summaryrefslogtreecommitdiff
path: root/src/signal
diff options
context:
space:
mode:
authorRich Felker <dalias@aerifal.cx>2011-04-17 11:43:03 -0400
committerRich Felker <dalias@aerifal.cx>2011-04-17 11:43:03 -0400
commitfeee98903cd8119d9a3db62589246a940f44a9f5 (patch)
tree37922ce54f00145d7fc0ac795216fce611e0806a /src/signal
parent90f09a0dde3b37ebfabc4d3f6e2bb64086b7e804 (diff)
downloadmusl-feee98903cd8119d9a3db62589246a940f44a9f5.tar.gz
musl-feee98903cd8119d9a3db62589246a940f44a9f5.tar.bz2
musl-feee98903cd8119d9a3db62589246a940f44a9f5.tar.xz
musl-feee98903cd8119d9a3db62589246a940f44a9f5.zip
overhaul pthread cancellation
this patch improves the correctness, simplicity, and size of cancellation-related code. modulo any small errors, it should now be completely conformant, safe, and resource-leak free. the notion of entering and exiting cancellation-point context has been completely eliminated and replaced with alternative syscall assembly code for cancellable syscalls. the assembly is responsible for setting up execution context information (stack pointer and address of the syscall instruction) which the cancellation signal handler can use to determine whether the interrupted code was in a cancellable state. these changes eliminate race conditions in the previous generation of cancellation handling code (whereby a cancellation request received just prior to the syscall would not be processed, leaving the syscall to block, potentially indefinitely), and remedy an issue where non-cancellable syscalls made from signal handlers became cancellable if the signal handler interrupted a cancellation point. x86_64 asm is untested and may need a second try to get it right.
Diffstat (limited to 'src/signal')
-rw-r--r--src/signal/sigsuspend.c7
-rw-r--r--src/signal/sigtimedwait.c8
2 files changed, 3 insertions, 12 deletions
diff --git a/src/signal/sigsuspend.c b/src/signal/sigsuspend.c
index cec5ddce..cd3a7b59 100644
--- a/src/signal/sigsuspend.c
+++ b/src/signal/sigsuspend.c
@@ -4,10 +4,5 @@
int sigsuspend(const sigset_t *mask)
{
- int ret;
- CANCELPT_BEGIN;
- ret = syscall(SYS_rt_sigsuspend, mask, 8);
- if (ret<0) CANCELPT_TRY;
- CANCELPT_END;
- return ret;
+ return syscall_cp(SYS_rt_sigsuspend, mask, 8);
}
diff --git a/src/signal/sigtimedwait.c b/src/signal/sigtimedwait.c
index 1694cbe1..7eea58ab 100644
--- a/src/signal/sigtimedwait.c
+++ b/src/signal/sigtimedwait.c
@@ -6,11 +6,7 @@
int sigtimedwait(const sigset_t *mask, siginfo_t *si, const struct timespec *timeout)
{
int ret;
- CANCELPT_BEGIN;
- do {
- ret = syscall(SYS_rt_sigtimedwait, mask, si, timeout, 8);
- if (ret<0) CANCELPT_TRY;
- } while (ret<0 && errno==EINTR);
- CANCELPT_END;
+ do ret = syscall_cp(SYS_rt_sigtimedwait, mask, si, timeout, 8);
+ while (ret<0 && errno==EINTR);
return ret;
}