1 /* libunwind - a platform-independent unwind library
2 Copyright (C) 2002-2004 Hewlett-Packard Co
3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
5 This file is part of libunwind.
7 Permission is hereby granted, free of charge, to any person obtaining
8 a copy of this software and associated documentation files (the
9 "Software"), to deal in the Software without restriction, including
10 without limitation the rights to use, copy, modify, merge, publish,
11 distribute, sublicense, and/or sell copies of the Software, and to
12 permit persons to whom the Software is furnished to do so, subject to
13 the following conditions:
15 The above copyright notice and this permission notice shall be
16 included in all copies or substantial portions of the Software.
18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
29 #include <sys/syscall.h>
32 unw_is_signal_frame (unw_cursor_t *cursor)
34 struct cursor *c = (struct cursor *) cursor;
35 unw_word_t w0, w1, ip;
42 a = unw_get_accessors_int (as);
43 arg = c->dwarf.as_arg;
45 /* Check if EIP points at sigreturn() sequence. On Linux, this is:
49 0xb8 0x77 0x00 0x00 0x00 movl 0x77,%eax
52 without SA_SIGINFO, and
55 0xb8 0xad 0x00 0x00 0x00 movl 0xad,%eax
59 if SA_SIGINFO is specified.
62 if ((*a->access_mem) (as, ip, &w0, 0, arg) < 0
63 || (*a->access_mem) (as, ip + 4, &w1, 0, arg) < 0)
66 ret = ((w0 == 0x0077b858 && w1 == 0x80cd0000)
67 || (w0 == 0x0000adb8 && (w1 & 0xffffff) == 0x80cd00));
68 Debug (16, "returning %d\n", ret);
73 x86_handle_signal_frame (unw_cursor_t *cursor)
75 struct cursor *c = (struct cursor *) cursor;
78 /* c->esp points at the arguments to the handler. Without
79 SA_SIGINFO, the arguments consist of a signal number
80 followed by a struct sigcontext. With SA_SIGINFO, the
81 arguments consist a signal number, a siginfo *, and a
84 unw_word_t siginfo_ptr_addr = c->dwarf.cfa + 4;
85 unw_word_t sigcontext_ptr_addr = c->dwarf.cfa + 8;
86 unw_word_t siginfo_ptr, sigcontext_ptr;
87 struct dwarf_loc esp_loc, siginfo_ptr_loc, sigcontext_ptr_loc;
89 siginfo_ptr_loc = DWARF_LOC (siginfo_ptr_addr, 0);
90 sigcontext_ptr_loc = DWARF_LOC (sigcontext_ptr_addr, 0);
91 ret = (dwarf_get (&c->dwarf, siginfo_ptr_loc, &siginfo_ptr)
92 | dwarf_get (&c->dwarf, sigcontext_ptr_loc, &sigcontext_ptr));
95 Debug (2, "returning 0\n");
98 if (siginfo_ptr < c->dwarf.cfa
99 || siginfo_ptr > c->dwarf.cfa + 256
100 || sigcontext_ptr < c->dwarf.cfa
101 || sigcontext_ptr > c->dwarf.cfa + 256)
103 /* Not plausible for SA_SIGINFO signal */
104 c->sigcontext_format = X86_SCF_LINUX_SIGFRAME;
105 c->sigcontext_addr = sc_addr = c->dwarf.cfa + 4;
109 /* If SA_SIGINFO were not specified, we actually read
110 various segment pointers instead. We believe that at
111 least fs and _fsh are always zero for linux, so it is
112 not just unlikely, but impossible that we would end
114 c->sigcontext_format = X86_SCF_LINUX_RT_SIGFRAME;
115 c->sigcontext_addr = sigcontext_ptr;
116 sc_addr = sigcontext_ptr + LINUX_UC_MCONTEXT_OFF;
118 esp_loc = DWARF_LOC (sc_addr + LINUX_SC_ESP_OFF, 0);
119 ret = dwarf_get (&c->dwarf, esp_loc, &c->dwarf.cfa);
122 Debug (2, "returning 0\n");
