From 687c5e560079cf11f6e5406bfca35567bb485fdd Mon Sep 17 00:00:00 2001
From: Carlos Llamas <cmllamas@google.com>
Date: Thu, 5 Dec 2024 19:48:07 +0000
Subject: [PATCH 01/20] selftest: media_tests: fix trivial UAF typo

Stumbled upon this typo while looking for something else.

Link: https://lore.kernel.org/lkml/20241205194829.3449669-1-cmllamas@google.com/
Cc: Shuah Khan <shuah@kernel.org>
Fixes: fe8777a8a0a1 ("selftests: add media controller regression test scripts and document")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/media_tests/regression_test.txt | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/media_tests/regression_test.txt b/tools/testing/selftests/media_tests/regression_test.txt
index 2627367681f78..9d0fcd98c085c 100644
--- a/tools/testing/selftests/media_tests/regression_test.txt
+++ b/tools/testing/selftests/media_tests/regression_test.txt
@@ -1,5 +1,5 @@
 Testing for regressions in Media Controller API register, ioctl, syscall,
-and unregister paths. There have a few problems that result in user-after
+and unregister paths. There have a few problems that result in use-after
 free on media_device, media_devnode, and cdev pointers when the driver is
 unbound while ioctl is in progress.
 
@@ -15,11 +15,11 @@ Build media_device_test
 cd tools/testing/selftests/media_tests
 make
 
-Regressions test for cdev user-after free error on /dev/mediaX when driver
+Regressions test for cdev use-after-free error on /dev/mediaX when driver
 is unbound:
 
 Start media_device_test to regression test media devnode dynamic alloc
-and cdev user-after-free fixes. This opens media dev files and sits in
+and cdev use-after-free fixes. This opens media dev files and sits in
 a loop running media ioctl MEDIA_IOC_DEVICE_INFO command once every 10
 seconds. The idea is when device file goes away, media devnode and cdev
 should stick around until this test exits.
@@ -40,4 +40,4 @@ keep ioctls going while bind/unbind runs.
 Copy bind_unbind_sample.txt and make changes to specify the driver name
 and number to run bind and unbind. Start the bind_unbind.sh
 
-Run dmesg looking for any user-after free errors or mutex lock errors.
+Run dmesg looking for any use-after-free errors or mutex lock errors.

From eed8ecdf123e6d7874b5d3b71dab8a01747a4305 Mon Sep 17 00:00:00 2001
From: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Date: Mon, 2 Dec 2024 12:58:27 +0800
Subject: [PATCH 02/20] selftests/ipc: Remove unused variables

Delete variables "msg" and "pid" that have never been used.

Link: https://lore.kernel.org/r/20241202045827.4704-1-zhangjiao2@cmss.chinamobile.com
Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/ipc/msgque.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ipc/msgque.c b/tools/testing/selftests/ipc/msgque.c
index c75ea4094870d..e9dbb84c100ac 100644
--- a/tools/testing/selftests/ipc/msgque.c
+++ b/tools/testing/selftests/ipc/msgque.c
@@ -194,7 +194,7 @@ int fill_msgque(struct msgque_data *msgque)
 
 int main(int argc, char **argv)
 {
-	int msg, pid, err;
+	int err;
 	struct msgque_data msgque;
 
 	if (getuid() != 0)

From e0746bde6f820a6239628a5c17653b5c3c3d56df Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Fri, 6 Dec 2024 21:07:25 +0800
Subject: [PATCH 03/20] selftests/vDSO: support DT_GNU_HASH

glibc added support for DT_GNU_HASH in 2006 and DT_HASH has been
obsoleted for more than one decade in many Linux distributions.

Many vDSOs support DT_GNU_HASH. This patch adds selftests support.

Link: https://lore.kernel.org/r/20241206130724.7944-2-xry111@xry111.site
Signed-off-by: Fangrui Song <i@maskray.me>
Tested-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Xi Ruoyao <xry111@xry111.site> # rebase
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/vDSO/parse_vdso.c | 110 ++++++++++++++++------
 1 file changed, 82 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 28f35620c4991..2fe5e983cb22f 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -53,6 +53,7 @@ static struct vdso_info
 	/* Symbol table */
 	ELF(Sym) *symtab;
 	const char *symstrings;
+	ELF(Word) *gnu_hash;
 	ELF_HASH_ENTRY *bucket, *chain;
 	ELF_HASH_ENTRY nbucket, nchain;
 
@@ -81,6 +82,16 @@ static unsigned long elf_hash(const char *name)
 	return h;
 }
 
+static uint32_t gnu_hash(const char *name)
+{
+	const unsigned char *s = (void *)name;
+	uint32_t h = 5381;
+
+	for (; *s; s++)
+		h += h * 32 + *s;
+	return h;
+}
+
 void vdso_init_from_sysinfo_ehdr(uintptr_t base)
 {
 	size_t i;
@@ -123,6 +134,7 @@ void vdso_init_from_sysinfo_ehdr(uintptr_t base)
 	 */
 	ELF_HASH_ENTRY *hash = 0;
 	vdso_info.symstrings = 0;
+	vdso_info.gnu_hash = 0;
 	vdso_info.symtab = 0;
 	vdso_info.versym = 0;
 	vdso_info.verdef = 0;
@@ -143,6 +155,11 @@ void vdso_init_from_sysinfo_ehdr(uintptr_t base)
 				((uintptr_t)dyn[i].d_un.d_ptr
 				 + vdso_info.load_offset);
 			break;
+		case DT_GNU_HASH:
+			vdso_info.gnu_hash =
+				(ELF(Word) *)((uintptr_t)dyn[i].d_un.d_ptr +
+					      vdso_info.load_offset);
+			break;
 		case DT_VERSYM:
 			vdso_info.versym = (ELF(Versym) *)
 				((uintptr_t)dyn[i].d_un.d_ptr
@@ -155,17 +172,27 @@ void vdso_init_from_sysinfo_ehdr(uintptr_t base)
 			break;
 		}
 	}
-	if (!vdso_info.symstrings || !vdso_info.symtab || !hash)
+	if (!vdso_info.symstrings || !vdso_info.symtab ||
+	    (!hash && !vdso_info.gnu_hash))
 		return;  /* Failed */
 
 	if (!vdso_info.verdef)
 		vdso_info.versym = 0;
 
 	/* Parse the hash table header. */
-	vdso_info.nbucket = hash[0];
-	vdso_info.nchain = hash[1];
-	vdso_info.bucket = &hash[2];
-	vdso_info.chain = &hash[vdso_info.nbucket + 2];
+	if (vdso_info.gnu_hash) {
+		vdso_info.nbucket = vdso_info.gnu_hash[0];
+		/* The bucket array is located after the header (4 uint32) and the bloom
+		 * filter (size_t array of gnu_hash[2] elements).
+		 */
+		vdso_info.bucket = vdso_info.gnu_hash + 4 +
+				   sizeof(size_t) / 4 * vdso_info.gnu_hash[2];
+	} else {
+		vdso_info.nbucket = hash[0];
+		vdso_info.nchain = hash[1];
+		vdso_info.bucket = &hash[2];
+		vdso_info.chain = &hash[vdso_info.nbucket + 2];
+	}
 
