1 /* Target-dependent code for GNU/Linux running on x86-64, for GDB.
3 Copyright 2001 Free Software Foundation, Inc.
5 Contributed by Jiri Smid, SuSE Labs.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
27 #include "gdb_string.h"
29 #include "x86-64-tdep.h"
30 #include "dwarf2cfi.h"
32 #define LINUX_SIGTRAMP_INSN0 (0x48) /* mov $NNNNNNNN,%rax */
33 #define LINUX_SIGTRAMP_OFFSET0 (0)
34 #define LINUX_SIGTRAMP_INSN1 (0x0f) /* syscall */
35 #define LINUX_SIGTRAMP_OFFSET1 (7)
37 static const unsigned char linux_sigtramp_code[] = {
38 /* mov $__NR_rt_sigreturn,%rax */
39 LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
41 LINUX_SIGTRAMP_INSN1, 0x05
44 #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
46 /* If PC is in a sigtramp routine, return the address of the start of
47 the routine. Otherwise, return 0. */
50 x86_64_linux_sigtramp_start (CORE_ADDR pc)
52 unsigned char buf[LINUX_SIGTRAMP_LEN];
53 if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
56 if (buf[0] != LINUX_SIGTRAMP_INSN0)
58 if (buf[0] != LINUX_SIGTRAMP_INSN1)
61 pc -= LINUX_SIGTRAMP_OFFSET1;
63 if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
67 if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
73 #define LINUX_SIGINFO_SIZE 0
75 /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
76 #define LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
78 /* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
79 #define LINUX_SIGCONTEXT_PC_OFFSET 128
80 #define LINUX_SIGCONTEXT_FP_OFFSET 120
82 /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
83 address of the associated sigcontext structure. */
85 x86_64_linux_sigcontext_addr (struct frame_info *frame)
90 pc = x86_64_linux_sigtramp_start (frame->pc);
94 /* If this isn't the top frame, the next frame must be for the
95 signal handler itself. The sigcontext structure is part of
97 return frame->next->frame + LINUX_SIGINFO_SIZE +
98 LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
101 /* This is the top frame. */
102 rsp = read_register (SP_REGNUM);
103 return rsp + LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
107 error ("Couldn't recognize signal trampoline.");
111 /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
112 saved program counter. */
115 x86_64_linux_sigtramp_saved_pc (struct frame_info *frame)
119 addr = x86_64_linux_sigcontext_addr (frame);
120 return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
123 /* Immediately after a function call, return the saved pc. */
126 x86_64_linux_saved_pc_after_call (struct frame_info *frame)
128 if (frame->signal_handler_caller)
129 return x86_64_linux_sigtramp_saved_pc (frame);
131 return read_memory_integer (read_register (SP_REGNUM), 8);
134 /* Saved Pc. Get it from sigcontext if within sigtramp. */
136 x86_64_linux_frame_saved_pc (struct frame_info *frame)
138 if (frame->signal_handler_caller)
139 return x86_64_linux_sigtramp_saved_pc (frame);
140 return cfi_get_ra (frame);
143 /* Return whether PC is in a GNU/Linux sigtramp routine. */
146 x86_64_linux_in_sigtramp (CORE_ADDR pc, char *name)
149 return STREQ ("__restore_rt", name);
151 return (x86_64_linux_sigtramp_start (pc) != 0);
155 x86_64_linux_frame_chain (struct frame_info *fi)
160 if (!fi->signal_handler_caller)
162 fp = cfi_frame_chain (fi);
169 addr = fi->next->frame;
171 addr += LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
173 fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8) + 8;
179 x86_64_init_frame_pc (int fromleaf, struct frame_info *fi)
183 if (fi->next && fi->next->signal_handler_caller)
185 addr = fi->next->next->frame
186 + LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
187 fi->pc = read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
190 cfi_init_frame_pc (fromleaf, fi);
194 x86_64_init_extra_frame_info (int fromleaf, struct frame_info *fi)
196 cfi_init_extra_frame_info (fromleaf, fi);