Add a test case to verify that unused states are excluded, by leaving a known pattern on the signal stack and verifying that it is still intact after taking a subsequent signal.

Signed-off-by: Chang S. Bae chang.seok.bae@intel.com Reviewed-by: Len Brown len.brown@intel.com Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-kselftest@vger.kernel.org --- Changes from v4: * Separated out as a new patch. * Improved the test routine by explicitly checking sigframe write. --- tools/testing/selftests/x86/amx.c | 137 ++++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+)

diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c index 7d177c03cdcf..c5a5582e2b6f 100644 --- a/tools/testing/selftests/x86/amx.c +++ b/tools/testing/selftests/x86/amx.c @@ -562,6 +562,142 @@ static void test_ptrace(void) test_tile_write(); }

+/* Signal handling test */ + +static bool init_tiledata_state_before_signal; +static bool load_tiledata_at_first; +static bool sigalarmed, sigused; + +#define SIGFRAME_TILEDATA_SIGNATURE 0xFF + +static void handle_sigusr1(int sig, siginfo_t *info, void *ctx_void) +{ + void *xsave = ((ucontext_t *)ctx_void)->uc_mcontext.fpregs; + + memset(xsave + xsave_xtiledata_offset, SIGFRAME_TILEDATA_SIGNATURE, xsave_xtiledata_size); + + sigused = true; +} + +static void handle_sigalrm(int sig, siginfo_t *info, void *ctx_void) +{ + void *xsave = ((ucontext_t *)ctx_void)->uc_mcontext.fpregs; + char d = SIGFRAME_TILEDATA_SIGNATURE; + bool written = false; + int i; + + for (i = 0; i < xsave_xtiledata_size; i++) { + written = memcmp(xsave + xsave_xtiledata_offset + i, &d, 1); + if (written) + break; + } + + if (__xgetbv(1) & XFEATURE_MASK_XTILEDATA) + err(1, "tile data state at signal delivery"); + + if (init_tiledata_state_before_signal && written) { + errs++; + printf("[FAIL]\tTile data was %swritten on sigframe.\n", !written ? "not " : ""); + } + + set_xstatebv(xsave_buffer, XFEATURE_MASK_XTILEDATA); + set_tiledata(xsave_buffer + xsave_xtiledata_offset); + xrstor(xsave_buffer, -1, -1); + sigalarmed = true; +} + +static void test_signal_handling(void) +{ + pid_t child; + + sigalarmed = false; + sigused = false; + + child = fork(); + if (child < 0) { + err(1, "fork"); + } else if (child > 0) { + do { + int status; + + wait(&status); + if (WIFSTOPPED(status)) + kill(child, SIGCONT); + else if (WIFEXITED(status) && !WEXITSTATUS(status)) + break; + else + err(1, "signal test child"); + } while (1); + return; + } + + printf("\tBefore signal, load tile data -- %s, re-initialized -- %s:\n", + load_tiledata_at_first ? "yes" : "no", + init_tiledata_state_before_signal ? "yes" : "no"); + + syscall(SYS_arch_prctl, ARCH_GET_XSTATE, XFEATURE_MASK_XTILE); + + raise(SIGUSR1); + if (!sigused) + err(1, "SIGUSR1"); + + if (load_tiledata_at_first) { + set_xstatebv(xsave_buffer, XFEATURE_MASK_XTILEDATA); + set_tiledata(xsave_buffer + xsave_xtiledata_offset); + xrstor(xsave_buffer, -1, -1); + memcpy(tiledata, xsave_buffer + xsave_xtiledata_offset, xsave_xtiledata_size); + } + + if (init_tiledata_state_before_signal) { + set_xstatebv(xsave_buffer, 0); + xrstor(xsave_buffer, -1, -1); + memset(tiledata, 0, xsave_xtiledata_size); + } + + raise(SIGALRM); + if (!sigalarmed) + err(1, "SIGALRM"); + + __xsave(xsave_buffer, XFEATURE_MASK_XTILEDATA, 0); + if (memcmp(tiledata, xsave_buffer + xsave_xtiledata_offset, xsave_xtiledata_size)) { + errs++; + printf("[FAIL]\tTile data was not restored at sigreturn\n"); + } + + if (errs) + nerrs++; + else + printf("[OK]\tTile data was %swritten on sigframe and restored at sigreturn\n", + init_tiledata_state_before_signal ? "not " : ""); + _exit(0); +} + +static void test_signal(void) +{ + printf("[RUN]\tCheck tile data state in signal path:\n"); + + sethandler(SIGALRM, handle_sigalrm, 0); + sethandler(SIGUSR1, handle_sigusr1, 0); + + load_tiledata_at_first = false; + init_tiledata_state_before_signal = true; + errs = 0; + test_signal_handling(); + + load_tiledata_at_first = true; + init_tiledata_state_before_signal = false; + errs = 0; + test_signal_handling(); + + load_tiledata_at_first = true; + init_tiledata_state_before_signal = true; + errs = 0; + test_signal_handling(); + + clearhandler(SIGALRM); + clearhandler(SIGUSR1); +} + int main(void) { /* Check hardware availability at first */ @@ -592,6 +728,7 @@ int main(void) test_fork(); test_context_switch(); test_ptrace(); + test_signal();

clearhandler(SIGSEGV);