_write_pc (struct regcache *regs, ULONGEST val)
{
ULONGEST ps;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
if ((val & 1) == 1)
{
- regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps | CPSR_T);
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps | t_bit);
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffe);
}
else if ((val & 2) == 0)
{
- regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM,
- ps & ~(ULONGEST) CPSR_T);
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val);
}
else
/* Unpredictable behaviour. Try to do something sensible (switch to ARM
mode, align dest to 4 bytes). */
warning (_("Single-stepping BX to non-word-aligned ARM instruction."));
- regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM,
- ps & ~(ULONGEST) CPSR_T);
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffc);
}
}
/* Write to the PC as if from a load instruction. */
static void
-load_write_pc (struct regcache *regs, ULONGEST val)
+load_write_pc (struct regcache *regs, struct displaced_step_closure *dsc,
+ ULONGEST val)
{
if (DISPLACED_STEPPING_ARCH_VERSION >= 5)
bx_write_pc (regs, val);
else
- branch_write_pc (regs, val);
+ branch_write_pc (regs, dsc, val);
}
/* Write to the PC as if from an ALU instruction. */
static void
-alu_write_pc (struct regcache *regs, ULONGEST val)
+alu_write_pc (struct regcache *regs, struct displaced_step_closure *dsc,
+ ULONGEST val)
{
- if (DISPLACED_STEPPING_ARCH_VERSION >= 7 && displaced_in_arm_mode (regs))
+ if (DISPLACED_STEPPING_ARCH_VERSION >= 7 && !dsc->is_thumb)
bx_write_pc (regs, val);
else
- branch_write_pc (regs, val);
+ branch_write_pc (regs, dsc, val);
}
/* Helper for writing to registers for displaced stepping. Writing to the PC
displaced_write_reg (struct regcache *regs, struct displaced_step_closure *dsc,
int regno, ULONGEST val, enum pc_write_style write_pc)
{
- if (regno == 15)
+ if (regno == ARM_PC_REGNUM)
{
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: writing pc %.8lx\n",
switch (write_pc)
{
case BRANCH_WRITE_PC:
- branch_write_pc (regs, val);
+ branch_write_pc (regs, dsc, val);
break;
case BX_WRITE_PC:
break;
case LOAD_WRITE_PC:
- load_write_pc (regs, val);
+ load_write_pc (regs, dsc, val);
break;
case ALU_WRITE_PC:
- alu_write_pc (regs, val);
+ alu_write_pc (regs, dsc, val);
break;
case CANNOT_WRITE_PC:
/* This function is used to concisely determine if an instruction INSN
references PC. Register fields of interest in INSN should have the
- corresponding fields of BITMASK set to 0b1111. The function returns return 1
- if any of these fields in INSN reference the PC (also 0b1111, r15), else it
- returns 0. */
+ corresponding fields of BITMASK set to 0b1111. The function
+ returns return 1 if any of these fields in INSN reference the PC
+ (also 0b1111, r15), else it returns 0. */
static int
insn_references_pc (uint32_t insn, uint32_t bitmask)
matter what address they are executed at: in those cases, use this. */
static int
-copy_unmodified (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
+copy_unmodified (struct gdbarch *gdbarch, uint32_t insn,
const char *iname, struct displaced_step_closure *dsc)
{
if (debug_displaced)
/* Preload instructions with immediate offset. */
static void
-cleanup_preload (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+cleanup_preload (struct gdbarch *gdbarch,
struct regcache *regs, struct displaced_step_closure *dsc)
{
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
{
unsigned int rn = bits (insn, 16, 19);
ULONGEST rn_val;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000f0000ul))
return copy_unmodified (gdbarch, insn, "preload", dsc);
->
{pli/pld} [r0, #+/-imm]. */
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- rn_val = displaced_read_reg (regs, from, rn);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ rn_val = displaced_read_reg (regs, dsc, rn);
displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
dsc->u.preload.immed = 1;
/* Preload instructions with register offset. */
static int
-copy_preload_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+copy_preload_reg (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
struct displaced_step_closure *dsc)
{
unsigned int rn = bits (insn, 16, 19);
unsigned int rm = bits (insn, 0, 3);
ULONGEST rn_val, rm_val;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000f000ful))
return copy_unmodified (gdbarch, insn, "preload reg", dsc);
->
{pli/pld} [r0, r1 {, shift}]. */
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- rn_val = displaced_read_reg (regs, from, rn);
- rm_val = displaced_read_reg (regs, from, rm);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rm_val = displaced_read_reg (regs, dsc, rm);
displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 1, rm_val, CANNOT_WRITE_PC);
/* Copy/cleanup coprocessor load and store instructions. */
static void
-cleanup_copro_load_store (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+cleanup_copro_load_store (struct gdbarch *gdbarch,
struct regcache *regs,
struct displaced_step_closure *dsc)
{
- ULONGEST rn_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+ ULONGEST rn_val = displaced_read_reg (regs, dsc, 0);
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
{
unsigned int rn = bits (insn, 16, 19);
ULONGEST rn_val;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000f0000ul))
return copy_unmodified (gdbarch, insn, "copro load/store", dsc);
ldc/ldc2 are handled identically. */
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- rn_val = displaced_read_reg (regs, from, rn);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ rn_val = displaced_read_reg (regs, dsc, rn);
displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
dsc->u.ldst.writeback = bit (insn, 25);
PC). */
static void
-cleanup_branch (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
+cleanup_branch (struct gdbarch *gdbarch, struct regcache *regs,
struct displaced_step_closure *dsc)
{
- ULONGEST from = dsc->insn_addr;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
int branch_taken = condition_true (dsc->u.branch.cond, status);
enum pc_write_style write_pc = dsc->u.branch.exchange
? BX_WRITE_PC : BRANCH_WRITE_PC;
if (dsc->u.branch.link)
{
- ULONGEST pc = displaced_read_reg (regs, from, 15);
- displaced_write_reg (regs, dsc, 14, pc - 4, CANNOT_WRITE_PC);
+ ULONGEST pc = displaced_read_reg (regs, dsc, ARM_PC_REGNUM);
+ displaced_write_reg (regs, dsc, ARM_LR_REGNUM, pc - 4, CANNOT_WRITE_PC);
}
- displaced_write_reg (regs, dsc, 15, dsc->u.branch.dest, write_pc);
+ displaced_write_reg (regs, dsc, ARM_PC_REGNUM, dsc->u.branch.dest, write_pc);
}
/* Copy B/BL/BLX instructions with immediate destinations. */
