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 ((get_frame_type (frame
) == SIGTRAMP_FRAME
))
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 ((get_frame_type (frame
) == SIGTRAMP_FRAME
))
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 (!(get_frame_type (fi
) == SIGTRAMP_FRAME
))
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 (get_next_frame (fi
) && (get_frame_type (fi
->next
) == SIGTRAMP_FRAME
))
185 addr
= get_frame_base (get_next_frame (get_next_frame (fi
)))
186 + LINUX_SIGINFO_SIZE
+ LINUX_UCONTEXT_SIGCONTEXT_OFFSET
;
187 return read_memory_integer (addr
+ LINUX_SIGCONTEXT_PC_OFFSET
, 8);
190 return cfi_init_frame_pc (fromleaf
, fi
);