In order to ensure that FPU, AVX2, AVX512 opmask and PKRU XSAVE content in the same process is not affected by signal handling, this case tests that: 1. In nested signal processing, the signal handling will use each signal's own xstates, and the xstates of the signal handling under test should not be changed after another nested signal handling is completed; 2. The xstates content of the process should not change after the nested signal handling. Process will change FPU, AVX2, AVX512, PKRU xstates before signal handling test to ensure that the entire processing of these xstates works as expected.

Signed-off-by: Pengfei Xu pengfei.xu@intel.com --- tools/testing/selftests/x86/Makefile | 4 +- tools/testing/selftests/x86/xsave_common.h | 426 ++++++++++++++++++ .../selftests/x86/xsave_signal_handle.c | 192 ++++++++ 3 files changed, 620 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/x86/xsave_common.h create mode 100644 tools/testing/selftests/x86/xsave_signal_handle.c

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 8a1f62ab3c8e..b51f02bc38c2 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -18,7 +18,7 @@ TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering \ - corrupt_xstate_header amx + corrupt_xstate_header amx xsave_signal_handle # Some selftests require 32bit support enabled also on 64bit systems TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall

@@ -75,7 +75,7 @@ $(BINARIES_32): $(OUTPUT)/%_32: %.c helpers.h $(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl -lm

$(BINARIES_64): $(OUTPUT)/%_64: %.c helpers.h - $(CC) -m64 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl + $(CC) -m64 -mxsave -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl

# x86_64 users should be encouraged to install 32-bit libraries ifeq ($(CAN_BUILD_I386)$(CAN_BUILD_X86_64),01) diff --git a/tools/testing/selftests/x86/xsave_common.h b/tools/testing/selftests/x86/xsave_common.h new file mode 100644 index 000000000000..76fcecc4b775 --- /dev/null +++ b/tools/testing/selftests/x86/xsave_common.h @@ -0,0 +1,426 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <x86intrin.h> +#include <string.h> +#include <signal.h> +#include <unistd.h> +#include "../kselftest.h" + +#ifdef __i386__ +#define XSAVE _xsave +#else +#define XSAVE _xsave64 +#endif + +#ifdef __i386__ +#define XRSTOR _xrstor +#else +#define XRSTOR _xrstor64 +#endif + +#define XSAVE_MASK_FP (1 << XFEATURE_FP) +#define XSAVE_MASK_YMM (1 << XFEATURE_YMM) +#define XSAVE_MASK_OPMASK (1 << XFEATURE_OPMASK) +#define XSAVE_MASK_PKRU (1 << XFEATURE_PKRU) +#define XSAVE_TEST_MASK (XSAVE_MASK_FP | XSAVE_MASK_YMM | XSAVE_MASK_OPMASK \ + | XSAVE_MASK_PKRU) +#define RESULT_PASS 0 +#define RESULT_FAIL 1 +#define RESULT_ERROR 3 +#define CHANGE 10 +#define NO_CHANGE 11 + +/* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */ +#define X86_FEATURE_AVX2 (1U << 5) /* AVX2 instructions */ +#define X86_FEATURE_AVX512F (1U << 16) /* AVX-512 Foundation */ + +/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */ +#define X86_FEATURE_PKU (1U << 3) /* Protection Keys for Userspace */ +#define X86_FEATURE_OSPKE (1U << 4) /* OS Protection Keys Enable */ + +#define XSTATE_CPUID (0xd) + +/* + * List of XSAVE features Linux knows about: + */ +enum xfeature { + XFEATURE_FP, + XFEATURE_SSE, + /* + * Values above here are "legacy states". + * Those below are "extended states". + */ + XFEATURE_YMM, + XFEATURE_BNDREGS, + XFEATURE_BNDCSR, + XFEATURE_OPMASK, + XFEATURE_ZMM_Hi256, + XFEATURE_Hi16_ZMM, + XFEATURE_PT_UNIMPLEMENTED_SO_FAR, + XFEATURE_PKRU, + XFEATURE_PASID, + XFEATURE_RSRVD_COMP_11, + XFEATURE_RSRVD_COMP_12, + XFEATURE_RSRVD_COMP_13, + XFEATURE_RSRVD_COMP_14, + XFEATURE_LBR, + + XFEATURE_MAX, +}; + +/* Copied from Linux kernel */ +static inline