static int
-copy_b_bl_blx (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
+copy_b_bl_blx (struct gdbarch *gdbarch, uint32_t insn,
struct regcache *regs, struct displaced_step_closure *dsc)
{
unsigned int cond = bits (insn, 28, 31);
/* Copy BX/BLX with register-specified destinations. */
static int
-copy_bx_blx_reg (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
+copy_bx_blx_reg (struct gdbarch *gdbarch, uint32_t insn,
struct regcache *regs, struct displaced_step_closure *dsc)
{
unsigned int cond = bits (insn, 28, 31);
BLX: x12xxx3x. */
int link = bit (insn, 5);
unsigned int rm = bits (insn, 0, 3);
- CORE_ADDR from = dsc->insn_addr;
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: copying %s register insn "
- "%.8lx\n", (link) ? "blx" : "bx", (unsigned long) insn);
+ "%.8lx\n", (link) ? "blx" : "bx",
+ (unsigned long) insn);
/* Implement {BX,BLX}<cond> <reg>" as:
Don't set r14 in cleanup for BX. */
- dsc->u.branch.dest = displaced_read_reg (regs, from, rm);
+ dsc->u.branch.dest = displaced_read_reg (regs, dsc, rm);
dsc->u.branch.cond = cond;
dsc->u.branch.link = link;
return 0;
}
-/* Copy/cleanup arithmetic/logic instruction with immediate RHS. */
+/* Copy/cleanup arithmetic/logic instruction with immediate RHS. */
static void
-cleanup_alu_imm (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+cleanup_alu_imm (struct gdbarch *gdbarch,
struct regcache *regs, struct displaced_step_closure *dsc)
{
- ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+ ULONGEST rd_val = displaced_read_reg (regs, dsc, 0);
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
unsigned int op = bits (insn, 21, 24);
int is_mov = (op == 0xd);
ULONGEST rd_val, rn_val;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000ff000ul))
return copy_unmodified (gdbarch, insn, "ALU immediate", dsc);
Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2
*/
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- rn_val = displaced_read_reg (regs, from, rn);
- rd_val = displaced_read_reg (regs, from, rd);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rd_val = displaced_read_reg (regs, dsc, rd);
displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
dsc->rd = rd;
/* Copy/cleanup arithmetic/logic insns with register RHS. */
static void
-cleanup_alu_reg (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+cleanup_alu_reg (struct gdbarch *gdbarch,
struct regcache *regs, struct displaced_step_closure *dsc)
{
ULONGEST rd_val;
int i;
- rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+ rd_val = displaced_read_reg (regs, dsc, 0);
for (i = 0; i < 3; i++)
displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
unsigned int op = bits (insn, 21, 24);
int is_mov = (op == 0xd);
ULONGEST rd_val, rn_val, rm_val;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000ff00ful))
return copy_unmodified (gdbarch, insn, "ALU reg", dsc);
Cleanup: rd <- r0; r0, r1, r2 <- tmp1, tmp2, tmp3
*/
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- dsc->tmp[2] = displaced_read_reg (regs, from, 2);
- rd_val = displaced_read_reg (regs, from, rd);
- rn_val = displaced_read_reg (regs, from, rn);
- rm_val = displaced_read_reg (regs, from, rm);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
+ rd_val = displaced_read_reg (regs, dsc, rd);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rm_val = displaced_read_reg (regs, dsc, rm);
displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
/* Cleanup/copy arithmetic/logic insns with shifted register RHS. */
static void
-cleanup_alu_shifted_reg (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+cleanup_alu_shifted_reg (struct gdbarch *gdbarch,
struct regcache *regs,
struct displaced_step_closure *dsc)
{
- ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+ ULONGEST rd_val = displaced_read_reg (regs, dsc, 0);
int i;
for (i = 0; i < 4; i++)
static int
copy_alu_shifted_reg (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs, struct displaced_step_closure *dsc)
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
unsigned int rn = bits (insn, 16, 19);
unsigned int rm = bits (insn, 0, 3);
unsigned int op = bits (insn, 21, 24);
int is_mov = (op == 0xd), i;
ULONGEST rd_val, rn_val, rm_val, rs_val;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000fff0ful))
return copy_unmodified (gdbarch, insn, "ALU shifted reg", dsc);
*/
for (i = 0; i < 4; i++)
- dsc->tmp[i] = displaced_read_reg (regs, from, i);
+ dsc->tmp[i] = displaced_read_reg (regs, dsc, i);
- rd_val = displaced_read_reg (regs, from, rd);
- rn_val = displaced_read_reg (regs, from, rn);
- rm_val = displaced_read_reg (regs, from, rm);
- rs_val = displaced_read_reg (regs, from, rs);
+ rd_val = displaced_read_reg (regs, dsc, rd);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rm_val = displaced_read_reg (regs, dsc, rm);
+ rs_val = displaced_read_reg (regs, dsc, rs);
displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
/* Clean up load instructions. */
static void
-cleanup_load (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
+cleanup_load (struct gdbarch *gdbarch, struct regcache *regs,
struct displaced_step_closure *dsc)
{
ULONGEST rt_val, rt_val2 = 0, rn_val;
- CORE_ADDR from = dsc->insn_addr;
- rt_val = displaced_read_reg (regs, from, 0);
+ rt_val = displaced_read_reg (regs, dsc, 0);
if (dsc->u.ldst.xfersize == 8)
- rt_val2 = displaced_read_reg (regs, from, 1);
- rn_val = displaced_read_reg (regs, from, 2);
+ rt_val2 = displaced_read_reg (regs, dsc, 1);
+ rn_val = displaced_read_reg (regs, dsc, 2);
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
if (dsc->u.ldst.xfersize > 4)
/* Clean up store instructions. */
static void
-cleanup_store (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
+cleanup_store (struct gdbarch *gdbarch, struct regcache *regs,
struct displaced_step_closure *dsc)
{
- CORE_ADDR from = dsc->insn_addr;
- ULONGEST rn_val = displaced_read_reg (regs, from, 2);
+ ULONGEST rn_val = displaced_read_reg (regs, dsc, 2);
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
if (dsc->u.ldst.xfersize > 4)
int immed = (op1 & 0x4) != 0;
int opcode;
ULONGEST rt_val, rt_val2 = 0, rn_val, rm_val = 0;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000ff00ful))
return copy_unmodified (gdbarch, insn, "extra load/store", dsc);
internal_error (__FILE__, __LINE__,
_("copy_extra_ld_st: instruction decode error"));
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- dsc->tmp[2] = displaced_read_reg (regs, from, 2);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
if (!immed)
- dsc->tmp[3] = displaced_read_reg (regs, from, 3);
+ dsc->tmp[3] = displaced_read_reg (regs, dsc, 3);
- rt_val = displaced_read_reg (regs, from, rt);
+ rt_val = displaced_read_reg (regs, dsc, rt);
if (bytesize[opcode] == 8)
- rt_val2 = displaced_read_reg (regs, from, rt + 1);
- rn_val = displaced_read_reg (regs, from, rn);
+ rt_val2 = displaced_read_reg (regs, dsc, rt + 1);
+ rn_val = displaced_read_reg (regs, dsc, rn);
if (!immed)
- rm_val = displaced_read_reg (regs, from, rm);
+ rm_val = displaced_read_reg (regs, dsc, rm);
displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
if (bytesize[opcode] == 8)
unsigned int rn = bits (insn, 16, 19);
unsigned int rm = bits (insn, 0, 3); /* Only valid if !immed. */
ULONGEST rt_val, rn_val, rm_val = 0;
- CORE_ADDR from = dsc->insn_addr;
if (!insn_references_pc (insn, 0x000ff00ful))
return copy_unmodified (gdbarch, insn, "load/store", dsc);
: (byte ? "strb" : "str"), usermode ? "t" : "",
(unsigned long) insn);
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[2] = displaced_read_reg (regs, from, 2);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
if (!immed)
- dsc->tmp[3] = displaced_read_reg (regs, from, 3);
+ dsc->tmp[3] = displaced_read_reg (regs, dsc, 3);
if (!load)
- dsc->tmp[4] = displaced_read_reg (regs, from, 4);
+ dsc->tmp[4] = displaced_read_reg (regs, dsc, 4);
- rt_val = displaced_read_reg (regs, from, rt);
- rn_val = displaced_read_reg (regs, from, rn);
+ rt_val = displaced_read_reg (regs, dsc, rt);
+ rn_val = displaced_read_reg (regs, dsc, rn);
if (!immed)
- rm_val = displaced_read_reg (regs, from, rm);
+ rm_val = displaced_read_reg (regs, dsc, rm);
displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
/* To write PC we can do:
- scratch+0: str pc, temp (*temp = scratch + 8 + offset)
- scratch+4: ldr r4, temp
- scratch+8: sub r4, r4, pc (r4 = scratch + 8 + offset - scratch - 8 - 8)
- scratch+12: add r4, r4, #8 (r4 = offset)
- scratch+16: add r0, r0, r4
- scratch+20: str r0, [r2, #imm] (or str r0, [r2, r3])
- scratch+24: <temp>
+ Before this sequence of instructions:
+ r0 is the PC value got from displaced_read_reg, so r0 = from + 8;
+ r2 is the Rn value got from dispalced_read_reg.
+
+ Insn1: push {pc} Write address of STR instruction + offset on stack
+ Insn2: pop {r4} Read it back from stack, r4 = addr(Insn1) + offset
+ Insn3: sub r4, r4, pc r4 = addr(Insn1) + offset - pc
+ = addr(Insn1) + offset - addr(Insn3) - 8
+ = offset - 16
+ Insn4: add r4, r4, #8 r4 = offset - 8
+ Insn5: add r0, r0, r4 r0 = from + 8 + offset - 8
+ = from + offset
+ Insn6: str r0, [r2, #imm] (or str r0, [r2, r3])
Otherwise we don't know what value to write for PC, since the offset is
- architecture-dependent (sometimes PC+8, sometimes PC+12). */
+ architecture-dependent (sometimes PC+8, sometimes PC+12). More details
+ of this can be found in Section "Saving from r15" in
+ http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0204g/Cihbjifh.html */
- if (load || rt != 15)
+ if (load || rt != ARM_PC_REGNUM)
{
dsc->u.ldst.restore_r4 = 0;
{
/* We need to use r4 as scratch. Make sure it's restored afterwards. */
dsc->u.ldst.restore_r4 = 1;
-
- dsc->modinsn[0] = 0xe58ff014; /* str pc, [pc, #20]. */
- dsc->modinsn[1] = 0xe59f4010; /* ldr r4, [pc, #16]. */
+ dsc->modinsn[0] = 0xe92d8000; /* push {pc} */
+ dsc->modinsn[1] = 0xe8bd0010; /* pop {r4} */
dsc->modinsn[2] = 0xe044400f; /* sub r4, r4, pc. */
dsc->modinsn[3] = 0xe2844008; /* add r4, r4, #8. */
dsc->modinsn[4] = 0xe0800004; /* add r0, r0, r4. */
cleanup_block_load_all (struct gdbarch *gdbarch, struct regcache *regs,
struct displaced_step_closure *dsc)
{
- ULONGEST from = dsc->insn_addr;
int inc = dsc->u.block.increment;
int bump_before = dsc->u.block.before ? (inc ? 4 : -4) : 0;
int bump_after = dsc->u.block.before ? 0 : (inc ? 4 : -4);
CORE_ADDR xfer_addr = dsc->u.block.xfer_addr;
int exception_return = dsc->u.block.load && dsc->u.block.user
&& (regmask & 0x8000) != 0;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
int do_transfer = condition_true (dsc->u.block.cond, status);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
uint32_t memword;
if (inc)
- while (regno <= 15 && (regmask & (1 << regno)) == 0)
+ while (regno <= ARM_PC_REGNUM && (regmask & (1 << regno)) == 0)
regno++;
else
while (regno >= 0 && (regmask & (1 << regno)) == 0)
cleanup_block_store_pc (struct gdbarch *gdbarch, struct regcache *regs,
struct displaced_step_closure *dsc)
{
- ULONGEST from = dsc->insn_addr;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
int store_executed = condition_true (dsc->u.block.cond, status);
CORE_ADDR pc_stored_at, transferred_regs = bitcount (dsc->u.block.regmask);
CORE_ADDR stm_insn_addr;
must undo that here. */
static void
-cleanup_block_load_pc (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+cleanup_block_load_pc (struct gdbarch *gdbarch,
struct regcache *regs,
struct displaced_step_closure *dsc)
{
- ULONGEST from = dsc->insn_addr;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
int load_executed = condition_true (dsc->u.block.cond, status), i;
- unsigned int mask = dsc->u.block.regmask, write_reg = 15;
+ unsigned int mask = dsc->u.block.regmask, write_reg = ARM_PC_REGNUM;
unsigned int regs_loaded = bitcount (mask);
unsigned int num_to_shuffle = regs_loaded, clobbered;
if (read_reg != write_reg)
{
- ULONGEST rval = displaced_read_reg (regs, from, read_reg);
+ ULONGEST rval = displaced_read_reg (regs, dsc, read_reg);
displaced_write_reg (regs, dsc, write_reg, rval, LOAD_WRITE_PC);
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: move "
int before = bit (insn, 24);
int writeback = bit (insn, 21);
int rn = bits (insn, 16, 19);
- CORE_ADDR from = dsc->insn_addr;
- /* Block transfers which don't mention PC can be run directly out-of-line. */
- if (rn != 15 && (insn & 0x8000) == 0)
+ /* Block transfers which don't mention PC can be run directly
+ out-of-line. */
+ if (rn != ARM_PC_REGNUM && (insn & 0x8000) == 0)
return copy_unmodified (gdbarch, insn, "ldm/stm", dsc);
- if (rn == 15)
+ if (rn == ARM_PC_REGNUM)
{
- warning (_("displaced: Unpredictable LDM or STM with base register r15"));
+ warning (_("displaced: Unpredictable LDM or STM with "
+ "base register r15"));
return copy_unmodified (gdbarch, insn, "unpredictable ldm/stm", dsc);
}
fprintf_unfiltered (gdb_stdlog, "displaced: copying block transfer insn "
"%.8lx\n", (unsigned long) insn);
- dsc->u.block.xfer_addr = displaced_read_reg (regs, from, rn);
+ dsc->u.block.xfer_addr = displaced_read_reg (regs, dsc, rn);
dsc->u.block.rn = rn;
dsc->u.block.load = load;
unsigned int to = 0, from = 0, i, new_rn;
for (i = 0; i < num_in_list; i++)
- dsc->tmp[i] = displaced_read_reg (regs, from, i);
+ dsc->tmp[i] = displaced_read_reg (regs, dsc, i);
/* Writeback makes things complicated. We need to avoid clobbering