126 c->dwarf.loc[EAX] = DWARF_LOC (sc_addr + LINUX_SC_EAX_OFF, 0);
127 c->dwarf.loc[ECX] = DWARF_LOC (sc_addr + LINUX_SC_ECX_OFF, 0);
128 c->dwarf.loc[EDX] = DWARF_LOC (sc_addr + LINUX_SC_EDX_OFF, 0);
129 c->dwarf.loc[EBX] = DWARF_LOC (sc_addr + LINUX_SC_EBX_OFF, 0);
130 c->dwarf.loc[EBP] = DWARF_LOC (sc_addr + LINUX_SC_EBP_OFF, 0);
131 c->dwarf.loc[ESI] = DWARF_LOC (sc_addr + LINUX_SC_ESI_OFF, 0);
132 c->dwarf.loc[EDI] = DWARF_LOC (sc_addr + LINUX_SC_EDI_OFF, 0);
133 c->dwarf.loc[EFLAGS] = DWARF_NULL_LOC;
134 c->dwarf.loc[TRAPNO] = DWARF_NULL_LOC;
135 c->dwarf.loc[ST0] = DWARF_NULL_LOC;
136 c->dwarf.loc[EIP] = DWARF_LOC (sc_addr + LINUX_SC_EIP_OFF, 0);
137 c->dwarf.loc[ESP] = DWARF_LOC (sc_addr + LINUX_SC_ESP_OFF, 0);
143 x86_get_scratch_loc (struct cursor *c, unw_regnum_t reg)
145 unw_word_t addr = c->sigcontext_addr, fpstate_addr, off;
146 int ret, is_fpstate = 0;
148 switch (c->sigcontext_format)
151 return DWARF_REG_LOC (&c->dwarf, reg);
153 case X86_SCF_LINUX_SIGFRAME:
156 case X86_SCF_LINUX_RT_SIGFRAME:
157 addr += LINUX_UC_MCONTEXT_OFF;
161 return DWARF_NULL_LOC;
166 case UNW_X86_GS: off = LINUX_SC_GS_OFF; break;
167 case UNW_X86_FS: off = LINUX_SC_FS_OFF; break;
168 case UNW_X86_ES: off = LINUX_SC_ES_OFF; break;
169 case UNW_X86_DS: off = LINUX_SC_DS_OFF; break;
170 case UNW_X86_EDI: off = LINUX_SC_EDI_OFF; break;
171 case UNW_X86_ESI: off = LINUX_SC_ESI_OFF; break;
172 case UNW_X86_EBP: off = LINUX_SC_EBP_OFF; break;
173 case UNW_X86_ESP: off = LINUX_SC_ESP_OFF; break;
174 case UNW_X86_EBX: off = LINUX_SC_EBX_OFF; break;
175 case UNW_X86_EDX: off = LINUX_SC_EDX_OFF; break;
176 case UNW_X86_ECX: off = LINUX_SC_ECX_OFF; break;
177 case UNW_X86_EAX: off = LINUX_SC_EAX_OFF; break;
178 case UNW_X86_TRAPNO: off = LINUX_SC_TRAPNO_OFF; break;
179 case UNW_X86_EIP: off = LINUX_SC_EIP_OFF; break;
180 case UNW_X86_CS: off = LINUX_SC_CS_OFF; break;
181 case UNW_X86_EFLAGS: off = LINUX_SC_EFLAGS_OFF; break;
182 case UNW_X86_SS: off = LINUX_SC_SS_OFF; break;
184 /* The following is probably not correct for all possible cases.
185 Somebody who understands this better should review this for
188 case UNW_X86_FCW: is_fpstate = 1; off = LINUX_FPSTATE_CW_OFF; break;
189 case UNW_X86_FSW: is_fpstate = 1; off = LINUX_FPSTATE_SW_OFF; break;
190 case UNW_X86_FTW: is_fpstate = 1; off = LINUX_FPSTATE_TAG_OFF; break;
191 case UNW_X86_FCS: is_fpstate = 1; off = LINUX_FPSTATE_CSSEL_OFF; break;
192 case UNW_X86_FIP: is_fpstate = 1; off = LINUX_FPSTATE_IPOFF_OFF; break;
193 case UNW_X86_FEA: is_fpstate = 1; off = LINUX_FPSTATE_DATAOFF_OFF; break;
194 case UNW_X86_FDS: is_fpstate = 1; off = LINUX_FPSTATE_DATASEL_OFF; break;
195 case UNW_X86_MXCSR: is_fpstate = 1; off = LINUX_FPSTATE_MXCSR_OFF; break;
197 /* stacked fp registers */
198 case UNW_X86_ST0: case UNW_X86_ST1: case UNW_X86_ST2: case UNW_X86_ST3:
199 case UNW_X86_ST4: case UNW_X86_ST5: case UNW_X86_ST6: case UNW_X86_ST7:
201 off = LINUX_FPSTATE_ST0_OFF + 10*(reg - UNW_X86_ST0);
204 /* SSE fp registers */
205 case UNW_X86_XMM0_lo: case UNW_X86_XMM0_hi:
206 case UNW_X86_XMM1_lo: case UNW_X86_XMM1_hi:
207 case UNW_X86_XMM2_lo: case UNW_X86_XMM2_hi:
208 case UNW_X86_XMM3_lo: case UNW_X86_XMM3_hi:
209 case UNW_X86_XMM4_lo: case UNW_X86_XMM4_hi:
210 case UNW_X86_XMM5_lo: case UNW_X86_XMM5_hi:
211 case UNW_X86_XMM6_lo: case UNW_X86_XMM6_hi:
212 case UNW_X86_XMM7_lo: case UNW_X86_XMM7_hi:
214 off = LINUX_FPSTATE_XMM0_OFF + 8*(reg - UNW_X86_XMM0_lo);
225 off = LINUX_FPSTATE_XMM0_OFF + 16*(reg - UNW_X86_XMM0);
232 return DWARF_REG_LOC (&c->dwarf, reg);
237 if ((ret = dwarf_get (&c->dwarf,
238 DWARF_MEM_LOC (&c->dwarf,
239 addr + LINUX_SC_FPSTATE_OFF),
241 return DWARF_NULL_LOC;
244 return DWARF_NULL_LOC;
246 return DWARF_MEM_LOC (c, fpstate_addr + off);
249 return DWARF_MEM_LOC (c, addr + off);
252 #ifndef UNW_REMOTE_ONLY
254 x86_r_uc_addr (ucontext_t *uc, int reg)
260 case UNW_X86_GS: addr = &uc->uc_mcontext.gregs[REG_GS]; break;
261 case UNW_X86_FS: addr = &uc->uc_mcontext.gregs[REG_FS]; break;
262 case UNW_X86_ES: addr = &uc->uc_mcontext.gregs[REG_ES]; break;
263 case UNW_X86_DS: addr = &uc->uc_mcontext.gregs[REG_DS]; break;
264 case UNW_X86_EAX: addr = &uc->uc_mcontext.gregs[REG_EAX]; break;
265 case UNW_X86_EBX: addr = &uc->uc_mcontext.gregs[REG_EBX]; break;
266 case UNW_X86_ECX: addr = &uc->uc_mcontext.gregs[REG_ECX]; break;
267 case UNW_X86_EDX: addr = &uc->uc_mcontext.gregs[REG_EDX]; break;
268 case UNW_X86_ESI: addr = &uc->uc_mcontext.gregs[REG_ESI]; break;
269 case UNW_X86_EDI: addr = &uc->uc_mcontext.gregs[REG_EDI]; break;
270 case UNW_X86_EBP: addr = &uc->uc_mcontext.gregs[REG_EBP]; break;
271 case UNW_X86_EIP: addr = &uc->uc_mcontext.gregs[REG_EIP]; break;
272 case UNW_X86_ESP: addr = &uc->uc_mcontext.gregs[REG_ESP]; break;
273 case UNW_X86_TRAPNO: addr = &uc->uc_mcontext.gregs[REG_TRAPNO]; break;
274 case UNW_X86_CS: addr = &uc->uc_mcontext.gregs[REG_CS]; break;
275 case UNW_X86_EFLAGS: addr = &uc->uc_mcontext.gregs[REG_EFL]; break;
276 case UNW_X86_SS: addr = &uc->uc_mcontext.gregs[REG_SS]; break;
285 x86_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
287 struct cursor *c = (struct cursor *) cursor;
288 ucontext_t *uc = c->uc;
290 /* Ensure c->pi is up-to-date. On x86, it's relatively common to be
291 missing DWARF unwind info. We don't want to fail in that case,
292 because the frame-chain still would let us do a backtrace at
294 dwarf_make_proc_info (&c->dwarf);
296 if (unlikely (c->sigcontext_format != X86_SCF_NONE))
298 struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
300 Debug (8, "resuming at ip=%x via sigreturn(%p)\n", c->dwarf.ip, sc);
305 Debug (8, "resuming at ip=%x via setcontext()\n", c->dwarf.ip);
311 /* sigreturn() is a no-op on x86 glibc. */
313 x86_sigreturn (unw_cursor_t *cursor)
315 struct cursor *c = (struct cursor *) cursor;
316 struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
317 mcontext_t *sc_mcontext = &((ucontext_t*)sc)->uc_mcontext;
318 /* Copy in saved uc - all preserved regs are at the start of sigcontext */
319 memcpy(sc_mcontext, &c->uc->uc_mcontext,
320 DWARF_NUM_PRESERVED_REGS * sizeof(unw_word_t));
322 Debug (8, "resuming at ip=%llx via sigreturn(%p)\n",
323 (unsigned long long) c->dwarf.ip, sc);
324 __asm__ __volatile__ ("mov %0, %%esp;"
327 :: "r"(sc), "i"(SYS_rt_sigreturn)