/* Target-dependent code for GNU/Linux SPARC.
- Copyright 2003 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005 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, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
#include "defs.h"
+#include "dwarf2-frame.h"
#include "floatformat.h"
#include "frame.h"
#include "frame-unwind.h"
#include "solib-svr4.h"
#include "symtab.h"
#include "trad-frame.h"
-
-#include "gdb_assert.h"
-#include "gdb_string.h"
+#include "tramp-frame.h"
#include "sparc-tdep.h"
-/* Recognizing signal handler frames. */
+/* Signal trampoline support. */
+
+static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
+ struct frame_info *next_frame,
+ struct trad_frame_cache *this_cache,
+ CORE_ADDR func);
/* GNU/Linux has two flavors of signals. Normal signal handlers, and
"realtime" (RT) signals. The RT signals can provide additional
/* When the sparc Linux kernel calls a signal handler and the
SA_RESTORER flag isn't set, the return address points to a bit of
- code on the stack. This function returns whether the PC appears to
- be within this bit of code.
-
- The instruction sequence for normal signals is
- mov __NR_sigreturn, %g1 ! hex: 0x821020d8
- ta 0x10 ! hex: 0x91d02010
+ code on the stack. This code checks whether the PC appears to be
+ within this bit of code.
+ The instruction sequence for normal signals is encoded below.
Checking for the code sequence should be somewhat reliable, because
the effect is to call the system call sigreturn. This is unlikely
- to occur anywhere other than a signal trampoline.
-
- It kind of sucks that we have to read memory from the process in
- order to identify a signal trampoline, but there doesn't seem to be
- any other way. However, sparc32_linux_pc_in_sigtramp arranges to
- only call us if no function name could be identified, which should
- be the case since the code is on the stack. */
-
-#define LINUX32_SIGTRAMP_INSN0 0x821020d8 /* mov __NR_sigreturn, %g1 */
-#define LINUX32_SIGTRAMP_INSN1 0x91d02010 /* ta 0x10 */
-
-/* The instruction sequence for RT signals is
- mov __NR_rt_sigreturn, %g1 ! hex: 0x82102065
- ta {0x10,0x6d} ! hex: 0x91d02010 or 0x91d0206d
-
- The effect is to call the system call rt_sigreturn. The trap number
- is variable based upon whether this is a 32-bit or 64-bit sparc binary.
- Note that 64-bit binaries only use this RT signal return method. */
-
-#define LINUX32_RT_SIGTRAMP_INSN0 0x82102065
-#define LINUX32_RT_SIGTRAMP_INSN1 0x91d02010
-
-/* If PC is in a sigtramp routine consisting of the instructions INSN0
- and INSN1, return the address of the start of the routine.
- Otherwise, return 0. */
-
-CORE_ADDR
-sparc_linux_sigtramp_start (CORE_ADDR pc, ULONGEST insn0, ULONGEST insn1)
-{
- ULONGEST word0, word1;
- char buf[8]; /* Two instructions. */
-
- /* We only recognize a signal trampoline if PC is at the start of
- one of the instructions. We optimize for finding the PC at the
- start of the instruction sequence, as will be the case when the
- trampoline is not the first frame on the stack. We assume that
- in the case where the PC is not at the start of the instruction
- sequence, there will be a few trailing readable bytes on the
- stack. */
-
- if (deprecated_read_memory_nobpt (pc, buf, sizeof buf) != 0)
- return 0;
-
- word0 = extract_unsigned_integer (buf, 4);
- if (word0 != insn0)
- {
- if (word0 != insn1)
- return 0;
-
- pc -= 4;
- if (deprecated_read_memory_nobpt (pc, buf, sizeof buf) != 0)
- return 0;
-
- word0 = extract_unsigned_integer (buf, 4);
- }
-
- word1 = extract_unsigned_integer (buf + 4, 4);
- if (word0 != insn0 || word1 != insn1)
- return 0;
-
- return pc;
-}
+ to occur anywhere other than a signal trampoline. */
-static CORE_ADDR
-sparc32_linux_sigtramp_start (CORE_ADDR pc)
+static const struct tramp_frame sparc32_linux_sigframe =
{
- return sparc_linux_sigtramp_start (pc, LINUX32_SIGTRAMP_INSN0,
- LINUX32_SIGTRAMP_INSN1);
-}
+ SIGTRAMP_FRAME,
+ 4,
+ {