the base register with one of the registers in our modified
for Linux, where some SVC instructions must be treated specially. */
static void
-cleanup_svc (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
+cleanup_svc (struct gdbarch *gdbarch, struct regcache *regs,
struct displaced_step_closure *dsc)
{
- CORE_ADDR from = dsc->insn_addr;
- CORE_ADDR resume_addr = from + 4;
+ CORE_ADDR resume_addr = dsc->insn_addr + 4;
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: cleanup for svc, resume at "
copy_svc (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
struct regcache *regs, struct displaced_step_closure *dsc)
{
- CORE_ADDR from = dsc->insn_addr;
-
/* Allow OS-specific code to override SVC handling. */
if (dsc->u.svc.copy_svc_os)
return dsc->u.svc.copy_svc_os (gdbarch, insn, to, regs, dsc);
/* Copy undefined instructions. */
static int
-copy_undef (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
+copy_undef (struct gdbarch *gdbarch, uint32_t insn,
struct displaced_step_closure *dsc)
{
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying undefined insn %.8lx\n",
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying undefined insn %.8lx\n",
(unsigned long) insn);
dsc->modinsn[0] = insn;
/* Copy unpredictable instructions. */
static int
-copy_unpred (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
+copy_unpred (struct gdbarch *gdbarch, uint32_t insn,
struct displaced_step_closure *dsc)
{
if (debug_displaced)
static int
decode_unconditional (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs, struct displaced_step_closure *dsc)
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
if (bit (insn, 27) == 0)
return decode_misc_memhint_neon (gdbarch, insn, regs, dsc);
static int
decode_miscellaneous (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs, struct displaced_step_closure *dsc)
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
unsigned int op2 = bits (insn, 4, 6);
unsigned int op = bits (insn, 21, 22);
case 0x3:
if (op == 0x1)
- return copy_bx_blx_reg (gdbarch, insn, regs, dsc); /* blx register. */
+ return copy_bx_blx_reg (gdbarch, insn,
+ regs, dsc); /* blx register. */
else
return copy_undef (gdbarch, insn, dsc);
static int
decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs, struct displaced_step_closure *dsc)
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
unsigned int opcode = bits (insn, 20, 24);
return copy_undef (gdbarch, insn, dsc); /* Possibly unreachable. */
}
+static void
+thumb_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from,
+ CORE_ADDR to, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ error (_("Displaced stepping is only supported in ARM mode"));
+}
+
void
-arm_process_displaced_insn (struct gdbarch *gdbarch, uint32_t insn,
- CORE_ADDR from, CORE_ADDR to, struct regcache *regs,
+arm_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from,
+ CORE_ADDR to, struct regcache *regs,
struct displaced_step_closure *dsc)
{
int err = 0;
-
- if (!displaced_in_arm_mode (regs))
- error (_("Displaced stepping is only supported in ARM mode"));
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ uint32_t insn;
/* Most displaced instructions use a 1-instruction scratch space, so set this
here and override below if/when necessary. */
dsc->cleanup = NULL;
dsc->wrote_to_pc = 0;
+ if (!displaced_in_arm_mode (regs))
+ return thumb_process_displaced_insn (gdbarch, from, to, regs, dsc);
+
+ dsc->is_thumb = 0;
+ dsc->insn_size = 4;
+ insn = read_memory_unsigned_integer (from, 4, byte_order_for_code);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
+ "at %.8lx\n", (unsigned long) insn,
+ (unsigned long) from);
+
if ((insn & 0xf0000000) == 0xf0000000)
err = decode_unconditional (gdbarch, insn, regs, dsc);
else switch (((insn & 0x10) >> 4) | ((insn & 0xe000000) >> 24))
CORE_ADDR to, struct displaced_step_closure *dsc)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
- unsigned int i;
+ unsigned int i, len, offset;
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ int size = dsc->is_thumb? 2 : 4;
+ const unsigned char *bkp_insn;
+ offset = 0;
/* Poke modified instruction(s). */
for (i = 0; i < dsc->numinsns; i++)
{
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: writing insn %.8lx at "
- "%.8lx\n", (unsigned long) dsc->modinsn[i],
- (unsigned long) to + i * 4);
- write_memory_unsigned_integer (to + i * 4, 4, byte_order_for_code,
+ {
+ fprintf_unfiltered (gdb_stdlog, "displaced: writing insn ");
+ if (size == 4)
+ fprintf_unfiltered (gdb_stdlog, "%.8lx",
+ dsc->modinsn[i]);
+ else if (size == 2)
+ fprintf_unfiltered (gdb_stdlog, "%.4x",
+ (unsigned short)dsc->modinsn[i]);
+
+ fprintf_unfiltered (gdb_stdlog, " at %.8lx\n",
+ (unsigned long) to + offset);
+
+ }
+ write_memory_unsigned_integer (to + offset, size,
+ byte_order_for_code,
dsc->modinsn[i]);
+ offset += size;
+ }
+
+ /* Choose the correct breakpoint instruction. */
+ if (dsc->is_thumb)
+ {
+ bkp_insn = tdep->thumb_breakpoint;
+ len = tdep->thumb_breakpoint_size;
+ }
+ else
+ {
+ bkp_insn = tdep->arm_breakpoint;
+ len = tdep->arm_breakpoint_size;
}
/* Put breakpoint afterwards. */
- write_memory (to + dsc->numinsns * 4, tdep->arm_breakpoint,
- tdep->arm_breakpoint_size);
+ write_memory (to + offset, bkp_insn, len);
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ",
{
struct displaced_step_closure *dsc
= xmalloc (sizeof (struct displaced_step_closure));
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- uint32_t insn = read_memory_unsigned_integer (from, 4, byte_order_for_code);
-
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
- "at %.8lx\n", (unsigned long) insn,
- (unsigned long) from);
-
- arm_process_displaced_insn (gdbarch, insn, from, to, regs, dsc);
+ arm_process_displaced_insn (gdbarch, from, to, regs, dsc);
arm_displaced_init_closure (gdbarch, from, to, dsc);
return dsc;
dsc->cleanup (gdbarch, regs, dsc);
if (!dsc->wrote_to_pc)
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, dsc->insn_addr + 4);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
+ dsc->insn_addr + dsc->insn_size);
+
}
#include "bfd-in2.h"
static int
gdb_print_insn_arm (bfd_vma memaddr, disassemble_info *info)
{
- if (arm_pc_is_thumb (memaddr))
+ struct gdbarch *gdbarch = info->application_data;
+
+ if (arm_pc_is_thumb (gdbarch, memaddr))
{
static asymbol *asym;
static combined_entry_type ce;
1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
C C C C 0 1 1 x x x x x x x x x x x x x x x x x x x x 1 x x x x
- Even this may only true if the condition predicate is true. The
+ Even this may only true if the condition predicate is true. The
following use a condition predicate of ALWAYS so it is always TRUE.
