Merge tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - In the series "treewide: Refactor heap related implementation",
   Kuan-Wei Chiu has significantly reworked the min_heap library code
   and has taught bcachefs to use the new more generic implementation.

 - Yury Norov's series "Cleanup cpumask.h inclusion in core headers"
   reworks the cpumask and nodemask headers to make things generally
   more rational.

 - Kuan-Wei Chiu has sent along some maintenance work against our
   sorting library code in the series "lib/sort: Optimizations and
   cleanups".

 - More library maintainance work from Christophe Jaillet in the series
   "Remove usage of the deprecated ida_simple_xx() API".

 - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the
   series "nilfs2: eliminate the call to inode_attach_wb()".

 - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix
   GDB command error".

 - Plus the usual shower of singleton patches all over the place. Please
   see the relevant changelogs for details.

* tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits)
  ia64: scrub ia64 from poison.h
  watchdog/perf: properly initialize the turbo mode timestamp and rearm counter
  tsacct: replace strncpy() with strscpy()
  lib/bch.c: use swap() to improve code
  test_bpf: convert comma to semicolon
  init/modpost: conditionally check section mismatch to __meminit*
  init: remove unused __MEMINIT* macros
  nilfs2: Constify struct kobj_type
  nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro
  math: rational: add missing MODULE_DESCRIPTION() macro
  lib/zlib: add missing MODULE_DESCRIPTION() macro
  fs: ufs: add MODULE_DESCRIPTION()
  lib/rbtree.c: fix the example typo
  ocfs2: add bounds checking to ocfs2_check_dir_entry()
  fs: add kernel-doc comments to ocfs2_prepare_orphan_dir()
  coredump: simplify zap_process()
  selftests/fpu: add missing MODULE_DESCRIPTION() macro
  compiler.h: simplify data_race() macro
  build-id: require program headers to be right after ELF header
  resource: add missing MODULE_DESCRIPTION()
  ...

11 files changed, 232 insertions, 20 deletions

diff --git a/tools/lib/list_sort.c b/tools/lib/list_sort.c
index 10c067e3a8d2..69affa251fa7 100644
--- a/tools/lib/list_sort.c
+++ b/tools/lib/list_sort.c
@@ -52,7 +52,6 @@ static void merge_final(void *priv, list_cmp_func_t cmp, struct list_head *head,
 			struct list_head *a, struct list_head *b)
 {
 	struct list_head *tail = head;
-	u8 count = 0;
 
 	for (;;) {
 		/* if equal, take 'a' -- important for sort stability */
@@ -78,15 +77,6 @@ static void merge_final(void *priv, list_cmp_func_t cmp, struct list_head *head,
 	/* Finish linking remainder of list b on to tail */
 	tail->next = b;
 	do {
-		/*
-		 * If the merge is highly unbalanced (e.g. the input is
-		 * already sorted), this loop may run many iterations.
-		 * Continue callbacks to the client even though no
-		 * element comparison is needed, so the client's cmp()
-		 * routine can invoke cond_resched() periodically.
-		 */
-		if (unlikely(!++count))
-			cmp(priv, b, b);
 		b->prev = tail;
 		tail = b;
 		b = b->next;
diff --git a/tools/testing/radix-tree/idr-test.c b/tools/testing/radix-tree/idr-test.c
index ca24f6839d50..84b8c3c92c79 100644
--- a/tools/testing/radix-tree/idr-test.c
+++ b/tools/testing/radix-tree/idr-test.c
@@ -424,6 +424,7 @@ void idr_checks(void)
 #define module_init(x)
 #define module_exit(x)
 #define MODULE_AUTHOR(x)
+#define MODULE_DESCRIPTION(X)
 #define MODULE_LICENSE(x)
 #define dump_stack()    assert(0)
 void ida_dump(struct ida *);
diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c
index f1caf4bcf937..cd1cf05503b4 100644
--- a/tools/testing/radix-tree/maple.c
+++ b/tools/testing/radix-tree/maple.c
@@ -19,6 +19,7 @@
 #define module_init(x)
 #define module_exit(x)
 #define MODULE_AUTHOR(x)
+#define MODULE_DESCRIPTION(X)
 #define MODULE_LICENSE(x)
 #define dump_stack()	assert(0)
 