+ { 0x821020d8, -1 }, /* mov __NR_sugreturn, %g1 */
+ { 0x91d02010, -1 }, /* ta 0x10 */
+ { TRAMP_SENTINEL_INSN, -1 }
+ },
+ sparc32_linux_sigframe_init
+};
-static CORE_ADDR
-sparc32_linux_rt_sigtramp_start (CORE_ADDR pc)
-{
- return sparc_linux_sigtramp_start (pc, LINUX32_RT_SIGTRAMP_INSN0,
- LINUX32_RT_SIGTRAMP_INSN1);
-}
+/* The instruction sequence for RT signals is slightly different. The
+ effect is to call the system call rt_sigreturn. */
-static int
-sparc32_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
+static const struct tramp_frame sparc32_linux_rt_sigframe =
{
- /* If we have NAME, we can optimize the search. The trampolines are
- named __restore and __restore_rt. However, they aren't dynamically
- exported from the shared C library, so the trampoline may appear to
- be part of the preceding function. This should always be sigaction,
- __sigaction, or __libc_sigaction (all aliases to the same function). */
- if (name == NULL || strstr (name, "sigaction") != NULL)
- return (sparc32_linux_sigtramp_start (pc) != 0
- || sparc32_linux_rt_sigtramp_start (pc) != 0);
-
- return (strcmp ("__restore", name) == 0
- || strcmp ("__restore_rt", name) == 0);
-}
+ SIGTRAMP_FRAME,
+ 4,
+ {
+ { 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */
+ { 0x91d02010, -1 }, /* ta 0x10 */
+ { TRAMP_SENTINEL_INSN, -1 }
+ },
+ sparc32_linux_sigframe_init
+};
-static struct sparc_frame_cache *
-sparc32_linux_sigtramp_frame_cache (struct frame_info *next_frame,
- void **this_cache)
+static void
+sparc32_linux_sigframe_init (const struct tramp_frame *self,
+ struct frame_info *next_frame,
+ struct trad_frame_cache *this_cache,
+ CORE_ADDR func)
{
- struct sparc_frame_cache *cache;
- CORE_ADDR sigcontext_addr, addr;
+ CORE_ADDR base, addr, sp_addr;
int regnum;
- if (*this_cache)
- return *this_cache;
-
- cache = sparc32_frame_cache (next_frame, this_cache);
- gdb_assert (cache == *this_cache);
+ base = frame_unwind_register_unsigned (next_frame, SPARC_O1_REGNUM);
+ if (self == &sparc32_linux_rt_sigframe)
+ base += 128;
- /* ??? What about signal trampolines that aren't frameless? */
- regnum = SPARC_SP_REGNUM;
- cache->base = frame_unwind_register_unsigned (next_frame, regnum);
+ /* Offsets from <bits/sigcontext.h>. */
- regnum = SPARC_O1_REGNUM;
- sigcontext_addr = frame_unwind_register_unsigned (next_frame, regnum);
+ trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0);
+ trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4);
+ trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8);
+ trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12);
- cache->pc = frame_pc_unwind (next_frame);
- addr = sparc32_linux_sigtramp_start (cache->pc);
- if (addr == 0)
+ /* Since %g0 is always zero, keep the identity encoding. */
+ addr = base + 20;
+ sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4);
+ for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
{
- /* If this is a RT signal trampoline, adjust SIGCONTEXT_ADDR
- accordingly. */
- addr = sparc32_linux_rt_sigtramp_start (cache->pc);
- if (addr)
- sigcontext_addr += 128;
- else
- addr = frame_func_unwind (next_frame);
+ trad_frame_set_reg_addr (this_cache, regnum, addr);
+ addr += 4;
}
- cache->pc = addr;
-
- cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
-
- cache->saved_regs[SPARC32_PSR_REGNUM].addr = sigcontext_addr + 0;
- cache->saved_regs[SPARC32_PC_REGNUM].addr = sigcontext_addr + 4;
- cache->saved_regs[SPARC32_NPC_REGNUM].addr = sigcontext_addr + 8;
- cache->saved_regs[SPARC32_Y_REGNUM].addr = sigcontext_addr + 12;
-
- /* Since %g0 is always zero, keep the identity encoding. */
- for (regnum = SPARC_G1_REGNUM, addr = sigcontext_addr + 20;
- regnum <= SPARC_O7_REGNUM; regnum++, addr += 4)
- cache->saved_regs[regnum].addr = addr;
- for (regnum = SPARC_L0_REGNUM, addr = cache->base;
- regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
- cache->saved_regs[regnum].addr = addr;
+ base = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
