| /* Target-dependent code for GNU/Linux running on x86-64, for GDB. |
| |
| Copyright 2001 Free Software Foundation, Inc. |
| |
| Contributed by Jiri Smid, SuSE Labs. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #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) /* mov $NNNNNNNN,%rax */ |
| #define LINUX_SIGTRAMP_OFFSET0 (0) |
| #define LINUX_SIGTRAMP_INSN1 (0x0f) /* syscall */ |
| #define LINUX_SIGTRAMP_OFFSET1 (7) |
| |
| static const unsigned char linux_sigtramp_code[] = { |
| /* mov $__NR_rt_sigreturn,%rax */ |
| LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00, |
| /* syscall */ |
| LINUX_SIGTRAMP_INSN1, 0x05 |
| }; |
| |
| #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code) |
| |
| /* If PC is in a sigtramp routine, return the address of the start of |
| the routine. Otherwise, return 0. */ |
| |
| 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 0 |
| |
| /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */ |
| #define LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40 |
| |
| /* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */ |
| #define LINUX_SIGCONTEXT_PC_OFFSET 128 |
| #define LINUX_SIGCONTEXT_FP_OFFSET 120 |
| |
| /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the |
| address of the associated sigcontext structure. */ |
| static CORE_ADDR |
| x86_64_linux_sigcontext_addr (struct frame_info *frame) |
| { |
| CORE_ADDR pc; |
| ULONGEST rsp; |
| |
| pc = x86_64_linux_sigtramp_start (frame->pc); |
| if (pc) |
| { |
| if (frame->next) |
| /* If this isn't the top frame, the next frame must be for the |
| signal handler itself. The sigcontext structure is part of |
| the user context. */ |
| return frame->next->frame + LINUX_SIGINFO_SIZE + |
| LINUX_UCONTEXT_SIGCONTEXT_OFFSET; |
| |
| |
| /* This is the top frame. */ |
| rsp = read_register (SP_REGNUM); |
| return rsp + LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET; |
| |
| } |
| |
| error ("Couldn't recognize signal trampoline."); |
| return 0; |
| } |
| |
| /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the |
| saved program counter. */ |
| |
| static 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); |
| } |
| |
| /* Immediately after a function call, return the saved pc. */ |
| |
| 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); |
| } |
| |
| /* Saved Pc. Get it from sigcontext if within sigtramp. */ |
| 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); |
| } |
| |
| /* Return whether PC is in a GNU/Linux sigtramp routine. */ |
| |
| int |
| x86_64_linux_in_sigtramp (CORE_ADDR pc, char *name) |
| { |
| if (name) |
| return STREQ ("__restore_rt", name); |
| |
| return (x86_64_linux_sigtramp_start (pc) != 0); |
| } |
| |
| CORE_ADDR |
| x86_64_linux_frame_chain (struct frame_info *fi) |
| { |
| ULONGEST addr; |
| CORE_ADDR fp, pc; |
| |
| if (!fi->signal_handler_caller) |
| { |
| fp = cfi_frame_chain (fi); |
| if (fp) |
| return fp; |
| else |
| addr = fi->frame; |
| } |
| else |
| addr = fi->next->frame; |
| |
| addr += LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET; |
| |
| fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8) + 8; |
| |
| return fp; |
| } |
| |
| void |
| x86_64_init_frame_pc (int fromleaf, struct frame_info *fi) |
| { |
| CORE_ADDR addr; |
| |
| if (fi->next && fi->next->signal_handler_caller) |
| { |
| addr = fi->next->next->frame |
| + LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET; |
| fi->pc = read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8); |
| } |
| else |
| cfi_init_frame_pc (fromleaf, fi); |
| } |