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[PATCH v3 00/13] stackleak: Support Clang stack depth tracking

by Kees Cook

v3: - split up and drop __init vs inline patches that went via arch trees - apply feedback about preferring __init to __always_inline - incorporate Ritesh Harjani's patch for __init cleanups in powerpc - wider build testing on older compilers v2: https://lore.kernel.org/lkml/20250523043251.it.550-kees@kernel.org/ v1: https://lore.kernel.org/lkml/20250507180852.work.231-kees@kernel.org/ Hi, As part of looking at what GCC plugins could be replaced with Clang implementations, this series uses the recently landed stack depth tracking callback in Clang[1] to implement the stackleak feature. Since the Clang feature is now landed, I'm moving this out of RFC to a v1. Since this touches a lot of arch-specific Makefiles, I tried to trim the CC list down to just mailing lists in those cases, otherwise the CC was giant. Thanks! -Kees [1] https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-stack-depth Kees Cook (12): stackleak: Rename STACKLEAK to KSTACK_ERASE stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS x86: Handle KCOV __init vs inline mismatches arm: Handle KCOV __init vs inline mismatches arm64: Handle KCOV __init vs inline mismatches s390: Handle KCOV __init vs inline mismatches mips: Handle KCOV __init vs inline mismatch init.h: Disable sanitizer coverage for __init and __head kstack_erase: Support Clang stack depth tracking configs/hardening: Enable CONFIG_KSTACK_ERASE configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON Ritesh Harjani (IBM) (1): powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section arch/Kconfig | 4 +- arch/arm/Kconfig | 2 +- arch/arm64/Kconfig | 2 +- arch/riscv/Kconfig | 2 +- arch/s390/Kconfig | 2 +- arch/x86/Kconfig | 2 +- security/Kconfig.hardening | 45 +++++++++------- Makefile | 1 + arch/arm/boot/compressed/Makefile | 2 +- arch/arm/vdso/Makefile | 2 +- arch/arm64/kernel/pi/Makefile | 2 +- arch/arm64/kernel/vdso/Makefile | 3 +- arch/arm64/kvm/hyp/nvhe/Makefile | 2 +- arch/riscv/kernel/pi/Makefile | 2 +- arch/riscv/purgatory/Makefile | 2 +- arch/sparc/vdso/Makefile | 3 +- arch/x86/entry/vdso/Makefile | 3 +- arch/x86/purgatory/Makefile | 2 +- drivers/firmware/efi/libstub/Makefile | 8 +-- drivers/misc/lkdtm/Makefile | 2 +- kernel/Makefile | 10 ++-- lib/Makefile | 2 +- scripts/Makefile.gcc-plugins | 16 +----- scripts/Makefile.kstack_erase | 21 ++++++++ scripts/gcc-plugins/stackleak_plugin.c | 52 +++++++++---------- Documentation/admin-guide/sysctl/kernel.rst | 4 +- Documentation/arch/x86/x86_64/mm.rst | 2 +- Documentation/security/self-protection.rst | 2 +- .../zh_CN/security/self-protection.rst | 2 +- arch/arm64/include/asm/acpi.h | 2 +- arch/mips/include/asm/time.h | 2 +- arch/s390/hypfs/hypfs.h | 2 +- arch/s390/hypfs/hypfs_diag.h | 2 +- arch/x86/entry/calling.h | 4 +- arch/x86/include/asm/acpi.h | 4 +- arch/x86/include/asm/init.h | 2 +- arch/x86/include/asm/realmode.h | 2 +- include/linux/acpi.h | 4 +- include/linux/bootconfig.h | 2 +- include/linux/efi.h | 2 +- include/linux/init.h | 4 +- include/linux/{stackleak.h => kstack_erase.h} | 20 +++---- include/linux/memblock.h | 2 +- include/linux/mfd/dbx500-prcmu.h | 2 +- include/linux/sched.h | 4 +- include/linux/smp.h | 2 +- arch/arm/kernel/entry-common.S | 2 +- arch/arm64/kernel/entry.S | 2 +- arch/riscv/kernel/entry.S | 2 +- arch/s390/kernel/entry.S | 2 +- arch/arm/mm/cache-feroceon-l2.c | 2 +- arch/arm/mm/cache-tauros2.c | 2 +- arch/powerpc/mm/book3s64/hash_utils.c | 6 +-- arch/powerpc/mm/book3s64/radix_pgtable.c | 4 +- arch/s390/mm/init.c | 2 +- arch/x86/kernel/kvm.c | 2 +- arch/x86/mm/init_64.c | 2 +- drivers/clocksource/timer-orion.c | 2 +- .../lkdtm/{stackleak.c => kstack_erase.c} | 26 +++++----- drivers/soc/ti/pm33xx.c | 2 +- fs/proc/base.c | 6 +-- kernel/fork.c | 2 +- kernel/kexec_handover.c | 4 +- kernel/{stackleak.c => kstack_erase.c} | 22 ++++---- tools/objtool/check.c | 4 +- tools/testing/selftests/lkdtm/config | 2 +- MAINTAINERS | 6 ++- kernel/configs/hardening.config | 6 +++ 68 files changed, 204 insertions(+), 172 deletions(-) create mode 100644 scripts/Makefile.kstack_erase rename include/linux/{stackleak.h => kstack_erase.h} (81%) rename drivers/misc/lkdtm/{stackleak.c => kstack_erase.c} (89%) rename kernel/{stackleak.c => kstack_erase.c} (87%) -- 2.34.1

