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1 /* libunwind - a platform-independent unwind library
2    Copyright (c) 2002-2004 Hewlett-Packard Development Company, L.P.
3         Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
4 
5    Modified for x86_64 by Max Asbock <masbock@us.ibm.com>
6 
7 This file is part of libunwind.
8 
9 Permission is hereby granted, free of charge, to any person obtaining
10 a copy of this software and associated documentation files (the
11 "Software"), to deal in the Software without restriction, including
12 without limitation the rights to use, copy, modify, merge, publish,
13 distribute, sublicense, and/or sell copies of the Software, and to
14 permit persons to whom the Software is furnished to do so, subject to
15 the following conditions:
16 
17 The above copyright notice and this permission notice shall be
18 included in all copies or substantial portions of the Software.
19 
20 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
27 
28 #include <stdlib.h>
29 
30 #include "unwind_i.h"
31 
32 #ifndef UNW_REMOTE_ONLY
33 
34 HIDDEN inline int
s390x_local_resume(unw_addr_space_t as,unw_cursor_t * cursor,void * arg)35 s390x_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
36 {
37   struct cursor *c = (struct cursor *) cursor;
38   ucontext_t uc = *c->uc;
39   ucontext_t *rt = NULL;
40   struct sigcontext *sc = NULL;
41   int i;
42   unw_word_t sp, ip;
43   uc.uc_mcontext.psw.addr = c->dwarf.ip;
44 
45   /* Ensure c->pi is up-to-date.  On x86-64, it's relatively common to
46      be missing DWARF unwind info.  We don't want to fail in that
47      case, because the frame-chain still would let us do a backtrace
48      at least.  */
49   dwarf_make_proc_info (&c->dwarf);
50 
51   switch (c->sigcontext_format)
52     {
53     case S390X_SCF_NONE:
54       Debug (8, "resuming at ip=%llx via setcontext()\n",
55                 (unsigned long long) c->dwarf.ip);
56       setcontext (&uc);
57       abort(); /* unreachable */
58     case S390X_SCF_LINUX_SIGFRAME:
59       Debug (8, "resuming at ip=%llx via signal trampoline\n",
60                 (unsigned long long) c->dwarf.ip);
61       sc = (struct sigcontext*)c->sigcontext_addr;
62       for (i = UNW_S390X_R0; i <= UNW_S390X_R15; ++i)
63         sc->sregs->regs.gprs[i-UNW_S390X_R0] = uc.uc_mcontext.gregs[i-UNW_S390X_R0];
64       for (i = UNW_S390X_F0; i <= UNW_S390X_F15; ++i)
65         sc->sregs->fpregs.fprs[i-UNW_S390X_F0] = uc.uc_mcontext.fpregs.fprs[i-UNW_S390X_F0].d;
66       sc->sregs->regs.psw.addr = uc.uc_mcontext.psw.addr;
67 
68       sp = c->sigcontext_sp;
69       ip = c->sigcontext_pc;
70       __asm__ __volatile__ (
71         "lgr %%r15, %[sp]\n"
72         "br %[ip]\n"
73         : : [sp] "r" (sp), [ip] "r" (ip)
74       );
75       abort(); /* unreachable */
76     case S390X_SCF_LINUX_RT_SIGFRAME:
77       Debug (8, "resuming at ip=%llx via signal trampoline\n",
78                 (unsigned long long) c->dwarf.ip);
79       rt = (ucontext_t*)c->sigcontext_addr;
80       for (i = UNW_S390X_R0; i <= UNW_S390X_R15; ++i)
81         rt->uc_mcontext.gregs[i-UNW_S390X_R0] = uc.uc_mcontext.gregs[i-UNW_S390X_R0];
82       for (i = UNW_S390X_F0; i <= UNW_S390X_F15; ++i)
83         rt->uc_mcontext.fpregs.fprs[i-UNW_S390X_F0] = uc.uc_mcontext.fpregs.fprs[i-UNW_S390X_F0];
84       rt->uc_mcontext.psw.addr = uc.uc_mcontext.psw.addr;
85 
86       sp = c->sigcontext_sp;
87       ip = c->sigcontext_pc;
88       __asm__ __volatile__ (
89         "lgr %%r15, %[sp]\n"
90         "br %[ip]\n"
91         : : [sp] "r" (sp), [ip] "r" (ip)
92       );
93       abort(); /* unreachable */
94     }
95   return -UNW_EINVAL;
96 }
97 
98 #endif /* !UNW_REMOTE_ONLY */
99 
100 /* This routine is responsible for copying the register values in
101    cursor C and establishing them as the current machine state. */
102 
103 static inline int
establish_machine_state(struct cursor * c)104 establish_machine_state (struct cursor *c)
105 {
106   int (*access_reg) (unw_addr_space_t, unw_regnum_t, unw_word_t *,
107                      int write, void *);
108   int (*access_fpreg) (unw_addr_space_t, unw_regnum_t, unw_fpreg_t *,
109                        int write, void *);
110   unw_addr_space_t as = c->dwarf.as;
111   void *arg = c->dwarf.as_arg;
112   unw_fpreg_t fpval;
113   unw_word_t val;
114   int reg;
115 
116   access_reg = as->acc.access_reg;
117   access_fpreg = as->acc.access_fpreg;
118 
119   Debug (8, "copying out cursor state\n");
120 
121   for (reg = 0; reg <= UNW_REG_LAST; ++reg)
122     {
123       Debug (16, "copying %s %d\n", unw_regname (reg), reg);
124       if (unw_is_fpreg (reg))
125         {
126           if (tdep_access_fpreg (c, reg, &fpval, 0) >= 0)
127             (*access_fpreg) (as, reg, &fpval, 1, arg);
128         }
129       else
130         {
131           if (tdep_access_reg (c, reg, &val, 0) >= 0)
132             (*access_reg) (as, reg, &val, 1, arg);
133         }
134     }
135 
136   if (c->dwarf.args_size)
137     {
138       if (tdep_access_reg (c, UNW_S390X_R15, &val, 0) >= 0)
139         {
140           val += c->dwarf.args_size;
141           (*access_reg) (as, UNW_S390X_R15, &val, 1, arg);
142         }
143     }
144   return 0;
145 }
146 
147 int
unw_resume(unw_cursor_t * cursor)148 unw_resume (unw_cursor_t *cursor)
149 {
150   struct cursor *c = (struct cursor *) cursor;
151   int ret;
152 
153   Debug (1, "(cursor=%p)\n", c);
154 
155   if ((ret = establish_machine_state (c)) < 0)
156     return ret;
157 
158   return (*c->dwarf.as->acc.resume) (c->dwarf.as, (unw_cursor_t *) c,
159                                      c->dwarf.as_arg);
160 }
161