FreeChainXenon/binutils-gdb
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

gdb: LoongArch: Implement loongarch_linux_syscall_next_pc()

Browse source 
When FRAME is at a syscall instruction, return the PC of the next
instruction to be executed.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
This commit is contained in:
Tiezhu Yang 2022-06-25 09:21:16 +08:00
parent 0757a50396
commit af6e3f77e9
3 changed files with 36 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
gdb/loongarch-linux-tdep.c
View file

@ -161,11 +161,35 @@ loongarch_iterate_over_regset_sections (struct gdbarch *gdbarch,
LOONGARCH_LINUX_NUM_GREGSET * regsize, &loongarch_gregset, NULL, cb_data);
}
/* The following value is derived from __NR_rt_sigreturn in
<include/uapi/asm-generic/unistd.h> from the Linux source tree. */
#define LOONGARCH_NR_rt_sigreturn 139
/* When FRAME is at a syscall instruction, return the PC of the next
instruction to be executed. */
static CORE_ADDR
loongarch_linux_syscall_next_pc (struct frame_info *frame)
{
const CORE_ADDR pc = get_frame_pc (frame);
ULONGEST a7 = get_frame_register_unsigned (frame, LOONGARCH_A7_REGNUM);
/* If we are about to make a sigreturn syscall, use the unwinder to
decode the signal frame. */
if (a7 == LOONGARCH_NR_rt_sigreturn)
return frame_unwind_caller_pc (frame);
return pc + 4;
}
/* Initialize LoongArch Linux ABI info. */
static void
loongarch_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
loongarch_gdbarch_tdep *tdep = (loongarch_gdbarch_tdep *) gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, 0);
set_solib_svr4_fetch_link_map_offsets (gdbarch,
@ -187,6 +211,8 @@ loongarch_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
/* Core file support. */
set_gdbarch_iterate_over_regset_sections (gdbarch, loongarch_iterate_over_regset_sections);
tdep->syscall_next_pc = loongarch_linux_syscall_next_pc;
}
/* Initialize LoongArch Linux target support. */

7
gdb/loongarch-tdep.c
View file

@ -224,6 +224,8 @@ loongarch_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
static CORE_ADDR
loongarch_next_pc (struct regcache *regcache, CORE_ADDR cur_pc)
{
struct gdbarch *gdbarch = regcache->arch ();
loongarch_gdbarch_tdep *tdep = (loongarch_gdbarch_tdep *) gdbarch_tdep (gdbarch);
insn_t insn = loongarch_fetch_instruction (cur_pc);
size_t insn_len = loongarch_insn_length (insn);
CORE_ADDR next_pc = cur_pc + insn_len;
@ -307,6 +309,11 @@ loongarch_next_pc (struct regcache *regcache, CORE_ADDR cur_pc)
if (rj != 0)
next_pc = cur_pc + loongarch_decode_imm ("0:5|10:16<<2", insn, 1);
}
else if ((insn & 0xffff8000) == 0x002b0000) /* syscall */
{
if (tdep->syscall_next_pc != nullptr)
next_pc = tdep->syscall_next_pc (get_current_frame ());
}
return next_pc;
}

3
gdb/loongarch-tdep.h
View file

@ -48,6 +48,9 @@ struct loongarch_gdbarch_tdep : gdbarch_tdep
{
/* Features about the abi that impact how the gdbarch is configured. */
struct loongarch_gdbarch_features abi_features;
/* Return the expected next PC if FRAME is stopped at a syscall instruction. */
CORE_ADDR (*syscall_next_pc) (struct frame_info *frame) = nullptr;
};
#endif /* LOONGARCH_TDEP_H */