4 months, 4 weeks

[PATCH -rebased 15/15] selftests/sched_ext: Add test for DL server total_bw consistency

by Joel Fernandes

Add a new kselftest to verify that the total_bw value in /sys/kernel/debug/sched/debug remains consistent across all CPUs under different sched_ext BPF program states: 1. Before a BPF scheduler is loaded 2. While a BPF scheduler is loaded and active 3. After a BPF scheduler is unloaded The test runs CPU stress threads to ensure DL server bandwidth values stabilize before checking consistency. This helps catch potential issues with DL server bandwidth accounting during sched_ext transitions. Signed-off-by: Joel Fernandes <joelagnelf(a)nvidia.com> --- tools/testing/selftests/sched_ext/Makefile | 1 + tools/testing/selftests/sched_ext/total_bw.c | 282 +++++++++++++++++++ 2 files changed, 283 insertions(+) create mode 100644 tools/testing/selftests/sched_ext/total_bw.c diff --git a/tools/testing/selftests/sched_ext/Makefile b/tools/testing/selftests/sched_ext/Makefile index f0a8cba3a99f..d48be158b0a1 100644 --- a/tools/testing/selftests/sched_ext/Makefile +++ b/tools/testing/selftests/sched_ext/Makefile @@ -184,6 +184,7 @@ auto-test-targets := \ select_cpu_vtime \ rt_stall \ test_example \ + total_bw \ testcase-targets := $(addsuffix .o,$(addprefix $(SCXOBJ_DIR)/,$(auto-test-targets))) diff --git a/tools/testing/selftests/sched_ext/total_bw.c b/tools/testing/selftests/sched_ext/total_bw.c new file mode 100644 index 000000000000..d70852cee358 --- /dev/null +++ b/tools/testing/selftests/sched_ext/total_bw.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test to verify that total_bw value remains consistent across all CPUs + * in different BPF program states. + * + * Copyright (C) 2025 Nvidia Corporation. + */ +#include <bpf/bpf.h> +#include <errno.h> +#include <pthread.h> +#include <scx/common.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/wait.h> +#include <unistd.h> +#include "minimal.bpf.skel.h" +#include "scx_test.h" + +#define MAX_CPUS 512 +#define STRESS_DURATION_SEC 5 + +struct total_bw_ctx { + struct minimal *skel; + long baseline_bw[MAX_CPUS]; + int nr_cpus; +}; + +static void *cpu_stress_thread(void *arg) +{ + volatile int i; + time_t end_time = time(NULL) + STRESS_DURATION_SEC; + + while (time(NULL) < end_time) { + for (i = 0; i < 1000000; i++); + } + + return NULL; +} + +/* + * The first enqueue on a CPU causes the DL server to start, for that + * reason run stressor threads in the hopes it schedules on all CPUs. + */ +static int run_cpu_stress(int nr_cpus) +{ + pthread_t *threads; + int i, ret = 0; + + threads = calloc(nr_cpus, sizeof(pthread_t)); + if (!threads) + return -ENOMEM; + + /* Create threads to run on each CPU */ + for (i = 0; i < nr_cpus; i++) { + if (pthread_create(&threads[i], NULL, cpu_stress_thread, NULL)) { + ret = -errno; + fprintf(stderr, "Failed to create thread %d: %s\n", i, strerror(-ret)); + break; + } + } + + /* Wait for all threads to complete */ + for (i = 0; i < nr_cpus; i++) { + if (threads[i]) + pthread_join(threads[i], NULL); + } + + free(threads); + return ret; +} + +static int read_total_bw_values(long *bw_values, int max_cpus) +{ + FILE *fp; + char line[256]; + int cpu_count = 0; + + fp = fopen("/sys/kernel/debug/sched/debug", "r"); + if (!fp) { + SCX_ERR("Failed to open debug file"); + return -1; + } + + while (fgets(line, sizeof(line), fp)) { + char *bw_str = strstr(line, "total_bw"); + if (bw_str) { + bw_str = strchr(bw_str, ':'); + if (bw_str) { + /* Only store up to max_cpus values */ + if (cpu_count < max_cpus) { + bw_values[cpu_count] = atol(bw_str + 1); + } + cpu_count++; + } + } + } + + fclose(fp); + return cpu_count; +} + +static bool verify_total_bw_consistency(long *bw_values, int count) +{ + int i; + long first_value; + + if (count <= 0) + return false; + + first_value = bw_values[0]; + + for (i = 1; i < count; i++) { + if (bw_values[i] != first_value) { + SCX_ERR("Inconsistent total_bw: CPU0=%ld, CPU%d=%ld", + first_value, i, bw_values[i]); + return false; + } + } + + return true; +} + +static int fetch_verify_total_bw(long *bw_values, int nr_cpus) +{ + int attempts = 0; + int max_attempts = 10; + int