 	/* That's all we need. */
 	vdso_info.valid = true;
@@ -209,6 +236,26 @@ static bool vdso_match_version(ELF(Versym) ver,
 		&& !strcmp(name, vdso_info.symstrings + aux->vda_name);
 }
 
+static bool check_sym(ELF(Sym) *sym, ELF(Word) i, const char *name,
+		      const char *version, unsigned long ver_hash)
+{
+	/* Check for a defined global or weak function w/ right name. */
+	if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC)
+		return false;
+	if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL &&
+	    ELF64_ST_BIND(sym->st_info) != STB_WEAK)
+		return false;
+	if (strcmp(name, vdso_info.symstrings + sym->st_name))
+		return false;
+
+	/* Check symbol version. */
+	if (vdso_info.versym &&
+	    !vdso_match_version(vdso_info.versym[i], version, ver_hash))
+		return false;
+
+	return true;
+}
+
 void *vdso_sym(const char *version, const char *name)
 {
 	unsigned long ver_hash;
@@ -216,29 +263,36 @@ void *vdso_sym(const char *version, const char *name)
 		return 0;
 
 	ver_hash = elf_hash(version);
-	ELF(Word) chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket];
-
-	for (; chain != STN_UNDEF; chain = vdso_info.chain[chain]) {
-		ELF(Sym) *sym = &vdso_info.symtab[chain];
-
-		/* Check for a defined global or weak function w/ right name. */
-		if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC)
-			continue;
-		if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL &&
-		    ELF64_ST_BIND(sym->st_info) != STB_WEAK)
-			continue;
-		if (sym->st_shndx == SHN_UNDEF)
-			continue;
-		if (strcmp(name, vdso_info.symstrings + sym->st_name))
-			continue;
-
-		/* Check symbol version. */
-		if (vdso_info.versym
-		    && !vdso_match_version(vdso_info.versym[chain],
-					   version, ver_hash))
-			continue;
-
-		return (void *)(vdso_info.load_offset + sym->st_value);
+	ELF(Word) i;
+
+	if (vdso_info.gnu_hash) {
+		uint32_t h1 = gnu_hash(name), h2, *hashval;
+
+		i = vdso_info.bucket[h1 % vdso_info.nbucket];
+		if (i == 0)
+			return 0;
+		h1 |= 1;
+		hashval = vdso_info.bucket + vdso_info.nbucket +
+			  (i - vdso_info.gnu_hash[1]);
+		for (;; i++) {
+			ELF(Sym) *sym = &vdso_info.symtab[i];
+			h2 = *hashval++;
+			if (h1 == (h2 | 1) &&
+			    check_sym(sym, i, name, version, ver_hash))
+				return (void *)(vdso_info.load_offset +
+						sym->st_value);
+			if (h2 & 1)
+				break;
+		}
+	} else {
+		i = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket];
+		for (; i; i = vdso_info.chain[i]) {
+			ELF(Sym) *sym = &vdso_info.symtab[i];
+			if (sym->st_shndx != SHN_UNDEF &&
+			    check_sym(sym, i, name, version, ver_hash))
+				return (void *)(vdso_info.load_offset +
+						sym->st_value);
+		}
 	}
 
 	return 0;

From e8731ecdd67d3d32a2e15a1eea66cfb1e4a5871a Mon Sep 17 00:00:00 2001
From: Stefano Pigozzi <me@steffo.eu>
Date: Sat, 7 Dec 2024 02:23:25 +0100
Subject: [PATCH 04/20] selftests: kselftest: Add ksft_test_result_xpass

The functions ksft_test_result_pass, ksft_test_result_fail,
ksft_test_result_xfail, and ksft_test_result_skip already exist and are
available for use in selftests, but no XPASS equivalent is
available.

This adds a new function to that family that outputs XPASS, so that it's
available for future test writers.

Link: https://lore.kernel.org/r/20241207012325.56611-1-me@steffo.eu
Signed-off-by: Stefano Pigozzi <me@steffo.eu>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/kselftest.h | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index 29fedf609611a..685d9f9554fcb 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -18,7 +18,8 @@
  *     ksft_print_msg(fmt, ...);
  *     ksft_perror(msg);
  *
- * and finally report the pass/fail/skip/xfail state of the test with one of:
+ * and finally report the pass/fail/skip/xfail/xpass state of the test
+ * with one of:
  *
  *     ksft_test_result(condition, fmt, ...);
  *     ksft_test_result_report(result, fmt, ...);
@@ -26,6 +27,7 @@
  *     ksft_test_result_fail(fmt, ...);
  *     ksft_test_result_skip(fmt, ...);
  *     ksft_test_result_xfail(fmt, ...);
+ *     ksft_test_result_xpass(fmt, ...);
  *     ksft_test_result_error(fmt, ...);
  *     ksft_test_result_code(exit_code, test_name, fmt, ...);
  *
@@ -227,6 +229,20 @@ static inline __printf(1, 2) void ksft_test_result_xfail(const char *msg, ...)
 	va_end(args);
 }
 
+static inline __printf(1, 2) void ksft_test_result_xpass(const char *msg, ...)
+{
+	int saved_errno = errno;
+	va_list args;
+
+	ksft_cnt.ksft_xpass++;
+
+	va_start(args, msg);
+	printf("ok %u # XPASS ", ksft_test_num());
+	errno = saved_errno;
+	vprintf(msg, args);
+	va_end(args);
+}
+
 static inline __printf(1, 2) void ksft_test_result_skip(const char *msg, ...)
 {
 	int saved_errno = errno;
@@ -318,6 +334,9 @@ void ksft_test_result_code(int exit_code, const char *test_name,
 	case KSFT_XFAIL:					\
 		ksft_test_result_xfail(fmt, ##__VA_ARGS__);	\
 		break;						\
+	case KSFT_XPASS:					\
+		ksft_test_result_xpass(fmt, ##__VA_ARGS__);	\
+		break;						\
 	case KSFT_SKIP:						\
 		ksft_test_result_skip(fmt, ##__VA_ARGS__);	\
 		break;						\

From 74864403c578d9caa92fb9b2743a4b7aa5240e44 Mon Sep 17 00:00:00 2001
From: Laura Nao <laura.nao@collabora.com>
Date: Tue, 26 Nov 2024 10:37:10 +0100
Subject: [PATCH 05/20] selftests: Warn about skipped tests in result summary

Update the functions that print the test totals at the end of a selftest
to include a warning message when skipped tests are detected. The
message advises users that skipped tests may indicate missing
configuration options and suggests enabling them to improve coverage.

