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8662eb14 | 1 | /* DWARF2 EH unwinding support for S/390 Linux. |
748086b7 | 2 | Copyright (C) 2004, 2005, 2006, 2009 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 | { | |
34 | unsigned char *pc = context->ra; | |
35 | long new_cfa; | |
36 | int i; | |
37 | ||
38 | typedef struct | |
39 | { | |
40 | unsigned long psw_mask; | |
41 | unsigned long psw_addr; | |
42 | unsigned long gprs[16]; | |
43 | unsigned int acrs[16]; | |
44 | unsigned int fpc; | |
45 | unsigned int __pad; | |
46 | double fprs[16]; | |
47 | } __attribute__ ((__aligned__ (8))) sigregs_; | |
48 | ||
49 | sigregs_ *regs; | |
47a4949a | 50 | int *signo; |
8662eb14 AM |
51 | |
52 | /* svc $__NR_sigreturn or svc $__NR_rt_sigreturn */ | |
53 | if (pc[0] != 0x0a || (pc[1] != 119 && pc[1] != 173)) | |
54 | return _URC_END_OF_STACK; | |
55 | ||
47a4949a UW |
56 | /* Legacy frames: |
57 | old signal mask (8 bytes) | |
58 | pointer to sigregs (8 bytes) - points always to next location | |
59 | sigregs | |
60 | retcode | |
61 | This frame layout was used on kernels < 2.6.9 for non-RT frames, | |
62 | and on kernels < 2.4.13 for RT frames as well. Note that we need | |
63 | to look at RA to detect this layout -- this means that if you use | |
64 | sa_restorer to install a different signal restorer on a legacy | |
65 | kernel, unwinding from signal frames will not work. */ | |
66 | if (context->ra == context->cfa + 16 + sizeof (sigregs_)) | |
67 | { | |
68 | regs = (sigregs_ *)(context->cfa + 16); | |
69 | signo = NULL; | |
70 | } | |
71 | ||
8662eb14 AM |
72 | /* New-style RT frame: |
73 | retcode + alignment (8 bytes) | |
74 | siginfo (128 bytes) | |
75 | ucontext (contains sigregs) */ | |
47a4949a | 76 | else if (pc[1] == 173 /* __NR_rt_sigreturn */) |
8662eb14 AM |
77 | { |
78 | struct ucontext_ | |
79 | { | |
80 | unsigned long uc_flags; | |
81 | struct ucontext_ *uc_link; | |
82 | unsigned long uc_stack[3]; | |
83 | sigregs_ uc_mcontext; | |
84 | } *uc = context->cfa + 8 + 128; | |
85 | ||
86 | regs = &uc->uc_mcontext; | |
87 | signo = context->cfa + sizeof(long); | |
88 | } | |
89 | ||
47a4949a | 90 | /* New-style non-RT frame: |
8662eb14 | 91 | old signal mask (8 bytes) |
47a4949a | 92 | pointer to sigregs (followed by signal number) */ |
8662eb14 AM |
93 | else |
94 | { | |
95 | regs = *(sigregs_ **)(context->cfa + 8); | |
47a4949a | 96 | signo = (int *)(regs + 1); |
8662eb14 AM |
97 | } |
98 | ||
99 | new_cfa = regs->gprs[15] + 16*sizeof(long) + 32; | |
6673f90b NF |
100 | fs->regs.cfa_how = CFA_REG_OFFSET; |
101 | fs->regs.cfa_reg = 15; | |
102 | fs->regs.cfa_offset = | |
8662eb14 AM |
103 | new_cfa - (long) context->cfa + 16*sizeof(long) + 32; |
104 | ||
105 | for (i = 0; i < 16; i++) | |
106 | { | |
107 | fs->regs.reg[i].how = REG_SAVED_OFFSET; | |
108 | fs->regs.reg[i].loc.offset = | |
109 | (long)®s->gprs[i] - new_cfa; | |
110 | } | |
111 | for (i = 0; i < 16; i++) | |
112 | { | |
113 | fs->regs.reg[16+i].how = REG_SAVED_OFFSET; | |
114 | fs->regs.reg[16+i].loc.offset = | |
115 | (long)®s->fprs[i] - new_cfa; | |
116 | } | |
117 | ||
118 | /* Load return addr from PSW into dummy register 32. */ | |
119 | ||
120 | fs->regs.reg[32].how = REG_SAVED_OFFSET; | |
121 | fs->regs.reg[32].loc.offset = (long)®s->psw_addr - new_cfa; | |
122 | fs->retaddr_column = 32; | |
754e45a8 JJ |
123 | /* SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr |
124 | after the faulting instruction rather than before it. | |
125 | Don't set FS->signal_frame in that case. */ | |
126 | if (!signo || (*signo != 4 && *signo != 5 && *signo != 8)) | |
127 | fs->signal_frame = 1; | |
8662eb14 AM |
128 | |
129 | return _URC_NO_REASON; | |
130 | } |