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931b8415 | 1 | .\" Copyright (c) 1983, 1991 The Regents of the University of California. |
88b3ccf2 | 2 | .\" All rights reserved. |
39861f6c | 3 | .\" |
af359dea C |
4 | .\" Redistribution and use in source and binary forms, with or without |
5 | .\" modification, are permitted provided that the following conditions | |
6 | .\" are met: | |
7 | .\" 1. Redistributions of source code must retain the above copyright | |
8 | .\" notice, this list of conditions and the following disclaimer. | |
9 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
10 | .\" notice, this list of conditions and the following disclaimer in the | |
11 | .\" documentation and/or other materials provided with the distribution. | |
12 | .\" 3. All advertising materials mentioning features or use of this software | |
13 | .\" must display the following acknowledgement: | |
14 | .\" This product includes software developed by the University of | |
15 | .\" California, Berkeley and its contributors. | |
16 | .\" 4. Neither the name of the University nor the names of its contributors | |
17 | .\" may be used to endorse or promote products derived from this software | |
18 | .\" without specific prior written permission. | |
88b3ccf2 | 19 | .\" |
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20 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
21 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
24 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
25 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
26 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
27 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
28 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
29 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
30 | .\" SUCH DAMAGE. | |
39861f6c | 31 | .\" |
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32 | .\" @(#)sigstack.2 6.5 (Berkeley) 3/10/91 |
33 | .\" | |
34 | .Dd March 10, 1991 | |
931b8415 CL |
35 | .Dt SIGSTACK 2 |
36 | .Os BSD 4.2 | |
37 | .Sh NAME | |
38 | .Nm sigstack | |
39 | .Nd set and/or get signal stack context | |
40 | .Sh SYNOPSIS | |
41 | .Fd #include <sys/signal.h> | |
42 | .Bd -literal | |
43 | struct sigstack { | |
44 | caddr_t ss_sp; | |
45 | int ss_onstack; | |
46 | }; | |
47 | .Ed | |
48 | .Ft int | |
49 | .Fn sigstack "const struct sigstack *ss" "struct sigstack *oss" | |
50 | .Sh DESCRIPTION | |
51 | .Fn Sigstack | |
39861f6c KM |
52 | allows users to define an alternate stack on which signals |
53 | are to be processed. If | |
931b8415 | 54 | .Fa ss |
39861f6c KM |
55 | is non-zero, |
56 | it specifies a | |
931b8415 | 57 | .Em "signal stack" |
39861f6c KM |
58 | on which to deliver signals |
59 | and tells the system if the process is currently executing | |
60 | on that stack. When a signal's action indicates its handler | |
61 | should execute on the signal stack (specified with a | |
931b8415 | 62 | .Xr sigvec 2 |
39861f6c KM |
63 | call), the system checks to see |
64 | if the process is currently executing on that stack. If the | |
65 | process is not currently executing on the signal stack, | |
66 | the system arranges a switch to the signal stack for the | |
67 | duration of the signal handler's execution. | |
68 | If | |
931b8415 | 69 | .Fa oss |
39861f6c | 70 | is non-zero, the current signal stack state is returned. |
931b8415 | 71 | .Sh NOTES |
39861f6c KM |
72 | Signal stacks are not ``grown'' automatically, as is |
73 | done for the normal stack. If the stack overflows | |
74 | unpredictable results may occur. | |
931b8415 | 75 | .Sh RETURN VALUES |
39861f6c | 76 | Upon successful completion, a value of 0 is returned. |
931b8415 CL |
77 | Otherwise, a value of -1 is returned and |
78 | .Va errno | |
39861f6c | 79 | is set to indicate the error. |
931b8415 CL |
80 | .Sh ERRORS |
81 | .Fn Sigstack | |
39861f6c KM |
82 | will fail and the signal stack context will remain unchanged |
83 | if one of the following occurs. | |
931b8415 CL |
84 | .Bl -tag -width [EFAULT] |
85 | .It Bq Er EFAULT | |
39861f6c | 86 | Either |
931b8415 | 87 | .Fa ss |
39861f6c | 88 | or |
931b8415 | 89 | .Fa oss |
eff6446c | 90 | points to memory that is not a valid part of the process |
39861f6c | 91 | address space. |
931b8415 CL |
92 | .El |
93 | .Sh SEE ALSO | |
94 | .Xr sigvec 2 , | |
95 | .Xr setjmp 3 | |
96 | .Sh HISTORY | |
97 | The | |
98 | .Nm | |
99 | function call appeared in | |
100 | .Bx 4.2 . |