count; + + /* + * The first enqueue on a CPU causes the DL server to start, for that + * reason run stressor threads in the hopes it schedules on all CPUs. + */ + if (run_cpu_stress(nr_cpus) < 0) { + SCX_ERR("Failed to run CPU stress"); + return -1; + } + + /* Try multiple times to get stable values */ + while (attempts < max_attempts) { + count = read_total_bw_values(bw_values, nr_cpus); + fprintf(stderr, "Read %d total_bw values (testing %d CPUs)\n", count, nr_cpus); + /* If system has more CPUs than we're testing, that's OK */ + if (count < nr_cpus) { + SCX_ERR("Expected at least %d CPUs, got %d", nr_cpus, count); + attempts++; + sleep(1); + continue; + } + + /* Only verify the CPUs we're testing */ + if (verify_total_bw_consistency(bw_values, nr_cpus)) { + fprintf(stderr, "Values are consistent: %ld\n", bw_values[0]); + return 0; + } + + attempts++; + sleep(1); + } + + return -1; +} + +static enum scx_test_status setup(void **ctx) +{ + struct total_bw_ctx *test_ctx; + + if (access("/sys/kernel/debug/sched/debug", R_OK) != 0) { + fprintf(stderr, "Skipping test: debugfs sched/debug not accessible\n"); + return SCX_TEST_SKIP; + } + + test_ctx = calloc(1, sizeof(*test_ctx)); + if (!test_ctx) + return SCX_TEST_FAIL; + + test_ctx->nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); + if (test_ctx->nr_cpus <= 0) { + free(test_ctx); + return SCX_TEST_FAIL; + } + + /* If system has more CPUs than MAX_CPUS, just test the first MAX_CPUS */ + if (test_ctx->nr_cpus > MAX_CPUS) { + test_ctx->nr_cpus = MAX_CPUS; + } + + /* Test scenario 1: BPF program not loaded */ + /* Read and verify baseline total_bw before loading BPF program */ + fprintf(stderr, "BPF prog initially not loaded, reading total_bw values\n"); + if (fetch_verify_total_bw(test_ctx->baseline_bw, test_ctx->nr_cpus) < 0) { + SCX_ERR("Failed to get stable baseline values"); + free(test_ctx); + return SCX_TEST_FAIL; + } + + /* Load the BPF skeleton */ + test_ctx->skel = minimal__open(); + if (!test_ctx->skel) { + free(test_ctx); + return SCX_TEST_FAIL; + } + + SCX_ENUM_INIT(test_ctx->skel); + if (minimal__load(test_ctx->skel)) { + minimal__destroy(test_ctx->skel); + free(test_ctx); + return SCX_TEST_FAIL; + } + + *ctx = test_ctx; + return SCX_TEST_PASS; +} + +static enum scx_test_status run(void *ctx) +{ + struct total_bw_ctx *test_ctx = ctx; + struct bpf_link *link; + long loaded_bw[MAX_CPUS]; + long unloaded_bw[MAX_CPUS]; + int i; + + /* Test scenario 2: BPF program loaded */ + link = bpf_map__attach_struct_ops(test_ctx->skel->maps.minimal_ops); + if (!link) { + SCX_ERR("Failed to attach scheduler"); + return SCX_TEST_FAIL; + } + + fprintf(stderr, "BPF program loaded, reading total_bw values\n"); + if (fetch_verify_total_bw(loaded_bw, test_ctx->nr_cpus) < 0) { + SCX_ERR("Failed to get stable values with BPF loaded"); + bpf_link__destroy(link); + return SCX_TEST_FAIL; + } + bpf_link__destroy(link); + + /* Test scenario 3: BPF program unloaded */ + fprintf(stderr, "BPF program unloaded, reading total_bw values\n"); + if (fetch_verify_total_bw(unloaded_bw, test_ctx->nr_cpus) < 0) { + SCX_ERR("Failed to get stable values after BPF unload"); + return SCX_TEST_FAIL; + } + + /* Verify all three scenarios have the same total_bw values */ + for (i = 0; i < test_ctx->nr_cpus; i++) { + if (test_ctx->baseline_bw[i] != loaded_bw[i]) { + SCX_ERR("CPU%d: baseline_bw=%ld != loaded_bw=%ld", + i, test_ctx->baseline_bw[i], loaded_bw[i]); + return SCX_TEST_FAIL; + } + + if (test_ctx->baseline_bw[i] != unloaded_bw[i]) { + SCX_ERR("CPU%d: baseline_bw=%ld != unloaded_bw=%ld", + i, test_ctx->baseline_bw[i], unloaded_bw[i]); + return SCX_TEST_FAIL; + } + } + + fprintf(stderr, "All total_bw values are consistent across all scenarios\n"); + return SCX_TEST_PASS; +} + +static void cleanup(void *ctx) +{ + struct total_bw_ctx *test_ctx = ctx; + + if (test_ctx) { + if (test_ctx->skel) + minimal__destroy(test_ctx->skel); + free(test_ctx); + } +} + +struct scx_test total_bw = { + .name = "total_bw", + .description = "Verify total_bw consistency across BPF program states", + .setup = setup, + .run = run, + .cleanup = cleanup, +}; +REGISTER_SCX_TEST(&total_bw) -- 2.34.1