Link: https://lore.kernel.org/r/20241126093710.13314-1-laura.nao@collabora.com
Signed-off-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/kselftest.h               | 5 +++++
 tools/testing/selftests/kselftest/ksft.py         | 3 +++
 tools/testing/selftests/kselftest/ktap_helpers.sh | 4 ++++
 3 files changed, 12 insertions(+)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index 685d9f9554fcb..5263961db51f9 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -149,6 +149,11 @@ static inline void ksft_set_plan(unsigned int plan)
 
 static inline void ksft_print_cnts(void)
 {
+	if (ksft_cnt.ksft_xskip > 0)
+		printf(
+			"# %u skipped test(s) detected. Consider enabling relevant config options to improve coverage.\n",
+			ksft_cnt.ksft_xskip
+		);
 	if (ksft_plan != ksft_test_num())
 		printf("# Planned tests != run tests (%u != %u)\n",
 			ksft_plan, ksft_test_num());
diff --git a/tools/testing/selftests/kselftest/ksft.py b/tools/testing/selftests/kselftest/ksft.py
index bf215790a89d7..0e030837fc175 100644
--- a/tools/testing/selftests/kselftest/ksft.py
+++ b/tools/testing/selftests/kselftest/ksft.py
@@ -27,6 +27,9 @@ def set_plan(num_tests):
 
 
 def print_cnts():
+    if ksft_cnt['skip'] > 0:
+        print(f"# {ksft_cnt['skip']} skipped test(s) detected. Consider enabling relevant config options to improve coverage.")
+
     print(
         f"# Totals: pass:{ksft_cnt['pass']} fail:{ksft_cnt['fail']} xfail:0 xpass:0 skip:{ksft_cnt['skip']} error:0"
     )
diff --git a/tools/testing/selftests/kselftest/ktap_helpers.sh b/tools/testing/selftests/kselftest/ktap_helpers.sh
index 79a125eb24c2e..531094d81f03d 100644
--- a/tools/testing/selftests/kselftest/ktap_helpers.sh
+++ b/tools/testing/selftests/kselftest/ktap_helpers.sh
@@ -107,5 +107,9 @@ ktap_finished() {
 }
 
 ktap_print_totals() {
+	if [ "$KTAP_CNT_SKIP" -gt 0 ]; then
+		echo "# $KTAP_CNT_SKIP skipped test(s) detected. " \
+			"Consider enabling relevant config options to improve coverage."
+	fi
 	echo "# Totals: pass:$KTAP_CNT_PASS fail:$KTAP_CNT_FAIL xfail:0 xpass:0 skip:$KTAP_CNT_SKIP error:0"
 }

From 6d59d557e3ec3bde3102efdf4038ccffb848666f Mon Sep 17 00:00:00 2001
From: Li Zhijian <lizhijian@fujitsu.com>
Date: Wed, 11 Dec 2024 08:49:47 +0800
Subject: [PATCH 06/20] selftests/filesystems: Add missing gitignore file

Compiled binary files should be added to .gitignore

'git status' complains:
Untracked files:
(use "git add <file>..." to include in what will be committed)
     filesystems/statmount/statmount_test_ns

Link: https://lore.kernel.org/r/20241211004947.5806-1-lizhijian@fujitsu.com
Cc: Shuah Khan <shuah@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/filesystems/statmount/.gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/filesystems/statmount/.gitignore b/tools/testing/selftests/filesystems/statmount/.gitignore
index 82a4846cbc4b2..973363ad66a21 100644
--- a/tools/testing/selftests/filesystems/statmount/.gitignore
+++ b/tools/testing/selftests/filesystems/statmount/.gitignore
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
+statmount_test_ns
 /*_test

From d54d3f69b7a13f193fd537c60b0184aefc35bc24 Mon Sep 17 00:00:00 2001
From: Li Zhijian <lizhijian@fujitsu.com>
Date: Wed, 11 Dec 2024 08:46:25 +0800
Subject: [PATCH 07/20] selftests/zram: gitignore output file

After `make run_tests`, the git status complains:
Untracked files:
    (use "git add <file>..." to include in what will be committed)
        zram/err.log

This file will be cleaned up when execute 'make clean'

Link: https://lore.kernel.org/r/20241211004625.5308-1-lizhijian@fujitsu.com
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/zram/.gitignore | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 tools/testing/selftests/zram/.gitignore

diff --git a/tools/testing/selftests/zram/.gitignore b/tools/testing/selftests/zram/.gitignore
new file mode 100644
index 0000000000000..088cd9bad87a7
--- /dev/null
+++ b/tools/testing/selftests/zram/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+err.log

From 8694e6a7f7dba23d3abd9f5a96f64d161704c7b1 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Thu, 12 Dec 2024 10:02:56 +0100
Subject: [PATCH 08/20] selftests: timers: clocksource-switch: Adapt progress
 to kselftest framework

When adapting the test to the kselftest framework, a few printf() calls
indicating test progress were not updated.

Fix this by replacing these printf() calls by ksft_print_msg() calls.

Link: https://lore.kernel.org/r/7dd4b9ab6e43268846e250878ebf25ae6d3d01ce.1733994134.git.geert+renesas@glider.be
Fixes: ce7d101750ff ("selftests: timers: clocksource-switch: adapt to kselftest framework")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/timers/clocksource-switch.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/timers/clocksource-switch.c b/tools/testing/selftests/timers/clocksource-switch.c
index c5264594064c8..83faa4e354e38 100644
--- a/tools/testing/selftests/timers/clocksource-switch.c
+++ b/tools/testing/selftests/timers/clocksource-switch.c
@@ -156,8 +156,8 @@ int main(int argc, char **argv)
 	/* Check everything is sane before we start switching asynchronously */
 	if (do_sanity_check) {
 		for (i = 0; i < count; i++) {
-			printf("Validating clocksource %s\n",
-				clocksource_list[i]);
+			ksft_print_msg("Validating clocksource %s\n",
+					clocksource_list[i]);
 			if (change_clocksource(clocksource_list[i])) {
 				status = -1;
 				goto out;
@@ -169,7 +169,7 @@ int main(int argc, char **argv)
 		}
 	}
 
-	printf("Running Asynchronous Switching Tests...\n");
+	ksft_print_msg("Running Asynchronous Switching Tests...\n");
 	pid = fork();
 	if (!pid)
 		return run_tests(runtime);

From 5a7a4e46f85ebc87853b4edc4436008d2372c3c3 Mon Sep 17 00:00:00 2001
From: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Date: Mon, 2 Dec 2024 12:31:11 +0800
Subject: [PATCH 09/20] selftests: kselftest: Fix the wrong format specifier

The format specifier of "unsigned int" in printf()
should be "%u", not "%d".

