Merge tag 'locking-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Thomas Gleixner:

 - Move futex code into kernel/futex/ and split up the kitchen sink into
   seperate files to make integration of sys_futex_waitv() simpler.

 - Add a new sys_futex_waitv() syscall which allows to wait on multiple
   futexes.

   The main use case is emulating Windows' WaitForMultipleObjects which
   allows Wine to improve the performance of Windows Games. Also native
   Linux games can benefit from this interface as this is a common wait
   pattern for this kind of applications.

 - Add context to ww_mutex_trylock() to provide a path for i915 to
   rework their eviction code step by step without making lockdep upset
   until the final steps of rework are completed. It's also useful for
   regulator and TTM to avoid dropping locks in the non contended path.

 - Lockdep and might_sleep() cleanups and improvements

 - A few improvements for the RT substitutions.

 - The usual small improvements and cleanups.

* tag 'locking-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  locking: Remove spin_lock_flags() etc
  locking/rwsem: Fix comments about reader optimistic lock stealing conditions
  locking: Remove rcu_read_{,un}lock() for preempt_{dis,en}able()
  locking/rwsem: Disable preemption for spinning region
  docs: futex: Fix kernel-doc references
  futex: Fix PREEMPT_RT build
  futex2: Documentation: Document sys_futex_waitv() uAPI
  selftests: futex: Test sys_futex_waitv() wouldblock
  selftests: futex: Test sys_futex_waitv() timeout
  selftests: futex: Add sys_futex_waitv() test
  futex,arm: Wire up sys_futex_waitv()
  futex,x86: Wire up sys_futex_waitv()
  futex: Implement sys_futex_waitv()
  futex: Simplify double_lock_hb()
  futex: Split out wait/wake
  futex: Split out requeue
  futex: Rename mark_wake_futex()
  futex: Rename: match_futex()
  futex: Rename: hb_waiter_{inc,dec,pending}()
  futex: Split out PI futex
  ...

7 files changed, 322 insertions, 6 deletions

diff --git a/tools/testing/selftests/futex/functional/.gitignore b/tools/testing/selftests/futex/functional/.gitignore
index 0e78b49d0f2f..fbcbdb6963b3 100644
--- a/tools/testing/selftests/futex/functional/.gitignore
+++ b/tools/testing/selftests/futex/functional/.gitignore
@@ -8,3 +8,4 @@ futex_wait_uninitialized_heap
 futex_wait_wouldblock
 futex_wait
 futex_requeue
+futex_waitv
diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile
index bd1fec59e010..5cc38de9d8ea 100644
--- a/tools/testing/selftests/futex/functional/Makefile
+++ b/tools/testing/selftests/futex/functional/Makefile
@@ -17,7 +17,8 @@ TEST_GEN_FILES := \
 	futex_wait_uninitialized_heap \
 	futex_wait_private_mapped_file \
 	futex_wait \
-	futex_requeue
+	futex_requeue \
+	futex_waitv
 
 TEST_PROGS := run.sh
 
diff --git a/tools/testing/selftests/futex/functional/futex_wait_timeout.c b/tools/testing/selftests/futex/functional/futex_wait_timeout.c
index 1f8f6daaf1e7..3651ce17beeb 100644
--- a/tools/testing/selftests/futex/functional/futex_wait_timeout.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_timeout.c
@@ -17,6 +17,7 @@
 
 #include <pthread.h>
 #include "futextest.h"
+#include "futex2test.h"
 #include "logging.h"
 
 #define TEST_NAME "futex-wait-timeout"
@@ -96,6 +97,12 @@ int main(int argc, char *argv[])
 	struct timespec to;
 	pthread_t thread;
 	int c;
+	struct futex_waitv waitv = {
+			.uaddr = (uintptr_t)&f1,
+			.val = f1,
+			.flags = FUTEX_32,
+			.__reserved = 0
+		};
 
 	while ((c = getopt(argc, argv, "cht:v:")) != -1) {
 		switch (c) {
@@ -118,7 +125,7 @@ int main(int argc, char *argv[])
 	}
 
 	ksft_print_header();
-	ksft_set_plan(7);
+	ksft_set_plan(9);
 	ksft_print_msg("%s: Block on a futex and wait for timeout\n",
 	       basename(argv[0]));
 	ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns);
@@ -175,6 +182,18 @@ int main(int argc, char *argv[])
 	res = futex_lock_pi(&futex_pi, NULL, 0, FUTEX_CLOCK_REALTIME);
 	test_timeout(res, &ret, "futex_lock_pi invalid timeout flag", ENOSYS);
 
+	/* futex_waitv with CLOCK_MONOTONIC */
+	if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
+		return RET_FAIL;
+	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC);
+	test_timeout(res, &ret, "futex_waitv monotonic", ETIMEDOUT);
+
+	/* futex_waitv with CLOCK_REALTIME */
+	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
+		return RET_FAIL;
+	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_REALTIME);
+	test_timeout(res, &ret, "futex_waitv realtime", ETIMEDOUT);
+
 	ksft_print_cnts();
 	return ret;
 }
diff --git a/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c b/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
index 0ae390ff8164..7d7a6a06cdb7 100644
--- a/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
@@ -22,6 +22,7 @@
 #include <string.h>
 #include <time.h>
 #include "futextest.h"
+#include "futex2test.h"
 #include "logging.h"
 
 #define TEST_NAME "futex-wait-wouldblock"
@@ -42,6 +43,12 @@ int main(int argc, char *argv[])
 	futex_t f1 = FUTEX_INITIALIZER;
 	int res, ret = RET_PASS;
 	int c;
+	struct futex_waitv waitv = {
+			.uaddr = (uintptr_t)&f1,
+			.val = f1+1,
+			.flags = FUTEX_32,
+			.__reserved = 0
+		};
 
 	while ((c = getopt(argc, argv, "cht:v:")) != -1) {
 		switch (c) {
@@ -61,18 +68,44 @@ int main(int argc, char *argv[])
 	}
 
 	ksft_print_header();
-	ksft_set_plan(1);
+	ksft_set_plan(2);
 	ksft_print_msg("%s: Test the unexpected futex value in FUTEX_WAIT\n",
 	       basename(argv[0]));
 
 	info("Calling futex_wait on f1: %u @ %p with val=%u\n", f1, &f1, f1+1);
 	res = futex_wait(&f1, f1+1, &to, FUTEX_PRIVATE_FLAG);
 	if (!res || errno != EWOULDBLOCK) {
-		fail("futex_wait returned: %d %s\n",
-		     res ? errno : res, res ? strerror(errno) : "");
+		ksft_test_result_fail("futex_wait returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
 		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_wait\n");
 	}
 
