musl/src/signal/sigprocmask.c

#include <signal.h>
#include <errno.h>
#include "syscall.h"
#include "libc.h"
#include "pthread_impl.h"

int sigprocmask(int how, const sigset_t *set, sigset_t *old)
{
	if (how > 2U) {
		errno = EINVAL;
		return -1;
	}
	return syscall(SYS_rt_sigprocmask, how, set, old, 8);
}
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00			`#include <signal.h>`
fix error handling for pthread_sigmask it must return errno, not -1, and should reject invalud values for how. 2011-03-09 20:31:06 -05:00			`#include <errno.h>`
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00			`#include "syscall.h"`
			`#include "libc.h"`
prevent sigprocmask/pthread_sigmask from blocking implementation signals this code was wrongly disabled because the old version was trying to be too clever and didn't work. replaced it with a simple version for now. 2011-02-19 10:51:13 -05:00			`#include "pthread_impl.h"`
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00
overhaul implementation-internal signal protections the new approach relies on the fact that the only ways to create sigset_t objects without invoking UB are to use the sigset() functions, or from the masks returned by sigprocmask, sigaction, etc. or in the ucontext_t argument to a signal handler. thus, as long as sigfillset and sigaddset avoid adding the "protected" signals, there is no way the application will ever obtain a sigset_t including these bits, and thus no need to add the overhead of checking/clearing them when sigprocmask or sigaction is called. note that the old code actually failed* to remove the bits from sa_mask when sigaction was called. the new implementations are also significantly smaller, simpler, and faster due to ignoring the useless "GNU HURD signals" 65-1024, which are not used and, if there's any sanity in the world, never will be used. 2011-05-07 23:23:58 -04:00			`int sigprocmask(int how, const sigset_t set, sigset_t old)`
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00			`{`
fix error handling for pthread_sigmask it must return errno, not -1, and should reject invalud values for how. 2011-03-09 20:31:06 -05:00			`if (how > 2U) {`
			`errno = EINVAL;`
			`return -1;`
			`}`
overhaul implementation-internal signal protections the new approach relies on the fact that the only ways to create sigset_t objects without invoking UB are to use the sigset() functions, or from the masks returned by sigprocmask, sigaction, etc. or in the ucontext_t argument to a signal handler. thus, as long as sigfillset and sigaddset avoid adding the "protected" signals, there is no way the application will ever obtain a sigset_t including these bits, and thus no need to add the overhead of checking/clearing them when sigprocmask or sigaction is called. note that the old code actually failed* to remove the bits from sa_mask when sigaction was called. the new implementations are also significantly smaller, simpler, and faster due to ignoring the useless "GNU HURD signals" 65-1024, which are not used and, if there's any sanity in the world, never will be used. 2011-05-07 23:23:58 -04:00			`return syscall(SYS_rt_sigprocmask, how, set, old, 8);`
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00			`}`