There are other ways of forcing a breakpoint. GNU/Linux, RISC iX,
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- if (arm_pc_is_thumb (*pcptr))
+ if (arm_pc_is_thumb (gdbarch, *pcptr))
{
*pcptr = UNMAKE_THUMB_ADDR (*pcptr);
arm_breakpoint_from_pc (gdbarch, pcptr, kindptr);
- if (arm_pc_is_thumb (*pcptr) && *kindptr == 4)
+ if (arm_pc_is_thumb (gdbarch, *pcptr) && *kindptr == 4)
/* The documented magic value for a 32-bit Thumb-2 breakpoint, so
that this is not confused with a 32-bit ARM breakpoint. */
*kindptr = 3;
break;
default:
- internal_error
- (__FILE__, __LINE__,
- _("arm_extract_return_value: Floating point model not supported"));
+ internal_error (__FILE__, __LINE__,
+ _("arm_extract_return_value: "
+ "Floating point model not supported"));
break;
}
}
|| TYPE_CODE (type) == TYPE_CODE_REF
|| TYPE_CODE (type) == TYPE_CODE_ENUM)
{
- /* If the the type is a plain integer, then the access is
- straight-forward. Otherwise we have to play around a bit more. */
+ /* If the type is a plain integer, then the access is
+ straight-forward. Otherwise we have to play around a bit
+ more. */
int len = TYPE_LENGTH (type);
int regno = ARM_A1_REGNUM;
ULONGEST tmp;
for (i = 0; i < TYPE_NFIELDS (type); i++)
{
enum type_code field_type_code;
- field_type_code = TYPE_CODE (check_typedef (TYPE_FIELD_TYPE (type, i)));
+ field_type_code = TYPE_CODE (check_typedef (TYPE_FIELD_TYPE (type,
+ i)));
/* Is it a floating point type field? */
if (field_type_code == TYPE_CODE_FLT)
break;
default:
- internal_error
- (__FILE__, __LINE__,
- _("arm_store_return_value: Floating point model not supported"));
+ internal_error (__FILE__, __LINE__,
+ _("arm_store_return_value: Floating "
+ "point model not supported"));
break;
}
}
gdbarch_info_init (&info);
if (!gdbarch_update_p (info))
- internal_error (__FILE__, __LINE__, "could not update architecture");
+ internal_error (__FILE__, __LINE__, _("could not update architecture"));
}
static void
{
struct gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch);
- fprintf_filtered (file, _("\
-The current execution mode assumed (when symbols are unavailable) is \"%s\".\n"),
+ fprintf_filtered (file,
+ _("The current execution mode assumed "
+ "(when symbols are unavailable) is \"%s\".\n"),
arm_fallback_mode_string);
}
{
struct gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch);
- fprintf_filtered (file, _("\
-The current execution mode assumed (even when symbols are available) is \"%s\".\n"),
+ fprintf_filtered (file,
+ _("The current execution mode assumed "
+ "(even when symbols are available) is \"%s\".\n"),
arm_force_mode_string);
}
static void
arm_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
regcache_cooked_write_unsigned (regcache, ARM_PC_REGNUM, pc);
/* If necessary, set the T bit. */
if (arm_apcs_32)
{
- ULONGEST val;
+ ULONGEST val, t_bit;
regcache_cooked_read_unsigned (regcache, ARM_PS_REGNUM, &val);
- if (arm_pc_is_thumb (pc))
- regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM, val | CPSR_T);
+ t_bit = arm_psr_thumb_bit (gdbarch);
+ if (arm_pc_is_thumb (gdbarch, pc))
+ regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM,
+ val | t_bit);
else
regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM,
- val & ~(ULONGEST) CPSR_T);
+ val & ~t_bit);
}
}
else
offset = 0;
- regcache_raw_write (regcache, double_regnum, buf + offset);
- offset = 8 - offset;
- regcache_raw_write (regcache, double_regnum + 1, buf + offset);
-}
+ regcache_raw_write (regcache, double_regnum, buf + offset);
+ offset = 8 - offset;
+ regcache_raw_write (regcache, double_regnum + 1, buf + offset);
+}
+
+static void
+arm_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache,
+ int regnum, const gdb_byte *buf)
+{
+ const int num_regs = gdbarch_num_regs (gdbarch);
+ char name_buf[4];
+ gdb_byte reg_buf[8];
+ int offset, double_regnum;
+
+ gdb_assert (regnum >= num_regs);
+ regnum -= num_regs;
+
+ if (gdbarch_tdep (gdbarch)->have_neon_pseudos && regnum >= 32 && regnum < 48)
+ /* Quad-precision register. */
+ arm_neon_quad_write (gdbarch, regcache, regnum - 32, buf);
+ else
+ {
+ /* Single-precision register. */
+ gdb_assert (regnum < 32);
+
+ /* s0 is always the least significant half of d0. */
+ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
+ offset = (regnum & 1) ? 0 : 4;
+ else
+ offset = (regnum & 1) ? 4 : 0;
+
+ sprintf (name_buf, "d%d", regnum >> 1);
+ double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
+ strlen (name_buf));
+
+ regcache_raw_read (regcache, double_regnum, reg_buf);
+ memcpy (reg_buf + offset, buf, 4);
+ regcache_raw_write (regcache, double_regnum, reg_buf);
+ }
+}
+
+static struct value *
+value_of_arm_user_reg (struct frame_info *frame, const void *baton)
+{
+ const int *reg_p = baton;
+ return value_of_register (*reg_p, frame);
+}
+\f
+static enum gdb_osabi
+arm_elf_osabi_sniffer (bfd *abfd)
+{
+ unsigned int elfosabi;
+ enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
+
+ elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
+
+ if (elfosabi == ELFOSABI_ARM)
+ /* GNU tools use this value. Check note sections in this case,
+ as well. */
+ bfd_map_over_sections (abfd,
+ generic_elf_osabi_sniff_abi_tag_sections,
+ &osabi);
+
+ /* Anything else will be handled by the generic ELF sniffer. */
+ return osabi;
+}
+
+static int
+arm_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
+ struct reggroup *group)
+{
+ /* FPS register's type is INT, but belongs to float_reggroup. Beside
+ this, FPS register belongs to save_regroup, restore_reggroup, and
+ all_reggroup, of course. */
+ if (regnum == ARM_FPS_REGNUM)
+ return (group == float_reggroup
+ || group == save_reggroup
+ || group == restore_reggroup
+ || group == all_reggroup);
+ else
+ return default_register_reggroup_p (gdbarch, regnum, group);
+}
+
+\f
+/* Initialize the current architecture based on INFO. If possible,
+ re-use an architecture from ARCHES, which is a list of
+ architectures already created during this debugging session.