5 months

[PATCH -rebased 14/15] selftests/sched_ext: Add test for sched_ext dl_server

by Joel Fernandes

From: Andrea Righi <arighi(a)nvidia.com> Add a selftest to validate the correct behavior of the deadline server for the ext_sched_class. [ Joel: Replaced occurences of CFS in the test with EXT. ] Signed-off-by: Joel Fernandes <joelagnelf(a)nvidia.com> Signed-off-by: Andrea Righi <arighi(a)nvidia.com> --- tools/testing/selftests/sched_ext/Makefile | 1 + .../selftests/sched_ext/rt_stall.bpf.c | 23 ++ tools/testing/selftests/sched_ext/rt_stall.c | 213 ++++++++++++++++++ 3 files changed, 237 insertions(+) create mode 100644 tools/testing/selftests/sched_ext/rt_stall.bpf.c create mode 100644 tools/testing/selftests/sched_ext/rt_stall.c diff --git a/tools/testing/selftests/sched_ext/Makefile b/tools/testing/selftests/sched_ext/Makefile index 9d9d6b4c38b0..f0a8cba3a99f 100644 --- a/tools/testing/selftests/sched_ext/Makefile +++ b/tools/testing/selftests/sched_ext/Makefile @@ -182,6 +182,7 @@ auto-test-targets := \ select_cpu_dispatch_bad_dsq \ select_cpu_dispatch_dbl_dsp \ select_cpu_vtime \ + rt_stall \ test_example \ testcase-targets := $(addsuffix .o,$(addprefix $(SCXOBJ_DIR)/,$(auto-test-targets))) diff --git a/tools/testing/selftests/sched_ext/rt_stall.bpf.c b/tools/testing/selftests/sched_ext/rt_stall.bpf.c new file mode 100644 index 000000000000..80086779dd1e --- /dev/null +++ b/tools/testing/selftests/sched_ext/rt_stall.bpf.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * A scheduler that verified if RT tasks can stall SCHED_EXT tasks. + * + * Copyright (c) 2025 NVIDIA Corporation. + */ + +#include <scx/common.bpf.h> + +char _license[] SEC("license") = "GPL"; + +UEI_DEFINE(uei); + +void BPF_STRUCT_OPS(rt_stall_exit, struct scx_exit_info *ei) +{ + UEI_RECORD(uei, ei); +} + +SEC(".struct_ops.link") +struct sched_ext_ops rt_stall_ops = { + .exit = (void *)rt_stall_exit, + .name = "rt_stall", +}; diff --git a/tools/testing/selftests/sched_ext/rt_stall.c b/tools/testing/selftests/sched_ext/rt_stall.c new file mode 100644 index 000000000000..d4cb545ebfd8 --- /dev/null +++ b/tools/testing/selftests/sched_ext/rt_stall.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2025 NVIDIA Corporation. + */ +#define _GNU_SOURCE +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <sched.h> +#include <sys/prctl.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <time.h> +#include <linux/sched.h> +#include <signal.h> +#include <bpf/bpf.h> +#include <scx/common.h> +#include <sys/wait.h> +#include <unistd.h> +#include "rt_stall.bpf.skel.h" +#include "scx_test.h" +#include "../kselftest.h" + +#define CORE_ID 0 /* CPU to pin tasks to */ +#define RUN_TIME 5 /* How long to run the test in seconds */ + +/* Simple busy-wait function for test tasks */ +static void process_func(void) +{ + while (1) { + /* Busy wait */ + for (volatile unsigned long i = 0; i < 10000000UL; i++); + } +} + +/* Set CPU affinity to a specific core */ +static void set_affinity(int cpu) +{ + cpu_set_t mask; + + CPU_ZERO(&mask); + CPU_SET(cpu, &mask); + if (sched_setaffinity(0, sizeof(mask), &mask) != 0) { + perror("sched_setaffinity"); + exit(EXIT_FAILURE); + } +} + +/* Set task scheduling policy and priority */ +static void set_sched(int policy, int priority) +{ + struct sched_param param; + + param.sched_priority = priority; + if (sched_setscheduler(0, policy, &param) != 0) { + perror("sched_setscheduler"); + exit(EXIT_FAILURE); + } +} + +/* Get process runtime from /proc/<pid>/stat */ +static float get_process_runtime(int pid) +{ + char path[256]; + FILE *file; + long utime, stime; + int fields; + + snprintf(path, sizeof(path), "/proc/%d/stat", pid); + file = fopen(path, "r"); + if (file == NULL) { + perror("Failed to open stat file"); + return -1; + } + + /* Skip the first 13 fields and read the 14th and 15th */ + fields = fscanf(file, + "%*d %*s %*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u %lu %lu", + &utime, &stime); + fclose(file); + + if (fields != 2) { + fprintf(stderr, "Failed to read stat file\n"); + return -1; + } + + /* Calculate the total time spent in the process */ + long total_time = utime + stime; + long ticks_per_second = sysconf(_SC_CLK_TCK); + float runtime_seconds = total_time * 1.0 / ticks_per_second; + + return runtime_seconds; +} + +static enum scx_test_status setup(void **ctx) +{ + struct rt_stall *skel; + + skel = rt_stall__open(); + SCX_FAIL_IF(!skel, "Failed to open"); + SCX_ENUM_INIT(skel); + SCX_FAIL_IF(rt_stall__load(skel), "Failed to load skel"); + + *ctx = skel; + + return SCX_TEST_PASS; +} + +static bool sched_stress_test(void) +{ + float cfs_runtime, rt_runtime; + int cfs_pid, rt_pid; + float expected_min_ratio = 0.04; /* 4% */ + + ksft_print_header(); + ksft_set_plan(1); + + /* Create and set up a EXT task */ + cfs_pid = fork(); + if (cfs_pid == 0) { + set_affinity(CORE_ID); + process_func(); + exit(0); + } else if (cfs_pid < 0) { + perror("fork for EXT task"); + ksft_exit_fail(); + } + + /* Create an RT task */ + rt_pid = fork(); + if (rt_pid == 0) { + set_affinity(CORE_ID); + set_sched(SCHED_FIFO, 50); + process_func(); + exit(0); + } else if (rt_pid < 0) { + perror("fork for RT task"); + ksft_exit_fail(); + } + + /* Let the processes run for the specified time */ + sleep(RUN_TIME); + + /* Get runtime for the EXT task */ + cfs_runtime = get_process_runtime(cfs_pid); + if (cfs_runtime != -1) + ksft_print_msg("Runtime of EXT task (PID %d) is %f seconds\n", cfs_pid, cfs_runtime); + else + ksft_exit_fail_msg("Error getting runtime for EXT task (PID %d)\n", cfs_pid); + + /* Get runtime for the RT task */ + rt_runtime = get_process_runtime(rt_pid); + if (rt_runtime != -1) + ksft_print_msg("Runtime of RT task (PID %d) is %f seconds\n", rt_pid, rt_runtime); + else + ksft_exit_fail_msg("Error getting runtime for RT task (PID %d)\n", rt_pid); + + /* Kill the processes */ + kill(cfs_pid, SIGKILL); + kill(rt_pid, SIGKILL); + waitpid(cfs_pid, NULL, 0); + waitpid(rt_pid, NULL, 0); + + /* Verify that the scx task got enough runtime */ + float actual_ratio = cfs_runtime / (cfs_runtime + rt_runtime); + ksft_print_msg("EXT task got %.2f%% of total runtime\n", actual_ratio * 100); + + if (actual_ratio >= expected_min_ratio) { + ksft_test_result_pass("PASS: EXT task got more than %.2f%% of runtime\n", + expected_min_ratio * 100); + return true; + } else { + ksft_test_result_fail("FAIL: EXT task got less than %.2f%% of runtime\n", + expected_min_ratio * 100); + return false; + } +} + +static enum scx_test_status run(void *ctx) +{ + struct rt_stall *skel = ctx; + struct bpf_link *link; + bool res; + + link = bpf_map__attach_struct_ops(skel->maps.rt_stall_ops); + SCX_FAIL_IF(!link, "Failed to attach scheduler"); + + res = sched_stress_test(); + + SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE)); + bpf_link__destroy(link); + + if (!res) + ksft_exit_fail(); + + return SCX_TEST_PASS; +} + +static void cleanup(void *ctx) +{ + struct rt_stall *skel = ctx; + + rt_stall__destroy(skel); +} + +struct scx_test rt_stall = { + .name = "rt_stall", + .description = "Verify that RT tasks cannot stall SCHED_EXT tasks", + .setup = setup, + .run = run, + .cleanup = cleanup, +}; +REGISTER_SCX_TEST(&rt_stall) -- 2.34.1