void native_cpuid(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx) +{ + /* ecx is often an input as well as an output. */ + asm volatile("cpuid" + : "=a" (*eax), + "=b" (*ebx), + "=c" (*ecx), + "=d" (*edx) + : "0" (*eax), "2" (*ecx) + : "memory"); +} + +static inline int cpu_has_avx2(void) +{ + unsigned int eax, ebx, ecx, edx; + + eax = 0x7; + ecx = 0x0; + native_cpuid(&eax, &ebx, &ecx, &edx); + + /* Is avx2(Advanced Vector Extensions-2) enabled? */ + return (ebx & X86_FEATURE_AVX2); +} + +static inline int cpu_has_avx512f(void) +{ + unsigned int eax, ebx, ecx, edx; + + eax = 0x7; + ecx = 0x0; + native_cpuid(&eax, &ebx, &ecx, &edx); + + /* Is avx512f(Advanced Vector Extensions-512 Foundation) enabled? */ + return (ebx & X86_FEATURE_AVX512F); +} + +static inline int cpu_has_pkeys(void) +{ + unsigned int eax, ebx, ecx, edx; + + eax = 0x7; + ecx = 0x0; + native_cpuid(&eax, &ebx, &ecx, &edx); + + /* check if the cpu supports protection keys for user-mode pages */ + if (!(ecx & X86_FEATURE_PKU)) { + printf("cpu does not have PKU\n"); + return 0; + } + /* check if the cpu supports RDPKRU/WRPKRU instructions */ + if (!(ecx & X86_FEATURE_OSPKE)) { + printf("cpu does not have OSPKE\n"); + return 0; + } + + return 1; +} + +void execution_failed(char *reason, ...) +{ + ksft_test_result_xfail("%s", reason); + ksft_exit_fail(); +} + +int get_xsave_size(void) +{ + unsigned int eax, ebx, ecx, edx; + + eax = 0x0d; + ebx = 0; + ecx = 0; + edx = 0; + native_cpuid(&eax, &ebx, &ecx, &edx); + + return (int)ecx; +} + +void dump_buffer(unsigned char *buf, int size) +{ + int i, j; + + printf("xsave size = %d (%03xh)\n", size, size); + + for (i = 0; i < size; i += 16) { + printf("%04x: ", i); + + for (j = i; ((j < i + 16) && (j < size)); j++) + printf("%02x ", buf[j]); + printf("\n"); + } +} + +void show_part_buf(unsigned char *buf0, unsigned char *buf1, int start, + int size) +{ + int c; + + printf("%04x: ", start); + for (c = start; ((c < start + 16) && (c < size)); c++) + printf("%02x ", buf0[c]); + printf(" -> "); + for (c = start; ((c < start + 16) && (c < size)); c++) + printf("%02x ", buf1[c]); + printf("\n"); +} + +int show_buf_diff(unsigned char *buf0, unsigned char *buf1, int size) +{ + int a, b, result_buf = NO_CHANGE; + + for (a = 0; a < size; a += 16) { + for (b = a; ((b < a + 16) && (b < size)); b++) { + if (buf0[b] != buf1[b]) { + show_part_buf(buf0, buf1, a, size); + result_buf = CHANGE; + break; + } + } + } + + return result_buf; +} + +int check_xsave_reserved_header(unsigned char *buf0, + unsigned char *buf1, int size, const char *test_name) +{ + int a, b, result_resv_header = RESULT_PASS; + + /* SDM: Software should ensure that bytes 63:16 of the XSAVE header are 0 */ + for (a = 528; a < 576 ; a += 16) { + for (b = a; ((b < a + 16) && (b < size)); b++) { + if ((buf0[b] != 0) || (buf1[b] != 0)) { + ksft_print_msg("%s FAIL: buf0[%d]:%d or buf1[%d]:%d not 0\n", + test_name, b, buf0[b], b, buf1[b]); + show_part_buf(buf0, buf1, a, size); + result_resv_header = RESULT_FAIL; + break; + } + } + } + + return result_resv_header; +} + +int compare_xsave_buf(unsigned char *buf0, unsigned char *buf1, + int size, const char *test_name, int change) +{ + int result_buf = RESULT_ERROR, result_resv_header = RESULT_ERROR; + + switch (change) { + case CHANGE: + if (show_buf_diff(buf0, buf1, size) == CHANGE) + result_buf = RESULT_PASS; + else { + ksft_print_msg("%s FAIL: xsave content was same\n", test_name); + result_buf = RESULT_FAIL; + } + break; + case NO_CHANGE: + if (show_buf_diff(buf0, buf1, size) == CHANGE) { + ksft_print_msg("%s FAIL: xsave content changed\n", test_name); + show_buf_diff(buf0, buf1, size); + result_buf = RESULT_FAIL; + } else + result_buf = RESULT_PASS; + break; + default: + ksft_test_result_error("%s