1 /* libunwind - a platform-independent unwind library
2 Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org>
3
4 This file is part of libunwind.
5
6 Permission is hereby granted, free of charge, to any person obtaining
7 a copy of this software and associated documentation files (the
8 "Software"), to deal in the Software without restriction, including
9 without limitation the rights to use, copy, modify, merge, publish,
10 distribute, sublicense, and/or sell copies of the Software, and to
11 permit persons to whom the Software is furnished to do so, subject to
12 the following conditions:
13
14 The above copyright notice and this permission notice shall be
15 included in all copies or substantial portions of the Software.
16
17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
24
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28
29 #include <sys/ucontext.h>
30 #include <machine/sigframe.h>
31 #include <signal.h>
32 #include <stddef.h>
33 #include "unwind_i.h"
34 #include "ucontext_i.h"
35
36 PROTECTED int
unw_is_signal_frame(unw_cursor_t * cursor)37 unw_is_signal_frame (unw_cursor_t *cursor)
38 {
39 /* XXXKIB */
40 struct cursor *c = (struct cursor *) cursor;
41 unw_word_t w0, w1, w2, b0, ip;
42 unw_addr_space_t as;
43 unw_accessors_t *a;
44 void *arg;
45 int ret;
46
47 as = c->dwarf.as;
48 a = unw_get_accessors (as);
49 arg = c->dwarf.as_arg;
50
51 /* Check if RIP points at sigreturn sequence.
52 48 8d 7c 24 10 lea SIGF_UC(%rsp),%rdi
53 6a 00 pushq $0
54 48 c7 c0 a1 01 00 00 movq $SYS_sigreturn,%rax
55 0f 05 syscall
56 f4 0: hlt
57 eb fd jmp 0b
58 */
59
60 ip = c->dwarf.ip;
61 c->sigcontext_format = X86_64_SCF_NONE;
62 if ((ret = (*a->access_mem) (as, ip, &w0, 0, arg)) < 0
63 || (ret = (*a->access_mem) (as, ip + 8, &w1, 0, arg)) < 0
64 || (ret = (*a->access_mem) (as, ip + 16, &w2, 0, arg)) < 0)
65 return 0;
66 w2 &= 0xffffff;
67 if (w0 == 0x48006a10247c8d48 &&
68 w1 == 0x050f000001a1c0c7 &&
69 w2 == 0x0000000000fdebf4)
70 {
71 c->sigcontext_format = X86_64_SCF_FREEBSD_SIGFRAME;
72 return (c->sigcontext_format);
73 }
74 /* Check if RIP points at standard syscall sequence.
75 49 89 ca mov %rcx,%r10
76 0f 05 syscall
77 */
78 if ((ret = (*a->access_mem) (as, ip - 5, &b0, 0, arg)) < 0)
79 return (0);
80 Debug (12, "b0 0x%lx\n", b0);
81 if ((b0 & 0xffffffffffffff) == 0x050fca89490000 ||
82 (b0 & 0xffffffffff) == 0x050fca8949)
83 {
84 c->sigcontext_format = X86_64_SCF_FREEBSD_SYSCALL;
85 return (c->sigcontext_format);
86 }
87 return (X86_64_SCF_NONE);
88 }
89
90 PROTECTED int
unw_handle_signal_frame(unw_cursor_t * cursor)91 unw_handle_signal_frame (unw_cursor_t *cursor)
92 {
93 struct cursor *c = (struct cursor *) cursor;
94 unw_word_t ucontext;
95 int ret;
96
97 if (c->sigcontext_format == X86_64_SCF_FREEBSD_SIGFRAME)
98 {
99 ucontext = c->dwarf.cfa + offsetof(struct sigframe, sf_uc);
100 c->sigcontext_addr = c->dwarf.cfa;
101 Debug(1, "signal frame, skip over trampoline\n");
102
103 struct dwarf_loc rsp_loc = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RSP, 0);
104 ret = dwarf_get (&c->dwarf, rsp_loc, &c->dwarf.cfa);
105 if (ret < 0)
106 {
107 Debug (2, "returning %d\n", ret);
108 return ret;
109 }
110
111 c->dwarf.loc[RAX] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RAX, 0);
112 c->dwarf.loc[RDX] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RDX, 0);
113 c->dwarf.loc[RCX] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RCX, 0);
114 c->dwarf.loc[RBX] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RBX, 0);