5 months

[PATCH v3 0/7] selftests/mm: Fix false positives and skip unsupported tests

by Aboorva Devarajan

Hi all, This patch series addresses false positives in the generic mm selftests and skips tests that cannot run correctly due to missing features or system limitations. v2: https://lore.kernel.org/all/20250703060656.54345-1-aboorvad@linux.ibm.com/ Changes in v3: - Rebased onto the latest mm-new branch, top commit of the base is commit 0709ddf8951f ("mm: add zblock allocator"). - Minor refactor based on the review comments. - Included the tags from the previous version. --- v1: https://lore.kernel.org/all/20250616160632.35250-1-aboorvad@linux.ibm.com/ Changes in v2: - Rebased onto the mm-new branch, top commit of the base is commit 3b4a8ad89f7e ("mm: add zblock allocator"). - Split some patches for clarity. - Updated virtual_address_range test to support testing 4PB VA on PPC64. - Added proper Fixes: tags. - Included a patch to skip a failing userfaultfd test when unsupported, instead of reporting a failure. --- Please let us know if you have any further comments. Thanks, Aboorva Aboorva Devarajan (3): selftests/mm: Fix child process exit codes in ksm_functional_tests selftests/mm: Skip thuge-gen test if system is not setup properly selftests/mm: Skip hugepage-mremap test if userfaultfd unavailable Donet Tom (4): mm/selftests: Fix incorrect pointer being passed to mark_range() selftests/mm: Add support to test 4PB VA on PPC64 selftest/mm: Fix ksm_funtional_test failures mm/selftests: Fix split_huge_page_test failure on systems with 64KB page size tools/testing/selftests/mm/hugepage-mremap.c | 16 +++++++++-- .../selftests/mm/ksm_functional_tests.c | 28 +++++++++++++------ .../selftests/mm/split_huge_page_test.c | 23 +++++++++------ tools/testing/selftests/mm/thuge-gen.c | 11 +++++--- .../selftests/mm/virtual_address_range.c | 13 ++++++++- 5 files changed, 67 insertions(+), 24 deletions(-) -- 2.47.1

5 months

[PATCH v2 0/1] selftests/futex: Check for shmget support at runtime

by Wake Liu

Changes in v2: - Restore RET_FAIL assignments in error paths to ensure the test's exit code accurately reflects the failure status. Wake Liu (1): selftests/futex: Check for shmget support at runtime .../selftests/futex/functional/futex_wait.c | 49 +++++++------ .../selftests/futex/functional/futex_waitv.c | 73 ++++++++++++------- 2 files changed, 73 insertions(+), 49 deletions(-) -- 2.50.1.703.g449372360f-goog

5 months

[PATCH] selftests/filesystems/binderfs: Skip tests if user namespaces are unavailable

by Wake Liu

The binderfs selftests, specifically `binderfs_stress` and `binderfs_test_unprivileged`, depend on user namespaces to run. On kernels built without user namespace support (CONFIG_USER_NS=n), these tests will fail. To prevent these failures, add a check for the availability of user namespaces by testing for the existence of "/proc/self/ns/user". If the check fails, skip the tests and print an informative message. Signed-off-by: Wake Liu <wakel(a)google.com> --- .../selftests/filesystems/binderfs/binderfs_test.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/testing/selftests/filesystems/binderfs/binderfs_test.c b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c index 81db85a5cc16..e77ed34ebd06 100644 --- a/tools/testing/selftests/filesystems/binderfs/binderfs_test.c +++ b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c @@ -291,6 +291,11 @@ static int write_id_mapping(enum idmap_type type, pid_t pid, const char *buf, return 0; } +static bool has_userns(void) +{ + return (access("/proc/self/ns/user", F_OK) == 0); +} + static void change_userns(struct __test_metadata *_metadata, int syncfds[2]) { int ret; @@ -378,6 +383,9 @@ static void *binder_version_thread(void *data) */ TEST(binderfs_stress) { + if (!has_userns()) + SKIP(return, "%s: user namespace not supported\n", __func__); + int fds[1000]; int syncfds[2]; pid_t pid; @@ -502,6 +510,8 @@ TEST(binderfs_test_privileged) TEST(binderfs_test_unprivileged) { + if (!has_userns()) + SKIP(return, "%s: user namespace not supported\n", __func__); int ret; int syncfds[2]; pid_t pid; -- 2.50.1.703.g449372360f-goog

5 months

[PATCH] selftests/futex: Skip futex_waitv tests if ENOSYS

by Wake Liu

The futex_waitv() syscall was introduced in Linux 5.16. The existing test in futex_wait_timeout.c will fail on kernels older than 5.16 due to the syscall not being implemented. Modify the test_timeout() function to check if the error returned is ENOSYS. If it is, skip the test and report it as such, rather than failing. This ensures the selftests can be run on a wider range of kernel versions without false negatives. Signed-off-by: Wake Liu <wakel(a)google.com> --- .../selftests/futex/functional/futex_wait_timeout.c | 11 ++++++++--- .../testing/selftests/futex/functional/futex_waitv.c | 8 ++++++++ 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/futex/functional/futex_wait_timeout.c b/tools/testing/selftests/futex/functional/futex_wait_timeout.c index d183f878360b..323cab339814 100644 --- a/tools/testing/selftests/futex/functional/futex_wait_timeout.c +++ b/tools/testing/selftests/futex/functional/futex_wait_timeout.c @@ -64,9 +64,14 @@ void *get_pi_lock(void *arg) static void test_timeout(int res, int *ret, char *test_name, int err) { if (!res || errno != err) { - ksft_test_result_fail("%s returned %d\n", test_name, - res < 0 ? errno : res); - *ret = RET_FAIL; + if (errno == ENOSYS) { + ksft_test_result_skip("%s: %s\n", + test_name, strerror(errno)); + } else { + ksft_test_result_fail("%s returned %d\n", test_name, + res < 0 ? errno : res); + *ret = RET_FAIL; + } } else { ksft_test_result_pass("%s succeeds\n", test_name); } diff --git a/tools/testing/selftests/futex/functional/futex_waitv.c b/tools/testing/selftests/futex/functional/futex_waitv.c index 034dbfef40cb..2a86fd3ea657 100644 --- a/tools/testing/selftests/futex/functional/futex_waitv.c +++ b/tools/testing/selftests/futex/functional/futex_waitv.c @@ -59,6 +59,14 @@ void *waiterfn(void *arg) int main(int argc, char *argv[]) { + if (!ksft_min_kernel_version(5, 16)) { + ksft_print_header(); + ksft_set_plan(0); + ksft_print_msg("%s: FUTEX_WAITV not implemented until 5.16\n", + basename(argv[0])); + ksft_print_cnts(); + return KSFT_SKIP; + } pthread_t waiter; int res, ret = RET_PASS; struct timespec to; -- 2.50.1.703.g449372360f-goog

