1 /* libunwind - a platform-independent unwind library
2 Copyright (C) 2001-2005 Hewlett-Packard Co
3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
4
5 This file is part of libunwind.
6
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:
14
15 The above copyright notice and this permission notice shall be
16 included in all copies or substantial portions of the Software.
17
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. */
25
26 #include "offsets.h"
27 #include "unwind_i.h"
28
29 static inline int
linux_sigtramp(struct cursor * c,ia64_loc_t prev_cfm_loc,unw_word_t * num_regsp)30 linux_sigtramp (struct cursor *c, ia64_loc_t prev_cfm_loc,
31 unw_word_t *num_regsp)
32 {
33 #if defined(UNW_LOCAL_ONLY) && !defined(__linux)
34 return -UNW_EINVAL;
35 #else
36 unw_word_t sc_addr;
37 int ret;
38
39 if ((ret = ia64_get (c, IA64_LOC_ADDR (c->sp + 0x10
40 + LINUX_SIGFRAME_ARG2_OFF, 0),
41 &sc_addr)) < 0)
42 return ret;
43
44 c->sigcontext_addr = sc_addr;
45
46 if (!IA64_IS_REG_LOC (c->loc[IA64_REG_IP])
47 && IA64_GET_ADDR (c->loc[IA64_REG_IP]) == sc_addr + LINUX_SC_BR_OFF + 8)
48 {
49 /* Linux kernels before 2.4.19 and 2.5.10 had buggy
50 unwind info for sigtramp. Fix it up here. */
51 c->loc[IA64_REG_IP] = IA64_LOC_ADDR (sc_addr + LINUX_SC_IP_OFF, 0);
52 c->cfm_loc = IA64_LOC_ADDR (sc_addr + LINUX_SC_CFM_OFF, 0);
53 }
54
55 /* do what can't be described by unwind directives: */
56 c->loc[IA64_REG_PFS] = IA64_LOC_ADDR (sc_addr + LINUX_SC_AR_PFS_OFF, 0);
57 c->ec_loc = prev_cfm_loc;
58 *num_regsp = c->cfm & 0x7f; /* size of frame */
59 return 0;
60 #endif
61 }
62
63 static inline int
linux_interrupt(struct cursor * c,ia64_loc_t prev_cfm_loc,unw_word_t * num_regsp,int marker)64 linux_interrupt (struct cursor *c, ia64_loc_t prev_cfm_loc,
65 unw_word_t *num_regsp, int marker)
66 {
67 #if defined(UNW_LOCAL_ONLY) && !(defined(__linux) && defined(__KERNEL__))
68 return -UNW_EINVAL;
69 #else
70 unw_word_t sc_addr, num_regs;
71 ia64_loc_t pfs_loc;
72
73 sc_addr = c->sigcontext_addr = c->sp + 0x10;
74
75 if ((c->pr & (1UL << LINUX_PT_P_NONSYS)) != 0)
76 num_regs = c->cfm & 0x7f;
77 else
78 num_regs = 0;
79
80 /* do what can't be described by unwind directives: */
81 if (marker == ABI_MARKER_OLD_LINUX_INTERRUPT)
82 pfs_loc = IA64_LOC_ADDR (sc_addr + LINUX_OLD_PT_PFS_OFF, 0);
83 else
84 pfs_loc = IA64_LOC_ADDR (sc_addr + LINUX_PT_PFS_OFF, 0);
85 c->loc[IA64_REG_PFS] = pfs_loc;
86 c->ec_loc = prev_cfm_loc;
87 *num_regsp = num_regs; /* size of frame */
88 return 0;
89 #endif
90 }
91
92 static inline int
hpux_sigtramp(struct cursor * c,ia64_loc_t prev_cfm_loc,unw_word_t * num_regsp)93 hpux_sigtramp (struct cursor *c, ia64_loc_t prev_cfm_loc,
94 unw_word_t *num_regsp)
95 {
96 #if defined(UNW_LOCAL_ONLY) && !defined(__hpux)
97 return -UNW_EINVAL;
98 #else
99 unw_word_t sc_addr, bsp, bspstore;
100 ia64_loc_t sc_loc;
101 int ret, i;
102
103 /* HP-UX passes the address of ucontext_t in r32: */
104 if ((ret = ia64_get_stacked (c, 32, &sc_loc, NULL)) < 0)
105 return ret;
