[PATCH] nptl: Fix PTHREAD_PRIO_PROTECT timed lock
Adhemerval Zanella
adhemerval.zanella@linaro.org
Wed Nov 25 20:27:23 GMT 2020
The 878fe624d4 changed lll_futex_timed_wait, which expects a relative
timeout, with a __futex_abstimed_wait64, which expects an absolute
timeout. However the code still passes a relative timeout.
Also, the PTHREAD_PRIO_PROTECT support for clocks different than
CLOCK_REALTIME was broken since the inclusion of
pthread_mutex_clocklock (9d20e22e46) since lll_futex_timed_wait
always use CLOCK_REALTIME.
This patch fixes by removing the relative time calculation. It
also adds some xtests that tests both thread and inter-process
usage.
Checked on x86_64-linux-gnu.
---
nptl/Makefile | 3 ++-
nptl/pthread_mutex_timedlock.c | 29 +++++------------------------
nptl/tst-mutexpp5.c | 2 ++
nptl/tst-mutexpp9.c | 2 ++
sysdeps/pthread/tst-mutex5.c | 12 +++++++++++-
sysdeps/pthread/tst-mutex9.c | 13 ++++++++++++-
6 files changed, 34 insertions(+), 27 deletions(-)
create mode 100644 nptl/tst-mutexpp5.c
create mode 100644 nptl/tst-mutexpp9.c
diff --git a/nptl/Makefile b/nptl/Makefile
index a48426a396..94d805f0d4 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -309,7 +309,8 @@ tests-internal := tst-robustpi8 tst-rwlock19 tst-rwlock20 \
tst-setgetname \
xtests = tst-setuid1 tst-setuid1-static tst-setuid2 \
- tst-mutexpp1 tst-mutexpp6 tst-mutexpp10 tst-setgroups
+ tst-mutexpp1 tst-mutexpp6 tst-mutexpp10 tst-setgroups \
+ tst-mutexpp5 tst-mutexpp9
# This test can run into task limits because of a linux kernel bug
# and then cause the make process to fail too, see bug 24537.
diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c
index aaaafa21ce..74adffe790 100644
--- a/nptl/pthread_mutex_timedlock.c
+++ b/nptl/pthread_mutex_timedlock.c
@@ -547,30 +547,11 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
goto failpp;
}
- struct __timespec64 rt;
-
- /* Get the current time. */
- __clock_gettime64 (CLOCK_REALTIME, &rt);
-
- /* Compute relative timeout. */
- rt.tv_sec = abstime->tv_sec - rt.tv_sec;
- rt.tv_nsec = abstime->tv_nsec - rt.tv_nsec;
- if (rt.tv_nsec < 0)
- {
- rt.tv_nsec += 1000000000;
- --rt.tv_sec;
- }
-
- /* Already timed out? */
- if (rt.tv_sec < 0)
- {
- result = ETIMEDOUT;
- goto failpp;
- }
-
- __futex_abstimed_wait64 (
- (unsigned int *) &mutex->__data.__lock, clockid,
- ceilval | 2, &rt, PTHREAD_MUTEX_PSHARED (mutex));
+ int e = __futex_abstimed_wait64 (
+ (unsigned int *) &mutex->__data.__lock, ceilval | 2,
+ clockid, abstime, PTHREAD_MUTEX_PSHARED (mutex));
+ if (e == ETIMEDOUT)
+ return ETIMEDOUT;
}
}
while (atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
diff --git a/nptl/tst-mutexpp5.c b/nptl/tst-mutexpp5.c
new file mode 100644
index 0000000000..a864a390ca
--- /dev/null
+++ b/nptl/tst-mutexpp5.c
@@ -0,0 +1,2 @@
+#define ENABLE_PP 1
+#include "tst-mutex5.c"
diff --git a/nptl/tst-mutexpp9.c b/nptl/tst-mutexpp9.c
new file mode 100644
index 0000000000..c848c74c7e
--- /dev/null
+++ b/nptl/tst-mutexpp9.c
@@ -0,0 +1,2 @@
+#define ENABLE_PP 1
+#include "tst-mutex9.c"
diff --git a/sysdeps/pthread/tst-mutex5.c b/sysdeps/pthread/tst-mutex5.c
index bfe1a79fa4..dbd2c3c15f 100644
--- a/sysdeps/pthread/tst-mutex5.c
+++ b/sysdeps/pthread/tst-mutex5.c
@@ -27,6 +27,9 @@
#include <support/check.h>
#include <support/timespec.h>
+#ifdef ENABLE_PP
+#include "tst-tpp.h"
+#endif
#ifndef TYPE
# define TYPE PTHREAD_MUTEX_NORMAL
@@ -47,8 +50,11 @@ do_test_clock (clockid_t clockid, const char *fnname)
TEST_COMPARE (pthread_mutexattr_init (&a), 0);
TEST_COMPARE (pthread_mutexattr_settype (&a, TYPE), 0);
-#ifdef ENABLE_PI
+#if defined ENABLE_PI
TEST_COMPARE (pthread_mutexattr_setprotocol (&a, PTHREAD_PRIO_INHERIT), 0);
+#elif defined ENABLE_PP
+ TEST_COMPARE (pthread_mutexattr_setprotocol (&a, PTHREAD_PRIO_PROTECT), 0);
+ TEST_COMPARE (pthread_mutexattr_setprioceiling (&a, 6), 0);
#endif
int err = pthread_mutex_init (&m, &a);
@@ -110,6 +116,10 @@ do_test_clock (clockid_t clockid, const char *fnname)
static int do_test (void)
{
+#ifdef ENABLE_PP
+ init_tpp_test ();
+#endif
+
do_test_clock (CLOCK_USE_TIMEDLOCK, "timedlock");
do_test_clock (CLOCK_REALTIME, "clocklock(realtime)");
#ifndef ENABLE_PI
diff --git a/sysdeps/pthread/tst-mutex9.c b/sysdeps/pthread/tst-mutex9.c
index bfc01f8c75..081aeff0f6 100644
--- a/sysdeps/pthread/tst-mutex9.c
+++ b/sysdeps/pthread/tst-mutex9.c
@@ -30,6 +30,10 @@
#include <support/timespec.h>
#include <support/xunistd.h>
+#ifdef ENABLE_PP
+#include "tst-tpp.h"
+#endif
+
/* A bogus clock value that tells run_test to use pthread_mutex_timedlock
rather than pthread_mutex_clocklock. */
@@ -73,8 +77,11 @@ do_test_clock (clockid_t clockid)
TEST_COMPARE (pthread_mutexattr_settype (&a, PTHREAD_MUTEX_RECURSIVE), 0);
-#ifdef ENABLE_PI
+#if defined ENABLE_PI
TEST_COMPARE (pthread_mutexattr_setprotocol (&a, PTHREAD_PRIO_INHERIT), 0);
+#elif defined ENABLE_PP
+ TEST_COMPARE (pthread_mutexattr_setprotocol (&a, PTHREAD_PRIO_PROTECT), 0);
+ TEST_COMPARE (pthread_mutexattr_setprioceiling (&a, 6), 0);
#endif
int e;
@@ -131,6 +138,10 @@ do_test_clock (clockid_t clockid)
static int
do_test (void)
{
+#ifdef ENABLE_PP
+ init_tpp_test ();
+#endif
+
do_test_clock (CLOCK_USE_TIMEDLOCK);
do_test_clock (CLOCK_REALTIME);
#ifndef ENABLE_PI
--
2.25.1
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