diff --git a/tools/testing/radix-tree/xarray.c b/tools/testing/radix-tree/xarray.c
index f20e12cbbfd4..d0e53bff1eb6 100644
--- a/tools/testing/radix-tree/xarray.c
+++ b/tools/testing/radix-tree/xarray.c
@@ -10,6 +10,7 @@
 #define module_init(x)
 #define module_exit(x)
 #define MODULE_AUTHOR(x)
+#define MODULE_DESCRIPTION(X)
 #define MODULE_LICENSE(x)
 #define dump_stack()	assert(0)
 
diff --git a/tools/testing/selftests/filesystems/eventfd/eventfd_test.c b/tools/testing/selftests/filesystems/eventfd/eventfd_test.c
index f142a137526c..85acb4e3ef00 100644
--- a/tools/testing/selftests/filesystems/eventfd/eventfd_test.c
+++ b/tools/testing/selftests/filesystems/eventfd/eventfd_test.c
@@ -13,6 +13,8 @@
 #include <sys/eventfd.h>
 #include "../../kselftest_harness.h"
 
+#define EVENTFD_TEST_ITERATIONS 100000UL
+
 struct error {
 	int  code;
 	char msg[512];
@@ -40,7 +42,7 @@ static inline int sys_eventfd2(unsigned int count, int flags)
 	return syscall(__NR_eventfd2, count, flags);
 }
 
-TEST(eventfd01)
+TEST(eventfd_check_flag_rdwr)
 {
 	int fd, flags;
 
@@ -54,7 +56,7 @@ TEST(eventfd01)
 	close(fd);
 }
 
-TEST(eventfd02)
+TEST(eventfd_check_flag_cloexec)
 {
 	int fd, flags;
 
@@ -68,7 +70,7 @@ TEST(eventfd02)
 	close(fd);
 }
 
-TEST(eventfd03)
+TEST(eventfd_check_flag_nonblock)
 {
 	int fd, flags;
 
@@ -83,7 +85,7 @@ TEST(eventfd03)
 	close(fd);
 }
 
-TEST(eventfd04)
+TEST(eventfd_chek_flag_cloexec_and_nonblock)
 {
 	int fd, flags;
 
@@ -161,7 +163,7 @@ static int verify_fdinfo(int fd, struct error *err, const char *prefix,
 	return 0;
 }
 
-TEST(eventfd05)
+TEST(eventfd_check_flag_semaphore)
 {
 	struct error err = {0};
 	int fd, ret;
@@ -183,4 +185,128 @@ TEST(eventfd05)
 	close(fd);
 }
 
