/* Target-dependent code for the IA-64 for GDB, the GNU debugger.
- Copyright (C) 2010 Free Software Foundation, Inc.
+ Copyright (C) 2010, 2012 Free Software Foundation, Inc.
This file is part of GDB.
#include "osabi.h"
#include "gdbtypes.h"
#include "solib.h"
+#include "target.h"
+#include "frame.h"
+#include "regcache.h"
+#include "gdbcore.h"
+#include "inferior.h"
+
+/* A sequence of instructions pushed on the stack when we want to perform
+ an inferior function call. The main purpose of this code is to save
+ the output region of the register frame belonging to the function
+ from which we are making the call. Normally, all registers are saved
+ prior to the call, but this does not include stacked registers because
+ they are seen by GDB as pseudo registers.
+
+ With Linux kernels, these stacked registers can be saved by simply
+ creating a new register frame, or in other words by moving the BSP.
+ But the HP/UX kernel does not allow this. So we rely on this code
+ instead, that makes functions calls whose only purpose is to create
+ new register frames.
+
+ The array below is the result obtained after assembling the code
+ shown below. It's an array of bytes in order to make it independent
+ of the host endianess, in case it ends up being used on more than
+ one target.
+
+ start:
+ // Save b0 before using it (into preserved reg: r4).
+ mov r4 = b0
+ ;;
+
+ br.call.dptk.few b0 = stub#
+ ;;
+
+ // Add a nop bundle where we can insert our dummy breakpoint.
+ nop.m 0
+ nop.i 0
+ nop.i 0
+ ;;
+
+ stub:
+ // Alloc a new register stack frame. Here, we set the size
+ // of all regions to zero. Eventually, GDB will manually
+ // change the instruction to set the size of the local region
+ // to match size of the output region of the function from
+ // which we are making the function call. This is to protect
+ // the value of the output registers of the function from
+ // which we are making the call.
+ alloc r6 = ar.pfs, 0, 0, 0, 0
+
+ // Save b0 before using it again (into preserved reg: r5).
+ mov r5 = b0
+ ;;
+
+ // Now that we have protected the entire output region of the
+ // register stack frame, we can call our function that will
+ // setup the arguments, and call our target function.
+ br.call.dptk.few b0 = call_dummy#
+ ;;
+
+ // Restore b0, ar.pfs, and return
+ mov b0 = r5
+ mov.i ar.pfs = r6
+ ;;
+ br.ret.dptk.few b0
+ ;;
+
+ call_dummy:
+ // Alloc a new frame, with 2 local registers, and 8 output registers
+ // (8 output registers for the maximum of 8 slots passed by register).
+ alloc r32 = ar.pfs, 2, 0, 8, 0
+
+ // Save b0 before using it to call our target function.
+ mov r33 = b0
+
+ // Load the argument values placed by GDB inside r14-r21 in their
+ // proper registers.
+ or r34 = r14, r0
+ or r35 = r15, r0
+ or r36 = r16, r0
+ or r37 = r17, r0
+ or r38 = r18, r0
+ or r39 = r19, r0
+ or r40 = r20, r0
+ or r41 = r21, r0
+ ;;
+
+ // actual call
+ br.call.dptk.few b0 = b1
+ ;;
+
+ mov.i ar.pfs=r32
+ mov b0=r33
+ ;;
+
+ br.ret.dptk.few b0
+ ;;
+
+*/
+
+static const gdb_byte ia64_hpux_dummy_code[] =
+{
+ 0x02, 0x00, 0x00, 0x00, 0x01, 0x00, 0x40, 0x00,
+ 0x00, 0x62, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00,
+ 0x1d, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x00, 0x02, 0x00, 0x00, 0x20, 0x00, 0x00, 0x52,
+ 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00,
+ 0x02, 0x30, 0x00, 0x00, 0x80, 0x05, 0x50, 0x00,
+ 0x00, 0x62, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00,
+ 0x1d, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x00, 0x02, 0x00, 0x00, 0x30, 0x00, 0x00, 0x52,
+ 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x28,
+ 0x04, 0x80, 0x03, 0x00, 0x60, 0x00, 0xaa, 0x00,
+ 0x1d, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x00, 0x02, 0x00, 0x80, 0x00, 0x00, 0x84, 0x02,
+ 0x00, 0x00, 0x29, 0x04, 0x80, 0x05, 0x10, 0x02,
+ 0x00, 0x62, 0x00, 0x40, 0xe4, 0x00, 0x38, 0x80,
+ 0x00, 0x18, 0x3d, 0x00, 0x0e, 0x20, 0x40, 0x82,
+ 0x00, 0x1c, 0x40, 0xa0, 0x14, 0x01, 0x38, 0x80,
+ 0x00, 0x30, 0x49, 0x00, 0x0e, 0x20, 0x70, 0x9a,
+ 0x00, 0x1c, 0x40, 0x00, 0x45, 0x01, 0x38, 0x80,
+ 0x0a, 0x48, 0x55, 0x00, 0x0e, 0x20, 0x00, 0x00,
+ 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00,
+ 0x1d, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x00, 0x02, 0x00, 0x00, 0x10, 0x00, 0x80, 0x12,
+ 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x01, 0x55, 0x00, 0x00, 0x10, 0x0a, 0x00, 0x07,
+ 0x1d, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x00, 0x02, 0x00, 0x80, 0x00, 0x00, 0x84, 0x02
+};
+
+/* The offset to be used in order to get the __reason pseudo-register
+ when using one of the *UREGS ttrace requests (see system header file
+ /usr/include/ia64/sys/uregs.h for more details).
