From: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Subject: kselftest/arm64: check GCR_EL1 after context switch This test is specific to MTE and verifies that the GCR_EL1 register is context switched correctly. It spawns 1024 processes and each process spawns 5 threads. Each thread writes a random setting of GCR_EL1 through the prctl() system call and reads it back verifying that it is the same. If the values are not the same it reports a failure. Note: The test has been extended to verify that even SYNC and ASYNC mode setting is preserved correctly over context switching. Link: https://lkml.kernel.org/r/b51a165426e906e7ec8a68d806ef3f8cd92581a6.1606161801.git.andreyknvl@xxxxxxxxxx Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/arm64/mte/Makefile | 2 tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c | 155 ++++++++++ 2 files changed, 156 insertions(+), 1 deletion(-) --- /dev/null +++ a/tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2020 ARM Limited + +#define _GNU_SOURCE + +#include <errno.h> +#include <pthread.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <unistd.h> +#include <sys/auxv.h> +#include <sys/mman.h> +#include <sys/prctl.h> +#include <sys/types.h> +#include <sys/wait.h> + +#include "kselftest.h" +#include "mte_common_util.h" + +#define PR_SET_TAGGED_ADDR_CTRL 55 +#define PR_GET_TAGGED_ADDR_CTRL 56 +# define PR_TAGGED_ADDR_ENABLE (1UL << 0) +# define PR_MTE_TCF_SHIFT 1 +# define PR_MTE_TCF_NONE (0UL << PR_MTE_TCF_SHIFT) +# define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT) +# define PR_MTE_TCF_ASYNC (2UL << PR_MTE_TCF_SHIFT) +# define PR_MTE_TCF_MASK (3UL << PR_MTE_TCF_SHIFT) +# define PR_MTE_TAG_SHIFT 3 +# define PR_MTE_TAG_MASK (0xffffUL << PR_MTE_TAG_SHIFT) + +#include "mte_def.h" + +#define NUM_ITERATIONS 1024 +#define MAX_THREADS 5 +#define THREAD_ITERATIONS 1000 + +void *execute_thread(void *x) +{ + pid_t pid = *((pid_t *)x); + pid_t tid = gettid(); + uint64_t prctl_tag_mask; + uint64_t prctl_set; + uint64_t prctl_get; + uint64_t prctl_tcf; + + srand(time(NULL) ^ (pid << 16) ^ (tid << 16)); + + prctl_tag_mask = rand() & 0xffff; + + if (prctl_tag_mask % 2) + prctl_tcf = PR_MTE_TCF_SYNC; + else + prctl_tcf = PR_MTE_TCF_ASYNC; + + prctl_set = PR_TAGGED_ADDR_ENABLE | prctl_tcf | (prctl_tag_mask << PR_MTE_TAG_SHIFT); + + for (int j = 0; j < THREAD_ITERATIONS; j++) { + if (prctl(PR_SET_TAGGED_ADDR_CTRL, prctl_set, 0, 0, 0)) { + perror("prctl() failed"); + goto fail; + } + + prctl_get = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0); + + if (prctl_set != prctl_get) { + ksft_print_msg("Error: prctl_set: 0x%lx != prctl_get: 0x%lx\n", + prctl_set, prctl_get); + goto fail; + } + } + + return (void *)KSFT_PASS; + +fail: + return (void *)KSFT_FAIL; +} + +int execute_test(pid_t pid) +{ + pthread_t thread_id[MAX_THREADS]; + int thread_data[MAX_THREADS]; + + for (int i = 0; i < MAX_THREADS; i++) + pthread_create(&thread_id[i], NULL, + execute_thread, (void *)&pid); + + for (int i = 0; i < MAX_THREADS; i++) + pthread_join(thread_id[i], (void *)&thread_data[i]); + + for (int i = 0; i < MAX_THREADS; i++) + if (thread_data[i] == KSFT_FAIL) + return KSFT_FAIL; + + return KSFT_PASS; +} + +int mte_gcr_fork_test(void) +{ + pid_t pid; + int results[NUM_ITERATIONS]; + pid_t cpid; + int res; + + for (int i = 0; i < NUM_ITERATIONS; i++) { + pid = fork(); + + if (pid < 0) + return KSFT_FAIL; + + if (pid == 0) { + cpid = getpid(); + + res = execute_test(cpid); + + exit(res); + } + } + + for (int i = 0; i < NUM_ITERATIONS; i++) { + wait(&res); + + if (WIFEXITED(res)) + results[i] = WEXITSTATUS(res); + else + --i; + } + + for (int i = 0; i < NUM_ITERATIONS; i++) + if (results[i] == KSFT_FAIL) + return KSFT_FAIL; + + return KSFT_PASS; +} + +int main(int argc, char *argv[]) +{ + int err; + + err = mte_default_setup(); + if (err) + return err; + + ksft_set_plan(1); + + evaluate_test(mte_gcr_fork_test(), + "Verify that GCR_EL1 is set correctly on context switch\n"); + + mte_restore_setup(); + ksft_print_cnts(); + + return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL; +} + --- a/tools/testing/selftests/arm64/mte/Makefile~kselftest-arm64-check-gcr_el1-after-context-switch +++ a/tools/testing/selftests/arm64/mte/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 # Copyright (C) 2020 ARM Limited -CFLAGS += -std=gnu99 -I. +CFLAGS += -std=gnu99 -I. -lpthread SRCS := $(filter-out mte_common_util.c,$(wildcard *.c)) PROGS := $(patsubst %.c,%,$(SRCS)) _