+/*
+ * A write(2) fails with the error EINVAL if the size of the supplied buffer
+ * is less than 8 bytes, or if an attempt is made to write the value
+ * 0xffffffffffffffff.
+ */
+TEST(eventfd_check_write)
+{
+	uint64_t value = 1;
+	ssize_t size;
+	int fd;
+
+	fd = sys_eventfd2(0, 0);
+	ASSERT_GE(fd, 0);
+
+	size = write(fd, &value, sizeof(int));
+	EXPECT_EQ(size, -1);
+	EXPECT_EQ(errno, EINVAL);
+
+	size = write(fd, &value, sizeof(value));
+	EXPECT_EQ(size, sizeof(value));
+
+	value = (uint64_t)-1;
+	size = write(fd, &value, sizeof(value));
+	EXPECT_EQ(size, -1);
+	EXPECT_EQ(errno, EINVAL);
+
+	close(fd);
+}
+
+/*
+ * A read(2) fails with the error EINVAL if the size of the supplied buffer is
+ * less than 8 bytes.
+ */
+TEST(eventfd_check_read)
+{
+	uint64_t value;
+	ssize_t size;
+	int fd;
+
+	fd = sys_eventfd2(1, 0);
+	ASSERT_GE(fd, 0);
+
+	size = read(fd, &value, sizeof(int));
+	EXPECT_EQ(size, -1);
+	EXPECT_EQ(errno, EINVAL);
+
+	size = read(fd, &value, sizeof(value));
+	EXPECT_EQ(size, sizeof(value));
+	EXPECT_EQ(value, 1);
+
+	close(fd);
+}
+
+
+/*
+ * If EFD_SEMAPHORE was not specified and the eventfd counter has a nonzero
+ * value, then a read(2) returns 8 bytes containing that value, and the
+ * counter's value is reset to zero.
+ * If the eventfd counter is zero at the time of the call to read(2), then the
+ * call fails with the error EAGAIN if the file descriptor has been made nonblocking.
+ */
+TEST(eventfd_check_read_with_nonsemaphore)
+{
+	uint64_t value;
+	ssize_t size;
+	int fd;
+	int i;
+
+	fd = sys_eventfd2(0, EFD_NONBLOCK);
+	ASSERT_GE(fd, 0);
+
+	value = 1;
+	for (i = 0; i < EVENTFD_TEST_ITERATIONS; i++) {
+		size = write(fd, &value, sizeof(value));
+		EXPECT_EQ(size, sizeof(value));
+	}
+
+	size = read(fd, &value, sizeof(value));
+	EXPECT_EQ(size, sizeof(uint64_t));
+	EXPECT_EQ(value, EVENTFD_TEST_ITERATIONS);
+
+	size = read(fd, &value, sizeof(value));
+	EXPECT_EQ(size, -1);
+	EXPECT_EQ(errno, EAGAIN);
+
+	close(fd);
+}
+
+/*
+ * If EFD_SEMAPHORE was specified and the eventfd counter has a nonzero value,
+ * then a read(2) returns 8 bytes containing the value 1, and the counter's
+ * value is decremented by 1.
+ * If the eventfd counter is zero at the time of the call to read(2), then the
+ * call fails with the error EAGAIN if the file descriptor has been made nonblocking.
+ */
+TEST(eventfd_check_read_with_semaphore)
+{
+	uint64_t value;
+	ssize_t size;
+	int fd;
+	int i;
+
+	fd = sys_eventfd2(0, EFD_SEMAPHORE|EFD_NONBLOCK);
+	ASSERT_GE(fd, 0);
+
+	value = 1;
+	for (i = 0; i < EVENTFD_TEST_ITERATIONS; i++) {
+		size = write(fd, &value, sizeof(value));
+		EXPECT_EQ(size, sizeof(value));
+	}
+
+	for (i = 0; i < EVENTFD_TEST_ITERATIONS; i++) {
+		size = read(fd, &value, sizeof(value));
+		EXPECT_EQ(size, sizeof(value));
+		EXPECT_EQ(value, 1);
+	}
+
+	size = read(fd, &value, sizeof(value));
+	EXPECT_EQ(size, -1);
+	EXPECT_EQ(errno, EAGAIN);
+
+	close(fd);
+}
+
 TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/mqueue/mq_perf_tests.c b/tools/testing/selftests/mqueue/mq_perf_tests.c
index 5c16159d0bcd..fb898850867c 100644
--- a/tools/testing/selftests/mqueue/mq_perf_tests.c
+++ b/tools/testing/selftests/mqueue/mq_perf_tests.c
@@ -323,7 +323,8 @@ void *fake_cont_thread(void *arg)
 void *cont_thread(void *arg)
 {
 	char buff[MSG_SIZE];
-	int i, priority;
+	int i;
+	unsigned int priority;
 