+
+ The documentation for this pseudo-register says that a nonzero value
+ indicates that the thread stopped due to a fault, trap, or interrupt.
+ A null value indicates a stop inside a syscall. */
+#define IA64_HPUX_UREG_REASON 0x00070000
/* Return nonzero if the value of the register identified by REGNUM
can be modified. */
return 0;
}
+/* Return nonzero if the inferior is stopped inside a system call. */
+
+static int
+ia64_hpux_stopped_in_syscall (struct gdbarch *gdbarch)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct target_ops *ops = ¤t_target;
+ gdb_byte buf[8];
+ int len;
+
+ len = target_read (ops, TARGET_OBJECT_HPUX_UREGS, NULL,
+ buf, IA64_HPUX_UREG_REASON, sizeof (buf));
+ if (len == -1)
+ /* The target wasn't able to tell us. Assume we are not stopped
+ in a system call, which is the normal situation. */
+ return 0;
+ gdb_assert (len == 8);
+
+ return (extract_unsigned_integer (buf, len, byte_order) == 0);
+}
+
+/* The "size_of_register_frame" gdbarch_tdep routine for ia64-hpux. */
+
+static int
+ia64_hpux_size_of_register_frame (struct frame_info *this_frame,
+ ULONGEST cfm)
+{
+ int sof;
+
+ if (frame_relative_level (this_frame) == 0
+ && ia64_hpux_stopped_in_syscall (get_frame_arch (this_frame)))
+ /* If the inferior stopped in a system call, the base address
+ of the register frame is at BSP - SOL instead of BSP - SOF.
+ This is an HP-UX exception. */
+ sof = (cfm & 0x3f80) >> 7;
+ else
+ sof = (cfm & 0x7f);
+
+ return sof;
+}
+
+/* Implement the push_dummy_code gdbarch method.
+
+ This function assumes that the SP is already 16-byte-aligned. */
+
+static CORE_ADDR
+ia64_hpux_push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp,
+ CORE_ADDR funaddr, struct value **args, int nargs,
+ struct type *value_type, CORE_ADDR *real_pc,
+ CORE_ADDR *bp_addr, struct regcache *regcache)
+{
+ ULONGEST cfm;
+ int sof, sol, sor, soo;
+ char buf[16];
+
+ regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);
+ sof = cfm & 0x7f;
+ sol = (cfm >> 7) & 0x7f;
+ sor = (cfm >> 14) & 0xf;
+ soo = sof - sol - sor;
+
+ /* Reserve some space on the stack to hold the dummy code. */
+ sp = sp - sizeof (ia64_hpux_dummy_code);
+
+ /* Set the breakpoint address at the first instruction of the bundle
+ in the dummy code that has only nops. This is where the dummy code
+ expects us to break. */
+ *bp_addr = sp + 0x20;
+
+ /* Start the inferior function call from the dummy code. The dummy
+ code will then call our function. */
+ *real_pc = sp;
+
+ /* Transfer the dummy code to the inferior. */
+ write_memory (sp, ia64_hpux_dummy_code, sizeof (ia64_hpux_dummy_code));
+
+ /* Update the size of the local portion of the register frame allocated
+ by ``stub'' to match the size of the output region of the current
+ register frame. This allows us to save the stacked registers.
+
+ The "alloc" instruction is located at slot 0 of the bundle at +0x30.
+ Update the "sof" and "sol" portion of that instruction which are
+ respectively at bits 18-24 and 25-31 of the bundle. */
+ memcpy (buf, ia64_hpux_dummy_code + 0x30, sizeof (buf));
+
+ buf[2] |= ((soo & 0x3f) << 2);
+ buf[3] |= (soo << 1);
+ if (soo > 63)
+ buf[3] |= 1;
+
+ write_memory (sp + 0x30, buf, sizeof (buf));
+
+ /* Return the new (already properly aligned) SP. */
+ return sp;
+}
+
+/* The "allocate_new_rse_frame" ia64_infcall_ops routine for ia64-hpux. */
+
+static void
+ia64_hpux_allocate_new_rse_frame (struct regcache *regcache, ULONGEST bsp,
+ int sof)
+{
+ /* We cannot change the value of the BSP register on HP-UX,
+ so we can't allocate a new RSE frame. */
+}
+
+/* The "store_argument_in_slot" ia64_infcall_ops routine for ia64-hpux. */
+
+static void
+ia64_hpux_store_argument_in_slot (struct regcache *regcache, CORE_ADDR bsp,
+ int slotnum, gdb_byte *buf)
+{
+ /* The call sequence on this target expects us to place the arguments
+ inside r14 - r21. */
+ regcache_cooked_write (regcache, IA64_GR0_REGNUM + 14 + slotnum, buf);
+}
+
+/* The "set_function_addr" ia64_infcall_ops routine for ia64-hpux. */
+
+static void
+ia64_hpux_set_function_addr (struct regcache *regcache, CORE_ADDR func_addr)
+{
+ /* The calling sequence calls the function whose address is placed
+ in register b1. */
+ regcache_cooked_write_unsigned (regcache, IA64_BR1_REGNUM, func_addr);
+}
+
+/* The ia64_infcall_ops structure for ia64-hpux. */
+
+static const struct ia64_infcall_ops ia64_hpux_infcall_ops =
+{
+ ia64_hpux_allocate_new_rse_frame,
+ ia64_hpux_store_argument_in_slot,
+ ia64_hpux_set_function_addr
+};
+
+/* The "dummy_id" gdbarch routine for ia64-hpux. */
+
+static struct frame_id
+ia64_hpux_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
+{
+ CORE_ADDR sp, pc, bp_addr, bsp;
+
+ sp = get_frame_register_unsigned (this_frame, IA64_GR12_REGNUM);
+
+ /* Just double-check that the frame PC is within a certain region
+ of the stack that would be plausible for our dummy code (the dummy
+ code was pushed at SP + 16). If not, then return a null frame ID.
+ This is necessary in our case, because it is possible to produce
+ the same frame ID for a normal frame, if that frame corresponds
+ to the function called by our dummy code, and the function has not
+ modified the registers that we use to build the dummy frame ID. */
+ pc = get_frame_pc (this_frame);
+ if (pc < sp + 16 || pc >= sp + 16 + sizeof (ia64_hpux_dummy_code))
+ return null_frame_id;
+
+ /* The call sequence is such that the address of the dummy breakpoint
+ we inserted is stored in r5. */
+ bp_addr = get_frame_register_unsigned (this_frame, IA64_GR5_REGNUM);
+
+ bsp = get_frame_register_unsigned (this_frame, IA64_BSP_REGNUM);
+
+ return frame_id_build_special (sp, bp_addr, bsp);
+}
+
/* Should be set to non-NULL if the ia64-hpux solib module is linked in.
This may not be the case because the shared library support code can
only be compiled on ia64-hpux. */
struct target_so_ops *ia64_hpux_so_ops = NULL;
+/* The "find_global_pointer_from_solib" gdbarch_tdep routine for
+ ia64-hpux. */
+
+static CORE_ADDR
+ia64_hpux_find_global_pointer_from_solib (struct gdbarch *gdbarch,
+ CORE_ADDR faddr)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct target_ops *ops = ¤t_target;
+ gdb_byte buf[8];
+ LONGEST len;
+
+ len = target_read (ops, TARGET_OBJECT_HPUX_SOLIB_GOT,
+ paddress (gdbarch, faddr), buf, 0, sizeof (buf));
+
+ return extract_unsigned_integer (buf, len, byte_order);
+}
+
static void
ia64_hpux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ tdep->size_of_register_frame = ia64_hpux_size_of_register_frame;
+
set_gdbarch_long_double_format (gdbarch, floatformats_ia64_quad);
set_gdbarch_cannot_store_register (gdbarch, ia64_hpux_cannot_store_register);
+ /* Inferior functions must be called from stack. */
+ set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
+ set_gdbarch_push_dummy_code (gdbarch, ia64_hpux_push_dummy_code);
+ tdep->infcall_ops = ia64_hpux_infcall_ops;
+ tdep->find_global_pointer_from_solib
+ = ia64_hpux_find_global_pointer_from_solib;
+ set_gdbarch_dummy_id (gdbarch, ia64_hpux_dummy_id);
+
if (ia64_hpux_so_ops)
set_solib_ops (gdbarch, ia64_hpux_so_ops);
}