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8662eb14 | 1 | /* DWARF2 EH unwinding support for S/390 Linux. |
5d5bf775 | 2 | Copyright (C) 2004-2013 Free Software Foundation, Inc. |
8662eb14 AM |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
748086b7 | 8 | Software Foundation; either version 3, or (at your option) any later |
8662eb14 AM |
9 | version. |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
748086b7 JJ |
16 | Under Section 7 of GPL version 3, you are granted additional |
17 | permissions described in the GCC Runtime Library Exception, version | |
18 | 3.1, as published by the Free Software Foundation. | |
19 | ||
20 | You should have received a copy of the GNU General Public License and | |
21 | a copy of the GCC Runtime Library Exception along with this program; | |
22 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
23 | <http://www.gnu.org/licenses/>. */ | |
8662eb14 AM |
24 | |
25 | /* Do code reading to identify a signal frame, and set the frame | |
26 | state data appropriately. See unwind-dw2.c for the structs. */ | |
27 | ||
28 | #define MD_FALLBACK_FRAME_STATE_FOR s390_fallback_frame_state | |
29 | ||
30 | static _Unwind_Reason_Code | |
31 | s390_fallback_frame_state (struct _Unwind_Context *context, | |
32 | _Unwind_FrameState *fs) | |
33 | { | |
902a3faf AK |
34 | static const unsigned char dwarf_to_fpr_map[16] = |
35 | { 0, 2, 4, 6, 1, 3, 5, 7, 8, 10, 12, 14, 9, 11, 13, 15 }; | |
8662eb14 AM |
36 | unsigned char *pc = context->ra; |
37 | long new_cfa; | |
38 | int i; | |
39 | ||
40 | typedef struct | |
41 | { | |
42 | unsigned long psw_mask; | |
43 | unsigned long psw_addr; | |
44 | unsigned long gprs[16]; | |
45 | unsigned int acrs[16]; | |
46 | unsigned int fpc; | |
47 | unsigned int __pad; | |
48 | double fprs[16]; | |
49 | } __attribute__ ((__aligned__ (8))) sigregs_; | |
50 | ||
51 | sigregs_ *regs; | |
47a4949a | 52 | int *signo; |
8662eb14 AM |
53 | |
54 | /* svc $__NR_sigreturn or svc $__NR_rt_sigreturn */ | |
55 | if (pc[0] != 0x0a || (pc[1] != 119 && pc[1] != 173)) | |
56 | return _URC_END_OF_STACK; | |
57 | ||
47a4949a UW |
58 | /* Legacy frames: |
59 | old signal mask (8 bytes) | |
60 | pointer to sigregs (8 bytes) - points always to next location | |
61 | sigregs | |
62 | retcode | |
63 | This frame layout was used on kernels < 2.6.9 for non-RT frames, | |
64 | and on kernels < 2.4.13 for RT frames as well. Note that we need | |
65 | to look at RA to detect this layout -- this means that if you use | |
66 | sa_restorer to install a different signal restorer on a legacy | |
67 | kernel, unwinding from signal frames will not work. */ | |
68 | if (context->ra == context->cfa + 16 + sizeof (sigregs_)) | |
69 | { | |
70 | regs = (sigregs_ *)(context->cfa + 16); | |
71 | signo = NULL; | |
72 | } | |
73 | ||
8662eb14 AM |
74 | /* New-style RT frame: |
75 | retcode + alignment (8 bytes) | |
76 | siginfo (128 bytes) | |
77 | ucontext (contains sigregs) */ | |
47a4949a | 78 | else if (pc[1] == 173 /* __NR_rt_sigreturn */) |
8662eb14 AM |
79 | { |
80 | struct ucontext_ | |
81 | { | |
82 | unsigned long uc_flags; | |
83 | struct ucontext_ *uc_link; | |
84 | unsigned long uc_stack[3]; | |
85 | sigregs_ uc_mcontext; | |
86 | } *uc = context->cfa + 8 + 128; | |
87 | ||
88 | regs = &uc->uc_mcontext; | |
89 | signo = context->cfa + sizeof(long); | |
90 | } | |
91 | ||
47a4949a | 92 | /* New-style non-RT frame: |
8662eb14 | 93 | old signal mask (8 bytes) |
47a4949a | 94 | pointer to sigregs (followed by signal number) */ |
8662eb14 AM |
95 | else |
96 | { | |
97 | regs = *(sigregs_ **)(context->cfa + 8); | |
47a4949a | 98 | signo = (int *)(regs + 1); |
8662eb14 AM |
99 | } |
100 | ||
101 | new_cfa = regs->gprs[15] + 16*sizeof(long) + 32; | |
6673f90b NF |
102 | fs->regs.cfa_how = CFA_REG_OFFSET; |
103 | fs->regs.cfa_reg = 15; | |
104 | fs->regs.cfa_offset = | |
8662eb14 AM |
105 | new_cfa - (long) context->cfa + 16*sizeof(long) + 32; |
106 | ||
107 | for (i = 0; i < 16; i++) | |
108 | { | |
109 | fs->regs.reg[i].how = REG_SAVED_OFFSET; | |
110 | fs->regs.reg[i].loc.offset = | |
111 | (long)®s->gprs[i] - new_cfa; | |
112 | } | |
113 | for (i = 0; i < 16; i++) | |
114 | { | |
115 | fs->regs.reg[16+i].how = REG_SAVED_OFFSET; | |
116 | fs->regs.reg[16+i].loc.offset = | |
902a3faf | 117 | (long)®s->fprs[dwarf_to_fpr_map[i]] - new_cfa; |
8662eb14 AM |
118 | } |
119 | ||
120 | /* Load return addr from PSW into dummy register 32. */ | |
121 | ||
122 | fs->regs.reg[32].how = REG_SAVED_OFFSET; | |
123 | fs->regs.reg[32].loc.offset = (long)®s->psw_addr - new_cfa; | |
124 | fs->retaddr_column = 32; | |
754e45a8 JJ |
125 | /* SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr |
126 | after the faulting instruction rather than before it. | |
127 | Don't set FS->signal_frame in that case. */ | |
128 | if (!signo || (*signo != 4 && *signo != 5 && *signo != 8)) | |
129 | fs->signal_frame = 1; | |
8662eb14 AM |
130 | |
131 | return _URC_NO_REASON; | |
132 | } |