 	for (i = 0; i < num_cpus_to_pin; i++)
 		if (cpu_threads[i] == pthread_self())
@@ -425,7 +426,8 @@ struct test test2[] = {
 void *perf_test_thread(void *arg)
 {
 	char buff[MSG_SIZE];
-	int prio_out, prio_in;
+	int prio_out;
+	unsigned int prio_in;
 	int i;
 	clockid_t clock;
 	pthread_t *t;
diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore
index a156ac5dd2c6..973968f45bba 100644
--- a/tools/testing/selftests/proc/.gitignore
+++ b/tools/testing/selftests/proc/.gitignore
@@ -2,6 +2,7 @@
 /fd-001-lookup
 /fd-002-posix-eq
 /fd-003-kthread
+/proc-2-is-kthread
 /proc-fsconfig-hidepid
 /proc-loadavg-001
 /proc-multiple-procfs
@@ -9,6 +10,7 @@
 /proc-pid-vm
 /proc-self-map-files-001
 /proc-self-map-files-002
+/proc-self-isnt-kthread
 /proc-self-syscall
 /proc-self-wchan
 /proc-subset-pid
diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile
index 4d57f2a87510..b12921b9794b 100644
--- a/tools/testing/selftests/proc/Makefile
+++ b/tools/testing/selftests/proc/Makefile
@@ -7,11 +7,13 @@ TEST_GEN_PROGS :=
 TEST_GEN_PROGS += fd-001-lookup
 TEST_GEN_PROGS += fd-002-posix-eq
 TEST_GEN_PROGS += fd-003-kthread
+TEST_GEN_PROGS += proc-2-is-kthread
 TEST_GEN_PROGS += proc-loadavg-001
 TEST_GEN_PROGS += proc-empty-vm
 TEST_GEN_PROGS += proc-pid-vm
 TEST_GEN_PROGS += proc-self-map-files-001
 TEST_GEN_PROGS += proc-self-map-files-002
+TEST_GEN_PROGS += proc-self-isnt-kthread
 TEST_GEN_PROGS += proc-self-syscall
 TEST_GEN_PROGS += proc-self-wchan
 TEST_GEN_PROGS += proc-subset-pid
diff --git a/tools/testing/selftests/proc/proc-2-is-kthread.c b/tools/testing/selftests/proc/proc-2-is-kthread.c
new file mode 100644
index 000000000000..f13668fb482e
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-2-is-kthread.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2024 Alexey Dobriyan <adobriyan@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/* Test that kernel thread is reported as such. */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(void)
+{
+	/*
+	 * The following solutions don't really work:
+	 *
+	 * 1) jit kernel module which creates kernel thread:
+	 * test becomes arch-specific,
+	 * problems with mandatory module signing,
+	 * problems with lockdown mode,
+	 * doesn't work with CONFIG_MODULES=n at all,
+	 * kthread creation API is formally unstable internal kernel API,
+	 * need a mechanism to report test kernel thread's PID back,
+	 *
+	 * 2) ksoftirqd/0 and kswapd0 look like stable enough kernel threads,
+	 * but their PIDs are unstable.
+	 *
+	 * Check against kthreadd which always seem to exist under pid 2.
+	 */
+	int fd = open("/proc/2/status", O_RDONLY);
+	assert(fd >= 0);
+
+	char buf[4096];
+	ssize_t rv = read(fd, buf, sizeof(buf));
+	assert(0 <= rv && rv < sizeof(buf));
+	buf[rv] = '\0';
+
+	assert(strstr(buf, "Kthread:\t1\n"));
+
+	return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c
index 56198d4ca2bf..b3f898aab4ab 100644
--- a/tools/testing/selftests/proc/proc-empty-vm.c
+++ b/tools/testing/selftests/proc/proc-empty-vm.c
@@ -381,9 +381,6 @@ static int test_proc_pid_statm(pid_t pid)
 
 	assert(rv >= 0);
 	assert(rv <= sizeof(buf));
-	if (0) {
-		write(1, buf, rv);
-	}
 
 	const char *p = buf;
 	const char *const end = p + rv;
diff --git a/tools/testing/selftests/proc/proc-self-isnt-kthread.c b/tools/testing/selftests/proc/proc-self-isnt-kthread.c
new file mode 100644
index 000000000000..e01f4e0a91b4
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-isnt-kthread.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2024 Alexey Dobriyan <adobriyan@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/* Test that userspace program is not kernel thread. */
+#undef NDEBUG
+#include <assert.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(void)
+{
+	int fd = open("/proc/self/status", O_RDONLY);
+	assert(fd >= 0);
+
+	char buf[4096];
+	ssize_t rv = read(fd, buf, sizeof(buf));
+	assert(0 <= rv && rv < sizeof(buf));
+	buf[rv] = '\0';
+
+	/* This test is very much not kernel thread. */
+	assert(strstr(buf, "Kthread:\t0\n"));
+
+	return 0;
+}