+
+ Called e.g. at program startup, when reading a core file, and when
+ reading a binary file. */
+
+static struct gdbarch *
+arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+{
+ struct gdbarch_tdep *tdep;
+ struct gdbarch *gdbarch;
+ struct gdbarch_list *best_arch;
+ enum arm_abi_kind arm_abi = arm_abi_global;
+ enum arm_float_model fp_model = arm_fp_model;
+ struct tdesc_arch_data *tdesc_data = NULL;
+ int i, is_m = 0;
+ int have_vfp_registers = 0, have_vfp_pseudos = 0, have_neon_pseudos = 0;
+ int have_neon = 0;
+ int have_fpa_registers = 1;
+ const struct target_desc *tdesc = info.target_desc;
+
+ /* If we have an object to base this architecture on, try to determine
+ its ABI. */
+
+ if (arm_abi == ARM_ABI_AUTO && info.abfd != NULL)
+ {
+ int ei_osabi, e_flags;
+
+ switch (bfd_get_flavour (info.abfd))
+ {
+ case bfd_target_aout_flavour:
+ /* Assume it's an old APCS-style ABI. */
+ arm_abi = ARM_ABI_APCS;
+ break;
+
+ case bfd_target_coff_flavour:
+ /* Assume it's an old APCS-style ABI. */
+ /* XXX WinCE? */
+ arm_abi = ARM_ABI_APCS;
+ break;
+
+ case bfd_target_elf_flavour:
+ ei_osabi = elf_elfheader (info.abfd)->e_ident[EI_OSABI];
+ e_flags = elf_elfheader (info.abfd)->e_flags;
+
+ if (ei_osabi == ELFOSABI_ARM)
+ {
+ /* GNU tools used to use this value, but do not for EABI
+ objects. There's nowhere to tag an EABI version
+ anyway, so assume APCS. */
+ arm_abi = ARM_ABI_APCS;
+ }
+ else if (ei_osabi == ELFOSABI_NONE)
+ {
+ int eabi_ver = EF_ARM_EABI_VERSION (e_flags);
+ int attr_arch, attr_profile;
+
+ switch (eabi_ver)
+ {
+ case EF_ARM_EABI_UNKNOWN:
+ /* Assume GNU tools. */
+ arm_abi = ARM_ABI_APCS;
+ break;
+
+ case EF_ARM_EABI_VER4:
+ case EF_ARM_EABI_VER5:
+ arm_abi = ARM_ABI_AAPCS;
+ /* EABI binaries default to VFP float ordering.
+ They may also contain build attributes that can
+ be used to identify if the VFP argument-passing
+ ABI is in use. */
+ if (fp_model == ARM_FLOAT_AUTO)
+ {
+#ifdef HAVE_ELF
+ switch (bfd_elf_get_obj_attr_int (info.abfd,
+ OBJ_ATTR_PROC,
+ Tag_ABI_VFP_args))
+ {
+ case 0:
+ /* "The user intended FP parameter/result
+ passing to conform to AAPCS, base
+ variant". */
+ fp_model = ARM_FLOAT_SOFT_VFP;
+ break;
+ case 1:
+ /* "The user intended FP parameter/result
+ passing to conform to AAPCS, VFP
+ variant". */
+ fp_model = ARM_FLOAT_VFP;
+ break;
+ case 2:
+ /* "The user intended FP parameter/result
+ passing to conform to tool chain-specific
+ conventions" - we don't know any such
+ conventions, so leave it as "auto". */
+ break;
+ default:
+ /* Attribute value not mentioned in the
+ October 2008 ABI, so leave it as
+ "auto". */
+ break;
+ }
+#else
+ fp_model = ARM_FLOAT_SOFT_VFP;
+#endif
+ }
+ break;
+
+ default:
+ /* Leave it as "auto". */
+ warning (_("unknown ARM EABI version 0x%x"), eabi_ver);
+ break;
+ }
-static void
-arm_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache,
- int regnum, const gdb_byte *buf)
-{
- const int num_regs = gdbarch_num_regs (gdbarch);
- char name_buf[4];
- gdb_byte reg_buf[8];
- int offset, double_regnum;
+#ifdef HAVE_ELF
+ /* Detect M-profile programs. This only works if the
+ executable file includes build attributes; GCC does
+ copy them to the executable, but e.g. RealView does
+ not. */
+ attr_arch = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC,
+ Tag_CPU_arch);
+ attr_profile = bfd_elf_get_obj_attr_int (info.abfd,
+ OBJ_ATTR_PROC,
+ Tag_CPU_arch_profile);
+ /* GCC specifies the profile for v6-M; RealView only
+ specifies the profile for architectures starting with
+ V7 (as opposed to architectures with a tag
+ numerically greater than TAG_CPU_ARCH_V7). */
+ if (!tdesc_has_registers (tdesc)
+ && (attr_arch == TAG_CPU_ARCH_V6_M
+ || attr_arch == TAG_CPU_ARCH_V6S_M
+ || attr_profile == 'M'))
+ tdesc = tdesc_arm_with_m;
+#endif
+ }
- gdb_assert (regnum >= num_regs);
- regnum -= num_regs;
+ if (fp_model == ARM_FLOAT_AUTO)
+ {
+ int e_flags = elf_elfheader (info.abfd)->e_flags;
- if (gdbarch_tdep (gdbarch)->have_neon_pseudos && regnum >= 32 && regnum < 48)
- /* Quad-precision register. */
- arm_neon_quad_write (gdbarch, regcache, regnum - 32, buf);
- else
- {
- /* Single-precision register. */
- gdb_assert (regnum < 32);
+ switch (e_flags & (EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT))
+ {
+ case 0:
+ /* Leave it as "auto". Strictly speaking this case
+ means FPA, but almost nobody uses that now, and
+ many toolchains fail to set the appropriate bits
+ for the floating-point model they use. */
+ break;
+ case EF_ARM_SOFT_FLOAT:
+ fp_model = ARM_FLOAT_SOFT_FPA;
+ break;
+ case EF_ARM_VFP_FLOAT:
+ fp_model = ARM_FLOAT_VFP;
+ break;
+ case EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT:
+ fp_model = ARM_FLOAT_SOFT_VFP;
+ break;
+ }
+ }
- /* s0 is always the least significant half of d0. */