115 c->dwarf.loc[RSI] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RSI, 0);
116 c->dwarf.loc[RDI] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RDI, 0);
117 c->dwarf.loc[RBP] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RBP, 0);
118 c->dwarf.loc[RSP] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RSP, 0);
119 c->dwarf.loc[ R8] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R8, 0);
120 c->dwarf.loc[ R9] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R9, 0);
121 c->dwarf.loc[R10] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R10, 0);
122 c->dwarf.loc[R11] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R11, 0);
123 c->dwarf.loc[R12] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R12, 0);
124 c->dwarf.loc[R13] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R13, 0);
125 c->dwarf.loc[R14] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R14, 0);
126 c->dwarf.loc[R15] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R15, 0);
127 c->dwarf.loc[RIP] = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_RIP, 0);
128
129 return 0;
130 }
131 else if (c->sigcontext_format == X86_64_SCF_FREEBSD_SYSCALL)
132 {
133 c->dwarf.loc[RCX] = c->dwarf.loc[R10];
134 /* rsp_loc = DWARF_LOC(c->dwarf.cfa - 8, 0); */
135 /* rbp_loc = c->dwarf.loc[RBP]; */
136 c->dwarf.loc[RIP] = DWARF_LOC (c->dwarf.cfa, 0);
137 ret = dwarf_get (&c->dwarf, c->dwarf.loc[RIP], &c->dwarf.ip);
138 Debug (1, "Frame Chain [RIP=0x%Lx] = 0x%Lx\n",
139 (unsigned long long) DWARF_GET_LOC (c->dwarf.loc[RIP]),
140 (unsigned long long) c->dwarf.ip);
141 if (ret < 0)
142 {
143 Debug (2, "returning %d\n", ret);
144 return ret;
145 }
146 c->dwarf.cfa += 8;
147 return 1;
148 }
149 else
150 return -UNW_EBADFRAME;
151
152 }
153
154 #ifndef UNW_REMOTE_ONLY
155 HIDDEN void *
x86_64_r_uc_addr(ucontext_t * uc,int reg)156 x86_64_r_uc_addr (ucontext_t *uc, int reg)
157 {
158 /* NOTE: common_init() in init.h inlines these for fast path access. */
159 void *addr;
160
161 switch (reg)
162 {
163 case UNW_X86_64_R8: addr = &uc->uc_mcontext.mc_r8; break;
164 case UNW_X86_64_R9: addr = &uc->uc_mcontext.mc_r9; break;
165 case UNW_X86_64_R10: addr = &uc->uc_mcontext.mc_r10; break;
166 case UNW_X86_64_R11: addr = &uc->uc_mcontext.mc_r11; break;
167 case UNW_X86_64_R12: addr = &uc->uc_mcontext.mc_r12; break;
168 case UNW_X86_64_R13: addr = &uc->uc_mcontext.mc_r13; break;
169 case UNW_X86_64_R14: addr = &uc->uc_mcontext.mc_r14; break;
170 case UNW_X86_64_R15: addr = &uc->uc_mcontext.mc_r15; break;
171 case UNW_X86_64_RDI: addr = &uc->uc_mcontext.mc_rdi; break;
172 case UNW_X86_64_RSI: addr = &uc->uc_mcontext.mc_rsi; break;
173 case UNW_X86_64_RBP: addr = &uc->uc_mcontext.mc_rbp; break;
174 case UNW_X86_64_RBX: addr = &uc->uc_mcontext.mc_rbx; break;
175 case UNW_X86_64_RDX: addr = &uc->uc_mcontext.mc_rdx; break;
176 case UNW_X86_64_RAX: addr = &uc->uc_mcontext.mc_rax; break;
177 case UNW_X86_64_RCX: addr = &uc->uc_mcontext.mc_rcx; break;
178 case UNW_X86_64_RSP: addr = &uc->uc_mcontext.mc_rsp; break;
179 case UNW_X86_64_RIP: addr = &uc->uc_mcontext.mc_rip; break;
180
181 default:
182 addr = NULL;
183 }
184 return addr;
185 }
186
187 HIDDEN NORETURN void
x86_64_sigreturn(unw_cursor_t * cursor)188 x86_64_sigreturn (unw_cursor_t *cursor)
189 {
190 struct cursor *c = (struct cursor *) cursor;
191 ucontext_t *uc = (ucontext_t *)(c->sigcontext_addr +
192 offsetof(struct sigframe, sf_uc));
193
194 Debug (8, "resuming at ip=%llx via sigreturn(%p)\n",
195 (unsigned long long) c->dwarf.ip, uc);
196 sigreturn(uc);
197 abort();
198 }
199 #endif
200