diff options
author | Weihong Zhang <weihong.zhang@intel.com> | 2023-03-12 14:26:10 +0300 |
---|---|---|
committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-03-16 23:08:40 +0300 |
commit | 833c12ce0f4307675beb60b194833c6c7cb506d7 (patch) | |
tree | 5f3de37c556c9af65e1d40291225e90df9694d27 /tools/testing/selftests/x86/lam.c | |
parent | 72fd6d738c991225c1053ee5003dd45e9c04e0e6 (diff) | |
download | linux-833c12ce0f4307675beb60b194833c6c7cb506d7.tar.xz |
selftests/x86/lam: Add inherit test cases for linear-address masking
LAM is enabled per-thread and gets inherited on fork(2)/clone(2). exec()
reverts LAM status to the default disabled state.
There are two test scenarios:
- Fork test cases:
These cases were used to test the inheritance of LAM for per-thread,
Child process generated by fork() should inherit LAM feature from
parent process, Child process can get the LAM mode same as parent
process.
- Execve test cases:
Processes generated by execve() are different from processes
generated by fork(), these processes revert LAM status to disabled
status.
Signed-off-by: Weihong Zhang <weihong.zhang@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230312112612.31869-16-kirill.shutemov%40linux.intel.com
Diffstat (limited to 'tools/testing/selftests/x86/lam.c')
-rw-r--r-- | tools/testing/selftests/x86/lam.c | 125 |
1 files changed, 121 insertions, 4 deletions
diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c index 52750ebd0887..ebabd4333b7d 100644 --- a/tools/testing/selftests/x86/lam.c +++ b/tools/testing/selftests/x86/lam.c @@ -37,8 +37,9 @@ #define FUNC_MMAP 0x4 #define FUNC_SYSCALL 0x8 #define FUNC_URING 0x10 +#define FUNC_INHERITE 0x20 -#define TEST_MASK 0x1f +#define TEST_MASK 0x3f #define LOW_ADDR (0x1UL << 30) #define HIGH_ADDR (0x3UL << 48) @@ -174,6 +175,28 @@ static unsigned long get_default_tag_bits(void) return lam; } +/* + * Set tagged address and read back untag mask. + * check if the untag mask is expected. + */ +static int get_lam(void) +{ + uint64_t ptr = 0; + int ret = -1; + /* Get untagged mask */ + if (syscall(SYS_arch_prctl, ARCH_GET_UNTAG_MASK, &ptr) == -1) + return -1; + + /* Check mask returned is expected */ + if (ptr == ~(LAM_U57_MASK)) + ret = LAM_U57_BITS; + else if (ptr == -1ULL) + ret = LAM_NONE; + + + return ret; +} + /* According to LAM mode, set metadata in high bits */ static uint64_t set_metadata(uint64_t src, unsigned long lam) { @@ -581,7 +604,7 @@ out: switch (lam) { case LAM_U57_BITS: /* Clear bits 62:57 */ - addr = (addr & ~(0x3fULL << 57)); + addr = (addr & ~(LAM_U57_MASK)); break; } free((void *)addr); @@ -632,6 +655,72 @@ static int fork_test(struct testcases *test) return ret; } +static int handle_execve(struct testcases *test) +{ + int ret, child_ret; + int lam = test->lam; + pid_t pid; + + pid = fork(); + if (pid < 0) { + perror("Fork failed."); + ret = 1; + } else if (pid == 0) { + char path[PATH_MAX]; + + /* Set LAM mode in parent process */ + if (set_lam(lam) != 0) + return 1; + + /* Get current binary's path and the binary was run by execve */ + if (readlink("/proc/self/exe", path, PATH_MAX) <= 0) + exit(-1); + + /* run binary to get LAM mode and return to parent process */ + if (execlp(path, path, "-t 0x0", NULL) < 0) { + perror("error on exec"); + exit(-1); + } + } else { + wait(&child_ret); + ret = WEXITSTATUS(child_ret); + if (ret != LAM_NONE) + return 1; + } + + return 0; +} + +static int handle_inheritance(struct testcases *test) +{ + int ret, child_ret; + int lam = test->lam; + pid_t pid; + + /* Set LAM mode in parent process */ + if (set_lam(lam) != 0) + return 1; + + pid = fork(); + if (pid < 0) { + perror("Fork failed."); + return 1; + } else if (pid == 0) { + /* Set LAM mode in parent process */ + int child_lam = get_lam(); + + exit(child_lam); + } else { + wait(&child_ret); + ret = WEXITSTATUS(child_ret); + + if (lam != ret) + return 1; + } + + return 0; +} + static void run_test(struct testcases *test, int count) { int i, ret = 0; @@ -740,11 +829,26 @@ static struct testcases mmap_cases[] = { }, }; +static struct testcases inheritance_cases[] = { + { + .expected = 0, + .lam = LAM_U57_BITS, + .test_func = handle_inheritance, + .msg = "FORK: LAM_U57, child process should get LAM mode same as parent\n", + }, + { + .expected = 0, + .lam = LAM_U57_BITS, + .test_func = handle_execve, + .msg = "EXECVE: LAM_U57, child process should get disabled LAM mode\n", + }, +}; + static void cmd_help(void) { printf("usage: lam [-h] [-t test list]\n"); printf("\t-t test list: run tests specified in the test list, default:0x%x\n", TEST_MASK); - printf("\t\t0x1:malloc; 0x2:max_bits; 0x4:mmap; 0x8:syscall; 0x10:io_uring.\n"); + printf("\t\t0x1:malloc; 0x2:max_bits; 0x4:mmap; 0x8:syscall; 0x10:io_uring; 0x20:inherit;\n"); printf("\t-h: help\n"); } @@ -764,7 +868,7 @@ int main(int argc, char **argv) switch (c) { case 't': tests = strtoul(optarg, NULL, 16); - if (!(tests & TEST_MASK)) { + if (tests && !(tests & TEST_MASK)) { ksft_print_msg("Invalid argument!\n"); return -1; } @@ -778,6 +882,16 @@ int main(int argc, char **argv) } } + /* + * When tests is 0, it is not a real test case; + * the option used by test case(execve) to check the lam mode in + * process generated by execve, the process read back lam mode and + * check with lam mode in parent process. + */ + if (!tests) + return (get_lam()); + + /* Run test cases */ if (tests & FUNC_MALLOC) run_test(malloc_cases, ARRAY_SIZE(malloc_cases)); @@ -793,6 +907,9 @@ int main(int argc, char **argv) if (tests & FUNC_URING) run_test(uring_cases, ARRAY_SIZE(uring_cases)); + if (tests & FUNC_INHERITE) + run_test(inheritance_cases, ARRAY_SIZE(inheritance_cases)); + ksft_set_plan(tests_cnt); return ksft_exit_pass(); |