ERROR: invalid change:%d\n", test_name, + change); + break; + } + + result_resv_header = check_xsave_reserved_header(buf0, buf1, size, + test_name); + + return (result_buf || result_resv_header); +} + +int verify_xsave_buf(unsigned char *xsave_buf, int offset, int size, + unsigned char *verify_buf, const char *test_name) +{ + int check_byte, result = RESULT_PASS; + + printf("Verify offset:0x%x, size:0x%x\n%x: ", offset, size, offset); + for (check_byte = 0; check_byte < size; check_byte++) { + if (xsave_buf[offset + check_byte] == verify_buf[check_byte]) { + printf("%02x ", xsave_buf[offset + check_byte]); + continue; + } else { + ksft_print_msg("%s FAIL: xsave offset(0x%x+0x%x):%x, expect:%x\n", + test_name, offset, check_byte, xsave_buf[offset + check_byte], + verify_buf[check_byte]); + result = RESULT_FAIL; + break; + } + } + if (result == RESULT_PASS) + printf("xsave content check pass\n"); + + return result; +} + +void check_result(int result, const char *test_name) +{ + switch (result) { + case RESULT_PASS: + ksft_test_result_pass("%s PASS\n", test_name); + break; + case RESULT_FAIL: + ksft_test_result_fail("%s FAIL\n", test_name); + break; + case RESULT_ERROR: + ksft_test_result_fail("%s ERROR\n", test_name); + break; + default: + ksft_test_result_error("%s ERROR: invalid result:%c\n", + test_name, result); + break; + } +} + +static int set_avx2_ymm(void) +{ + uint32_t ui32_ymm_value = 0x1F2F3F4F; + + if (!cpu_has_avx2()) { + printf("[SKIP] AVX2 disabled, will not set ymm registers.\n"); + return 2; + } + + /* populate ymm0 to ymm15 with 0x1F2F3F4F in 64bit kernel */ + asm volatile ("vbroadcastss %0, %%ymm0" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm1" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm2" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm3" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm4" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm5" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm6" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm7" : : "m" (ui32_ymm_value)); + #ifndef __i386__ + asm volatile ("vbroadcastss %0, %%ymm8" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm9" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm10" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm11" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm12" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm13" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm14" : : "m" (ui32_ymm_value)); + asm volatile ("vbroadcastss %0, %%ymm15" : : "m" (ui32_ymm_value)); + #endif + + return 0; +} + +static inline unsigned int read_pkey_reg(void) +{ + unsigned int eax, edx, ecx = 0; + + asm volatile(".byte 0x0f, 0x01, 0xee\n\t" + : "=a" (eax), "=d" (edx) + : "c" (ecx)); + + return eax; +} + +static inline int write_pkey_reg(unsigned int pkey_reg) +{ + unsigned int eax = pkey_reg, ecx = 0, edx = 0, actual; + int ret; + + asm volatile(".byte 0x0f, 0x01, 0xef\n\t" + : : "a" (eax), "c" (ecx), "d" (edx)); + actual = read_pkey_reg(); + ret = (pkey_reg == actual); + if (!ret) + printf("[ERROR] Write pkey with error, expected:0x%x, actual:0x%x\n", + pkey_reg, actual); + + return ret; +} + +int set_avx512_opmask(void) +{ + if (!cpu_has_avx512f()) { + printf("[SKIP] avx512f disabled, skip avx512f part xstate.\n"); + return 2; + } + + /* populate avx512 opmask k0 to k7 with all ff */ + asm volatile("kxnorq %%k0, %%k0, %%k0;" : : : "rcx"); + asm volatile("kxnorq %%k1, %%k1, %%k1;" : : : "rcx"); + asm volatile("kxnorq %%k2, %%k2, %%k2;" : : : "rcx"); + asm volatile("kxnorq %%k3, %%k3, %%k3;" : : : "rcx"); + asm volatile("kxnorq %%k4, %%k4, %%k4;" : : : "rcx"); + asm volatile("kxnorq %%k5, %%k5, %%k5;" : : : "rcx"); + asm volatile("kxnorq %%k6, %%k6, %%k6;" : : : "rcx"); + asm volatile("kxnorq %%k7, %%k7, %%k7;" : : : "rcx"); + + return 0; +} + +int set_pkru_xstate(void) +{ + unsigned int pkey_change = 0xfffffffc; + + if (!cpu_has_pkeys()) { + printf("[SKIP] pkeys disabled, skip pkru part xstate.