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diff --git a/upstream/mageia-cauldron/man3p/sigaltstack.3p b/upstream/mageia-cauldron/man3p/sigaltstack.3p new file mode 100644 index 00000000..f9aac8f6 --- /dev/null +++ b/upstream/mageia-cauldron/man3p/sigaltstack.3p @@ -0,0 +1,183 @@ +'\" et +.TH SIGALTSTACK "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.\" +.SH NAME +sigaltstack +\(em set and get signal alternate stack context +.SH SYNOPSIS +.LP +.nf +#include <signal.h> +.P +int sigaltstack(const stack_t *restrict \fIss\fP, stack_t *restrict \fIoss\fP); +.fi +.SH DESCRIPTION +The +\fIsigaltstack\fR() +function allows a process to define and examine the state of an +alternate stack for signal handlers for the current thread. Signals +that have been explicitly declared to execute on the alternate stack +shall be delivered on the alternate stack. +.P +If +.IR ss +is not a null pointer, it points to a +.BR stack_t +structure that specifies the alternate signal stack that shall take +effect upon return from +\fIsigaltstack\fR(). +The +.IR ss_flags +member specifies the new stack state. If it is set to SS_DISABLE, the +stack is disabled and +.IR ss_sp +and +.IR ss_size +are ignored. Otherwise, the stack shall be enabled, and the +.IR ss_sp +and +.IR ss_size +members specify the new address and size of the stack. +.P +The range of addresses starting at +.IR ss_sp +up to but not including +.IR ss_sp +\c +.IR ss_size +is available to the implementation for use as the stack. This function +makes no assumptions regarding which end is the stack base and in which +direction the stack grows as items are pushed. +.P +If +.IR oss +is not a null pointer, upon successful completion it shall point to a +.BR stack_t +structure that specifies the alternate signal stack that was in effect +prior to the call to +\fIsigaltstack\fR(). +The +.IR ss_sp +and +.IR ss_size +members specify the address and size of that stack. The +.IR ss_flags +member specifies the stack's state, and may contain one of the +following values: +.IP SS_ONSTACK 12 +The process is currently executing on the alternate signal stack. +Attempts to modify the alternate signal stack while the process is +executing on it fail. This flag shall not be modified by processes. +.IP SS_DISABLE 12 +The alternate signal stack is currently disabled. +.P +The value SIGSTKSZ is a system default specifying the number of bytes +that would be used to cover the usual case when manually allocating an +alternate stack area. The value MINSIGSTKSZ is defined to be the +minimum stack size for +a signal handler. In computing an alternate stack size, a program +should add that amount to its stack requirements to allow for the +system implementation overhead. The constants SS_ONSTACK, SS_DISABLE, +SIGSTKSZ, and MINSIGSTKSZ are +defined in +.IR <signal.h> . +.P +After a successful call to one of the +.IR exec +functions, there are no alternate signal stacks in the new process +image. +.P +In some implementations, a signal (whether or not indicated to execute +on the alternate stack) shall always execute on the alternate stack if +it is delivered while another signal is being caught using the +alternate stack. +.P +Use of this function by library threads that are not bound to +kernel-scheduled entities results in undefined behavior. +.SH "RETURN VALUE" +Upon successful completion, +\fIsigaltstack\fR() +shall return 0; otherwise, it shall return \-1 and set +.IR errno +to indicate the error. +.SH ERRORS +The +\fIsigaltstack\fR() +function shall fail if: +.TP +.BR EINVAL +The +.IR ss +argument is not a null pointer, and the +.IR ss_flags +member pointed to by +.IR ss +contains flags other than SS_DISABLE. +.TP +.BR ENOMEM +The size of the alternate stack area is less than MINSIGSTKSZ. +.TP +.BR EPERM +An attempt was made to modify an active stack. +.LP +.IR "The following sections are informative." +.SH EXAMPLES +.SS "Allocating Memory for an Alternate Stack" +.P +The following example illustrates a method for allocating memory for an +alternate stack. +.sp +.RS 4 +.nf + +#include <signal.h> +\&... +if ((sigstk.ss_sp = malloc(SIGSTKSZ)) == NULL) + /* Error return. */ +sigstk.ss_size = SIGSTKSZ; +sigstk.ss_flags = 0; +if (sigaltstack(&sigstk,(stack_t *)0) < 0) + perror("sigaltstack"); +.fi +.P +.RE +.SH "APPLICATION USAGE" +On some implementations, stack space is automatically extended as +needed. On those implementations, automatic extension is typically not +available for an alternate stack. If the stack overflows, the +behavior is undefined. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "Section 2.4" ", " "Signal Concepts", +.IR "\fIexec\fR\^", +.IR "\fIsigaction\fR\^(\|)", +.IR "\fIsigsetjmp\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2017, +.IR "\fB<signal.h>\fP" +.\" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1-2017, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, 2018 Edition, +Copyright (C) 2018 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +In the event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . +.PP +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |