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1 /* libunwind - a platform-independent unwind library
2    Copyright (C) 2001-2004 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 <stdlib.h>
27 
28 #include "unwind_i.h"
29 #include "offsets.h"
30 
31 #ifndef UNW_REMOTE_ONLY
32 
33 static inline int
local_resume(unw_addr_space_t as,unw_cursor_t * cursor,void * arg)34 local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
35 {
36 #if defined(__linux__)
37   unw_word_t dirty_partition[2048]; /* AR.RSC.LOADRS is a 14-bit field */
38   unw_word_t val, sol, sof, pri_unat, n, pfs, bspstore, dirty_rnat;
39   struct cursor *c = (struct cursor *) cursor;
40   struct
41     {
42       unw_word_t r1;
43       unw_word_t r4;
44       unw_word_t r5;
45       unw_word_t r6;
46       unw_word_t r7;
47       unw_word_t r15;
48       unw_word_t r16;
49       unw_word_t r17;
50       unw_word_t r18;
51     }
52   extra;
53   int ret, dirty_size;
54 # define GET_NAT(n)                                             \
55   do                                                            \
56     {                                                           \
57       ret = tdep_access_reg (c, UNW_IA64_NAT + (n), &val, 0);   \
58       if (ret < 0)                                              \
59         return ret;                                             \
60       if (val)                                                  \
61         pri_unat |= (unw_word_t) 1 << n;                        \
62     }                                                           \
63   while (0)
64 
65   /* ensure c->pi is up-to-date: */
66   if ((ret = ia64_make_proc_info (c)) < 0)
67     return ret;
68 
69   /* Copy contents of r4-r7 into "extra", so that their values end up
70      contiguous, so we can use a single (primary-) UNaT value.  */
71   if ((ret = ia64_get (c, c->loc[IA64_REG_R4], &extra.r4)) < 0
72       || (ret = ia64_get (c, c->loc[IA64_REG_R5], &extra.r5)) < 0
73       || (ret = ia64_get (c, c->loc[IA64_REG_R6], &extra.r6)) < 0
74       || (ret = ia64_get (c, c->loc[IA64_REG_R7], &extra.r7)) < 0)
75     return ret;
76 
77   /* Form the primary UNaT value: */
78   pri_unat = 0;
79   GET_NAT (4); GET_NAT(5);
80   GET_NAT (6); GET_NAT(7);
81   n = (((uintptr_t) &extra.r4) / 8 - 4) % 64;
82   pri_unat = (pri_unat << n) | (pri_unat >> (64 - n));
83 
84   if (unlikely (c->sigcontext_addr))
85     {
86       struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
87 #     define PR_SCRATCH         0xffc0  /* p6-p15 are scratch */
88 #     define PR_PRESERVED       (~(PR_SCRATCH | 1))
89 
90       /* We're returning to a frame that was (either directly or
91          indirectly) interrupted by a signal.  We have to restore
92          _both_ "preserved" and "scratch" registers.  That doesn't
93          leave us any registers to work with, and the only way we can
94          achieve this is by doing a sigreturn().
95 
96          Note: it might be tempting to think that we don't have to
97          restore the scratch registers when returning to a frame that
98          was indirectly interrupted by a signal.  However, that is not
99          safe because that frame and its descendants could have been
100          using a special convention that stores "preserved" state in
101          scratch registers.  For example, the Linux fsyscall
102          convention does this with r11 (to save ar.pfs) and b6 (to
103          save "rp"). */
104 
105       sc->sc_gr[12] = c->psp;
106       c->psp = c->sigcontext_addr - c->sigcontext_off;
107 
108       sof = (c->cfm & 0x7f);
109       if ((dirty_size = rbs_cover_and_flush (c, sof, dirty_partition,
110                                              &dirty_rnat, &bspstore)) < 0)
111         return dirty_size;
112 
113       /* Clear the "in-syscall" flag, because in general we won't be
114          returning to the interruption-point and we need all registers
115          restored.  */
116       sc->sc_flags &= ~IA64_SC_FLAG_IN_SYSCALL;
117       sc->sc_ip = c->ip;
118       sc->sc_cfm = c->cfm & (((unw_word_t) 1 << 38) - 1);
119       sc->sc_pr = (c->pr & ~PR_SCRATCH) | (sc->sc_pr & ~PR_PRESERVED);
120       if ((ret = ia64_get (c, c->loc[IA64_REG_PFS], &sc->sc_ar_pfs)) < 0
121           || (ret = ia64_get (c, c->loc[IA64_REG_FPSR], &sc->sc_ar_fpsr)) < 0
122           || (ret = ia64_get (c, c->loc[IA64_REG_UNAT], &sc->sc_ar_unat)) < 0)
123         return ret;
124 
125       sc->sc_gr[1] = c->pi.gp;
126       if (c->eh_valid_mask & 0x1) sc->sc_gr[15] = c->eh_args[0];
127       if (c->eh_valid_mask & 0x2) sc->sc_gr[16] = c->eh_args[1];
128       if (c->eh_valid_mask & 0x4) sc->sc_gr[17] = c->eh_args[2];
129       if (c->eh_valid_mask & 0x8) sc->sc_gr[18] = c->eh_args[3];
130       Debug (9, "sc: r15=%lx,r16=%lx,r17=%lx,r18=%lx\n",
131              (long) sc->sc_gr[15], (long) sc->sc_gr[16],
132              (long) sc->sc_gr[17], (long) sc->sc_gr[18]);
133     }
134   else
135     {
136       /* Account for the fact that _Uia64_install_context() will
137          return via br.ret, which will decrement bsp by size-of-locals.  */
138       if ((ret = ia64_get (c, c->loc[IA64_REG_PFS], &pfs)) < 0)
139         return ret;
140       sol = (pfs >> 7) & 0x7f;
141       if ((dirty_size = rbs_cover_and_flush (c, sol, dirty_partition,
142                                              &dirty_rnat, &bspstore)) < 0)
143         return dirty_size;
144 
145       extra.r1 = c->pi.gp;
146       extra.r15 = c->eh_args[0];
147       extra.r16 = c->eh_args[1];
148       extra.r17 = c->eh_args[2];
149       extra.r18 = c->eh_args[3];
150       Debug (9, "extra: r15=%lx,r16=%lx,r17=%lx,r18=%lx\n",
151              (long) extra.r15, (long) extra.r16,
152              (long) extra.r17, (long) extra.r18);
153     }
154   Debug (8, "resuming at ip=%lx\n", (long) c->ip);
155   ia64_install_cursor (c, pri_unat, (unw_word_t *) &extra,
156                        bspstore, dirty_size, dirty_partition + dirty_size/8,
157                        dirty_rnat);
158 #elif defined(__hpux)
159   struct cursor *c = (struct cursor *) cursor;
160 
161   setcontext (c->as_arg);       /* should not return */
162 #endif
163   return -UNW_EINVAL;
164 }
165 
166 HIDDEN int
ia64_local_resume(unw_addr_space_t as,unw_cursor_t * cursor,void * arg)167 ia64_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
168 {
169   return local_resume (as, cursor, arg);
170 }
171 
172 #endif /* !UNW_REMOTE_ONLY */
173 
174 #ifndef UNW_LOCAL_ONLY
175 
176 static inline int
remote_install_cursor(struct cursor * c)177 remote_install_cursor (struct cursor *c)
178 {
179   int (*access_reg) (unw_addr_space_t, unw_regnum_t, unw_word_t *,
180                      int write, void *);
181   int (*access_fpreg) (unw_addr_space_t, unw_regnum_t, unw_fpreg_t *,
182                        int write, void *);
