static void
arm_catch_kernel_helper_return (struct gdbarch *gdbarch, CORE_ADDR from,
CORE_ADDR to, struct regcache *regs,
struct displaced_step_closure *dsc)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
dsc->numinsns = 1;
dsc->insn_addr = from;
dsc->cleanup = &cleanup_kernel_helper_return;
/* Say we wrote to the PC, else cleanup will set PC to the next
instruction in the helper, which isn't helpful. */
dsc->wrote_to_pc = 1;
/* Preparation: tmp[0] <- r14
r14 <- <scratch space>+4
*(<scratch space>+8) <- from
Insn: ldr pc, [r14, #4]
Cleanup: r14 <- tmp[0], pc <- tmp[0]. */
dsc->tmp[0] = displaced_read_reg (regs, dsc, ARM_LR_REGNUM);
displaced_write_reg (regs, dsc, ARM_LR_REGNUM, (ULONGEST) to + 4,
CANNOT_WRITE_PC);
write_memory_unsigned_integer (to + 8, 4, byte_order, from);
dsc->modinsn[0] = 0xe59ef004; /* ldr pc, [lr, #4]. */
}
static int
arm_linux_copy_svc (struct gdbarch *gdbarch, struct regcache *regs,
struct displaced_step_closure *dsc)
{
CORE_ADDR return_to = 0;
struct frame_info *frame;
unsigned int svc_number = displaced_read_reg (regs, dsc, 7);
int is_sigreturn = 0;
int is_thumb;
frame = get_current_frame ();
is_sigreturn = arm_linux_sigreturn_return_addr(frame, svc_number,
&return_to, &is_thumb);
if (is_sigreturn)
{
struct symtab_and_line sal;
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: found "
"sigreturn/rt_sigreturn SVC call. PC in frame = %lx\n",
(unsigned long) get_frame_pc (frame));
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: unwind pc = %lx. "
"Setting momentary breakpoint.\n", (unsigned long) return_to);
gdb_assert (inferior_thread ()->control.step_resume_breakpoint
== NULL);
sal = find_pc_line (return_to, 0);
sal.pc = return_to;
sal.section = find_pc_overlay (return_to);
sal.explicit_pc = 1;
frame = get_prev_frame (frame);
if (frame)
{
inferior_thread ()->control.step_resume_breakpoint
= set_momentary_breakpoint (gdbarch, sal, get_frame_id (frame),
bp_step_resume);
/* set_momentary_breakpoint invalidates FRAME. */
frame = NULL;
/* We need to make sure we actually insert the momentary
breakpoint set above. */
insert_breakpoints ();
}
else if (debug_displaced)
fprintf_unfiltered (gdb_stderr, "displaced: couldn't find previous "
"frame to set momentary breakpoint for "
"sigreturn/rt_sigreturn\n");
}
else if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: sigreturn/rt_sigreturn "
"SVC call not in signal trampoline frame\n");
/* Preparation: If we detect sigreturn, set momentary breakpoint at resume
location, else nothing.
Insn: unmodified svc.
Cleanup: if pc lands in scratch space, pc <- insn_addr + 4
else leave pc alone. */
dsc->cleanup = &arm_linux_cleanup_svc;
/* Pretend we wrote to the PC, so cleanup doesn't set PC to the next
instruction. */
dsc->wrote_to_pc = 1;
return 0;
}
static int
arm_linux_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;
struct frame_info *frame;
unsigned int svc_number = displaced_read_reg (regs, from, 7);
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: copying Linux svc insn %.8lx\n",
(unsigned long) insn);
frame = get_current_frame ();
/* Is this a sigreturn or rt_sigreturn syscall? Note: these are only useful
for EABI. */
if (svc_number == 119 || svc_number == 173)
{
if (get_frame_type (frame) == SIGTRAMP_FRAME)
{
CORE_ADDR return_to;
struct symtab_and_line sal;
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: found "
"sigreturn/rt_sigreturn SVC call. PC in frame = %lx\n",
(unsigned long) get_frame_pc (frame));
return_to = frame_unwind_caller_pc (frame);
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: unwind pc = %lx. "
"Setting momentary breakpoint.\n", (unsigned long) return_to);
gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL);
sal = find_pc_line (return_to, 0);
sal.pc = return_to;
sal.section = find_pc_overlay (return_to);
sal.explicit_pc = 1;
frame = get_prev_frame (frame);
if (frame)
{
inferior_thread ()->step_resume_breakpoint
= set_momentary_breakpoint (gdbarch, sal, get_frame_id (frame),
bp_step_resume);
/* We need to make sure we actually insert the momentary
breakpoint set above. */
insert_breakpoints ();
}
else if (debug_displaced)
fprintf_unfiltered (gdb_stderr, "displaced: couldn't find previous "
"frame to set momentary breakpoint for "
"sigreturn/rt_sigreturn\n");
}
else if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: sigreturn/rt_sigreturn "
"SVC call not in signal trampoline frame\n");
}
/* Preparation: If we detect sigreturn, set momentary breakpoint at resume
location, else nothing.
Insn: unmodified svc.
Cleanup: if pc lands in scratch space, pc <- insn_addr + 4
else leave pc alone. */
dsc->modinsn[0] = insn;
dsc->cleanup = &arm_linux_cleanup_svc;
/* Pretend we wrote to the PC, so cleanup doesn't set PC to the next
instruction. */
dsc->wrote_to_pc = 1;
return 0;
}