106 if ((ret = ia64_get (c, sc_loc, &sc_addr)) < 0)
107 return ret;
108
109 c->sigcontext_addr = sc_addr;
110
111 /* Now mark all (preserved) registers as coming from the
112 signal context: */
113 c->cfm_loc = IA64_LOC_UC_REG (UNW_IA64_CFM, sc_addr);
114 c->loc[IA64_REG_PRI_UNAT_MEM] = IA64_NULL_LOC;
115 c->loc[IA64_REG_PSP] = IA64_LOC_UC_REG (UNW_IA64_GR + 12, sc_addr);
116 c->loc[IA64_REG_BSP] = IA64_LOC_UC_REG (UNW_IA64_AR_BSP, sc_addr);
117 c->loc[IA64_REG_BSPSTORE] = IA64_LOC_UC_REG (UNW_IA64_AR_BSPSTORE, sc_addr);
118 c->loc[IA64_REG_PFS] = IA64_LOC_UC_REG (UNW_IA64_AR_PFS, sc_addr);
119 c->loc[IA64_REG_RNAT] = IA64_LOC_UC_REG (UNW_IA64_AR_RNAT, sc_addr);
120 c->loc[IA64_REG_IP] = IA64_LOC_UC_REG (UNW_IA64_IP, sc_addr);
121 c->loc[IA64_REG_R4] = IA64_LOC_UC_REG (UNW_IA64_GR + 4, sc_addr);
122 c->loc[IA64_REG_R5] = IA64_LOC_UC_REG (UNW_IA64_GR + 5, sc_addr);
123 c->loc[IA64_REG_R6] = IA64_LOC_UC_REG (UNW_IA64_GR + 6, sc_addr);
124 c->loc[IA64_REG_R7] = IA64_LOC_UC_REG (UNW_IA64_GR + 7, sc_addr);
125 c->loc[IA64_REG_NAT4] = IA64_LOC_UC_REG (UNW_IA64_NAT + 4, sc_addr);
126 c->loc[IA64_REG_NAT5] = IA64_LOC_UC_REG (UNW_IA64_NAT + 5, sc_addr);
127 c->loc[IA64_REG_NAT6] = IA64_LOC_UC_REG (UNW_IA64_NAT + 6, sc_addr);
128 c->loc[IA64_REG_NAT7] = IA64_LOC_UC_REG (UNW_IA64_NAT + 7, sc_addr);
129 c->loc[IA64_REG_UNAT] = IA64_LOC_UC_REG (UNW_IA64_AR_UNAT, sc_addr);
130 c->loc[IA64_REG_PR] = IA64_LOC_UC_REG (UNW_IA64_PR, sc_addr);
131 c->loc[IA64_REG_LC] = IA64_LOC_UC_REG (UNW_IA64_AR_LC, sc_addr);
132 c->loc[IA64_REG_FPSR] = IA64_LOC_UC_REG (UNW_IA64_AR_FPSR, sc_addr);
133 c->loc[IA64_REG_B1] = IA64_LOC_UC_REG (UNW_IA64_BR + 1, sc_addr);
134 c->loc[IA64_REG_B2] = IA64_LOC_UC_REG (UNW_IA64_BR + 2, sc_addr);
135 c->loc[IA64_REG_B3] = IA64_LOC_UC_REG (UNW_IA64_BR + 3, sc_addr);
136 c->loc[IA64_REG_B4] = IA64_LOC_UC_REG (UNW_IA64_BR + 4, sc_addr);
137 c->loc[IA64_REG_B5] = IA64_LOC_UC_REG (UNW_IA64_BR + 5, sc_addr);
138 c->loc[IA64_REG_F2] = IA64_LOC_UC_REG (UNW_IA64_FR + 2, sc_addr);
139 c->loc[IA64_REG_F3] = IA64_LOC_UC_REG (UNW_IA64_FR + 3, sc_addr);
140 c->loc[IA64_REG_F4] = IA64_LOC_UC_REG (UNW_IA64_FR + 4, sc_addr);
141 c->loc[IA64_REG_F5] = IA64_LOC_UC_REG (UNW_IA64_FR + 5, sc_addr);
142 for (i = 0; i < 16; ++i)
143 c->loc[IA64_REG_F16 + i] = IA64_LOC_UC_REG (UNW_IA64_FR + 16 + i, sc_addr);
144
145 c->pi.flags |= UNW_PI_FLAG_IA64_RBS_SWITCH;
146
147 /* update the CFM cache: */
148 if ((ret = ia64_get (c, c->cfm_loc, &c->cfm)) < 0)
149 return ret;
150 /* update the PSP cache: */
151 if ((ret = ia64_get (c, c->loc[IA64_REG_PSP], &c->psp)) < 0)
152 return ret;
153
154 if ((ret = ia64_get (c, c->loc[IA64_REG_BSP], &bsp)) < 0
155 || (ret = ia64_get (c, c->loc[IA64_REG_BSPSTORE], &bspstore)) < 0)
156 return ret;
157 if (bspstore < bsp)
158 /* Dirty partition got spilled into the ucontext_t structure
159 itself. We'll need to access it via uc_access(3). */
160 rbs_switch (c, bsp, bspstore, IA64_LOC_UC_ADDR (bsp | 0x1f8, 0));
161
162 c->ec_loc = prev_cfm_loc;
163