Link: https://lore.kernel.org/r/20241202043111.3888-1-zhangjiao2@cmss.chinamobile.com
Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/kselftest.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index 5263961db51f9..cdf91b0ca40fb 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -427,7 +427,7 @@ static inline __noreturn __printf(1, 2) void ksft_exit_skip(const char *msg, ...
 	 */
 	if (ksft_plan || ksft_test_num()) {
 		ksft_cnt.ksft_xskip++;
-		printf("ok %d # SKIP ", 1 + ksft_test_num());
+		printf("ok %u # SKIP ", 1 + ksft_test_num());
 	} else {
 		printf("1..0 # SKIP ");
 	}

From 9301be2ce104390d461442f1a092cd1c9c4d7b23 Mon Sep 17 00:00:00 2001
From: Shivam Chaudhary <cvam0000@gmail.com>
Date: Tue, 10 Dec 2024 18:02:12 +0530
Subject: [PATCH 10/20] selftests: acct: Add ksft_exit_skip if not running as
 root

If the selftest is not running as root, it should skip not
fail and give an appropriate warning to the user. This patch adds
ksft_exit_skip() if the test is not running as root.

Logs:

Before change:

TAP version 13
1..1
ok 1 # SKIP This test needs root to run!

After change:

TAP version 13
1..1
ok 2 # SKIP This test needs root to run!
Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0

Link: https://lore.kernel.org/r/20241210123212.332050-1-cvam0000@gmail.com
Signed-off-by: Shivam Chaudhary <cvam0000@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/acct/acct_syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/acct/acct_syscall.c b/tools/testing/selftests/acct/acct_syscall.c
index e44e8fe1f4a3c..87c044fb92938 100644
--- a/tools/testing/selftests/acct/acct_syscall.c
+++ b/tools/testing/selftests/acct/acct_syscall.c
@@ -24,7 +24,7 @@ int main(void)
 
 	// Check if test is run a root
 	if (geteuid()) {
-		ksft_test_result_skip("This test needs root to run!\n");
+		ksft_exit_skip("This test needs root to run!\n");
 		return 1;
 	}
 

From 103c0b5e82fb0f7c66c410897588095e9a1f64f6 Mon Sep 17 00:00:00 2001
From: Brendan Jackman <jackmanb@google.com>
Date: Fri, 20 Dec 2024 16:12:41 +0000
Subject: [PATCH 11/20] selftests/run_kselftest.sh: Fix help string for
 --per-test-log

This is documented as --per_test_log but the argument is actually
--per-test-log.

Link: https://lore.kernel.org/r/20241220-per-test-log-v1-1-de5afe69fdf4@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/run_kselftest.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/run_kselftest.sh b/tools/testing/selftests/run_kselftest.sh
index a28c1416cb89b..50e03eefe7ac7 100755
--- a/tools/testing/selftests/run_kselftest.sh
+++ b/tools/testing/selftests/run_kselftest.sh
@@ -21,7 +21,7 @@ usage()
 	cat <<EOF
 Usage: $0 [OPTIONS]
   -s | --summary		Print summary with detailed log in output.log (conflict with -p)
-  -p | --per_test_log		Print test log in /tmp with each test name (conflict with -s)
+  -p | --per-test-log		Print test log in /tmp with each test name (conflict with -s)
   -t | --test COLLECTION:TEST	Run TEST from COLLECTION
   -c | --collection COLLECTION	Run all tests from COLLECTION
   -l | --list			List the available collection:test entries

From b6f9cd83c60ebb48f580dd0ec9e9080590ebc053 Mon Sep 17 00:00:00 2001
From: Vincent Donnefort <vdonnefort@google.com>
Date: Wed, 18 Dec 2024 17:03:18 +0000
Subject: [PATCH 12/20] selftests/ring-buffer: Add test for out-of-bound pgoff
 mapping

Extend the ring-buffer mapping test coverage by checking an out-of-bound
pgoff which has proven to be problematic in the past.

Link: https://lore.kernel.org/r/20241218170318.2814991-1-vdonnefort@google.com
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/ring-buffer/map_test.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ring-buffer/map_test.c b/tools/testing/selftests/ring-buffer/map_test.c
index d10a847130fbc..a58f520f2f41a 100644
--- a/tools/testing/selftests/ring-buffer/map_test.c
+++ b/tools/testing/selftests/ring-buffer/map_test.c
@@ -233,12 +233,18 @@ TEST_F(map, data_mmap)
 	ASSERT_NE(data, MAP_FAILED);
 	munmap(data, data_len);
 
-	/* Overflow the available subbufs by 1 */
+	/* Offset within ring-buffer bounds, mapping size overflow */
 	meta_len += desc->meta->subbuf_size * 2;
 	data = mmap(NULL, data_len, PROT_READ, MAP_SHARED,
 		    desc->cpu_fd, meta_len);
 	ASSERT_EQ(data, MAP_FAILED);
 
+	/* Offset outside ring-buffer bounds */
+	data_len = desc->meta->subbuf_size * desc->meta->nr_subbufs;
+	data = mmap(NULL, data_len, PROT_READ, MAP_SHARED,
+		    desc->cpu_fd, data_len + (desc->meta->subbuf_size * 2));
+	ASSERT_EQ(data, MAP_FAILED);
+
 	/* Verify meta-page padding */
 	if (desc->meta->meta_page_size > getpagesize()) {
 		data_len = desc->meta->meta_page_size;

From 02bc220dc6dc7c56edc4859bc5dd2c08b95d5fb5 Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@strace.io>
Date: Wed, 8 Jan 2025 19:07:57 +0200
Subject: [PATCH 13/20] selftests: harness: fix printing of mismatch values in
 __EXPECT()

intptr_t and uintptr_t are not big enough types on 32-bit architectures
when printing 64-bit values, resulting to the following incorrect
diagnostic output:

  # get_syscall_info.c:209:get_syscall_info:Expected exp_args[2] (3134324433) == info.entry.args[1] (3134324433)

Replace intptr_t and uintptr_t with intmax_t and uintmax_t, respectively.
With this fix, the same test produces more usable diagnostic output:

  # get_syscall_info.c:209:get_syscall_info:Expected exp_args[2] (3134324433) == info.entry.args[1] (18446744072548908753)

Link: https://lore.kernel.org/r/20250108170757.GA6723@strace.io
Fixes: b5bb6d3068ea ("selftests/seccomp: fix 32-bit build warnings")
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/kselftest_harness.h | 24 ++++++++++-----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index a5a72415e37b0..666c9fde76da9 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -760,33 +760,33 @@
 		/* Report with actual signedness to avoid weird output. */ \
 		switch (is_signed_type(__exp) * 2 + is_signed_type(__seen)) { \
 		case 0: { \
-			unsigned long long __exp_print = (uintptr_t)__exp; \
-			unsigned long long __seen_print = (uintptr_t)__seen; \
-			__TH_LOG("Expected %s (%llu) %s %s (%llu)", \
+			uintmax_t __exp_print = (uintmax_t)__exp; \
+			uintmax_t __seen_print = (uintmax_t)__seen; \
+			__TH_LOG("Expected %s (%ju) %s %s (%ju)", \
 				 _expected_str, __exp_print, #_t, \
 				 _seen_str, __seen_print); \
 			break; \
 			} \
 		case 1: { \
-			unsigned long long __exp_print = (uintptr_t)__exp; \
-			long long __seen_print = (intptr_t)__seen; \
-			__TH_LOG("Expected %s (%llu) %s %s (%lld)", \
+			uintmax_t __exp_print = (uintmax_t)__exp; \
+			intmax_t  __seen_print = (intmax_t)__seen; \
+			__TH_LOG("Expected %s (%ju) %s %s (%jd)", \
 				 _expected_str, __exp_print, #_t, \
 				 _seen_str, __seen_print); \
 			break; \
 			} \
 		case 2: { \
-			long long __exp_print = (intptr_t)__exp; \
-			unsigned long long __seen_print = (uintptr_t)__seen; \
-			__TH_LOG("Expected %s (%lld) %s %s (%llu)", \
+			intmax_t  __exp_print = (intmax_t)__exp; \
+			uintmax_t __seen_print = (uintmax_t)__seen; \
+			__TH_LOG("Expected %s (%jd) %s %s (%ju)", \
 				 _expected_str, __exp_print, #_t, \
 				 _seen_str, __seen_print); \
 			break; \
 			} \
 		case 3: { \
-			long long __exp_print = (intptr_t)__exp; \
-			long long __seen_print = (intptr_t)__seen; \
-			__TH_LOG("Expected %s (%lld) %s %s (%lld)", \
+			intmax_t  __exp_print = (intmax_t)__exp; \
+			intmax_t  __seen_print = (intmax_t)__seen; \
+			__TH_LOG("Expected %s (%jd) %s %s (%jd)", \
 				 _expected_str, __exp_print, #_t, \
 				 _seen_str, __seen_print); \
 			break; \

From 41ca14efaf850c3694ccc5abc18ba552ce1a3fce Mon Sep 17 00:00:00 2001
From: Shivam Chaudhary <cvam0000@gmail.com>
Date: Sun, 5 Jan 2025 14:22:54 +0530
Subject: [PATCH 14/20] selftests: tmpfs: Add Test-skip if not run as root

Add 'ksft_exit_skip()', if  not run as root, with an appropriate
Warning.

Add 'ksft_print_header()' and 'ksft_set_plan()' to structure test
outputs more effectively.

Test logs:

Before Change:
- Without root
 error: unshare, errno 1

- With root
 No, output

After change:

- Without root
TAP version 13
1..1
ok 2 # SKIP This test needs root to run!
Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0

- With root
TAP version 13
1..1

Link: https://lore.kernel.org/r/20250105085255.124929-2-cvam0000@gmail.com
Signed-off-by: Shivam Chaudhary <cvam0000@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
index b5c3ddb90942f..657b64857e826 100644
--- a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
+++ b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
@@ -23,10 +23,22 @@
 #include <sys/mount.h>
 #include <unistd.h>
 
+#include "../kselftest.h"
+
 int main(void)
 {
 	int fd;
 
+	// Setting up kselftest framework
+	ksft_print_header();
+	ksft_set_plan(1);
+
+	// Check if test is run as root
+	if (geteuid()) {
+		ksft_exit_skip("This test needs root to run!\n");
+		return 1;
+	}
+
 	if (unshare(CLONE_NEWNS) == -1) {
 		if (errno == ENOSYS || errno == EPERM) {
 			fprintf(stderr, "error: unshare, errno %d\n", errno);

From 58beae2585d5a31bb27559b437630b61424834bb Mon Sep 17 00:00:00 2001
From: Shivam Chaudhary <cvam0000@gmail.com>
Date: Sun, 5 Jan 2025 14:22:55 +0530
Subject: [PATCH 15/20] selftests: tmpfs: Add kselftest support to tmpfs

Replace direct error handling with 'ksft_test_result_*'
macros for better reporting.

Test logs:

Before change:
- Without root
 error: unshare, errno 1

- With root
 No, output

After change:
- Without root
TAP version 13
1..1
ok 2 # SKIP This test needs root to run!
Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0

- With root
TAP version 13
1..1
ok 1 Test : Success
Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0

Link: https://lore.kernel.org/r/20250105085255.124929-3-cvam0000@gmail.com
Signed-off-by: Shivam Chaudhary <cvam0000@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 .../selftests/tmpfs/bug-link-o-tmpfile.c      | 29 +++++++++----------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
index 657b64857e826..02ecfe687dc25 100644
--- a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
+++ b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
@@ -41,39 +41,38 @@ int main(void)
 
 	if (unshare(CLONE_NEWNS) == -1) {
 		if (errno == ENOSYS || errno == EPERM) {
-			fprintf(stderr, "error: unshare, errno %d\n", errno);
-			return 4;
+			ksft_exit_skip("unshare() error: unshare, errno %d\n", errno);
+		} else {
+			ksft_exit_fail_msg("unshare() error: unshare, errno %d\n", errno);
 		}
-		fprintf(stderr, "error: unshare, errno %d\n", errno);
-		return 1;
 	}
+
 	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
-		fprintf(stderr, "error: mount '/', errno %d\n", errno);
-		return 1;
+		ksft_exit_fail_msg("mount() error: Root filesystem private mount: Fail %d\n", errno);
 	}
 
 	/* Our heroes: 1 root inode, 1 O_TMPFILE inode, 1 permanent inode. */
 	if (mount(NULL, "/tmp", "tmpfs", 0, "nr_inodes=3") == -1) {
-		fprintf(stderr, "error: mount tmpfs, errno %d\n", errno);
-		return 1;
+		ksft_exit_fail_msg("mount() error: Mounting tmpfs on /tmp: Fail %d\n", errno);
 	}
 
 	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
 	if (fd == -1) {
-		fprintf(stderr, "error: open 1, errno %d\n", errno);
-		return 1;
+		ksft_exit_fail_msg("openat() error: Open first temporary file: Fail %d\n", errno);
 	}
+
 	if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) {
-		fprintf(stderr, "error: linkat, errno %d\n", errno);
-		return 1;
+		ksft_exit_fail_msg("linkat() error: Linking the temporary file: Fail %d\n", errno);
+		/* Ensure fd is closed on failure */
+		close(fd);
 	}
 	close(fd);
 
 	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
 	if (fd == -1) {
-		fprintf(stderr, "error: open 2, errno %d\n", errno);
-		return 1;
+		ksft_exit_fail_msg("openat() error: Opening the second temporary file: Fail %d\n", errno);
 	}
-
+	ksft_test_result_pass(" ");
+	ksft_exit_pass();
 	return 0;
 }

From 159ca65c42d90d5ab98fc31b708b12c0be2c26e0 Mon Sep 17 00:00:00 2001
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: Tue, 7 Jan 2025 21:11:07 +0900
Subject: [PATCH 16/20] selftests/ftrace: Fix to use remount when testing mount
 GID option

Fix mount_options.tc to use remount option to mount the tracefs.
Since the current implementation does not umount the tracefs,
this test always fails because of -EBUSY error.
Using remount option will allow us to change the mount option.