+ addr = get_frame_memory_unsigned (next_frame, sp_addr, 4);
- return cache;
+ for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
+ {
+ trad_frame_set_reg_addr (this_cache, regnum, addr);
+ addr += 4;
+ }
+ trad_frame_set_id (this_cache, frame_id_build (base, func));
}
+\f
+/* Return the address of a system call's alternative return
+ address. */
-static void
-sparc32_linux_sigtramp_frame_this_id (struct frame_info *next_frame,
- void **this_cache,
- struct frame_id *this_id)
+static CORE_ADDR
+sparc32_linux_step_trap (unsigned long insn)
{
- struct sparc_frame_cache *cache =
- sparc32_linux_sigtramp_frame_cache (next_frame, this_cache);
+ if (insn == 0x91d02010)
+ {
+ ULONGEST sc_num;
- (*this_id) = frame_id_build (cache->base, cache->pc);
-}
+ regcache_cooked_read_unsigned (current_regcache,
+ SPARC_G1_REGNUM, &sc_num);
-static void
-sparc32_linux_sigtramp_frame_prev_register (struct frame_info *next_frame,
- void **this_cache,
- int regnum, int *optimizedp,
- enum lval_type *lvalp,
- CORE_ADDR *addrp,
- int *realnump, void *valuep)
-{
- struct sparc_frame_cache *cache =
- sparc32_linux_sigtramp_frame_cache (next_frame, this_cache);
+ /* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216 */
+ if (sc_num == 101 || sc_num == 216)
+ {
+ ULONGEST sp, pc_offset;
- trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
- optimizedp, lvalp, addrp, realnump, valuep);
-}
+ regcache_cooked_read_unsigned (current_regcache,
+ SPARC_SP_REGNUM, &sp);
-static const struct frame_unwind sparc32_linux_sigtramp_frame_unwind =
-{
- SIGTRAMP_FRAME,
- sparc32_linux_sigtramp_frame_this_id,
- sparc32_linux_sigtramp_frame_prev_register
-};
+ /* The kernel puts the sigreturn registers on the stack,
+ and this is where the signal unwinding state is take from
+ when returning from a signal.
-static const struct frame_unwind *
-sparc32_linux_sigtramp_frame_sniffer (struct frame_info *next_frame)
-{
- CORE_ADDR pc = frame_pc_unwind (next_frame);
- char *name;
+ For __NR_sigreturn, this register area sits 96 bytes from
+ the base of the stack. The saved PC sits 4 bytes into the
+ sigreturn register save area.
- find_pc_partial_function (pc, &name, NULL, NULL);
- if (sparc32_linux_pc_in_sigtramp (pc, name))
- return &sparc32_linux_sigtramp_frame_unwind;
+ For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
+ right before the sigreturn register save area. */
- return NULL;
+ pc_offset = 96 + 4;
+ if (sc_num == 101)
+ pc_offset += 128;
+
+ return read_memory_unsigned_integer (sp + pc_offset, 4);
+ }
+ }
+
+ return 0;
}
\f
static void
sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
- /* GNU/Linux is very similar to Solaris ... */
- sparc32_sol2_init_abi (info, gdbarch);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe);
+ tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe);
- /* ... but doesn't have kernel-assisted single-stepping support. */
- set_gdbarch_software_single_step (gdbarch, sparc_software_single_step);
+ /* GNU/Linux has SVR4-style shared libraries... */
+ set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+ set_solib_svr4_fetch_link_map_offsets
+ (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+
+ /* ...which means that we need some special handling when doing
+ prologue analysis. */
+ tdep->plt_entry_size = 12;
/* GNU/Linux doesn't support the 128-bit `long double' from the psABI. */
set_gdbarch_long_double_bit (gdbarch, 64);
set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
- frame_unwind_append_sniffer (gdbarch, sparc32_linux_sigtramp_frame_sniffer);
+ /* Enable TLS support. */
+ set_gdbarch_fetch_tls_load_module_address (gdbarch,
+ svr4_fetch_objfile_link_map);
+
+ /* Make sure we can single-step over signal return system calls. */
+ tdep->step_trap = sparc32_linux_step_trap;
+
+ /* Hook in the DWARF CFI frame unwinder. */
+ frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
projects / deliverable / binutils-gdb.git / blobdiff