164 *num_regsp = 0;
165 return 0;
166 #endif
167 }
168
169
170 static inline int
check_rbs_switch(struct cursor * c)171 check_rbs_switch (struct cursor *c)
172 {
173 unw_word_t saved_bsp, saved_bspstore, loadrs, ndirty;
174 int ret = 0;
175
176 saved_bsp = c->bsp;
177 if (c->pi.flags & UNW_PI_FLAG_IA64_RBS_SWITCH)
178 {
179 /* Got ourselves a frame that has saved ar.bspstore, ar.bsp,
180 and ar.rnat, so we're all set for rbs-switching: */
181 if ((ret = ia64_get (c, c->loc[IA64_REG_BSP], &saved_bsp)) < 0
182 || (ret = ia64_get (c, c->loc[IA64_REG_BSPSTORE], &saved_bspstore)))
183 return ret;
184 }
185 else if ((c->abi_marker == ABI_MARKER_LINUX_SIGTRAMP
186 || c->abi_marker == ABI_MARKER_OLD_LINUX_SIGTRAMP)
187 && !IA64_IS_REG_LOC (c->loc[IA64_REG_BSP])
188 && (IA64_GET_ADDR (c->loc[IA64_REG_BSP])
189 == c->sigcontext_addr + LINUX_SC_AR_BSP_OFF))
190 {
191 /* When Linux delivers a signal on an alternate stack, it
192 does things a bit differently from what the unwind
193 conventions allow us to describe: instead of saving
194 ar.rnat, ar.bsp, and ar.bspstore, it saves the former two
195 plus the "loadrs" value. Because of this, we need to
196 detect & record a potential rbs-area switch
197 manually... */
198
199 /* If ar.bsp has been saved already AND the current bsp is
200 not equal to the saved value, then we know for sure that
201 we're past the point where the backing store has been
202 switched (and before the point where it's restored). */
203 if ((ret = ia64_get (c, IA64_LOC_ADDR (c->sigcontext_addr
204 + LINUX_SC_AR_BSP_OFF, 0),
205 &saved_bsp) < 0)
206 || (ret = ia64_get (c, IA64_LOC_ADDR (c->sigcontext_addr
207 + LINUX_SC_LOADRS_OFF, 0),
208 &loadrs) < 0))
209 return ret;
210 loadrs >>= 16;
211 ndirty = rse_num_regs (c->bsp - loadrs, c->bsp);
212 saved_bspstore = rse_skip_regs (saved_bsp, -ndirty);
213 }
214
215 if (saved_bsp == c->bsp)
216 return 0;
217
218 return rbs_switch (c, saved_bsp, saved_bspstore, c->loc[IA64_REG_RNAT]);
219 }
220
221 static inline int
update_frame_state(struct cursor * c)222 update_frame_state (struct cursor *c)
223 {
224 unw_word_t prev_ip, prev_sp, prev_bsp, ip, num_regs;
225 ia64_loc_t prev_cfm_loc;
226 int ret;
227
228 prev_cfm_loc = c->cfm_loc;
229 prev_ip = c->ip;
230 prev_sp = c->sp;
231 prev_bsp = c->bsp;
232
233 /* Update the IP cache (do this first: if we reach the end of the
234 frame-chain, the rest of the info may not be valid/useful
235 anymore. */
236 ret = ia64_get (c, c->loc[IA64_REG_IP], &ip);
237 if (ret < 0)
238 return ret;
239 c->ip = ip;
240
241 if ((ip & 0xc) != 0)
242 {
243 /* don't let obviously bad addresses pollute the cache */
244 Debug (1, "rejecting bad ip=0x%lx\n", (long) c->ip);
245 return -UNW_EINVALIDIP;
246 }
247
248 c->cfm_loc = c->loc[IA64_REG_PFS];
249 /* update the CFM cache: */
250 ret = ia64_get (c, c->cfm_loc, &c->cfm);
251 if (ret < 0)
252 return ret;
253
254 /* Normally, AR.EC is stored in the CFM save-location. That
255 save-location contains the full function-state as defined by