- if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
- offset = (regnum & 1) ? 0 : 4;
- else
- offset = (regnum & 1) ? 4 : 0;
+ if (e_flags & EF_ARM_BE8)
+ info.byte_order_for_code = BFD_ENDIAN_LITTLE;
- sprintf (name_buf, "d%d", regnum >> 1);
- double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
- strlen (name_buf));
+ break;
- regcache_raw_read (regcache, double_regnum, reg_buf);
- memcpy (reg_buf + offset, buf, 4);
- regcache_raw_write (regcache, double_regnum, reg_buf);
+ default:
+ /* Leave it as "auto". */
+ break;
+ }
}
-}
-
-static struct value *
-value_of_arm_user_reg (struct frame_info *frame, const void *baton)
-{
- const int *reg_p = baton;
- return value_of_register (*reg_p, frame);
-}
-\f
-static enum gdb_osabi
-arm_elf_osabi_sniffer (bfd *abfd)
-{
- unsigned int elfosabi;
- enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
-
- elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
-
- if (elfosabi == ELFOSABI_ARM)
- /* GNU tools use this value. Check note sections in this case,
- as well. */
- bfd_map_over_sections (abfd,
- generic_elf_osabi_sniff_abi_tag_sections,
- &osabi);
-
- /* Anything else will be handled by the generic ELF sniffer. */
- return osabi;
-}
-
-\f
-/* Initialize the current architecture based on INFO. If possible,
- re-use an architecture from ARCHES, which is a list of
- architectures already created during this debugging session.
-
- Called e.g. at program startup, when reading a core file, and when
- reading a binary file. */
-
-static struct gdbarch *
-arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
-{
- struct gdbarch_tdep *tdep;
- struct gdbarch *gdbarch;
- struct gdbarch_list *best_arch;
- enum arm_abi_kind arm_abi = arm_abi_global;
- enum arm_float_model fp_model = arm_fp_model;
- struct tdesc_arch_data *tdesc_data = NULL;
- int i;
- int have_vfp_registers = 0, have_vfp_pseudos = 0, have_neon_pseudos = 0;
- int have_neon = 0;
- int have_fpa_registers = 1;
/* Check any target description for validity. */
- if (tdesc_has_registers (info.target_desc))
+ if (tdesc_has_registers (tdesc))
{
/* For most registers we require GDB's default names; but also allow
the numeric names for sp / lr / pc, as a convenience. */
const struct tdesc_feature *feature;
int valid_p;
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.core");
if (feature == NULL)
- return NULL;
+ {
+ feature = tdesc_find_feature (tdesc,
+ "org.gnu.gdb.arm.m-profile");
+ if (feature == NULL)
+ return NULL;
+ else
+ is_m = 1;
+ }
tdesc_data = tdesc_data_alloc ();
valid_p &= tdesc_numbered_register_choices (feature, tdesc_data,
ARM_PC_REGNUM,
arm_pc_names);
- valid_p &= tdesc_numbered_register (feature, tdesc_data,
- ARM_PS_REGNUM, "cpsr");
+ if (is_m)
+ valid_p &= tdesc_numbered_register (feature, tdesc_data,
+ ARM_PS_REGNUM, "xpsr");
+ else
+ valid_p &= tdesc_numbered_register (feature, tdesc_data,
+ ARM_PS_REGNUM, "cpsr");
if (!valid_p)
{
return NULL;
}
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.fpa");
if (feature != NULL)
{
else
have_fpa_registers = 0;
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.xscale.iwmmxt");
if (feature != NULL)
{
/* If we have a VFP unit, check whether the single precision registers
are present. If not, then we will synthesize them as pseudo
registers. */
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.vfp");
if (feature != NULL)
{
/* If we have VFP, also check for NEON. The architecture allows
NEON without VFP (integer vector operations only), but GDB
does not support that. */
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.neon");
if (feature != NULL)
{
}
}
- /* If we have an object to base this architecture on, try to determine
- its ABI. */
-
- if (arm_abi == ARM_ABI_AUTO && info.abfd != NULL)
- {
- int ei_osabi, e_flags;
-
- switch (bfd_get_flavour (info.abfd))
- {
- case bfd_target_aout_flavour:
- /* Assume it's an old APCS-style ABI. */
- arm_abi = ARM_ABI_APCS;
- break;
-
- case bfd_target_coff_flavour:
- /* Assume it's an old APCS-style ABI. */
- /* XXX WinCE? */
- arm_abi = ARM_ABI_APCS;
- break;
-
- case bfd_target_elf_flavour:
- ei_osabi = elf_elfheader (info.abfd)->e_ident[EI_OSABI];
- e_flags = elf_elfheader (info.abfd)->e_flags;
-
- if (ei_osabi == ELFOSABI_ARM)
- {
- /* GNU tools used to use this value, but do not for EABI
- objects. There's nowhere to tag an EABI version
- anyway, so assume APCS. */
- arm_abi = ARM_ABI_APCS;
- }
- else if (ei_osabi == ELFOSABI_NONE)
- {
- int eabi_ver = EF_ARM_EABI_VERSION (e_flags);
-
- switch (eabi_ver)
- {
- case EF_ARM_EABI_UNKNOWN:
- /* Assume GNU tools. */
- arm_abi = ARM_ABI_APCS;
- break;
-
- case EF_ARM_EABI_VER4:
- case EF_ARM_EABI_VER5:
- arm_abi = ARM_ABI_AAPCS;
- /* EABI binaries default to VFP float ordering.
