diff options
Diffstat (limited to '')
| -rw-r--r-- | man2/sigaltstack.2 | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/man2/sigaltstack.2 b/man2/sigaltstack.2 index 0ebfebd..82ba812 100644 --- a/man2/sigaltstack.2 +++ b/man2/sigaltstack.2 @@ -4,7 +4,7 @@ .\" SPDX-License-Identifier: Linux-man-pages-copyleft .\" .\" aeb, various minor fixes -.TH sigaltstack 2 2023-07-20 "Linux man-pages 6.05.01" +.TH sigaltstack 2 2023-10-31 "Linux man-pages 6.7" .SH NAME sigaltstack \- set and/or get signal stack context .SH LIBRARY @@ -13,16 +13,16 @@ Standard C library .SH SYNOPSIS .nf .B #include <signal.h> -.PP +.P .BI "int sigaltstack(const stack_t *_Nullable restrict " ss , .BI " stack_t *_Nullable restrict " old_ss ); .fi -.PP +.P .RS -4 Feature Test Macro Requirements for glibc (see .BR feature_test_macros (7)): .RE -.PP +.P .BR sigaltstack (): .nf _XOPEN_SOURCE >= 500 @@ -39,7 +39,7 @@ An alternate signal stack is used during the execution of a signal handler if the establishment of that handler (see .BR sigaction (2)) requested it. -.PP +.P The normal sequence of events for using an alternate signal stack is the following: .TP 3 @@ -59,18 +59,18 @@ When establishing a signal handler using inform the system that the signal handler should be executed on the alternate signal stack by specifying the \fBSA_ONSTACK\fP flag. -.PP +.P The \fIss\fP argument is used to specify a new alternate signal stack, while the \fIold_ss\fP argument is used to retrieve information about the currently established signal stack. If we are interested in performing just one of these tasks, then the other argument can be specified as NULL. -.PP +.P The .I stack_t type used to type the arguments of this function is defined as follows: -.PP +.P .in +4n .EX typedef struct { @@ -80,7 +80,7 @@ typedef struct { } stack_t; .EE .in -.PP +.P To establish a new alternate signal stack, the fields of this structure are set as follows: .TP @@ -119,14 +119,14 @@ The constant \fBSIGSTKSZ\fP is defined to be large enough to cover the usual size requirements for an alternate signal stack, and the constant \fBMINSIGSTKSZ\fP defines the minimum size required to execute a signal handler. -.PP +.P To disable an existing stack, specify \fIss.ss_flags\fP as \fBSS_DISABLE\fP. In this case, the kernel ignores any other flags in .I ss.ss_flags and the remaining fields in \fIss\fP. -.PP +.P If \fIold_ss\fP is not NULL, then it is used to return information about the alternate signal stack which was in effect prior to the call to @@ -162,7 +162,7 @@ using a further call to .B SS_AUTODISARM The alternate signal stack has been marked to be autodisarmed as described above. -.PP +.P By specifying .I ss as NULL, and @@ -207,10 +207,9 @@ T{ .BR sigaltstack () T} Thread safety MT-Safe .TE -.sp 1 .SH STANDARDS POSIX.1-2008. -.PP +.P .B SS_AUTODISARM is a Linux extension. .SH HISTORY @@ -223,7 +222,7 @@ standard stack is exhausted: in this case, a signal handler for .B SIGSEGV cannot be invoked on the standard stack; if we wish to handle it, we must use an alternate signal stack. -.PP +.P Establishing an alternate signal stack is useful if a thread expects that it may exhaust its standard stack. This may occur, for example, because the stack grows so large @@ -233,13 +232,13 @@ If the standard stack is exhausted, the kernel sends the thread a \fBSIGSEGV\fP signal. In these circumstances the only way to catch this signal is on an alternate signal stack. -.PP +.P On most hardware architectures supported by Linux, stacks grow downward. .BR sigaltstack () automatically takes account of the direction of stack growth. -.PP +.P Functions called from a signal handler executing on an alternate signal stack will also use the alternate signal stack. (This also applies to any handlers invoked for other signals while @@ -248,7 +247,7 @@ Unlike the standard stack, the system does not automatically extend the alternate signal stack. Exceeding the allocated size of the alternate signal stack will lead to unpredictable results. -.PP +.P A successful call to .BR execve (2) removes any existing alternate @@ -264,7 +263,7 @@ and do not include .BR CLONE_VFORK , in which case any alternate signal stack that was established in the parent is disabled in the child process. -.PP +.P .BR sigaltstack () supersedes the older .BR sigstack () @@ -327,7 +326,7 @@ to install an alternate signal stack that is employed by a handler for the .B SIGSEGV signal: -.PP +.P .in +4n .EX stack_t ss; |