Link: https://lore.kernel.org/r/173625186741.1383744.16707876180798573039.stgit@devnote2
Fixes: 8b55572e5180 ("tracing/selftests: Add tracefs mount options test")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 .../selftests/ftrace/test.d/00basic/mount_options.tc      | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/ftrace/test.d/00basic/mount_options.tc b/tools/testing/selftests/ftrace/test.d/00basic/mount_options.tc
index 35e8d47d60725..8a7ce647a60d1 100644
--- a/tools/testing/selftests/ftrace/test.d/00basic/mount_options.tc
+++ b/tools/testing/selftests/ftrace/test.d/00basic/mount_options.tc
@@ -15,11 +15,11 @@ find_alternate_gid() {
 	tac /etc/group | grep -v ":$original_gid:" | head -1 | cut -d: -f3
 }
 
-mount_tracefs_with_options() {
+remount_tracefs_with_options() {
 	local mount_point="$1"
 	local options="$2"
 
-	mount -t tracefs -o "$options" nodev "$mount_point"
+	mount -t tracefs -o "remount,$options" nodev "$mount_point"
 
 	setup
 }
@@ -81,7 +81,7 @@ test_gid_mount_option() {
 
 	# Unmount existing tracefs instance and mount with new GID
 	unmount_tracefs "$mount_point"
-	mount_tracefs_with_options "$mount_point" "$new_options"
+	remount_tracefs_with_options "$mount_point" "$new_options"
 
 	check_gid "$mount_point" "$other_group"
 
@@ -92,7 +92,7 @@ test_gid_mount_option() {
 
 	# Unmount and remount with the original GID
 	unmount_tracefs "$mount_point"
-	mount_tracefs_with_options "$mount_point" "$mount_options"
+	remount_tracefs_with_options "$mount_point" "$mount_options"
 	check_gid "$mount_point" "$original_group"
 }
 

From 89ae64384e5886e8e7c9cc0fcc31e50f4987fae8 Mon Sep 17 00:00:00 2001
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: Tue, 7 Jan 2025 21:11:16 +0900
Subject: [PATCH 17/20] selftests/ftrace: Make uprobe test more robust against
 binary name

Make add_remove_uprobe test case more robust against various real
binary name.
Current add_remove_uprobe.tc test expects the real binary of /bin/sh
is '*/bin/*sh', but it does not work on busybox environment.
Instead of using fixed pattern, use readlink to identify real binary
name.

Link: https://lore.kernel.org/r/173625187633.1383744.2840679071525852811.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 .../selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc     | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc
index a275decdc880c..86c76679c56e9 100644
--- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc
@@ -6,8 +6,10 @@
 echo 0 > events/enable
 echo > dynamic_events
 
+REALBIN=`readlink -f /bin/sh`
+
 echo 'cat /proc/$$/maps' | /bin/sh | \
-	grep "r-xp .*/bin/.*sh$" | \
+	grep "r-xp .*${REALBIN}$" | \
 	awk '{printf "p:myevent %s:0x%s\n", $6,$3 }' >> uprobe_events
 
 grep -q myevent uprobe_events

From a1cd99e700ec006c36c4f01be984e2a19eb3e2f1 Mon Sep 17 00:00:00 2001
From: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Date: Mon, 16 Dec 2024 16:18:53 +0100
Subject: [PATCH 18/20] selftests/resctrl: Adjust effective L3 cache size with
 SNC enabled

Sub-NUMA Cluster divides CPUs sharing an L3 cache into separate NUMA
nodes. Systems may support splitting into either two, three, four or six
nodes. When SNC mode is enabled the effective amount of L3 cache
available for allocation is divided by the number of nodes per L3.

It's possible to detect which SNC mode is active by comparing the number
of CPUs that share a cache with CPU0, with the number of CPUs on node0.

Detect SNC mode once and let other tests inherit that information.

Update CFLAGS after including lib.mk in the Makefile so that fallthrough
macro can be used.

To check if SNC detection is reliable one can check the
/sys/devices/system/cpu/offline file. If it's empty, it means all cores
are operational and the ratio should be calculated correctly. If it has
any contents, it means the detected SNC mode can't be trusted and should
be disabled.

Check if detection was not reliable due to offline cpus. If it was skip
running tests since the results couldn't be trusted.

Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/resctrl/Makefile      |   1 +
 tools/testing/selftests/resctrl/resctrl.h     |   5 +
 .../testing/selftests/resctrl/resctrl_tests.c |   9 +-
 tools/testing/selftests/resctrl/resctrlfs.c   | 105 ++++++++++++++++++
 4 files changed, 119 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/Makefile b/tools/testing/selftests/resctrl/Makefile
index f408bd6bfc3d4..984534cfbf1b6 100644
--- a/tools/testing/selftests/resctrl/Makefile
+++ b/tools/testing/selftests/resctrl/Makefile
@@ -8,5 +8,6 @@ TEST_GEN_PROGS := resctrl_tests
 LOCAL_HDRS += $(wildcard *.h)
 
 include ../lib.mk
+CFLAGS += -I$(top_srcdir)/tools/include
 
 $(OUTPUT)/resctrl_tests: $(wildcard *.c)
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index dab1953fc7a06..35fa3afee9c3c 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -11,6 +11,7 @@
 #include <signal.h>
 #include <dirent.h>
 #include <stdbool.h>
+#include <ctype.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
 #include <sys/mount.h>
@@ -21,6 +22,7 @@
 #include <sys/eventfd.h>
 #include <asm/unistd.h>
 #include <linux/perf_event.h>
+#include <linux/compiler.h>
 #include "../kselftest.h"
 
 #define MB			(1024 * 1024)
@@ -156,8 +158,11 @@ struct perf_event_read {
  */
 extern volatile int *value_sink;
 
+extern int snc_unreliable;
+
 extern char llc_occup_path[1024];
 
+int snc_nodes_per_l3_cache(void);
 int get_vendor(void);
 bool check_resctrlfs_support(void);
 int filter_dmesg(void);
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 3335af815b210..5154ffd821c44 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -118,7 +118,7 @@ static bool test_vendor_specific_check(const struct resctrl_test *test)
 
 static void run_single_test(const struct resctrl_test *test, const struct user_params *uparams)
 {
-	int ret;
+	int ret, snc_mode;
 
 	if (test->disabled)
 		return;
@@ -128,8 +128,15 @@ static void run_single_test(const struct resctrl_test *test, const struct user_p
 		return;
 	}
 
