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-rw-r--r--src/internal/pthread_impl.h1
-rw-r--r--src/signal/sigaction.c6
-rw-r--r--src/thread/__timedwait.c8
3 files changed, 15 insertions, 0 deletions
diff --git a/src/internal/pthread_impl.h b/src/internal/pthread_impl.h
index 7a25b88e..58ecce90 100644
--- a/src/internal/pthread_impl.h
+++ b/src/internal/pthread_impl.h
@@ -156,6 +156,7 @@ extern hidden volatile int __block_new_threads;
extern hidden volatile size_t __pthread_tsd_size;
extern hidden void *__pthread_tsd_main[];
extern hidden volatile int __aio_fut;
+extern hidden volatile int __eintr_valid_flag;
hidden int __clone(int (*)(void *), void *, int, void *, ...);
hidden int __set_thread_area(void *);
diff --git a/src/signal/sigaction.c b/src/signal/sigaction.c
index af47195e..05445089 100644
--- a/src/signal/sigaction.c
+++ b/src/signal/sigaction.c
@@ -21,6 +21,8 @@ void __get_handler_set(sigset_t *set)
memcpy(set, handler_set, sizeof handler_set);
}
+volatile int __eintr_valid_flag;
+
int __libc_sigaction(int sig, const struct sigaction *restrict sa, struct sigaction *restrict old)
{
struct k_sigaction ksa, ksa_old;
@@ -43,6 +45,10 @@ int __libc_sigaction(int sig, const struct sigaction *restrict sa, struct sigact
SIGPT_SET, 0, _NSIG/8);
unmask_done = 1;
}
+
+ if (!(sa->sa_flags & SA_RESTART)) {
+ a_store(&__eintr_valid_flag, 1);
+ }
}
/* Changing the disposition of SIGABRT to anything but
* SIG_DFL requires a lock, so that it cannot be changed
diff --git a/src/thread/__timedwait.c b/src/thread/__timedwait.c
index 229db313..ae19bd63 100644
--- a/src/thread/__timedwait.c
+++ b/src/thread/__timedwait.c
@@ -5,6 +5,9 @@
#include "syscall.h"
#include "pthread_impl.h"
+static volatile int dummy = 0;
+weak_alias(dummy, __eintr_valid_flag);
+
int __timedwait_cp(volatile int *addr, int val,
clockid_t clk, const struct timespec *at, int priv)
{
@@ -28,6 +31,11 @@ int __timedwait_cp(volatile int *addr, int val,
r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT|priv, val, top);
if (r == ENOSYS) r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT, val, top);
if (r != EINTR && r != ETIMEDOUT && r != ECANCELED) r = 0;
+ /* Mitigate bug in old kernels wrongly reporting EINTR for non-
+ * interrupting (SA_RESTART) signal handlers. This is only practical
+ * when NO interrupting signal handlers have been installed, and
+ * works by sigaction tracking whether that's the case. */
+ if (r == EINTR && !__eintr_valid_flag) r = 0;
return r;
}