path: root/src/signal/sigemptyset.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/sigemptyset.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/sigemptyset.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/src/signal/sigemptyset.c b/src/signal/sigemptyset.c
index 91f77adf..ca9b8920 100644
--- a/src/signal/sigemptyset.c
+++ b/src/signal/sigemptyset.c
@@ -3,6 +3,7 @@
int sigemptyset(sigset_t *set)
- memset(set, 0, sizeof *set);
+ set->__bits[0] = 0;
+ if (sizeof(long)==4) set->__bits[1] = 0;
return 0;