sigprocmask(2) System Calls Manual sigprocmask(2) sigprocmask, rt_sigprocmask - C (libc, -lc) #include /* Prototype for the glibc wrapper function */ int sigprocmask(int how, const sigset_t *_Nullable restrict set, sigset_t *_Nullable restrict oldset); #include /* Definition of SIG_* constants */ #include /* Definition of SYS_* constants */ #include /* Prototype for the underlying system call */ int syscall(SYS_rt_sigprocmask, int how, const kernel_sigset_t *_Nullable set, kernel_sigset_t *_Nullable oldset, size_t sigsetsize); /* Prototype for the legacy system call */ [[deprecated]] int syscall(SYS_sigprocmask, int how, const old_kernel_sigset_t *_Nullable set, old_kernel_sigset_t *_Nullable oldset); glibc (. feature_test_macros(7)): sigprocmask(): _POSIX_C_SOURCE sigprocmask() / . , ( signal(7)). how: SIG_BLOCK -- set. SIG_UNBLOCK set . . SIG_SETMASK set. oldset NULL, oldset. set NULL, (.., how ), oldset ( NULL). sigset_t (<< >>) sigsetops(3). sigprocmask() ; pthread_sigmask(3). sigprocmask() returns 0 on success. On failure, -1 is returned and errno is set to indicate the error. EFAULT set oldset . EINVAL how , sigsetsize. C sigset_t C. kernel_sigset_t ( sigset_t). glibc sigprocmask() , NPTL. nptl(7). , Linux sigprocmask(). - Linux 2.2, 32- sigset_t ( old_kernel_sigset_t ) , , . rt_sigprocmask(), sigset_t ( kernel_sigset_t ). , size_t sigsetsize, ( ) set oldset. ( sizeof(kernel_sigset_t)). glibc sigprocmask() , rt_sigprocmask(), . POSIX.1-2024. POSIX.1-2001. SIGKILL SIGSTOP. . . , fork(2), ; execve(2). SIGBUS, SIGFPE, SIGILL SIGSEGV, , , kill(3), sigqueue(3) raise(3). sigsetops(3). , ( ) set oldset NULL. kill(2), pause(2), sigaction(2), signal(2), sigpending(2), sigsuspend(2), pthread_sigmask(3), sigqueue(3), sigsetops(3), signal(7) () Alexander Golubev , Azamat Hackimov , Hotellook, Nikita , Spiros Georgaras , Vladislav , Yuri Kozlov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () . Linux man-pages 6.18 8 2026 . sigprocmask(2)