1 /* DWARF2 EH unwinding support for S/390 Linux.
2 Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
4 This file is part of GCC.
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
8 Software Foundation; either version 2, or (at your option) any later
11 In addition to the permissions in the GNU General Public License, the
12 Free Software Foundation gives you unlimited permission to link the
13 compiled version of this file with other programs, and to distribute
14 those programs without any restriction coming from the use of this
15 file. (The General Public License restrictions do apply in other
16 respects; for example, they cover modification of the file, and
17 distribution when not linked into another program.)
19 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
20 WARRANTY; without even the implied warranty of MERCHANTABILITY or
21 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
24 You should have received a copy of the GNU General Public License
25 along with GCC; see the file COPYING. If not, write to the Free
26 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
29 /* Do code reading to identify a signal frame, and set the frame
30 state data appropriately. See unwind-dw2.c for the structs. */
32 #define MD_FALLBACK_FRAME_STATE_FOR s390_fallback_frame_state
34 static _Unwind_Reason_Code
35 s390_fallback_frame_state (struct _Unwind_Context
*context
,
36 _Unwind_FrameState
*fs
)
38 unsigned char *pc
= context
->ra
;
44 unsigned long psw_mask
;
45 unsigned long psw_addr
;
46 unsigned long gprs
[16];
47 unsigned int acrs
[16];
51 } __attribute__ ((__aligned__ (8))) sigregs_
;
56 /* svc $__NR_sigreturn or svc $__NR_rt_sigreturn */
57 if (pc
[0] != 0x0a || (pc
[1] != 119 && pc
[1] != 173))
58 return _URC_END_OF_STACK
;
61 old signal mask (8 bytes)
62 pointer to sigregs (8 bytes) - points always to next location
65 This frame layout was used on kernels < 2.6.9 for non-RT frames,
66 and on kernels < 2.4.13 for RT frames as well. Note that we need
67 to look at RA to detect this layout -- this means that if you use
68 sa_restorer to install a different signal restorer on a legacy
69 kernel, unwinding from signal frames will not work. */
70 if (context
->ra
== context
->cfa
+ 16 + sizeof (sigregs_
))
72 regs
= (sigregs_
*)(context
->cfa
+ 16);
76 /* New-style RT frame:
77 retcode + alignment (8 bytes)
79 ucontext (contains sigregs) */
80 else if (pc
[1] == 173 /* __NR_rt_sigreturn */)
84 unsigned long uc_flags
;
85 struct ucontext_
*uc_link
;
86 unsigned long uc_stack
[3];
88 } *uc
= context
->cfa
+ 8 + 128;
90 regs
= &uc
->uc_mcontext
;
91 signo
= context
->cfa
+ sizeof(long);
94 /* New-style non-RT frame:
95 old signal mask (8 bytes)
96 pointer to sigregs (followed by signal number) */
99 regs
= *(sigregs_
**)(context
->cfa
+ 8);
100 signo
= (int *)(regs
+ 1);
103 new_cfa
= regs
->gprs
[15] + 16*sizeof(long) + 32;
104 fs
->cfa_how
= CFA_REG_OFFSET
;
107 new_cfa
- (long) context
->cfa
+ 16*sizeof(long) + 32;
109 for (i
= 0; i
< 16; i
++)
111 fs
->regs
.reg
[i
].how
= REG_SAVED_OFFSET
;
112 fs
->regs
.reg
[i
].loc
.offset
=
113 (long)®s
->gprs
[i
] - new_cfa
;
115 for (i
= 0; i
< 16; i
++)
117 fs
->regs
.reg
[16+i
].how
= REG_SAVED_OFFSET
;
118 fs
->regs
.reg
[16+i
].loc
.offset
=
119 (long)®s
->fprs
[i
] - new_cfa
;
122 /* Load return addr from PSW into dummy register 32. */
124 fs
->regs
.reg
[32].how
= REG_SAVED_OFFSET
;
125 fs
->regs
.reg
[32].loc
.offset
= (long)®s
->psw_addr
- new_cfa
;
126 fs
->retaddr_column
= 32;
127 /* SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
128 after the faulting instruction rather than before it.
129 Don't set FS->signal_frame in that case. */
130 if (!signo
|| (*signo
!= 4 && *signo
!= 5 && *signo
!= 8))
131 fs
->signal_frame
= 1;
133 return _URC_NO_REASON
;