5 months

[PATCH v3] selftests/futex: Check for shmget support at runtime

by Wake Liu

The futex tests `futex_wait.c` and `futex_waitv.c` rely on the `shmget()` syscall, which may not be available if the kernel is built without System V IPC support (CONFIG_SYSVIPC=n). This can lead to test failures on such systems. This patch modifies the tests to check for `shmget()` support at runtime by calling it and checking for an `ENOSYS` error. If `shmget()` is not supported, the tests are skipped with a clear message, improving the user experience and preventing false negatives. This approach is more robust than relying on compile-time checks and ensures that the tests run only when the required kernel features are present. Signed-off-by: Wake Liu <wakel(a)google.com> --- .../selftests/futex/functional/futex_wait.c | 57 ++++++++------- .../selftests/futex/functional/futex_waitv.c | 73 ++++++++++++------- 2 files changed, 78 insertions(+), 52 deletions(-) diff --git a/tools/testing/selftests/futex/functional/futex_wait.c b/tools/testing/selftests/futex/functional/futex_wait.c index 685140d9b93d..2a834f074959 100644 --- a/tools/testing/selftests/futex/functional/futex_wait.c +++ b/tools/testing/selftests/futex/functional/futex_wait.c @@ -48,7 +48,7 @@ static void *waiterfn(void *arg) int main(int argc, char *argv[]) { int res, ret = RET_PASS, fd, c, shm_id; - u_int32_t f_private = 0, *shared_data; + u_int32_t f_private = 0, *shared_data = NULL; unsigned int flags = FUTEX_PRIVATE_FLAG; pthread_t waiter; void *shm; @@ -96,32 +96,37 @@ int main(int argc, char *argv[]) /* Testing an anon page shared memory */ shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666); if (shm_id < 0) { - perror("shmget"); - exit(1); - } - - shared_data = shmat(shm_id, NULL, 0); - - *shared_data = 0; - futex = shared_data; - - info("Calling shared (page anon) futex_wait on futex: %p\n", futex); - if (pthread_create(&waiter, NULL, waiterfn, NULL)) - error("pthread_create failed\n", errno); - - usleep(WAKE_WAIT_US); - - info("Calling shared (page anon) futex_wake on futex: %p\n", futex); - res = futex_wake(futex, 1, 0); - if (res != 1) { - ksft_test_result_fail("futex_wake shared (page anon) returned: %d %s\n", - errno, strerror(errno)); - ret = RET_FAIL; + if (errno == ENOSYS) { + ksft_test_result_skip("Kernel does not support System V shared memory\n"); + } else { + ksft_test_result_fail("shmget() failed with error: %s\n", strerror(errno)); + ret = RET_FAIL; + } } else { - ksft_test_result_pass("futex_wake shared (page anon) succeeds\n"); + shared_data = shmat(shm_id, NULL, 0); + + *shared_data = 0; + futex = shared_data; + + info("Calling shared (page anon) futex_wait on futex: %p\n", futex); + if (pthread_create(&waiter, NULL, waiterfn, NULL)) + error("pthread_create failed\n", errno); + + usleep(WAKE_WAIT_US); + + info("Calling shared (page anon) futex_wake on futex: %p\n", futex); + res = futex_wake(futex, 1, 0); + if (res != 1) { + if (res < 0) + ksft_test_result_fail("futex_wake shared (page anon) failed with res=%d: %m\n", res); + else + ksft_test_result_fail("futex_wake shared (page anon) returned %d, expected 1\n", res); + ret = RET_FAIL; + } else { + ksft_test_result_pass("futex_wake shared (page anon) succeeds\n"); + } } - /* Testing a file backed shared memory */ fd = open(SHM_PATH, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR); if (fd < 0) { @@ -161,7 +166,8 @@ int main(int argc, char *argv[]) } /* Freeing resources */ - shmdt(shared_data); + if (shared_data) + shmdt(shared_data); munmap(shm, sizeof(f_private)); remove(SHM_PATH); close(fd); @@ -169,3 +175,4 @@ int main(int argc, char *argv[]) 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 index a94337f677e1..034dbfef40cb 100644 --- a/tools/testing/selftests/futex/functional/futex_waitv.c +++ b/tools/testing/selftests/futex/functional/futex_waitv.c @@ -110,40 +110,58 @@ int main(int argc, char *argv[]) } /* 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); + bool shm_supported = true; + int shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666); + + if (shm_id < 0) { + if (errno == ENOSYS) { + shm_supported = false; + ksft_test_result_skip("Kernel does not support System V shared memory\n"); + } else { + ksft_test_result_fail("shmget() failed with error: %s\n", strerror(errno)); + ret = RET_FAIL; + shm_supported = false; } + } else { + shmctl(shm_id, IPC_RMID, NULL); + } - unsigned int *shared_data = shmat(shm_id, NULL, 0); + if (shm_supported) { + for (i = 0; i < NR_FUTEXES; i++) { + int shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666); - *shared_data = 0; - waitv[i].uaddr = (uintptr_t)shared_data; - waitv[i].flags = FUTEX_32; - waitv[i].val = 0; - waitv[i].__reserved = 0; - } + if (shm_id < 0) { + perror("shmget"); + exit(1); + } - if (pthread_create(&waiter, NULL, waiterfn, NULL)) - error("pthread_create failed\n", errno); + unsigned int *shared_data = shmat(shm_id, NULL, 0); - usleep(WAKE_WAIT_US); + *shared_data = 0; + waitv[i].uaddr = (uintptr_t)shared_data; + waitv[i].flags = FUTEX_32; + waitv[i].val = 0; + waitv[i].__reserved = 0; + } - 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"); - } + if (pthread_create(&waiter, NULL, waiterfn, NULL)) + error("pthread_create failed\n", errno); - for (i = 0; i < NR_FUTEXES; i++) - shmdt(u64_to_ptr(waitv[i].uaddr)); + 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; @@ -235,3 +253,4 @@ int main(int argc, char *argv[]) ksft_print_cnts(); return ret; } + -- 2.50.1.703.g449372360f-goog

