#include <sys/syscall.h> /* Definition of SYS_* constants */ #include <unistd.h> long syscall(SYS_sgetmask, void); long syscall(SYS_ssetmask, long newmask);
Note: glibc provides no wrappers for these functions, necessitating the use of syscall(2).
These system calls are obsolete. Do not use them; use sigprocmask(2) instead.
sgetmask() returns the signal mask of the calling process.
ssetmask() sets the signal mask of the calling process to the value given in newmask. The previous signal mask is returned.
The signal masks dealt with by these two system calls are plain bit masks (unlike the sigset_t used by sigprocmask(2)); use sigmask(3) to create and inspect these masks.
sgetmask() always successfully returns the signal mask. ssetmask() always succeeds, and returns the previous signal mask.
These system calls always succeed.
Since Linux 3.16, support for these system calls is optional, depending on whether the kernel was built with the CONFIG_SGETMASK_SYSCALL option.
These system calls are Linux-specific.
These system calls are unaware of signal numbers greater than 31 (i.e., real-time signals).
These system calls do not exist on x86-64.
It is not possible to block SIGSTOP or SIGKILL.
This page is part of release 5.13 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
The man page ssetmask(2) is an alias of sgetmask(2).