1 /* Copyright (C) 1999, 2005, 2009, 2010 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 /* If no SA_RESTORER function was specified by the application we use
22 one of these. This avoids the need for the kernel to synthesise a return
23 instruction on the stack, which would involve expensive cache flushes.
25 Nowadays (2.6 series, and somewhat earlier) the kernel uses a high page
26 for signal trampolines, so the cache flushes are not an issue. But since
27 we do not have a vDSO, continue to use these so that we can provide
30 Start the unwind tables at least one instruction before the signal
31 trampoline, because the unwinder will assume we are returning after
34 Because the signal frame layout changed in 2.6.18, we provide two
35 copies of these functions with different unwind information. */
39 #define cfi_startproc \
40 .cfi_startproc simple; \
43 /* The CFA is not computed / used correctly here; this is neither trivial to
44 do, nor is it needed. */
46 cfi_def_cfa (sp, 0); \
47 cfi_offset (r0, OFFSET + 0 * 4); \
48 cfi_offset (r1, OFFSET + 1 * 4); \
49 cfi_offset (r2, OFFSET + 2 * 4); \
50 cfi_offset (r3, OFFSET + 3 * 4); \
51 cfi_offset (r4, OFFSET + 4 * 4); \
52 cfi_offset (r5, OFFSET + 5 * 4); \
53 cfi_offset (r6, OFFSET + 6 * 4); \
54 cfi_offset (r7, OFFSET + 7 * 4); \
55 cfi_offset (r8, OFFSET + 8 * 4); \
56 cfi_offset (r9, OFFSET + 9 * 4); \
57 cfi_offset (r10, OFFSET + 10 * 4); \
58 cfi_offset (r11, OFFSET + 11 * 4); \
59 cfi_offset (r12, OFFSET + 12 * 4); \
60 cfi_offset (r13, OFFSET + 13 * 4); \
61 cfi_offset (r14, OFFSET + 14 * 4); \
62 cfi_offset (r15, OFFSET + 15 * 4)
64 #ifndef __ASSUME_SIGFRAME_V2
70 ENTRY(__default_sa_restorer_v1)
72 mov r7, $SYS_ify(sigreturn)
75 END(__default_sa_restorer_v1)
77 #endif /* __ASSUME_SIGFRAME_V2 */
84 ENTRY(__default_sa_restorer_v2)
86 mov r7, $SYS_ify(sigreturn)
89 END(__default_sa_restorer_v2)
92 #ifdef __NR_rt_sigreturn
94 #ifndef __ASSUME_SIGFRAME_V2
100 ENTRY(__default_rt_sa_restorer_v1)
102 mov r7, $SYS_ify(rt_sigreturn)
105 END(__default_rt_sa_restorer_v1)
107 #endif /* __ASSUME_SIGFRAME_V2 */
114 ENTRY(__default_rt_sa_restorer_v2)
116 mov r7, $SYS_ify(rt_sigreturn)
119 END(__default_rt_sa_restorer_v2)
122 #endif /* __NR_rt_sigreturn */