path: root/src/signal/sigprocmask.c
diff options
authorRich Felker <>2011-05-07 23:23:58 -0400
committerRich Felker <>2011-05-07 23:23:58 -0400
commit99b8a25e941e54537bf39ca2f265c345f393f112 (patch)
tree758faba1a20af40b5d09221d008eddbc704636fa /src/signal/sigprocmask.c
parent77f15d108ee021d4dfbeebe793661131c4470d4d (diff)
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 sig*set() 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.
Diffstat (limited to 'src/signal/sigprocmask.c')
1 files changed, 2 insertions, 18 deletions
diff --git a/src/signal/sigprocmask.c b/src/signal/sigprocmask.c
index a272c10d..3f003afb 100644
--- a/src/signal/sigprocmask.c
+++ b/src/signal/sigprocmask.c
@@ -4,27 +4,11 @@
#include "libc.h"
#include "pthread_impl.h"
-int __libc_sigprocmask(int how, const sigset_t *set, sigset_t *old)
+int sigprocmask(int how, const sigset_t *set, sigset_t *old)
- return syscall(SYS_rt_sigprocmask, how, set, old, 8);
-int __sigprocmask(int how, const sigset_t *set, sigset_t *old)
- sigset_t tmp;
if (how > 2U) {
errno = EINVAL;
return -1;
- /* Disallow blocking thread control signals */
- if (set && how != SIG_UNBLOCK) {
- tmp = *set;
- set = &tmp;
- sigdelset(&tmp, SIGCANCEL);
- sigdelset(&tmp, SIGSYSCALL);
- sigdelset(&tmp, SIGTIMER);
- }
- return __libc_sigprocmask(how, set, old);
+ return syscall(SYS_rt_sigprocmask, how, set, old, 8);
-weak_alias(__sigprocmask, sigprocmask);