0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
0xcd, 0x80 /* int $0x80 */
};
+ size_t buflen = (sizeof sigreturn) + 1;
char *name, *buf;
/* If the function has a valid symbol name, it isn't a
return 0;
/* If we can't read the instructions at START_PC, return zero. */
- buf = alloca (sizeof sigreturn);
- if (target_read_memory (start_pc + 7, buf, sizeof sigreturn))
+ buf = alloca ((sizeof sigreturn) + 1);
+ if (!safe_frame_unwind_memory (next_frame, start_pc + 6, buf, buflen))
return 0;
- /* Check for sigreturn(2). */
- if (memcmp (buf, sigreturn, sizeof sigreturn))
+ /* Check for sigreturn(2). Depending on how the assembler encoded
+ the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
+ 7. */
+ if (memcmp (buf, sigreturn, sizeof sigreturn)
+ && memcpy (buf + 1, sigreturn, sizeof sigreturn))
return 0;
return 1;
(see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq'
instruction clobbers %rsp, but its value is saved in `%rdi'. */
- if (offset > 6)
+ if (offset > 5)
return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM);
else
return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);