5 months

[PATCH RFC v2 0/2] KVM: arm64: PMU: Use multiple host PMUs

by Akihiko Odaki

On heterogeneous arm64 systems, KVM's PMU emulation is based on the features of a single host PMU instance. When a vCPU is migrated to a pCPU with an incompatible PMU, counters such as PMCCNTR_EL0 stop incrementing. Although this behavior is permitted by the architecture, Windows does not handle it gracefully and may crash with a division-by-zero error. The current workaround requires VMMs to pin vCPUs to a set of pCPUs that share a compatible PMU. This is difficult to implement correctly in QEMU/libvirt, where pinning occurs after vCPU initialization, and it also restricts the guest to a subset of available pCPUs. This patch introduces the KVM_ARM_VCPU_PMU_V3_COMPOSITION attribute to create a "composite" PMU. When set, KVM exposes a PMU that is compatible with all pCPUs by advertising only a single cycle counter, a feature common to all PMUs. This allows Windows guests to run reliably on heterogeneous systems without crashing, even without vCPU pinning, and enables VMMs to schedule vCPUs across all available pCPUs, making full use of the host hardware. A QEMU patch that demonstrates the usage of the new attribute is available at: https://lore.kernel.org/qemu-devel/20250806-kvm-v1-1-d1d50b7058cd@rsg.ci.i.… ("[PATCH RFC] target/arm/kvm: Choose PMU backend") Signed-off-by: Akihiko Odaki <odaki(a)rsg.ci.i.u-tokyo.ac.jp> --- Changes in v2: - Added the KVM_ARM_VCPU_PMU_V3_COMPOSITION attribute to opt in the feature. - Added code to handle overflow. - Link to v1: https://lore.kernel.org/r/20250319-hybrid-v1-1-4d1ada10e705@daynix.com --- Akihiko Odaki (2): KVM: arm64: PMU: Introduce KVM_ARM_VCPU_PMU_V3_COMPOSITION KVM: arm64: selftests: Test guest PMUv3 composition Documentation/virt/kvm/devices/vcpu.rst | 30 ++ arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/include/uapi/asm/kvm.h | 1 + arch/arm64/kvm/arm.c | 5 +- arch/arm64/kvm/pmu-emul.c | 495 +++++++++++++-------- arch/arm64/kvm/sys_regs.c | 2 +- include/kvm/arm_pmu.h | 12 +- .../selftests/kvm/arm64/vpmu_counter_access.c | 148 ++++-- 8 files changed, 461 insertions(+), 234 deletions(-) --- base-commit: 8ec6d99a41e3d1dbdff2bdb3aa42951681e1e76c change-id: 20250224-hybrid-01d5ff47edd2 Best regards, -- Akihiko Odaki <odaki(a)rsg.ci.i.u-tokyo.ac.jp>

5 months

[PATCH v12 iproute2-next 0/3] DUALPI2 iproute2 patch

by chia-yu.chang＠nokia-bell-labs.com

From: Chia-Yu Chang <chia-yu.chang(a)nokia-bell-labs.com> Hello, Please find DUALPI2 iproute2 patch v12. For more details of DualPI2, please refer IETF RFC9332 (https://datatracker.ietf.org/doc/html/rfc9332). Best Regards, Chia-Yu --- v12 (04-Aug-2025) - Split into 3 patches: one move get_float(), one add get_float_min_max(), one for dualpi2 (David Ahern <dsahern(a)kernel.org>) - Repalce matches() with strcmp() within get_packets() (David Ahern <dsahern(a)kernel.org>) - Apply reverse xmas tree listing of variables (David Ahern <dsahern(a)kernel.org>) v11 (18-Jul-2025) - Replace TCA_DUALPI2 prefix with TC_DUALPI2 prefix for enums (Jakub Kicinski <kuba(a)kernel.org>) v10 (02-Jul-2025) - Replace STEP_THRESH and STEP_PACKETS w/ STEP_THRESH_PKTS and STEP_THRESH_US of net-next patch (Jakub Kicinski <kuba(a)kernel.org>) v9 (13-Jun-2025) - Fix space issue and typos (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) - Change 'rtt_typical' to 'typical_rtt' in tc/q_dualpi2.c (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) - Add the num of enum used by DualPI2 in pkt_sched.h v8 (09-May-2025) - Update pkt_sched.h with the one in nex-next - Correct a typo in the comment within pkt_sched.h (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) - Update manual content in man/man8/tc-dualpi2.8 (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) - Update tc/q_dualpi2.c to fix missing blank lines and add missing case (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) v7 (05-May-2025) - Align pkt_sched.h with the v14 version of net-next due to spec modification in tc.yaml - Reorganize dualpi2_print_opt() to match the order in tc.yaml - Remove credit-queue in PRINT_JSON v6 (26-Apr-2025) - Update JSON file output due to spec modification in tc.yaml of net-next v5 (25-Mar-2025) - Use matches() to replace current strcmp() (Stephen Hemminger <stephen(a)networkplumber.org>) - Use general parse_percent() for handling scaled percentage values (Stephen Hemminger <stephen(a)networkplumber.org>) - Add print function for JSON of dualpi2 stats (Stephen Hemminger <stephen(a)networkplumber.org>) v4 (16-Mar-2025) - Add min_qlen_step to the dualpi2 attribute as the minimum queue length in number of packets in the L-queue to start step marking. v3 (21-Feb-2025) - Add memlimit to the dualpi2 attribute, and add memory_used, max_memory_used, and memory_limit in dualpi2 stats (Dave Taht <dave.taht(a)gmail.com>) - Update the manual to align with the latest implementation and clarify the queue naming and default unit - Use common "get_scaled_alpha_beta" and clean print_opt for Dualpi2 v2 (23-Oct-2024) - Rename get_float in dualpi2 to get_float_min_max in utils.c - Move get_float from iplink_can.c in utils.c (Stephen Hemminger <stephen(a)networkplumber.org>) - Add print function for JSON of dualpi2 (Stephen Hemminger <stephen(a)networkplumber.org>) --- Chia-Yu Chang (3): Move get_float() from ip/iplink_can.c to lib/utils.c Add get_float_min_max() in lib/utils.c tc: add dualpi2 scheduler module bash-completion/tc | 11 +- include/utils.h | 2 + ip/iplink_can.c | 14 -- lib/utils.c | 30 +++ man/man8/tc-dualpi2.8 | 249 ++++++++++++++++++++ tc/Makefile | 1 + tc/q_dualpi2.c | 535 ++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 827 insertions(+), 15 deletions(-) create mode 100644 man/man8/tc-dualpi2.8 create mode 100644 tc/q_dualpi2.c -- 2.34.1

5 months

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