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authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-25 11:28:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-25 11:28:49 -0700
commit672f8871261597894d46454b8fa1660d6c952af6 (patch)
treec856b51d187bffa65ff6e79a055c43ab6f6ae528
parent87702a337f748d19a59a7826aeeffe0f6aeab7d4 (diff)
parenta4fd8414659bf470e2146b352574bbd274e54b7a (diff)
Merge tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner: "A time namespace fix and a matching selftest. The futex absolute timeouts which are based on CLOCK_MONOTONIC require time namespace corrected. This was missed in the original time namesapce support" * tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/timens: Add a test for futex() futex: Adjust absolute futex timeouts with per time namespace offset
-rw-r--r--kernel/futex.c5
-rw-r--r--tools/testing/selftests/timens/Makefile2
-rw-r--r--tools/testing/selftests/timens/futex.c110
3 files changed, 116 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index 680854dcf156..be68ac0d49ad 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -39,6 +39,7 @@
#include <linux/freezer.h>
#include <linux/memblock.h>
#include <linux/fault-inject.h>
+#include <linux/time_namespace.h>
#include <asm/futex.h>
@@ -3797,6 +3798,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
t = timespec64_to_ktime(ts);
if (cmd == FUTEX_WAIT)
t = ktime_add_safe(ktime_get(), t);
+ else if (!(op & FUTEX_CLOCK_REALTIME))
+ t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}
/*
@@ -3989,6 +3992,8 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
t = timespec64_to_ktime(ts);
if (cmd == FUTEX_WAIT)
t = ktime_add_safe(ktime_get(), t);
+ else if (!(op & FUTEX_CLOCK_REALTIME))
+ t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}
if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index b4fd9a934654..3a5936cc10ab 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,4 +1,4 @@
-TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex
TEST_GEN_PROGS_EXTENDED := gettime_perf
CFLAGS := -Wall -Werror -pthread
diff --git a/tools/testing/selftests/timens/futex.c b/tools/testing/selftests/timens/futex.c
new file mode 100644
index 000000000000..6b2b9264e851
--- /dev/null
+++ b/tools/testing/selftests/timens/futex.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <linux/unistd.h>
+#include <linux/futex.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "log.h"
+#include "timens.h"
+
+#define NSEC_PER_SEC 1000000000ULL
+
+static int run_test(int clockid)
+{
+ int futex_op = FUTEX_WAIT_BITSET;
+ struct timespec timeout, end;
+ int val = 0;
+
+ if (clockid == CLOCK_REALTIME)
+ futex_op |= FUTEX_CLOCK_REALTIME;
+
+ clock_gettime(clockid, &timeout);
+ timeout.tv_nsec += NSEC_PER_SEC / 10; // 100ms
+ if (timeout.tv_nsec > NSEC_PER_SEC) {
+ timeout.tv_sec++;
+ timeout.tv_nsec -= NSEC_PER_SEC;
+ }
+
+ if (syscall(__NR_futex, &val, futex_op, 0,
+ &timeout, 0, FUTEX_BITSET_MATCH_ANY) >= 0) {
+ ksft_test_result_fail("futex didn't return ETIMEDOUT\n");
+ return 1;
+ }
+
+ if (errno != ETIMEDOUT) {
+ ksft_test_result_fail("futex didn't return ETIMEDOUT: %s\n",
+ strerror(errno));
+ return 1;
+ }
+
+ clock_gettime(clockid, &end);
+
+ if (end.tv_sec < timeout.tv_sec ||
+ (end.tv_sec == timeout.tv_sec && end.tv_nsec < timeout.tv_nsec)) {
+ ksft_test_result_fail("futex slept less than 100ms\n");
+ return 1;
+ }
+
+
+ ksft_test_result_pass("futex with the %d clockid\n", clockid);
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int status, len, fd;
+ char buf[4096];
+ pid_t pid;
+ struct timespec mtime_now;
+
+ nscheck();
+
+ ksft_set_plan(2);
+
+ clock_gettime(CLOCK_MONOTONIC, &mtime_now);
+
+ if (unshare_timens())
+ return 1;
+
+ len = snprintf(buf, sizeof(buf), "%d %d 0",
+ CLOCK_MONOTONIC, 70 * 24 * 3600);
+ fd = open("/proc/self/timens_offsets", O_WRONLY);
+ if (fd < 0)
+ return pr_perror("/proc/self/timens_offsets");
+
+ if (write(fd, buf, len) != len)
+ return pr_perror("/proc/self/timens_offsets");
+
+ close(fd);
+
+ pid = fork();
+ if (pid < 0)
+ return pr_perror("Unable to fork");
+ if (pid == 0) {
+ int ret = 0;
+
+ ret |= run_test(CLOCK_REALTIME);
+ ret |= run_test(CLOCK_MONOTONIC);
+ if (ret)
+ ksft_exit_fail();
+ ksft_exit_pass();
+ return 0;
+ }
+
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Unable to wait the child process");
+
+ if (WIFEXITED(status))
+ return WEXITSTATUS(status);
+
+ return 1;
+}

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