183   unw_fpreg_t fpval;
184   unw_word_t val;
185   int reg;
186 
187 #if defined(__linux__) && !defined(UNW_REMOTE_ONLY)
188   if (c->as == unw_local_addr_space)
189     {
190       /* Take a short-cut: we directly resume out of the cursor and
191          all we need to do is make sure that all locations point to
192          memory, not registers.  Furthermore, R4-R7 and NAT4-NAT7 are
193          taken care of by ia64_local_resume() so they don't need to be
194          handled here.  */
195 #     define MEMIFY(preg, reg)                                           \
196       do {                                                               \
197         if (IA64_IS_REG_LOC (c->loc[(preg)]))                            \
198           c->loc[(preg)] = IA64_LOC_ADDR ((unw_word_t)                   \
199                                           tdep_uc_addr(c->as_arg, (reg), \
200                                                        NULL), 0);        \
201       } while (0)
202       MEMIFY (IA64_REG_PR,      UNW_IA64_PR);
203       MEMIFY (IA64_REG_PFS,     UNW_IA64_AR_PFS);
204       MEMIFY (IA64_REG_RNAT,    UNW_IA64_AR_RNAT);
205       MEMIFY (IA64_REG_UNAT,    UNW_IA64_AR_UNAT);
206       MEMIFY (IA64_REG_LC,      UNW_IA64_AR_LC);
207       MEMIFY (IA64_REG_FPSR,    UNW_IA64_AR_FPSR);
208       MEMIFY (IA64_REG_IP,      UNW_IA64_BR + 0);
209       MEMIFY (IA64_REG_B1,      UNW_IA64_BR + 1);
210       MEMIFY (IA64_REG_B2,      UNW_IA64_BR + 2);
211       MEMIFY (IA64_REG_B3,      UNW_IA64_BR + 3);
212       MEMIFY (IA64_REG_B4,      UNW_IA64_BR + 4);
213       MEMIFY (IA64_REG_B5,      UNW_IA64_BR + 5);
214       MEMIFY (IA64_REG_F2,      UNW_IA64_FR + 2);
215       MEMIFY (IA64_REG_F3,      UNW_IA64_FR + 3);
216       MEMIFY (IA64_REG_F4,      UNW_IA64_FR + 4);
217       MEMIFY (IA64_REG_F5,      UNW_IA64_FR + 5);
218       MEMIFY (IA64_REG_F16,     UNW_IA64_FR + 16);
219       MEMIFY (IA64_REG_F17,     UNW_IA64_FR + 17);
220       MEMIFY (IA64_REG_F18,     UNW_IA64_FR + 18);
221       MEMIFY (IA64_REG_F19,     UNW_IA64_FR + 19);
222       MEMIFY (IA64_REG_F20,     UNW_IA64_FR + 20);
223       MEMIFY (IA64_REG_F21,     UNW_IA64_FR + 21);
224       MEMIFY (IA64_REG_F22,     UNW_IA64_FR + 22);
225       MEMIFY (IA64_REG_F23,     UNW_IA64_FR + 23);
226       MEMIFY (IA64_REG_F24,     UNW_IA64_FR + 24);
227       MEMIFY (IA64_REG_F25,     UNW_IA64_FR + 25);
228       MEMIFY (IA64_REG_F26,     UNW_IA64_FR + 26);
229       MEMIFY (IA64_REG_F27,     UNW_IA64_FR + 27);
230       MEMIFY (IA64_REG_F28,     UNW_IA64_FR + 28);
231       MEMIFY (IA64_REG_F29,     UNW_IA64_FR + 29);
232       MEMIFY (IA64_REG_F30,     UNW_IA64_FR + 30);
233       MEMIFY (IA64_REG_F31,     UNW_IA64_FR + 31);
234     }
235   else
236 #endif /* __linux__ && !UNW_REMOTE_ONLY */
237     {
238       access_reg = c->as->acc.access_reg;
239       access_fpreg = c->as->acc.access_fpreg;
240 
241       Debug (8, "copying out cursor state\n");
242 
243       for (reg = 0; reg <= UNW_REG_LAST; ++reg)
244         {
245           if (unw_is_fpreg (reg))
246             {
247               if (tdep_access_fpreg (c, reg, &fpval, 0) >= 0)
248                 (*access_fpreg) (c->as, reg, &fpval, 1, c->as_arg);
249             }
250           else
251             {
252               if (tdep_access_reg (c, reg, &val, 0) >= 0)
253                 (*access_reg) (c->as, reg, &val, 1, c->as_arg);
254             }
255         }
256     }
257   return (*c->as->acc.resume) (c->as, (unw_cursor_t *) c, c->as_arg);
258 }
259 
260 #endif /* !UNW_LOCAL_ONLY */
261 
262 int
unw_resume(unw_cursor_t * cursor)263 unw_resume (unw_cursor_t *cursor)
264 {
265   struct cursor *c = (struct cursor *) cursor;
266 
267   Debug (1, "(cursor=%p, ip=0x%016lx)\n", c, (unsigned long) c->ip);
268 
269 #ifdef UNW_LOCAL_ONLY
270   return local_resume (c->as, cursor, c->as_arg);
271 #else
272   return remote_install_cursor (c);
273 #endif
274 }
275