Merge tag 'linux_kselftest-fixes-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:
 "Fixes for build, run-time errors, and reporting errors:

   - ftrace: regression test for a kernel crash when running function
     graph tracing and then enabling function profiler.

   - rseq: fix for mm_cid test failure.

   - vDSO:
      - fixes to reporting skip and other error conditions
      - changes unconditionally build chacha and getrandom tests on all
        architectures to make it easier for them to run in CIs
      - build error when sched.h to bring in CLONE_NEWTIME define"

* tag 'linux_kselftest-fixes-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  ftrace/selftest: Test combination of function_graph tracer and function profiler
  selftests/rseq: Fix mm_cid test failure
  selftests: vDSO: Explicitly include sched.h
  selftests: vDSO: improve getrandom and chacha error messages
  selftests: vDSO: unconditionally build getrandom test
  selftests: vDSO: unconditionally build chacha test

12 files changed, 183 insertions, 109 deletions

diff --git a/tools/arch/arm64/vdso b/tools/arch/arm64/vdso
deleted file mode 120000
index 233c7a26f6e5..000000000000
--- a/tools/arch/arm64/vdso
+++ /dev/null
@@ -1 +0,0 @@
-../../../arch/arm64/kernel/vdso
\ No newline at end of file
diff --git a/tools/arch/loongarch/vdso b/tools/arch/loongarch/vdso
deleted file mode 120000
index ebda43a82db7..000000000000
--- a/tools/arch/loongarch/vdso
+++ /dev/null
@@ -1 +0,0 @@
-../../../arch/loongarch/vdso
\ No newline at end of file
diff --git a/tools/arch/powerpc/vdso b/tools/arch/powerpc/vdso
deleted file mode 120000
index 4e676d1d1cb4..000000000000
--- a/tools/arch/powerpc/vdso
+++ /dev/null
@@ -1 +0,0 @@
-../../../arch/powerpc/kernel/vdso
\ No newline at end of file
diff --git a/tools/arch/s390/vdso b/tools/arch/s390/vdso
deleted file mode 120000
index 6cf4c1cebdcd..000000000000
--- a/tools/arch/s390/vdso
+++ /dev/null
@@ -1 +0,0 @@
-../../../arch/s390/kernel/vdso64
\ No newline at end of file
diff --git a/tools/arch/x86/vdso b/tools/arch/x86/vdso
deleted file mode 120000
index 7eb962fd3454..000000000000
--- a/tools/arch/x86/vdso
+++ /dev/null
@@ -1 +0,0 @@
-../../../arch/x86/entry/vdso/
\ No newline at end of file
diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc
new file mode 100644
index 000000000000..ffff8646733c
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc
@@ -0,0 +1,31 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: ftrace - function profiler with function graph tracing
+# requires: function_profile_enabled set_ftrace_filter function_graph:tracer
+
+# The function graph tracer can now be run along side of the function
+# profiler. But there was a bug that caused the combination of the two
+# to crash. It also required the function graph tracer to be started
+# first.
+#
+# This test triggers that bug
+#
+# We need both function_graph and profiling to run this test
+
+fail() { # mesg
+    echo $1
+    exit_fail
+}
+
+echo "Enabling function graph tracer:"
+echo function_graph > current_tracer
+echo "enable profiler"
+
+# Older kernels do not allow function_profile to be enabled with
+# function graph tracer. If the below fails, mark it as unsupported
+echo 1 > function_profile_enabled || exit_unsupported
+
+# Let it run for a bit to make sure nothing explodes
+sleep 1
+
+exit 0
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index 96e812bdf8a4..5b9772cdf265 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -60,12 +60,6 @@ unsigned int rseq_size = -1U;
 /* Flags used during rseq registration.  */
 unsigned int rseq_flags;
 
-/*
- * rseq feature size supported by the kernel. 0 if the registration was
- * unsuccessful.
- */
-unsigned int rseq_feature_size = -1U;
-
 static int rseq_ownership;
 static int rseq_reg_success;	/* At least one rseq registration has succeded. */
 
@@ -111,6 +105,43 @@ int rseq_available(void)
 	}
 }
 
+/* The rseq areas need to be at least 32 bytes. */
+static
+unsigned int get_rseq_min_alloc_size(void)
+{
+	unsigned int alloc_size = rseq_size;
+
+	if (alloc_size < ORIG_RSEQ_ALLOC_SIZE)
+		alloc_size = ORIG_RSEQ_ALLOC_SIZE;
+	return alloc_size;
+}
+
+/*
+ * Return the feature size supported by the kernel.
+ *
+ * Depending on the value returned by getauxval(AT_RSEQ_FEATURE_SIZE):
+ *
+ * 0:   Return ORIG_RSEQ_FEATURE_SIZE (20)
+ * > 0: Return the value from getauxval(AT_RSEQ_FEATURE_SIZE).
+ *
+ * It should never return a value below ORIG_RSEQ_FEATURE_SIZE.
+ */
+static
+unsigned int get_rseq_kernel_feature_size(void)
+{
+	unsigned long auxv_rseq_feature_size, auxv_rseq_align;
+
+	auxv_rseq_align = getauxval(AT_RSEQ_ALIGN);
+	assert(!auxv_rseq_align || auxv_rseq_align <= RSEQ_THREAD_AREA_ALLOC_SIZE);
+
+	auxv_rseq_feature_size = getauxval(AT_RSEQ_FEATURE_SIZE);
+	assert(!auxv_rseq_feature_size || auxv_rseq_feature_size <= RSEQ_THREAD_AREA_ALLOC_SIZE);
+	if (auxv_rseq_feature_size)
+		return auxv_rseq_feature_size;
+	else
+		return ORIG_RSEQ_FEATURE_SIZE;
+}
+
 int rseq_register_current_thread(void)
 {
 	int rc;
@@ -119,7 +150,7 @@ int rseq_register_current_thread(void)
 		/* Treat libc's ownership as a successful registration. */
 		return 0;
 	}
-	rc = sys_rseq(&__rseq_abi, rseq_size, 0, RSEQ_SIG);
+	rc = sys_rseq(&__rseq_abi, get_rseq_min_alloc_size(), 0, RSEQ_SIG);
 	if (rc) {
 		if (RSEQ_READ_ONCE(rseq_reg_success)) {
 			/* Incoherent success/failure within process. */
@@ -140,28 +171,12 @@ int rseq_unregister_current_thread(void)
 		/* Treat libc's ownership as a successful unregistration. */
 		return 0;
 	}
-	rc = sys_rseq(&__rseq_abi, rseq_size, RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
+	rc = sys_rseq(&__rseq_abi, get_rseq_min_alloc_size(), RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
 	if (rc)
 		return -1;
 	return 0;
 }
 
-static
-unsigned int get_rseq_feature_size(void)
-{
-	unsigned long auxv_rseq_feature_size, auxv_rseq_align;
-
-	auxv_rseq_align = getauxval(AT_RSEQ_ALIGN);
-	assert(!auxv_rseq_align || auxv_rseq_align <= RSEQ_THREAD_AREA_ALLOC_SIZE);
-
-	auxv_rseq_feature_size = getauxval(AT_RSEQ_FEATURE_SIZE);
-	assert(!auxv_rseq_feature_size || auxv_rseq_feature_size <= RSEQ_THREAD_AREA_ALLOC_SIZE);
-	if (auxv_rseq_feature_size)
-		return auxv_rseq_feature_size;
-	else
-		return ORIG_RSEQ_FEATURE_SIZE;
-}
-
 static __attribute__((constructor))
 void rseq_init(void)
 {
@@ -178,28 +193,54 @@ void rseq_init(void)
 	}
 	if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p &&
 			*libc_rseq_size_p != 0) {
+		unsigned int libc_rseq_size;
+
 		/* rseq registration owned by glibc */
 		rseq_offset = *libc_rseq_offset_p;
-		rseq_size = *libc_rseq_size_p;
+		libc_rseq_size = *libc_rseq_size_p;
 		rseq_flags = *libc_rseq_flags_p;
-		rseq_feature_size = get_rseq_feature_size();
-		if (rseq_feature_size > rseq_size)
-			rseq_feature_size = rseq_size;
+
+		/*
+		 * Previous versions of glibc expose the value
+		 * 32 even though the kernel only supported 20
+		 * bytes initially. Therefore treat 32 as a
+		 * special-case. glibc 2.40 exposes a 20 bytes
+		 * __rseq_size without using getauxval(3) to
+		 * query the supported size, while still allocating a 32
+		 * bytes area. Also treat 20 as a special-case.
+		 *
+		 * Special-cases are handled by using the following
+		 * value as active feature set size:
+		 *
+		 *   rseq_size = min(32, get_rseq_kernel_feature_size())
+		 */
+		switch (libc_rseq_size) {
+		case ORIG_RSEQ_FEATURE_SIZE:
+			fallthrough;
+		case ORIG_RSEQ_ALLOC_SIZE:
+		{
+			unsigned int rseq_kernel_feature_size = get_rseq_kernel_feature_size();
+
+			if (rseq_kernel_feature_size < ORIG_RSEQ_ALLOC_SIZE)
+				rseq_size = rseq_kernel_feature_size;
+			else
+				rseq_size = ORIG_RSEQ_ALLOC_SIZE;
+			break;
+		}
+		default:
+			/* Otherwise just use the __rseq_size from libc as rseq_size. */
+			rseq_size = libc_rseq_size;
+			break;
+		}
 		return;
 	}
 	rseq_ownership = 1;
 	if (!rseq_available()) {
 		rseq_size = 0;
-		rseq_feature_size = 0;
 		return;
 	}
 	rseq_offset = (void *)&__rseq_abi - rseq_thread_pointer();
 	rseq_flags = 0;
-	rseq_feature_size = get_rseq_feature_size();
-	if (rseq_feature_size == ORIG_RSEQ_FEATURE_SIZE)
-		rseq_size = ORIG_RSEQ_ALLOC_SIZE;
-	else
-		rseq_size = RSEQ_THREAD_AREA_ALLOC_SIZE;
 }
 
 static __attribute__((destructor))
@@ -209,7 +250,6 @@ void rseq_exit(void)
 		return;
 	rseq_offset = 0;
 	rseq_size = -1U;
-	rseq_feature_size = -1U;
 	rseq_ownership = 0;
 }
 
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index d7364ea4d201..4e217b620e0c 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -68,12 +68,6 @@ extern unsigned int rseq_size;
 /* Flags used during rseq registration. */
 extern unsigned int rseq_flags;
 
-/*
- * rseq feature size supported by the kernel. 0 if the registration was
- * unsuccessful.
- */
-extern unsigned int rseq_feature_size;
-
 enum rseq_mo {
 	RSEQ_MO_RELAXED = 0,
 	RSEQ_MO_CONSUME = 1,	/* Unused */
@@ -193,7 +187,7 @@ static inline uint32_t rseq_current_cpu(void)
 
 static inline bool rseq_node_id_available(void)
 {
-	return (int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, node_id);
+	return (int) rseq_size >= rseq_offsetofend(struct rseq_abi, node_id);
 }
 
 /*
@@ -207,7 +201,7 @@ static inline uint32_t rseq_current_node_id(void)
 
 static inline bool rseq_mm_cid_available(void)
 {
-	return (int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, mm_cid);
+	return (int) rseq_size >= rseq_offsetofend(struct rseq_abi, mm_cid);
 }
 
 static inline uint32_t rseq_current_mm_cid(void)
diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index af9cedbf5357..1cf14a8da438 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -9,10 +9,8 @@ ifeq ($(ARCH),$(filter $(ARCH),x86 x86_64))
 TEST_GEN_PROGS += vdso_standalone_test_x86
 endif
 TEST_GEN_PROGS += vdso_test_correctness
-ifeq ($(ARCH)$(CONFIG_X86_32),$(filter $(ARCH)$(CONFIG_X86_32),x86 x86_64 loongarch arm64 powerpc s390))
 TEST_GEN_PROGS += vdso_test_getrandom
 TEST_GEN_PROGS += vdso_test_chacha
-endif
 
 CFLAGS := -std=gnu99 -O2
 
@@ -37,9 +35,9 @@ $(OUTPUT)/vdso_test_getrandom: CFLAGS += -isystem $(top_srcdir)/tools/include \
                                          $(KHDR_INCLUDES) \
                                          -isystem $(top_srcdir)/include/uapi
 
-$(OUTPUT)/vdso_test_chacha: $(top_srcdir)/tools/arch/$(SRCARCH)/vdso/vgetrandom-chacha.S
+$(OUTPUT)/vdso_test_chacha: vgetrandom-chacha.S
 $(OUTPUT)/vdso_test_chacha: CFLAGS += -idirafter $(top_srcdir)/tools/include \
                                       -idirafter $(top_srcdir)/tools/include/generated \
                                       -idirafter $(top_srcdir)/arch/$(SRCARCH)/include \
                                       -idirafter $(top_srcdir)/include \
-                                      -D__ASSEMBLY__ -Wa,--noexecstack
+                                      -Wa,--noexecstack
diff --git a/tools/testing/selftests/vDSO/vdso_test_chacha.c b/tools/testing/selftests/vDSO/vdso_test_chacha.c
index b1ea532c5996..8757f738b0b1 100644
--- a/tools/testing/selftests/vDSO/vdso_test_chacha.c
+++ b/tools/testing/selftests/vDSO/vdso_test_chacha.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */
 
+#include <linux/compiler.h>
 #include <tools/le_byteshift.h>
 #include <sys/random.h>
 #include <sys/auxv.h>
@@ -73,10 +74,10 @@ static void reference_chacha20_blocks(uint8_t *dst_bytes, const uint32_t *key, u
 	counter[1] = s[13];
 }
 
-typedef uint8_t u8;
-typedef uint32_t u32;
-typedef uint64_t u64;
-#include <vdso/getrandom.h>
+void __weak __arch_chacha20_blocks_nostack(uint8_t *dst_bytes, const uint32_t *key, uint32_t *counter, size_t nblocks)
+{
+	ksft_exit_skip("Not implemented on architecture\n");
+}
 
 int main(int argc, char *argv[])
 {
@@ -90,10 +91,8 @@ int main(int argc, char *argv[])
 	ksft_set_plan(1);
 
 	for (unsigned int trial = 0; trial < TRIALS; ++trial) {
-		if (getrandom(key, sizeof(key), 0) != sizeof(key)) {
-			printf("getrandom() failed!\n");
-			return KSFT_SKIP;
-		}
+		if (getrandom(key, sizeof(key), 0) != sizeof(key))
+			ksft_exit_skip("getrandom() failed unexpectedly\n");
 		memset(counter1, 0, sizeof(counter1));
 		reference_chacha20_blocks(output1, key, counter1, BLOCKS);
 		for (unsigned int split = 0; split < BLOCKS; ++split) {
@@ -102,8 +101,10 @@ int main(int argc, char *argv[])
 			if (split)
 				__arch_chacha20_blocks_nostack(output2, key, counter2, split);
 			__arch_chacha20_blocks_nostack(output2 + split * BLOCK_SIZE, key, counter2, BLOCKS - split);
-			if (memcmp(output1, output2, sizeof(output1)) || memcmp(counter1, counter2, sizeof(counter1)))
-				return KSFT_FAIL;
+			if (memcmp(output1, output2, sizeof(output1)))
+				ksft_exit_fail_msg("Main loop outputs do not match on trial %u, split %u\n", trial, split);
+			if (memcmp(counter1, counter2, sizeof(counter1)))
+				ksft_exit_fail_msg("Main loop counters do not match on trial %u, split %u\n", trial, split);
 		}
 	}
 	memset(counter1, 0, sizeof(counter1));
@@ -113,14 +114,19 @@ int main(int argc, char *argv[])
 
 	reference_chacha20_blocks(output1, key, counter1, BLOCKS);
 	__arch_chacha20_blocks_nostack(output2, key, counter2, BLOCKS);
-	if (memcmp(output1, output2, sizeof(output1)) || memcmp(counter1, counter2, sizeof(counter1)))
-		return KSFT_FAIL;
+	if (memcmp(output1, output2, sizeof(output1)))
+		ksft_exit_fail_msg("Block limit outputs do not match after first round\n");
+	if (memcmp(counter1, counter2, sizeof(counter1)))
+		ksft_exit_fail_msg("Block limit counters do not match after first round\n");
 
 	reference_chacha20_blocks(output1, key, counter1, BLOCKS);
 	__arch_chacha20_blocks_nostack(output2, key, counter2, BLOCKS);
-	if (memcmp(output1, output2, sizeof(output1)) || memcmp(counter1, counter2, sizeof(counter1)))
-		return KSFT_FAIL;
+	if (memcmp(output1, output2, sizeof(output1)))
+		ksft_exit_fail_msg("Block limit outputs do not match after second round\n");
+	if (memcmp(counter1, counter2, sizeof(counter1)))
+		ksft_exit_fail_msg("Block limit counters do not match after second round\n");
 
 	ksft_test_result_pass("chacha: PASS\n");
-	return KSFT_PASS;
+	ksft_exit_pass();
+	return 0;
 }
diff --git a/tools/testing/selftests/vDSO/vdso_test_getrandom.c b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
index e5e83dbec589..95057f7567db 100644
--- a/tools/testing/selftests/vDSO/vdso_test_getrandom.c
+++ b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
@@ -11,6 +11,7 @@
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
+#include <sched.h>
 #include <signal.h>
 #include <sys/auxv.h>
 #include <sys/mman.h>
@@ -40,6 +41,9 @@
 	} while (0)
 #endif
 
+#define ksft_assert(condition) \
+	do { if (!(condition)) ksft_exit_fail_msg("Assertion failed: %s\n", #condition); } while (0)
+
 static struct {
 	pthread_mutex_t lock;
 	void **states;
@@ -111,26 +115,19 @@ static void vgetrandom_init(void)
 	const char *version = versions[VDSO_VERSION];
 	const char *name = names[VDSO_NAMES][6];
 	unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
-	size_t ret;
+	ssize_t ret;
 
-	if (!sysinfo_ehdr) {
-		printf("AT_SYSINFO_EHDR is not present!\n");
-		exit(KSFT_SKIP);
-	}
+	if (!sysinfo_ehdr)
+		ksft_exit_skip("AT_SYSINFO_EHDR is not present\n");
 	vdso_init_from_sysinfo_ehdr(sysinfo_ehdr);
 	vgrnd.fn = (__typeof__(vgrnd.fn))vdso_sym(version, name);
-	if (!vgrnd.fn) {
-		printf("%s is missing!\n", name);
-		exit(KSFT_FAIL);
-	}
+	if (!vgrnd.fn)
+		ksft_exit_skip("%s@%s symbol is missing from vDSO\n", name, version);
 	ret = VDSO_CALL(vgrnd.fn, 5, NULL, 0, 0, &vgrnd.params, ~0UL);
-	if (ret == -ENOSYS) {
-		printf("unsupported architecture\n");
-		exit(KSFT_SKIP);
-	} else if (ret) {
-		printf("failed to fetch vgetrandom params!\n");
-		exit(KSFT_FAIL);
-	}
+	if (ret == -ENOSYS)
+		ksft_exit_skip("CPU does not have runtime support\n");
+	else if (ret)
+		ksft_exit_fail_msg("Failed to fetch vgetrandom params: %zd\n", ret);
 }
 
 static ssize_t vgetrandom(void *buf, size_t len, unsigned long flags)
@@ -139,10 +136,7 @@ static ssize_t vgetrandom(void *buf, size_t len, unsigned long flags)
 
 	if (!state) {
 		state = vgetrandom_get_state();
-		if (!state) {
-			printf("vgetrandom_get_state failed!\n");
-			exit(KSFT_FAIL);
-		}
+		ksft_assert(state);
 	}
 	return VDSO_CALL(vgrnd.fn, 5, buf, len, flags, state, vgrnd.params.size_of_opaque_state);
 }
@@ -154,7 +148,7 @@ static void *test_vdso_getrandom(void *ctx)
 	for (size_t i = 0; i < TRIALS; ++i) {
 		unsigned int val;
 		ssize_t ret = vgetrandom(&val, sizeof(val), 0);
-		assert(ret == sizeof(val));
+		ksft_assert(ret == sizeof(val));
 	}
 	return NULL;
 }
@@ -164,7 +158,7 @@ static void *test_libc_getrandom(void *ctx)
 	for (size_t i = 0; i < TRIALS; ++i) {
 		unsigned int val;
 		ssize_t ret = getrandom(&val, sizeof(val), 0);
-		assert(ret == sizeof(val));
+		ksft_assert(ret == sizeof(val));
 	}
 	return NULL;
 }
@@ -174,7 +168,7 @@ static void *test_syscall_getrandom(void *ctx)
 	for (size_t i = 0; i < TRIALS; ++i) {
 		unsigned int val;
 		ssize_t ret = syscall(__NR_getrandom, &val, sizeof(val), 0);
-		assert(ret == sizeof(val));
+		ksft_assert(ret == sizeof(val));
 	}
 	return NULL;
 }
@@ -209,7 +203,7 @@ static void bench_multi(void)
 
 	clock_gettime(CLOCK_MONOTONIC, &start);
 	for (size_t i = 0; i < THREADS; ++i)
-		assert(pthread_create(&threads[i], NULL, test_vdso_getrandom, NULL) == 0);
+		ksft_assert(pthread_create(&threads[i], NULL, test_vdso_getrandom, NULL) == 0);
 	for (size_t i = 0; i < THREADS; ++i)
 		pthread_join(threads[i], NULL);
 	clock_gettime(CLOCK_MONOTONIC, &end);
@@ -218,7 +212,7 @@ static void bench_multi(void)
 
 	clock_gettime(CLOCK_MONOTONIC, &start);
 	for (size_t i = 0; i < THREADS; ++i)
-		assert(pthread_create(&threads[i], NULL, test_libc_getrandom, NULL) == 0);
+		ksft_assert(pthread_create(&threads[i], NULL, test_libc_getrandom, NULL) == 0);
 	for (size_t i = 0; i < THREADS; ++i)
 		pthread_join(threads[i], NULL);
 	clock_gettime(CLOCK_MONOTONIC, &end);
@@ -227,7 +221,7 @@ static void bench_multi(void)
 
 	clock_gettime(CLOCK_MONOTONIC, &start);
 	for (size_t i = 0; i < THREADS; ++i)
-		assert(pthread_create(&threads[i], NULL, test_syscall_getrandom, NULL) == 0);
+		ksft_assert(pthread_create(&threads[i], NULL, test_syscall_getrandom, NULL) == 0);
 	for (size_t i = 0; i < THREADS; ++i)
 		pthread_join(threads[i], NULL);
 	clock_gettime(CLOCK_MONOTONIC, &end);
@@ -252,48 +246,46 @@ static void kselftest(void)
 
 	for (size_t i = 0; i < 1000; ++i) {
 		ssize_t ret = vgetrandom(weird_size, sizeof(weird_size), 0);
-		if (ret != sizeof(weird_size))
-			exit(KSFT_FAIL);
+		ksft_assert(ret == sizeof(weird_size));
 	}
 
 	ksft_test_result_pass("getrandom: PASS\n");
 
 	unshare(CLONE_NEWUSER);
-	assert(unshare(CLONE_NEWTIME) == 0);
+	ksft_assert(unshare(CLONE_NEWTIME) == 0);
 	child = fork();
-	assert(child >= 0);
+	ksft_assert(child >= 0);
 	if (!child) {
 		vgetrandom_init();
 		child = getpid();
-		assert(ptrace(PTRACE_TRACEME, 0, NULL, NULL) == 0);
-		assert(kill(child, SIGSTOP) == 0);
-		assert(vgetrandom(weird_size, sizeof(weird_size), 0) == sizeof(weird_size));
+		ksft_assert(ptrace(PTRACE_TRACEME, 0, NULL, NULL) == 0);
+		ksft_assert(kill(child, SIGSTOP) == 0);
+		ksft_assert(vgetrandom(weird_size, sizeof(weird_size), 0) == sizeof(weird_size));
 		_exit(0);
 	}
 	for (;;) {
 		struct ptrace_syscall_info info = { 0 };
 		int status, ret;
-		assert(waitpid(child, &status, 0) >= 0);
+		ksft_assert(waitpid(child, &status, 0) >= 0);
 		if (WIFEXITED(status)) {
-			if (WEXITSTATUS(status) != 0)
-				exit(KSFT_FAIL);
+			ksft_assert(WEXITSTATUS(status) == 0);
 			break;
 		}
-		assert(WIFSTOPPED(status));
+		ksft_assert(WIFSTOPPED(status));
 		if (WSTOPSIG(status) == SIGSTOP)
-			assert(ptrace(PTRACE_SETOPTIONS, child, 0, PTRACE_O_TRACESYSGOOD) == 0);
+			ksft_assert(ptrace(PTRACE_SETOPTIONS, child, 0, PTRACE_O_TRACESYSGOOD) == 0);
 		else if (WSTOPSIG(status) == (SIGTRAP | 0x80)) {
-			assert(ptrace(PTRACE_GET_SYSCALL_INFO, child, sizeof(info), &info) > 0);
+			ksft_assert(ptrace(PTRACE_GET_SYSCALL_INFO, child, sizeof(info), &info) > 0);
 			if (info.op == PTRACE_SYSCALL_INFO_ENTRY && info.entry.nr == __NR_getrandom &&
 			    info.entry.args[0] == (uintptr_t)weird_size && info.entry.args[1] == sizeof(weird_size))
-				exit(KSFT_FAIL);
+				ksft_exit_fail_msg("vgetrandom passed buffer to syscall getrandom unexpectedly\n");
 		}
-		assert(ptrace(PTRACE_SYSCALL, child, 0, 0) == 0);
+		ksft_assert(ptrace(PTRACE_SYSCALL, child, 0, 0) == 0);
 	}
 
 	ksft_test_result_pass("getrandom timens: PASS\n");
 
-	exit(KSFT_PASS);
+	ksft_exit_pass();
 }
 
 static void usage(const char *argv0)
diff --git a/tools/testing/selftests/vDSO/vgetrandom-chacha.S b/tools/testing/selftests/vDSO/vgetrandom-chacha.S
new file mode 100644
index 000000000000..d6e09af7c0a9
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vgetrandom-chacha.S
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#define __ASSEMBLY__
+
+#if defined(__aarch64__)
+#include "../../../../arch/arm64/kernel/vdso/vgetrandom-chacha.S"
+#elif defined(__loongarch__)
+#include "../../../../arch/loongarch/vdso/vgetrandom-chacha.S"
+#elif defined(__powerpc__) || defined(__powerpc64__)
+#include "../../../../arch/powerpc/kernel/vdso/vgetrandom-chacha.S"
+#elif defined(__s390x__)
+#include "../../../../arch/s390/kernel/vdso64/vgetrandom-chacha.S"
+#elif defined(__x86_64__)
+#include "../../../../arch/x86/entry/vdso/vgetrandom-chacha.S"
+#endif