+	snc_mode = snc_nodes_per_l3_cache();
+
 	ksft_print_msg("Starting %s test ...\n", test->name);
 
+	if (snc_mode == 1 && snc_unreliable && get_vendor() == ARCH_INTEL) {
+		ksft_test_result_skip("SNC detection unreliable due to offline CPUs. Test results may not be accurate if SNC enabled.\n");
+		return;
+	}
+
 	if (test_prepare(test)) {
 		ksft_exit_fail_msg("Abnormal failure when preparing for the test\n");
 		return;
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index d38d6dd90be44..dc7ce3cbdb271 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -13,6 +13,8 @@
 
 #include "resctrl.h"
 
+int snc_unreliable;
+
 static int find_resctrl_mount(char *buffer)
 {
 	FILE *mounts;
@@ -156,6 +158,98 @@ int get_domain_id(const char *resource, int cpu_no, int *domain_id)
 	return 0;
 }
 
+/*
+ * Count number of CPUs in a /sys bitmap
+ */
+static unsigned int count_sys_bitmap_bits(char *name)
+{
+	FILE *fp = fopen(name, "r");
+	int count = 0, c;
+
+	if (!fp)
+		return 0;
+
+	while ((c = fgetc(fp)) != EOF) {
+		if (!isxdigit(c))
+			continue;
+		switch (c) {
+		case 'f':
+			count++;
+			fallthrough;
+		case '7': case 'b': case 'd': case 'e':
+			count++;
+			fallthrough;
+		case '3': case '5': case '6': case '9': case 'a': case 'c':
+			count++;
+			fallthrough;
+		case '1': case '2': case '4': case '8':
+			count++;
+			break;
+		}
+	}
+	fclose(fp);
+
+	return count;
+}
+
+static bool cpus_offline_empty(void)
+{
+	char offline_cpus_str[64];
+	FILE *fp;
+
+	fp = fopen("/sys/devices/system/cpu/offline", "r");
+	if (!fp) {
+		ksft_perror("Could not open /sys/devices/system/cpu/offline");
+		return 0;
+	}
+
+	if (fscanf(fp, "%63s", offline_cpus_str) < 0) {
+		if (!errno) {
+			fclose(fp);
+			return 1;
+		}
+		ksft_perror("Could not read /sys/devices/system/cpu/offline");
+	}
+
+	fclose(fp);
+
+	return 0;
+}
+
+/*
+ * Detect SNC by comparing #CPUs in node0 with #CPUs sharing LLC with CPU0.
+ * If any CPUs are offline declare the detection as unreliable.
+ */
+int snc_nodes_per_l3_cache(void)
+{
+	int node_cpus, cache_cpus;
+	static int snc_mode;
+
+	if (!snc_mode) {
+		snc_mode = 1;
+		if (!cpus_offline_empty()) {
+			ksft_print_msg("Runtime SNC detection unreliable due to offline CPUs.\n");
+			ksft_print_msg("Setting SNC mode to disabled.\n");
+			snc_unreliable = 1;
+			return snc_mode;
+		}
+		node_cpus = count_sys_bitmap_bits("/sys/devices/system/node/node0/cpumap");
+		cache_cpus = count_sys_bitmap_bits("/sys/devices/system/cpu/cpu0/cache/index3/shared_cpu_map");
+
+		if (!node_cpus || !cache_cpus) {
+			ksft_print_msg("Could not determine Sub-NUMA Cluster mode.\n");
+			snc_unreliable = 1;
+			return snc_mode;
+		}
+		snc_mode = cache_cpus / node_cpus;
+
+		if (snc_mode > 1)
+			ksft_print_msg("SNC-%d mode discovered.\n", snc_mode);
+	}
+
+	return snc_mode;
+}
+
 /*
  * get_cache_size - Get cache size for a specified CPU
  * @cpu_no:	CPU number
@@ -211,6 +305,17 @@ int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size
 			break;
 	}
 
+	/*
+	 * The amount of cache represented by each bit in the masks
+	 * in the schemata file is reduced by a factor equal to SNC
+	 * nodes per L3 cache.
+	 * E.g. on a SNC-2 system with a 100MB L3 cache a test that
+	 * allocates memory from its local SNC node (default behavior
+	 * without using libnuma) will only see 50 MB llc_occupancy
+	 * with a fully populated L3 mask in the schemata file.
+	 */
+	if (cache_num == 3)
+		*cache_size /= snc_nodes_per_l3_cache();
 	return 0;
 }
 

From d6d35d0b0f4267612eb905305f3f2f7aa048bfd4 Mon Sep 17 00:00:00 2001
From: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Date: Mon, 16 Dec 2024 16:18:54 +0100
Subject: [PATCH 19/20] selftests/resctrl: Discover SNC kernel support and
 adjust messages

Resctrl selftest prints a message on test failure that Sub-Numa
Clustering (SNC) could be enabled and points the user to check their BIOS
settings. No actual check is performed before printing that message so
it is not very accurate in pinpointing a problem.

When there is SNC support for kernel's resctrl subsystem and SNC is
enabled then sub node files are created for each node in the resctrlfs.
The sub node files exist in each regular node's L3 monitoring directory.
The reliable path to check for existence of sub node files is
/sys/fs/resctrl/mon_data/mon_L3_00/mon_sub_L3_00.

Add helper that checks for mon_sub_L3_00 existence.

Correct old messages to account for kernel support of SNC in
resctrl.

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/resctrl/cmt_test.c  |  4 +--
 tools/testing/selftests/resctrl/mba_test.c  |  2 ++
 tools/testing/selftests/resctrl/mbm_test.c  |  4 +--
 tools/testing/selftests/resctrl/resctrl.h   |  1 +
 tools/testing/selftests/resctrl/resctrlfs.c | 32 +++++++++++++++++++++
 5 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 3bbf3042fb06e..d09e693dc739c 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -169,8 +169,8 @@ static int cmt_run_test(const struct resctrl_test *test, const struct user_param
 		return ret;
 
 	ret = check_results(&param, span, n);
-	if (ret && (get_vendor() == ARCH_INTEL))
-		ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
+	if (ret && (get_vendor() == ARCH_INTEL) && !snc_kernel_support())
+		ksft_print_msg("Kernel doesn't support Sub-NUMA Clustering but it is enabled on the system.\n");
 
 	return ret;
 }
diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
index 536d9089d2f6c..c7e9adc0368f3 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -201,6 +201,8 @@ static int mba_run_test(const struct resctrl_test *test, const struct user_param
 		return ret;
 
