1 /* Target-dependent code for GNU/Linux running on x86-64, for GDB.
3 Copyright 2001, 2003 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"
33 #define LINUX_SIGTRAMP_INSN0 (0x48) /* mov $NNNNNNNN,%rax */
34 #define LINUX_SIGTRAMP_OFFSET0 (0)
35 #define LINUX_SIGTRAMP_INSN1 (0x0f) /* syscall */
36 #define LINUX_SIGTRAMP_OFFSET1 (7)
38 static const unsigned char linux_sigtramp_code
[] = {
39 /* mov $__NR_rt_sigreturn,%rax */
40 LINUX_SIGTRAMP_INSN0
, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
42 LINUX_SIGTRAMP_INSN1
, 0x05
45 #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
47 /* If PC is in a sigtramp routine, return the address of the start of
48 the routine. Otherwise, return 0. */
51 x86_64_linux_sigtramp_start (CORE_ADDR pc
)
53 unsigned char buf
[LINUX_SIGTRAMP_LEN
];
54 if (read_memory_nobpt (pc
, (char *) buf
, LINUX_SIGTRAMP_LEN
) != 0)
57 if (buf
[0] != LINUX_SIGTRAMP_INSN0
)
59 if (buf
[0] != LINUX_SIGTRAMP_INSN1
)
62 pc
-= LINUX_SIGTRAMP_OFFSET1
;
64 if (read_memory_nobpt (pc
, (char *) buf
, LINUX_SIGTRAMP_LEN
) != 0)
68 if (memcmp (buf
, linux_sigtramp_code
, LINUX_SIGTRAMP_LEN
) != 0)
74 #define LINUX_SIGINFO_SIZE 0
76 /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
77 #define LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
79 /* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
80 #define LINUX_SIGCONTEXT_PC_OFFSET 128
81 #define LINUX_SIGCONTEXT_FP_OFFSET 120
83 /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
84 address of the associated sigcontext structure. */
86 x86_64_linux_sigcontext_addr (struct frame_info
*frame
)
91 pc
= x86_64_linux_sigtramp_start (get_frame_pc (frame
));
94 if (get_next_frame (frame
))
95 /* If this isn't the top frame, the next frame must be for the
96 signal handler itself. The sigcontext structure is part of
98 return get_frame_base (get_next_frame (frame
)) + LINUX_SIGINFO_SIZE
+
99 LINUX_UCONTEXT_SIGCONTEXT_OFFSET
;
102 /* This is the top frame. */
103 rsp
= read_register (SP_REGNUM
);
104 return rsp
+ LINUX_SIGINFO_SIZE
+ LINUX_UCONTEXT_SIGCONTEXT_OFFSET
;
108 error ("Couldn't recognize signal trampoline.");
112 /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
113 saved program counter. */
116 x86_64_linux_sigtramp_saved_pc (struct frame_info
*frame
)
120 addr
= x86_64_linux_sigcontext_addr (frame
);
121 return read_memory_integer (addr
+ LINUX_SIGCONTEXT_PC_OFFSET
, 8);
124 /* Immediately after a function call, return the saved pc. */
127 x86_64_linux_saved_pc_after_call (struct frame_info
*frame
)
129 if ((get_frame_type (frame
) == SIGTRAMP_FRAME
))
130 return x86_64_linux_sigtramp_saved_pc (frame
);
132 return read_memory_integer (read_register (SP_REGNUM
), 8);
135 /* Saved Pc. Get it from sigcontext if within sigtramp. */
137 x86_64_linux_frame_saved_pc (struct frame_info
*frame
)
139 if ((get_frame_type (frame
) == SIGTRAMP_FRAME
))
140 return x86_64_linux_sigtramp_saved_pc (frame
);
141 return cfi_get_ra (frame
);
144 /* Return whether PC is in a GNU/Linux sigtramp routine. */
147 x86_64_linux_in_sigtramp (CORE_ADDR pc
, char *name
)
150 return strcmp ("__restore_rt", name
) == 0;
152 return (x86_64_linux_sigtramp_start (pc
) != 0);
156 x86_64_linux_frame_chain (struct frame_info
*fi
)
161 if (!(get_frame_type (fi
) == SIGTRAMP_FRAME
))
163 fp
= cfi_frame_chain (fi
);
167 addr
= get_frame_base (fi
);
170 addr
= get_frame_base (get_next_frame (fi
));
172 addr
+= LINUX_SIGINFO_SIZE
+ LINUX_UCONTEXT_SIGCONTEXT_OFFSET
;
174 fp
= read_memory_integer (addr
+ LINUX_SIGCONTEXT_FP_OFFSET
, 8) + 8;
180 x86_64_init_frame_pc (int fromleaf
, struct frame_info
*fi
)
184 if (get_next_frame (fi
)
185 && (get_frame_type (get_next_frame (fi
)) == SIGTRAMP_FRAME
))
187 addr
= get_frame_base (get_next_frame (get_next_frame (fi
)))
188 + LINUX_SIGINFO_SIZE
+ LINUX_UCONTEXT_SIGCONTEXT_OFFSET
;
189 return read_memory_integer (addr
+ LINUX_SIGCONTEXT_PC_OFFSET
, 8);
192 return cfi_init_frame_pc (fromleaf
, fi
);
197 x86_64_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
199 x86_64_init_abi (info
, gdbarch
);
202 /* Provide a prototype to silence -Wmissing-prototypes. */
203 extern void _initialize_x86_64_linux_tdep (void);
206 _initialize_x86_64_linux_tdep (void)
208 gdbarch_register_osabi (bfd_arch_i386
, bfd_mach_x86_64
, GDB_OSABI_LINUX
,
209 x86_64_linux_init_abi
);