1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
/* Copyright (C) 1998-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson <rth@cygnus.com>, 1998
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
/* On Alpha we desparately want to avoid having to issue an imb. Ordinarily
the kernel would have to issue one after setting up the signal return
stack, but the Linux rt_sigaction syscall is prepared to accept a pointer
to the sigreturn syscall, instead of inlining it on the stack.
This just about halves signal delivery time. */
.text
ENTRY(__syscall_rt_sigaction)
cfi_startproc
ldgp gp,0(pv)
#ifdef PROF
.set noat
lda AT, _mcount
jsr AT, (AT), _mcount
.set at
#endif
.prologue 1
beq a1, 0f
ldl t0, 8(a1) # sa_flags
ldah a4, __syscall_sigreturn(gp) !gprelhigh
ldah t1, __syscall_rt_sigreturn(gp) !gprelhigh
lda a4, __syscall_sigreturn(a4) !gprellow
lda t1, __syscall_rt_sigreturn(t1) !gprellow
and t0, 0x40, t0 # SA_SIGINFO
cmovne t0, t1, a4
0: ldi v0, __NR_rt_sigaction
callsys
bne a3, SYSCALL_ERROR_LABEL
ret
cfi_endproc
PSEUDO_END(__syscall_rt_sigaction)
/* To enable unwinding through the signal frame without special hackery
elsewhere, describe the entire struct sigcontext with unwind info.
In order to minimize the size of the encoding, we set the CFA to the
end of the sigcontext, which makes all of the registers have small
negative offsets from that. */
.macro SIGCONTEXT_REGS_I base, from=0
cfi_offset (\from, \base + (4 + \from) * 8)
.if 30-\from
SIGCONTEXT_REGS_I \base, "(\from+1)"
.endif
.endm
.macro SIGCONTEXT_REGS_F base, from=32
cfi_offset (\from, \base + (4 + 1 + \from) * 8)
.if 62-\from
SIGCONTEXT_REGS_F \base, "(\from+1)"
.endif
.endm
.macro SIGCONTEXT_REGS base
SIGCONTEXT_REGS_I \base
SIGCONTEXT_REGS_F \base
cfi_offset (63, \base + (4 + 32 + 1 + 32) * 8)
cfi_offset (64, \base + 2 * 8)
.endm
cfi_startproc
cfi_return_column (64)
.cfi_signal_frame
SIGCONTEXT_REGS -648
cfi_def_cfa_offset (648)
/* While this frame is marked as a signal frame, that only applies
to how this return address is handled for the outer frame.
The return address that arrived here, from the inner frame, is
not marked as a signal frame and so the unwinder still tries to
subtract 1 to examine the presumed call insn. Thus we must
extend the unwind info to a nop before the start. */
nop
.align 4
__syscall_sigreturn:
mov sp, a0
ldi v0, __NR_sigreturn
callsys
.size __syscall_sigreturn, .-__syscall_sigreturn
.type __syscall_sigreturn, @function
/* See above wrt including the nop. */
cfi_def_cfa_offset (176 + 648)
nop
.align 4
__syscall_rt_sigreturn:
mov sp,a0
ldi v0,__NR_rt_sigreturn
callsys
.size __syscall_rt_sigreturn, .-__syscall_rt_sigreturn
.type __syscall_rt_sigreturn, @function
cfi_endproc
|