256 AR.PFS. However, interruptions only save the frame-marker, not
257 any other info in CFM. Instead, AR.EC gets saved on the first
258 call by the interruption-handler. Thus, interruption-related
259 frames need to track the _previous_ CFM save-location since
260 that's were AR.EC is saved. We support this by setting ec_loc to
261 cfm_loc by default and giving frames marked with an ABI-marker
262 the chance to override this value with prev_cfm_loc. */
263 c->ec_loc = c->cfm_loc;
264
265 num_regs = 0;
266 if (unlikely (c->abi_marker))
267 {
268 c->last_abi_marker = c->abi_marker;
269 switch (ia64_get_abi_marker (c))
270 {
271 case ABI_MARKER_LINUX_SIGTRAMP:
272 case ABI_MARKER_OLD_LINUX_SIGTRAMP:
273 ia64_set_abi (c, ABI_LINUX);
274 if ((ret = linux_sigtramp (c, prev_cfm_loc, &num_regs)) < 0)
275 return ret;
276 break;
277
278 case ABI_MARKER_OLD_LINUX_INTERRUPT:
279 case ABI_MARKER_LINUX_INTERRUPT:
280 ia64_set_abi (c, ABI_LINUX);
281 if ((ret = linux_interrupt (c, prev_cfm_loc, &num_regs,
282 c->abi_marker)) < 0)
283 return ret;
284 break;
285
286 case ABI_MARKER_HP_UX_SIGTRAMP:
287 ia64_set_abi (c, ABI_HPUX);
288 if ((ret = hpux_sigtramp (c, prev_cfm_loc, &num_regs)) < 0)
289 return ret;
290 break;
291
292 default:
293 Debug (1, "unknown ABI marker: ABI=%u, context=%u\n",
294 c->abi_marker >> 8, c->abi_marker & 0xff);
295 return -UNW_EINVAL;
296 }
297 Debug (12, "sigcontext_addr=%lx (ret=%d)\n",
298 (unsigned long) c->sigcontext_addr, ret);
299
300 c->sigcontext_off = c->sigcontext_addr - c->sp;
301
302 /* update the IP cache: */
303 if ((ret = ia64_get (c, c->loc[IA64_REG_IP], &ip)) < 0)
304 return ret;
305 c->ip = ip;
306 if (ip == 0)
307 /* end of frame-chain reached */
308 return 0;
309 }
310 else
311 num_regs = (c->cfm >> 7) & 0x7f; /* size of locals */
312
313 if (!IA64_IS_NULL_LOC (c->loc[IA64_REG_BSP]))
314 {
315 ret = check_rbs_switch (c);
316 if (ret < 0)
317 return ret;
318 }
319
320 c->bsp = rse_skip_regs (c->bsp, -num_regs);
321
322 c->sp = c->psp;
323 c->abi_marker = 0;
324
325 if (c->ip == prev_ip && c->sp == prev_sp && c->bsp == prev_bsp)
326 {
327 Dprintf ("%s: ip, sp, and bsp unchanged; stopping here (ip=0x%lx)\n",
328 __FUNCTION__, (long) ip);
329 return -UNW_EBADFRAME;
330 }
331
332 /* as we unwind, the saved ar.unat becomes the primary unat: */
333 c->loc[IA64_REG_PRI_UNAT_MEM] = c->loc[IA64_REG_UNAT];
334
335 /* restore the predicates: */
336 ret = ia64_get (c, c->loc[IA64_REG_PR], &c->pr);
337 if (ret < 0)
338 return ret;
339
340 c->pi_valid = 0;
341 return 0;
342 }
343
344
345 PROTECTED int
unw_step(unw_cursor_t * cursor)346 unw_step (unw_cursor_t *cursor)
347 {
348 struct cursor *c = (struct cursor *) cursor;
349 int ret;
350
351 Debug (1, "(cursor=%p, ip=0x%016lx)\n", c, (unsigned long) c->ip);
352
353 if ((ret = ia64_find_save_locs (c)) >= 0
354 && (ret = update_frame_state (c)) >= 0)
355 ret = (c->ip == 0) ? 0 : 1;
356
357 Debug (2, "returning %d (ip=0x%016lx)\n", ret, (unsigned long) c->ip);
358 return ret;
359 }
360