 	ret = check_results();
+	if (ret && (get_vendor() == ARCH_INTEL) && !snc_kernel_support())
+		ksft_print_msg("Kernel doesn't support Sub-NUMA Clustering but it is enabled on the system.\n");
 
 	return ret;
 }
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index 315b2ef3b3bcb..84d8bc2505392 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -160,8 +160,8 @@ static int mbm_run_test(const struct resctrl_test *test, const struct user_param
 		return ret;
 
 	ret = check_results(param.fill_buf ? param.fill_buf->buf_size : 0);
-	if (ret && (get_vendor() == ARCH_INTEL))
-		ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
+	if (ret && (get_vendor() == ARCH_INTEL) && !snc_kernel_support())
+		ksft_print_msg("Kernel doesn't support Sub-NUMA Clustering but it is enabled on the system.\n");
 
 	return ret;
 }
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 35fa3afee9c3c..cd3adfc14969f 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -203,6 +203,7 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
 int signal_handler_register(const struct resctrl_test *test);
 void signal_handler_unregister(void);
 unsigned int count_bits(unsigned long n);
+int snc_kernel_support(void);
 
 void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config);
 void perf_event_initialize_read_format(struct perf_event_read *pe_read);
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index dc7ce3cbdb271..195f04c4d1586 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -957,3 +957,35 @@ unsigned int count_bits(unsigned long n)
 
 	return count;
 }
+
+/**
+ * snc_kernel_support - Check for existence of mon_sub_L3_00 file that indicates
+ * SNC resctrl support on the kernel side.
+ *
+ * Return: 0 if not supported, 1 if SNC is disabled or SNC discovery is
+ * unreliable or SNC is both enabled and supported.
+ */
+int snc_kernel_support(void)
+{
+	char node_path[PATH_MAX];
+	struct stat statbuf;
+	int ret;
+
+	ret = snc_nodes_per_l3_cache();
+	/*
+	 * If SNC is disabled then its kernel support isn't important. If SNC
+	 * got disabled because the discovery process was unreliable the
+	 * snc_unreliable variable was set. It can be used to verify the SNC
+	 * discovery reliability elsewhere in the selftest.
+	 */
+	if (ret == 1)
+		return ret;
+
+	snprintf(node_path, sizeof(node_path), "%s/%s", RESCTRL_PATH,
+		 "mon_data/mon_L3_00/mon_sub_L3_00");
+
+	if (!stat(node_path, &statbuf))
+		return 1;
+
+	return 0;
+}

From 336d02bc4c6bec5c3d933e5d470a94970f830957 Mon Sep 17 00:00:00 2001
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 14 Jan 2025 09:51:32 -0500
Subject: [PATCH 20/20] selftests/rseq: Fix handling of glibc without rseq
 support

When porting librseq commit:

commit c7b45750fa85 ("Adapt to glibc __rseq_size feature detection")

from librseq to the kernel selftests, the following line was missed
at the end of rseq_init():

  rseq_size = get_rseq_kernel_feature_size();

which effectively leaves rseq_size initialized to -1U when glibc does not
have rseq support. glibc supports rseq from version 2.35 onwards.

In a following librseq commit

commit c67d198627c2 ("Only set 'rseq_size' on first thread registration")

to mimic the libc behavior, a new approach is taken: don't set the
feature size in 'rseq_size' until at least one thread has successfully
registered. This allows using 'rseq_size' in fast-paths to test for both
registration status and available features. The caveat is that on libc
either all threads are registered or none are, while with bare librseq
it is the responsability of the user to register all threads using rseq.

This combines the changes from the following librseq git commits:

commit c7b45750fa85 ("Adapt to glibc __rseq_size feature detection")
commit c67d198627c2 ("Only set 'rseq_size' on first thread registration")

Fixes: a0cc649353bb ("selftests/rseq: Fix mm_cid test failure")
Reported-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Raghavendra Rao Ananta <rananta@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Carlos O'Donell <carlos@redhat.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: linux-kselftest@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/rseq/rseq.c | 32 ++++++++++++++++++++++-------
 tools/testing/selftests/rseq/rseq.h |  9 +++++++-
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index 5b9772cdf2651..f6156790c3b4d 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -61,7 +61,6 @@ unsigned int rseq_size = -1U;
 unsigned int rseq_flags;
 
 static int rseq_ownership;
-static int rseq_reg_success;	/* At least one rseq registration has succeded. */
 
 /* Allocate a large area for the TLS. */
 #define RSEQ_THREAD_AREA_ALLOC_SIZE	1024
@@ -152,14 +151,27 @@ int rseq_register_current_thread(void)
 	}
 	rc = sys_rseq(&__rseq_abi, get_rseq_min_alloc_size(), 0, RSEQ_SIG);
 	if (rc) {
-		if (RSEQ_READ_ONCE(rseq_reg_success)) {
+		/*
+		 * After at least one thread has registered successfully
+		 * (rseq_size > 0), the registration of other threads should
+		 * never fail.
+		 */
+		if (RSEQ_READ_ONCE(rseq_size) > 0) {
 			/* Incoherent success/failure within process. */
 			abort();
 		}
 		return -1;
 	}
 	assert(rseq_current_cpu_raw() >= 0);
-	RSEQ_WRITE_ONCE(rseq_reg_success, 1);
+
+	/*
+	 * The first thread to register sets the rseq_size to mimic the libc
+	 * behavior.
+	 */
+	if (RSEQ_READ_ONCE(rseq_size) == 0) {
+		RSEQ_WRITE_ONCE(rseq_size, get_rseq_kernel_feature_size());
+	}
+
 	return 0;
 }
 
@@ -235,12 +247,18 @@ void rseq_init(void)
 		return;
 	}
 	rseq_ownership = 1;
-	if (!rseq_available()) {
-		rseq_size = 0;
-		return;
-	}
+
+	/* Calculate the offset of the rseq area from the thread pointer. */
 	rseq_offset = (void *)&__rseq_abi - rseq_thread_pointer();
+
+	/* rseq flags are deprecated, always set to 0. */
 	rseq_flags = 0;
+
+	/*
+	 * Set the size to 0 until at least one thread registers to mimic the
+	 * libc behavior.
+	 */
+	rseq_size = 0;
 }
 
 static __attribute__((destructor))
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index 4e217b620e0c7..062d10925a101 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -60,7 +60,14 @@
 extern ptrdiff_t rseq_offset;
 
 /*
- * Size of the registered rseq area. 0 if the registration was
+ * The rseq ABI is composed of extensible feature fields. The extensions
+ * are done by appending additional fields at the end of the structure.
+ * The rseq_size defines the size of the active feature set which can be
+ * used by the application for the current rseq registration. Features
+ * starting at offset >= rseq_size are inactive and should not be used.
+ *
+ * The rseq_size is the intersection between the available allocation
+ * size for the rseq area and the feature size supported by the kernel.
  * unsuccessful.
  */
 extern unsigned int rseq_size;