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| author | Rich Felker <dalias@aerifal.cx> | 2014-05-29 16:35:09 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2014-05-29 16:35:09 -0400 |
| commit | 2e55da911896a91e95b24ab5dc8a9d9b0718f4de (patch) | |
| tree | 4a43f5d7b6b3f68d4e7a3df42e819643a0a50b11 /src/exit | |
| parent | d677d3fe830899926072af6dfffefb16ab6b50bd (diff) | |
| download | musl-2e55da911896a91e95b24ab5dc8a9d9b0718f4de.tar.gz musl-2e55da911896a91e95b24ab5dc8a9d9b0718f4de.tar.bz2 musl-2e55da911896a91e95b24ab5dc8a9d9b0718f4de.tar.xz musl-2e55da911896a91e95b24ab5dc8a9d9b0718f4de.zip | |
remove useless synchronization in exit and quick_exit
calling exit more than once invokes undefined behavior. in some cases
it's desirable to detect undefined behavior and diagnose it via a
predictable crash, but the code here was silently covering up an
uncommon case (exit from more than one thread) and turning a much more
common case (recursive calls to exit) into a permanent hang.
Diffstat (limited to 'src/exit')
| -rw-r--r-- | src/exit/exit.c | 7 | ||||
| -rw-r--r-- | src/exit/quick_exit.c | 4 |
2 files changed, 0 insertions, 11 deletions
diff --git a/src/exit/exit.c b/src/exit/exit.c index 353f50b7..695bdc05 100644 --- a/src/exit/exit.c +++ b/src/exit/exit.c @@ -1,8 +1,6 @@ #include <stdlib.h> #include <stdint.h> #include "libc.h" -#include "atomic.h" -#include "syscall.h" static void dummy() { @@ -21,11 +19,6 @@ extern void (*const __fini_array_end)() __attribute__((weak)); _Noreturn void exit(int code) { - static int lock; - - /* If more than one thread calls exit, hang until _Exit ends it all */ - while (a_swap(&lock, 1)) __syscall(SYS_pause); - __funcs_on_exit(); #ifndef SHARED diff --git a/src/exit/quick_exit.c b/src/exit/quick_exit.c index 1175d80c..ada91348 100644 --- a/src/exit/quick_exit.c +++ b/src/exit/quick_exit.c @@ -1,6 +1,4 @@ #include <stdlib.h> -#include "syscall.h" -#include "atomic.h" #include "libc.h" static void dummy() { } @@ -8,8 +6,6 @@ weak_alias(dummy, __funcs_on_quick_exit); _Noreturn void quick_exit(int code) { - static int lock; - while (a_swap(&lock, 1)) __syscall(SYS_pause); __funcs_on_quick_exit(); _Exit(code); } |