\n"); + return 2; + } + + /* populate PKRU xstate with 0xfffffffc */ + if (!write_pkey_reg(pkey_change)) { + execution_failed("Write pkey %x FAIL\n", pkey_change); + return RESULT_FAIL; + } + + return 0; +} + +void set_fpu_reg(void) +{ + uint32_t ui32; + uint64_t ui64; + float a = 0.12, b = 0.23; + + ui32 = 1; + ui64 = 0xBAB00500FAB7; + + /* Initialize FPU and push different values onto FPU register stack */ + asm volatile("finit"); + asm volatile("fldl %0" : : "m" (ui64)); + asm volatile("flds %0" : : "m" (ui32)); + ui64 += 0x93ABE13; + asm volatile("fldl %0" : : "m" (ui64)); + ui64 += 0x93; + asm volatile("fldl %0" : : "m" (ui64)); + asm volatile("flds %0" : : "m" (ui32)); + asm volatile("fldl %0" : : "m" (ui64)); + ui64 -= 0x21; + asm volatile("fldl %0" : : "m" (ui64)); + asm volatile("flds %0" : : "m" (ui32)); + asm volatile("fldl %0" : : "m" (ui64)); + a = a * b; +} + +void populate_xstate_regs(void) +{ + set_fpu_reg(); + set_avx2_ymm(); + set_avx512_opmask(); + set_pkru_xstate(); +} diff --git a/tools/testing/selftests/x86/xsave_signal_handle.c b/tools/testing/selftests/x86/xsave_signal_handle.c new file mode 100644 index 000000000000..7d6ada1896d0 --- /dev/null +++ b/tools/testing/selftests/x86/xsave_signal_handle.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * It's for xsave/xrstor during signal handling tests + */ + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <x86intrin.h> +#include <string.h> +#include <signal.h> +#include <unistd.h> +#include <sched.h> +#include <sys/wait.h> +#include <time.h> + +#include "../kselftest.h" +#include "xsave_common.h" + +void *aligned_alloc(size_t alignment, size_t size); +static unsigned char *xsave_buf0, *xsave_buf1, *xsave_buf2, *xsave_buf3; +static int result[2], xsave_size; + +static void change_fpu_content(uint32_t ui32_random, double flt) +{ + asm volatile("fldl %0" : : "m" (flt)); + asm volatile("vbroadcastss %0, %%ymm0" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm1" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm2" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm3" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm4" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm5" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm6" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm7" : : "m" (ui32_random)); + #ifndef __i386__ + asm volatile("vbroadcastss %0, %%ymm8" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm9" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm10" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm11" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm12" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm13" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm14" : : "m" (ui32_random)); + asm volatile("vbroadcastss %0, %%ymm15" : : "m" (ui32_random)); + #endif +} + +static void usr1_handler(int signum, siginfo_t *info, void *__ctxp) +{ + uint32_t ui32_random; + double flt; + int xsave_size; + const char *usr1_name = "Child XSAVE should not change in nested signal"; + + ui32_random = rand(); + flt = ui32_random/10000.0; + if (signum == SIGUSR1) { + ksft_print_msg("SIGUSR1:0x%x changed fld:%f & ymm0-15:0x%x\n", + SIGUSR1, flt, ui32_random); + change_fpu_content(ui32_random, flt); + } + xsave_size = get_xsave_size(); + /* + * SIGUSR1 handler has independent XSAVE content, which is not affected by + * the SIGUSR2 handler + */ + XSAVE(xsave_buf2, XSAVE_TEST_MASK); + raise(SIGUSR2); + XSAVE(xsave_buf3, XSAVE_TEST_MASK); + result[0] = compare_xsave_buf(xsave_buf2, xsave_buf3, xsave_size, usr1_name, + NO_CHANGE); +} + +static