diff options
Diffstat (limited to 'tools/testing/selftests/arm64/abi/tpidr2.c')
| -rw-r--r-- | tools/testing/selftests/arm64/abi/tpidr2.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/tools/testing/selftests/arm64/abi/tpidr2.c b/tools/testing/selftests/arm64/abi/tpidr2.c new file mode 100644 index 000000000000..1703543fb7c7 --- /dev/null +++ b/tools/testing/selftests/arm64/abi/tpidr2.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/sched.h> +#include <linux/wait.h> + +#include "kselftest.h" + +#define SYS_TPIDR2 "S3_3_C13_C0_5" + +#define EXPECTED_TESTS 5 + +static void set_tpidr2(uint64_t val) +{ + asm volatile ( + "msr " SYS_TPIDR2 ", %0\n" + : + : "r"(val) + : "cc"); +} + +static uint64_t get_tpidr2(void) +{ + uint64_t val; + + asm volatile ( + "mrs %0, " SYS_TPIDR2 "\n" + : "=r"(val) + : + : "cc"); + + return val; +} + +/* Processes should start with TPIDR2 == 0 */ +static int default_value(void) +{ + return get_tpidr2() == 0; +} + +/* If we set TPIDR2 we should read that value */ +static int write_read(void) +{ + set_tpidr2(getpid()); + + return getpid() == get_tpidr2(); +} + +/* If we set a value we should read the same value after scheduling out */ +static int write_sleep_read(void) +{ + set_tpidr2(getpid()); + + msleep(100); + + return getpid() == get_tpidr2(); +} + +/* + * If we fork the value in the parent should be unchanged and the + * child should start with the same value and be able to set its own + * value. + */ +static int write_fork_read(void) +{ + pid_t newpid, waiting, oldpid; + int status; + + set_tpidr2(getpid()); + + oldpid = getpid(); + newpid = fork(); + if (newpid == 0) { + /* In child */ + if (get_tpidr2() != oldpid) { + ksft_print_msg("TPIDR2 changed in child: %llx\n", + get_tpidr2()); + exit(0); + } + + set_tpidr2(getpid()); + if (get_tpidr2() == getpid()) { + exit(1); + } else { + ksft_print_msg("Failed to set TPIDR2 in child\n"); + exit(0); + } + } + if (newpid < 0) { + ksft_print_msg("fork() failed: %d\n", newpid); + return 0; + } + + for (;;) { + waiting = waitpid(newpid, &status, 0); + + if (waiting < 0) { + if (errno == EINTR) + continue; + ksft_print_msg("waitpid() failed: %d\n", errno); + return 0; + } + if (waiting != newpid) { + ksft_print_msg("waitpid() returned wrong PID: %d != %d\n", + waiting, newpid); + return 0; + } + + if (!WIFEXITED(status)) { + ksft_print_msg("child did not exit\n"); + return 0; + } + + if (getpid() != get_tpidr2()) { + ksft_print_msg("TPIDR2 corrupted in parent\n"); + return 0; + } + + return WEXITSTATUS(status); + } +} + +/* + * sys_clone() has a lot of per architecture variation so just define + * it here rather than adding it to nolibc, plus the raw API is a + * little more convenient for this test. + */ +static int sys_clone(unsigned long clone_flags, unsigned long newsp, + int *parent_tidptr, unsigned long tls, + int *child_tidptr) +{ + return my_syscall5(__NR_clone, clone_flags, newsp, parent_tidptr, tls, + child_tidptr); +} + +#define __STACK_SIZE (8 * 1024 * 1024) + +/* + * If we clone with CLONE_VM then the value in the parent should + * be unchanged and the child should start with zero and be able to + * set its own value. + */ +static int write_clone_read(void) +{ + int parent_tid, child_tid; + pid_t parent, waiting; + int ret, status; + void *stack; + + parent = getpid(); + set_tpidr2(parent); + + stack = malloc(__STACK_SIZE); + if (!stack) { + ksft_print_msg("malloc() failed\n"); + return 0; + } + + ret = sys_clone(CLONE_VM, (unsigned long)stack + __STACK_SIZE, + &parent_tid, 0, &child_tid); + if (ret == -1) { + ksft_print_msg("clone() failed: %d\n", errno); + return 0; + } + + if (ret == 0) { + /* In child */ + if (get_tpidr2() != 0) { + ksft_print_msg("TPIDR2 non-zero in child: %llx\n", + get_tpidr2()); + exit(0); + } + + if (gettid() == 0) + ksft_print_msg("Child TID==0\n"); + set_tpidr2(gettid()); + if (get_tpidr2() == gettid()) { + exit(1); + } else { + ksft_print_msg("Failed to set TPIDR2 in child\n"); + exit(0); + } + } + + for (;;) { + waiting = waitpid(ret, &status, __WCLONE); + + if (waiting < 0) { + if (errno == EINTR) + continue; + ksft_print_msg("waitpid() failed: %d\n", errno); + return 0; + } + if (waiting != ret) { + ksft_print_msg("waitpid() returned wrong PID %d\n", + waiting); + return 0; + } + + if (!WIFEXITED(status)) { + ksft_print_msg("child did not exit\n"); + return 0; + } + + if (parent != get_tpidr2()) { + ksft_print_msg("TPIDR2 corrupted in parent\n"); + return 0; + } + + return WEXITSTATUS(status); + } +} + +int main(int argc, char **argv) +{ + int ret; + + ksft_print_header(); + ksft_set_plan(5); + + ksft_print_msg("PID: %d\n", getpid()); + + /* + * This test is run with nolibc which doesn't support hwcap and + * it's probably disproportionate to implement so instead check + * for the default vector length configuration in /proc. + */ + ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0); + if (ret >= 0) { + ksft_test_result(default_value(), "default_value\n"); + ksft_test_result(write_read(), "write_read\n"); + ksft_test_result(write_sleep_read(), "write_sleep_read\n"); + ksft_test_result(write_fork_read(), "write_fork_read\n"); + ksft_test_result(write_clone_read(), "write_clone_read\n"); + + } else { + ksft_print_msg("SME support not present\n"); + + ksft_test_result_skip("default_value\n"); + ksft_test_result_skip("write_read\n"); + ksft_test_result_skip("write_sleep_read\n"); + ksft_test_result_skip("write_fork_read\n"); + ksft_test_result_skip("write_clone_read\n"); + } + + ksft_finished(); +} |