x86-64-linux-tdep.c [plain text]
#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include "gdb_string.h"
#include "regcache.h"
#include "x86-64-tdep.h"
#include "dwarf2cfi.h"
#define LINUX_SIGTRAMP_INSN0 (0x48)
#define LINUX_SIGTRAMP_OFFSET0 (0)
#define LINUX_SIGTRAMP_INSN1 (0x0f)
#define LINUX_SIGTRAMP_OFFSET1 (7)
static const unsigned char linux_sigtramp_code[] = {
LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x89, 0x00, 0x00, 0x00,
LINUX_SIGTRAMP_INSN1, 0x05
};
#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
static CORE_ADDR
x86_64_linux_sigtramp_start (CORE_ADDR pc)
{
unsigned char buf[LINUX_SIGTRAMP_LEN];
if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
return 0;
if (buf[0] != LINUX_SIGTRAMP_INSN0)
{
if (buf[0] != LINUX_SIGTRAMP_INSN1)
return 0;
pc -= LINUX_SIGTRAMP_OFFSET1;
if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
return 0;
}
if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
return 0;
return pc;
}
#define LINUX_SIGINFO_SIZE 128
#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET (36)
CORE_ADDR
x86_64_linux_sigcontext_addr (struct frame_info *frame)
{
CORE_ADDR pc;
pc = x86_64_linux_sigtramp_start (frame->pc);
if (pc)
{
if (frame->next)
return frame->next->frame + LINUX_SIGINFO_SIZE +
LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
return read_register (SP_REGNUM) + LINUX_SIGINFO_SIZE +
LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
}
error ("Couldn't recognize signal trampoline.");
return 0;
}
#define LINUX_SIGCONTEXT_PC_OFFSET (136)
CORE_ADDR
x86_64_linux_sigtramp_saved_pc (struct frame_info *frame)
{
CORE_ADDR addr;
addr = x86_64_linux_sigcontext_addr (frame);
return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
}
CORE_ADDR
x86_64_linux_saved_pc_after_call (struct frame_info *frame)
{
if (frame->signal_handler_caller)
return x86_64_linux_sigtramp_saved_pc (frame);
return read_memory_integer (read_register (SP_REGNUM), 8);
}
CORE_ADDR
x86_64_linux_frame_saved_pc (struct frame_info *frame)
{
if (frame->signal_handler_caller)
return x86_64_linux_sigtramp_saved_pc (frame);
return cfi_get_ra (frame);
}