void usr2_handler(int signum, siginfo_t *info, void *__ctxp) +{ + uint32_t ui32_random; + double flt; + + ui32_random = rand(); + flt = ui32_random/10000.0; + if (signum == SIGUSR2) { + ksft_print_msg("SIGUSR2:0x%x changed fld:%f & ymm0-15:0x%x\n", + SIGUSR2, flt, ui32_random); + change_fpu_content(ui32_random, flt); + } +} + +static void set_signal_handle(void) +{ + struct sigaction sigact; + + memset(&sigact, 0, sizeof(sigact)); + if (sigemptyset(&sigact.sa_mask)) + execution_failed("FAIL: sigemptyset error\n"); + + sigact.sa_flags = SA_SIGINFO; + + sigact.sa_sigaction = usr1_handler; + if (sigaction(SIGUSR1, &sigact, NULL)) + execution_failed("FAIL: SIGUSR1 handling failed\n"); + + sigact.sa_sigaction = usr2_handler; + if (sigaction(SIGUSR2, &sigact, NULL)) + execution_failed("FAIL: SIGUSR2 handling failed\n"); +} + +static void sig_handle_xsave_test(void) +{ + int i, loop_times = 100; + const char *sig_test_name = "Child XSAVE content was same after signal"; + + srand(time(NULL)); + + XSAVE(xsave_buf0, XSAVE_TEST_MASK); + for (i = 1; i <= loop_times; i++) { + raise(SIGUSR1); + XSAVE(xsave_buf1, XSAVE_TEST_MASK); + result[1] = compare_xsave_buf(xsave_buf0, xsave_buf1, xsave_size, + sig_test_name, NO_CHANGE); + if (result[1] != RESULT_PASS) + break; + } +} + +static int test_xsave_sig_handle(void) +{ + const char *test_name0 = "Siganl handling xstate was same after nested signal handling"; + const char *test_name1 = "xstate was same after child signal handling test"; + pid_t child; + int status, fd[2], readbuf[2]; + + set_signal_handle(); + + xsave_size = get_xsave_size(); + /* SDM XSAVE: misalignment to a 64-byte boundary will result in #GP */ + xsave_buf0 = aligned_alloc(64, xsave_size); + if (!xsave_buf0) + execution_failed("aligned_alloc xsave_buf0 failed\n"); + xsave_buf1 = aligned_alloc(64, xsave_size); + if (!xsave_buf1) + execution_failed("aligned_alloc xsave_buf1 failed\n"); + xsave_buf2 = aligned_alloc(64, xsave_size); + if (!xsave_buf2) + execution_failed("aligned_alloc xsave_buf2 failed\n"); + xsave_buf3 = aligned_alloc(64, xsave_size); + if (!xsave_buf3) + execution_failed("aligned_alloc xsave_buf3 failed\n"); + + /* Use pipe to transfer test result of child process to parent process */ + if (pipe(fd) < 0) + execution_failed("FAIL: create pipe failed\n"); + + populate_xstate_regs(); + + /* Use child process testing to avoid abnormal blocking the next test */ + child = fork(); + if (child < 0) + execution_failed("FAIL: create child pid failed\n"); + else if (child == 0) { + XSAVE(xsave_buf0, XSAVE_TEST_MASK); + + sig_handle_xsave_test(); + close(fd[0]); + if (!write(fd[1], &result, sizeof(result))) + execution_failed("FAIL: write fd failed.\n"); + return 0; + } + + if (child) { + if (waitpid(child, &status, 0) != child || !WIFEXITED(status)) + execution_failed("FAIL: Child died unexpectedly\n"); + else { + close(fd[1]); + if (!read(fd[0], &readbuf, sizeof(readbuf))) + execution_failed("FAIL: read fd failed.\n"); + } + } + + ksft_set_plan(2); + check_result(readbuf[0], test_name0); + check_result(readbuf[1], test_name1); + + return 0; +} + +int main(void) +{ + ksft_print_header(); + + test_xsave_sig_handle(); + + ksft_exit(!ksft_get_fail_cnt()); +}

It will change FPU, AVX2, AVX512, PKRU xstates before process switch test to ensure that the entire processing of these xstates works as expected. In order to ensure the above XSAVE content is not affected after process switch, this case tests that: 1. The xstates content of the child process should same as xstates of parent process. 2. The xstates content of the child process should not change after process switch back, even grandchild process cleaned up it's own XMM, YMM and ZMM xstates.