-	print_result(TEST_NAME, ret);
+	if (clock_gettime(CLOCK_MONOTONIC, &to)) {
+		error("clock_gettime failed\n", errno);
+		return errno;
+	}
+
+	to.tv_nsec += timeout_ns;
+
+	if (to.tv_nsec >= 1000000000) {
+		to.tv_sec++;
+		to.tv_nsec -= 1000000000;
+	}
+
+	info("Calling futex_waitv on f1: %u @ %p with val=%u\n", f1, &f1, f1+1);
+	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC);
+	if (!res || errno != EWOULDBLOCK) {
+		ksft_test_result_pass("futex_waitv returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv\n");
+	}
+
+	ksft_print_cnts();
 	return ret;
 }
diff --git a/tools/testing/selftests/futex/functional/futex_waitv.c b/tools/testing/selftests/futex/functional/futex_waitv.c
new file mode 100644
index 000000000000..a94337f677e1
--- /dev/null
+++ b/tools/testing/selftests/futex/functional/futex_waitv.c
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * futex_waitv() test by André Almeida <andrealmeid@collabora.com>
+ *
+ * Copyright 2021 Collabora Ltd.
+ */
+
+#include <errno.h>
+#include <error.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <sys/shm.h>
+#include "futextest.h"
+#include "futex2test.h"
+#include "logging.h"
+
+#define TEST_NAME "futex-wait"
+#define WAKE_WAIT_US 10000
+#define NR_FUTEXES 30
+static struct futex_waitv waitv[NR_FUTEXES];
+u_int32_t futexes[NR_FUTEXES] = {0};
+
+void usage(char *prog)
+{
+	printf("Usage: %s\n", prog);
+	printf("  -c	Use color\n");
+	printf("  -h	Display this help message\n");
+	printf("  -v L	Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
+	       VQUIET, VCRITICAL, VINFO);
+}
+
+void *waiterfn(void *arg)
+{
+	struct timespec to;
+	int res;
+
+	/* setting absolute timeout for futex2 */
+	if (clock_gettime(CLOCK_MONOTONIC, &to))
+		error("gettime64 failed\n", errno);
+
+	to.tv_sec++;
+
+	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
+	if (res < 0) {
+		ksft_test_result_fail("futex_waitv returned: %d %s\n",
+				      errno, strerror(errno));
+	} else if (res != NR_FUTEXES - 1) {
+		ksft_test_result_fail("futex_waitv returned: %d, expecting %d\n",
+				      res, NR_FUTEXES - 1);
+	}
+
+	return NULL;
+}
+
+int main(int argc, char *argv[])
+{
+	pthread_t waiter;
+	int res, ret = RET_PASS;
+	struct timespec to;
+	int c, i;
+
+	while ((c = getopt(argc, argv, "cht:v:")) != -1) {
+		switch (c) {
+		case 'c':
+			log_color(1);
+			break;
+		case 'h':
+			usage(basename(argv[0]));
+			exit(0);
+		case 'v':
+			log_verbosity(atoi(optarg));
+			break;
+		default:
+			usage(basename(argv[0]));
+			exit(1);
+		}
+	}
+
+	ksft_print_header();
+	ksft_set_plan(7);
+	ksft_print_msg("%s: Test FUTEX_WAITV\n",
+		       basename(argv[0]));
+
+	for (i = 0; i < NR_FUTEXES; i++) {
+		waitv[i].uaddr = (uintptr_t)&futexes[i];
+		waitv[i].flags = FUTEX_32 | FUTEX_PRIVATE_FLAG;
+		waitv[i].val = 0;
+		waitv[i].__reserved = 0;
+	}
+
+	/* Private waitv */
+	if (pthread_create(&waiter, NULL, waiterfn, NULL))
+		error("pthread_create failed\n", errno);
+
+	usleep(WAKE_WAIT_US);
+
+	res = futex_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), 1, FUTEX_PRIVATE_FLAG);
+	if (res != 1) {
+		ksft_test_result_fail("futex_wake private returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv private\n");
+	}
+
+	/* Shared waitv */
+	for (i = 0; i < NR_FUTEXES; i++) {
+		int shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666);
+
+		if (shm_id < 0) {
+			perror("shmget");
+			exit(1);
+		}
+
+		unsigned int *shared_data = shmat(shm_id, NULL, 0);
+
+		*shared_data = 0;
+		waitv[i].uaddr = (uintptr_t)shared_data;
+		waitv[i].flags = FUTEX_32;
+		waitv[i].val = 0;
+		waitv[i].__reserved = 0;
+	}
+
+	if (pthread_create(&waiter, NULL, waiterfn, NULL))
+		error("pthread_create failed\n", errno);
+
+	usleep(WAKE_WAIT_US);
+
+	res = futex_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), 1, 0);
+	if (res != 1) {
+		ksft_test_result_fail("futex_wake shared returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv shared\n");
+	}
+
+	for (i = 0; i < NR_FUTEXES; i++)
+		shmdt(u64_to_ptr(waitv[i].uaddr));
+
+	/* Testing a waiter without FUTEX_32 flag */
+	waitv[0].flags = FUTEX_PRIVATE_FLAG;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &to))
+		error("gettime64 failed\n", errno);
+
+	to.tv_sec++;
+
+	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
+	if (res == EINVAL) {
+		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv without FUTEX_32\n");
+	}
+
+	/* Testing a waiter with an unaligned address */
+	waitv[0].flags = FUTEX_PRIVATE_FLAG | FUTEX_32;
+	waitv[0].uaddr = 1;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &to))
+		error("gettime64 failed\n", errno);
+
+	to.tv_sec++;
+
+	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
+	if (res == EINVAL) {
+		ksft_test_result_fail("futex_wake private returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv with an unaligned address\n");
+	}
+
+	/* Testing a NULL address for waiters.uaddr */
+	waitv[0].uaddr = 0x00000000;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &to))
+		error("gettime64 failed\n", errno);
+
+	to.tv_sec++;
+
+	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
+	if (res == EINVAL) {
+		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv NULL address in waitv.uaddr\n");
+	}
+
+	/* Testing a NULL address for *waiters */
+	if (clock_gettime(CLOCK_MONOTONIC, &to))
+		error("gettime64 failed\n", errno);
+
+	to.tv_sec++;
+
+	res = futex_waitv(NULL, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
+	if (res == EINVAL) {
+		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv NULL address in *waiters\n");
+	}
+
+	/* Testing an invalid clockid */
+	if (clock_gettime(CLOCK_MONOTONIC, &to))
+		error("gettime64 failed\n", errno);
+
+	to.tv_sec++;
+
+	res = futex_waitv(NULL, NR_FUTEXES, 0, &to, CLOCK_TAI);
+	if (res == EINVAL) {
+		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
+				      res ? errno : res,
+				      res ? strerror(errno) : "");
+		ret = RET_FAIL;
+	} else {
+		ksft_test_result_pass("futex_waitv invalid clockid\n");
+	}
+
+	ksft_print_cnts();
+	return ret;
+}
diff --git a/tools/testing/selftests/futex/functional/run.sh b/tools/testing/selftests/futex/functional/run.sh
index 11a9d62290f5..5ccd599da6c3 100755
--- a/tools/testing/selftests/futex/functional/run.sh
+++ b/tools/testing/selftests/futex/functional/run.sh
@@ -79,3 +79,6 @@ echo
 
 echo
 ./futex_requeue $COLOR
+
+echo
+./futex_waitv $COLOR
diff --git a/tools/testing/selftests/futex/include/futex2test.h b/tools/testing/selftests/futex/include/futex2test.h
new file mode 100644
index 000000000000..9d305520e849
--- /dev/null
+++ b/tools/testing/selftests/futex/include/futex2test.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Futex2 library addons for futex tests
+ *
+ * Copyright 2021 Collabora Ltd.
+ */
+#include <stdint.h>
+
+#define u64_to_ptr(x) ((void *)(uintptr_t)(x))
+
+/**
+ * futex_waitv - Wait at multiple futexes, wake on any
+ * @waiters:    Array of waiters
+ * @nr_waiters: Length of waiters array
+ * @flags: Operation flags
+ * @timo:  Optional timeout for operation
+ */
+static inline int futex_waitv(volatile struct futex_waitv *waiters, unsigned long nr_waiters,
+			      unsigned long flags, struct timespec *timo, clockid_t clockid)
+{
+	return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, timo, clockid);
+}