diff options
| -rw-r--r-- | tools/testing/selftests/arm64/abi/.gitignore | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/arm64/abi/Makefile | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/arm64/abi/hwcap.c | 188 |
3 files changed, 190 insertions, 1 deletions
diff --git a/tools/testing/selftests/arm64/abi/.gitignore b/tools/testing/selftests/arm64/abi/.gitignore index b9e54417250d..c31d34d48a30 100644 --- a/tools/testing/selftests/arm64/abi/.gitignore +++ b/tools/testing/selftests/arm64/abi/.gitignore @@ -1,2 +1,3 @@ +hwcap syscall-abi tpidr2 diff --git a/tools/testing/selftests/arm64/abi/Makefile b/tools/testing/selftests/arm64/abi/Makefile index c8d7f2495eb2..e60752eb8334 100644 --- a/tools/testing/selftests/arm64/abi/Makefile +++ b/tools/testing/selftests/arm64/abi/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 # Copyright (C) 2021 ARM Limited -TEST_GEN_PROGS := syscall-abi tpidr2 +TEST_GEN_PROGS := hwcap syscall-abi tpidr2 include ../../lib.mk diff --git a/tools/testing/selftests/arm64/abi/hwcap.c b/tools/testing/selftests/arm64/abi/hwcap.c new file mode 100644 index 000000000000..8b5c646cea63 --- /dev/null +++ b/tools/testing/selftests/arm64/abi/hwcap.c @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 ARM Limited. + */ + +#include <errno.h> +#include <signal.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/auxv.h> +#include <sys/prctl.h> +#include <asm/hwcap.h> +#include <asm/sigcontext.h> +#include <asm/unistd.h> + +#include "../../kselftest.h" + +#define TESTS_PER_HWCAP 2 + +/* + * Function expected to generate SIGILL when the feature is not + * supported and return when it is supported. If SIGILL is generated + * then the handler must be able to skip over the instruction safely. + * + * Note that it is expected that for many architecture extensions + * there are no specific traps due to no architecture state being + * added so we may not fault if running on a kernel which doesn't know + * to add the hwcap. + */ +typedef void (*sigill_fn)(void); + +static void sme_sigill(void) +{ + /* RDSVL x0, #0 */ + asm volatile(".inst 0x04bf5800" : : : "x0"); +} + +static void sve_sigill(void) +{ + /* RDVL x0, #0 */ + asm volatile(".inst 0x04bf5000" : : : "x0"); +} + +static const struct hwcap_data { + const char *name; + unsigned long at_hwcap; + unsigned long hwcap_bit; + const char *cpuinfo; + sigill_fn sigill_fn; + bool sigill_reliable; +} hwcaps[] = { + { + .name = "SME", + .at_hwcap = AT_HWCAP2, + .hwcap_bit = HWCAP2_SME, + .cpuinfo = "sme", + .sigill_fn = sme_sigill, + .sigill_reliable = true, + }, + { + .name = "SVE", + .at_hwcap = AT_HWCAP, + .hwcap_bit = HWCAP_SVE, + .cpuinfo = "sve", + .sigill_fn = sve_sigill, + .sigill_reliable = true, + }, +}; + +static bool seen_sigill; + +static void handle_sigill(int sig, siginfo_t *info, void *context) +{ + ucontext_t *uc = context; + + seen_sigill = true; + + /* Skip over the offending instruction */ + uc->uc_mcontext.pc += 4; +} + +bool cpuinfo_present(const char *name) +{ + FILE *f; + char buf[2048], name_space[30], name_newline[30]; + char *s; + + /* + * The feature should appear with a leading space and either a + * trailing space or a newline. + */ + snprintf(name_space, sizeof(name_space), " %s ", name); + snprintf(name_newline, sizeof(name_newline), " %s\n", name); + + f = fopen("/proc/cpuinfo", "r"); + if (!f) { + ksft_print_msg("Failed to open /proc/cpuinfo\n"); + return false; + } + + while (fgets(buf, sizeof(buf), f)) { + /* Features: line? */ + if (strncmp(buf, "Features\t:", strlen("Features\t:")) != 0) + continue; + + /* All CPUs should be symmetric, don't read any more */ + fclose(f); + + s = strstr(buf, name_space); + if (s) + return true; + s = strstr(buf, name_newline); + if (s) + return true; + + return false; + } + + ksft_print_msg("Failed to find Features in /proc/cpuinfo\n"); + fclose(f); + return false; +} + +int main(void) +{ + const struct hwcap_data *hwcap; + int i, ret; + bool have_cpuinfo, have_hwcap; + struct sigaction sa; + + ksft_print_header(); + ksft_set_plan(ARRAY_SIZE(hwcaps) * TESTS_PER_HWCAP); + + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handle_sigill; + sa.sa_flags = SA_RESTART | SA_SIGINFO; + sigemptyset(&sa.sa_mask); + ret = sigaction(SIGILL, &sa, NULL); + if (ret < 0) + ksft_exit_fail_msg("Failed to install SIGILL handler: %s (%d)\n", + strerror(errno), errno); + + for (i = 0; i < ARRAY_SIZE(hwcaps); i++) { + hwcap = &hwcaps[i]; + + have_hwcap = getauxval(hwcaps->at_hwcap) & hwcap->hwcap_bit; + have_cpuinfo = cpuinfo_present(hwcap->cpuinfo); + + if (have_hwcap) + ksft_print_msg("%s present", hwcap->name); + + ksft_test_result(have_hwcap == have_cpuinfo, + "cpuinfo_match_%s\n", hwcap->name); + + if (hwcap->sigill_fn) { + seen_sigill = false; + hwcap->sigill_fn(); + + if (have_hwcap) { + /* Should be able to use the extension */ + ksft_test_result(!seen_sigill, "sigill_%s\n", + hwcap->name); + } else if (hwcap->sigill_reliable) { + /* Guaranteed a SIGILL */ + ksft_test_result(seen_sigill, "sigill_%s\n", + hwcap->name); + } else { + /* Missing SIGILL might be fine */ + ksft_print_msg("SIGILL %sreported for %s\n", + seen_sigill ? "" : "not ", + hwcap->name); + ksft_test_result_skip("sigill_%s\n", + hwcap->name); + } + } else { + ksft_test_result_skip("sigill_%s\n", + hwcap->name); + } + } + + ksft_print_cnts(); + + return 0; +} |