Signed-off-by: Pengfei Xu pengfei.xu@intel.com --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/xsave_fork_test.c | 127 ++++++++++++++++++ 2 files changed, 128 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/xsave_fork_test.c

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index b51f02bc38c2..5b627ae5e385 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -18,7 +18,7 @@ TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering \ - corrupt_xstate_header amx xsave_signal_handle + corrupt_xstate_header amx xsave_signal_handle xsave_fork_test # Some selftests require 32bit support enabled also on 64bit systems TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall

diff --git a/tools/testing/selftests/x86/xsave_fork_test.c b/tools/testing/selftests/x86/xsave_fork_test.c new file mode 100644 index 000000000000..00d1bfcfc6f7 --- /dev/null +++ b/tools/testing/selftests/x86/xsave_fork_test.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * It's for XSAVE fork test. + */ + +#define _GNU_SOURCE + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <x86intrin.h> +#include <string.h> +#include <sys/wait.h> +#include <unistd.h> +#include <sched.h> + +#include "xsave_common.h" + +static unsigned char *xsave_buf0, *xsave_buf1, *xsave_buf2; +static int xsave_size, read_result[2]; +static const char *fork_test = "xsave fork for xsave context switch test"; + +void set_xstates(void) +{ + /* SDM XSAVE: misalignment to a 64-byte boundary will result in #GP */ + xsave_buf0 = aligned_alloc(64, xsave_size); + if (!xsave_buf0) + execution_failed("aligned_alloc xsave_buf0 failed\n"); + xsave_buf1 = aligned_alloc(64, xsave_size); + if (!xsave_buf1) + execution_failed("aligned_alloc xsave_buf1 failed\n"); + xsave_buf2 = aligned_alloc(64, xsave_size); + if (!xsave_buf2) + execution_failed("aligned_alloc xsave_buf2 failed\n"); + + populate_xstate_regs(); +} + +void clear_avx(void) +{ + asm volatile("vzeroall"); +} + +/* use fork to create pid and trigger context switch test */ +int test_fork(void) +{ + pid_t child; + int status, fd[2], result[2]; + const char *test_xsave_child = "Child xstate was same as parent"; + const char *test_process_swich = "Xstate after process switch was same"; + + /* Use pipe to transfer test result of child process to parent process */ + if (pipe(fd) < 0) + execution_failed("FAIL: create pipe failed\n"); + + XSAVE(xsave_buf0, XSAVE_TEST_MASK); + child = fork(); + if (child < 0) + execution_failed("fork failed\n"); + if (child == 0) { + XSAVE(xsave_buf1, XSAVE_TEST_MASK); + result[0] = compare_xsave_buf(xsave_buf0, xsave_buf1, xsave_size, + fork_test, NO_CHANGE); + close(fd[0]); + if (!write(fd[1], &result, sizeof(result))) + execution_failed("FAIL: write fd failed.\n"); + + XSAVE(xsave_buf1, XSAVE_TEST_MASK); + pid_t grandchild; + + /* fork grandchild will trigger process switching in child */ + grandchild = fork(); + if (grandchild == 0) { + ksft_print_msg("Grandchild pid:%d clean it's XMM YMM ZMM xstates\n", + getpid()); + clear_avx(); + return 0; + } + if (grandchild) + waitpid(grandchild, NULL, 0); + + /* After swich back to child process and check xstate */ + XSAVE(xsave_buf2, XSAVE_TEST_MASK); + ksft_print_msg("Child pid:%d check xstate after swtich back\n", + getpid()); + result[1] = compare_xsave_buf(xsave_buf1, xsave_buf2, xsave_size, + fork_test, NO_CHANGE); + if (!write(fd[1], &result, sizeof(result))) + execution_failed("FAIL: write fd failed.\n"); + + return 0; + } + + if (child) { + if (waitpid(child, &status, 0) != child || !WIFEXITED(status)) + ksft_test_result_fail("Child exit with error, status:0x%x\n", + status); + else { + ksft_print_msg("Parent pid:%d get results\n", getpid()); + close(fd[1]); + if (!read(fd[0], &read_result, sizeof(read_result))) + execution_failed("FAIL: read fd failed.\n"); + } + } + + ksft_set_plan(2); + check_result(read_result[0], test_xsave_child); + check_result(read_result[1], test_process_swich); + + return 0; +} + +int main(int argc, char *argv[]) +{ + cpu_set_t set; + + xsave_size = get_xsave_size(); + ksft_print_header(); + + CPU_ZERO(&set); + CPU_SET(0, &set); + + set_xstates(); + test_fork(); + + ksft_exit(!ksft_get_fail_cnt()); +}