- They may also contain build attributes that can
- be used to identify if the VFP argument-passing
- ABI is in use. */
- if (fp_model == ARM_FLOAT_AUTO)
- {
-#ifdef HAVE_ELF
- switch (bfd_elf_get_obj_attr_int (info.abfd,
- OBJ_ATTR_PROC,
- Tag_ABI_VFP_args))
- {
- case 0:
- /* "The user intended FP parameter/result
- passing to conform to AAPCS, base
- variant". */
- fp_model = ARM_FLOAT_SOFT_VFP;
- break;
- case 1:
- /* "The user intended FP parameter/result
- passing to conform to AAPCS, VFP
- variant". */
- fp_model = ARM_FLOAT_VFP;
- break;
- case 2:
- /* "The user intended FP parameter/result
- passing to conform to tool chain-specific
- conventions" - we don't know any such
- conventions, so leave it as "auto". */
- break;
- default:
- /* Attribute value not mentioned in the
- October 2008 ABI, so leave it as
- "auto". */
- break;
- }
-#else
- fp_model = ARM_FLOAT_SOFT_VFP;
-#endif
- }
- break;
-
- default:
- /* Leave it as "auto". */
- warning (_("unknown ARM EABI version 0x%x"), eabi_ver);
- break;
- }
- }
-
- if (fp_model == ARM_FLOAT_AUTO)
- {
- int e_flags = elf_elfheader (info.abfd)->e_flags;
-
- switch (e_flags & (EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT))
- {
- case 0:
- /* Leave it as "auto". Strictly speaking this case
- means FPA, but almost nobody uses that now, and
- many toolchains fail to set the appropriate bits
- for the floating-point model they use. */
- break;
- case EF_ARM_SOFT_FLOAT:
- fp_model = ARM_FLOAT_SOFT_FPA;
- break;
- case EF_ARM_VFP_FLOAT:
- fp_model = ARM_FLOAT_VFP;
- break;
- case EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT:
- fp_model = ARM_FLOAT_SOFT_VFP;
- break;
- }
- }
-
- if (e_flags & EF_ARM_BE8)
- info.byte_order_for_code = BFD_ENDIAN_LITTLE;
-
- break;
-
- default:
- /* Leave it as "auto". */
- break;
- }
- }
-
/* If there is already a candidate, use it. */
for (best_arch = gdbarch_list_lookup_by_info (arches, &info);
best_arch != NULL;
since gdbarches with a different target description are
automatically disqualified. */
+ /* Do check is_m, though, since it might come from the binary. */
+ if (is_m != gdbarch_tdep (best_arch->gdbarch)->is_m)
+ continue;
+
/* Found a match. */
break;
}
These are gdbarch discriminators, like the OSABI. */
tdep->arm_abi = arm_abi;
tdep->fp_model = fp_model;
+ tdep->is_m = is_m;
tdep->have_fpa_registers = have_fpa_registers;
tdep->have_vfp_registers = have_vfp_registers;
tdep->have_vfp_pseudos = have_vfp_pseudos;
/* Advance PC across function entry code. */
set_gdbarch_skip_prologue (gdbarch, arm_skip_prologue);
+ /* Detect whether PC is in function epilogue. */
+ set_gdbarch_in_function_epilogue_p (gdbarch, arm_in_function_epilogue_p);
+
/* Skip trampolines. */
set_gdbarch_skip_trampoline_code (gdbarch, arm_skip_stub);
arm_remote_breakpoint_from_pc);
/* Information about registers, etc. */
- set_gdbarch_deprecated_fp_regnum (gdbarch, ARM_FP_REGNUM); /* ??? */
set_gdbarch_sp_regnum (gdbarch, ARM_SP_REGNUM);
set_gdbarch_pc_regnum (gdbarch, ARM_PC_REGNUM);
set_gdbarch_num_regs (gdbarch, ARM_NUM_REGS);
set_gdbarch_register_type (gdbarch, arm_register_type);
+ set_gdbarch_register_reggroup_p (gdbarch, arm_register_reggroup_p);
/* This "info float" is FPA-specific. Use the generic version if we
do not have FPA. */
/* Add some default predicates. */
frame_unwind_append_unwinder (gdbarch, &arm_stub_unwind);
dwarf2_append_unwinders (gdbarch);
+ frame_unwind_append_unwinder (gdbarch, &arm_exidx_unwind);
frame_unwind_append_unwinder (gdbarch, &arm_prologue_unwind);
/* Now we have tuned the configuration, set a few final things,
if (tdep->arm_abi == ARM_ABI_AUTO)
tdep->arm_abi = ARM_ABI_APCS;
+ /* Watchpoints are not steppable. */
+ set_gdbarch_have_nonsteppable_watchpoint (gdbarch, 1);
+
/* We used to default to FPA for generic ARM, but almost nobody
uses that now, and we now provide a way for the user to force
the model. So default to the most useful variant. */
{
set_tdesc_pseudo_register_name (gdbarch, arm_register_name);
- tdesc_use_registers (gdbarch, info.target_desc, tdesc_data);
+ tdesc_use_registers (gdbarch, tdesc, tdesc_data);
/* Override tdesc_register_type to adjust the types of VFP
registers for NEON. */
arm_objfile_data_key
= register_objfile_data_with_cleanup (NULL, arm_objfile_data_free);
+ /* Add ourselves to objfile event chain. */
+ observer_attach_new_objfile (arm_exidx_new_objfile);
+ arm_exidx_data_key
+ = register_objfile_data_with_cleanup (NULL, arm_exidx_data_free);
+
/* Register an ELF OS ABI sniffer for ARM binaries. */
gdbarch_register_osabi_sniffer (bfd_arch_arm,
bfd_target_elf_flavour,
arm_elf_osabi_sniffer);
+ /* Initialize the standard target descriptions. */
+ initialize_tdesc_arm_with_m ();
+
/* Get the number of possible sets of register names defined in opcodes. */
num_disassembly_options = get_arm_regname_num_options ();
_("Show the disassembly style."),
helptext,
set_disassembly_style_sfunc,
- NULL, /* FIXME: i18n: The disassembly style is \"%s\". */
+ NULL, /* FIXME: i18n: The disassembly style is
+ \"%s\". */
&setarmcmdlist, &showarmcmdlist);
add_setshow_boolean_cmd ("apcs32", no_class, &arm_apcs_32,
_("Show usage of ARM 32-bit mode."),
_("When off, a 26-bit PC will be used."),
NULL,
- NULL, /* FIXME: i18n: Usage of ARM 32-bit mode is %s. */
+ NULL, /* FIXME: i18n: Usage of ARM 32-bit
+ mode is %s. */
&setarmcmdlist, &showarmcmdlist);
/* Add a command to allow the user to force the FPU model. */