[RFC,v2,2/2] selftests/xsave: add xsave test during and after signal handling

diff --git a/tools/testing/selftests/xsave/.gitignore b/tools/testing/selftests/xsave/.gitignore
index 00b9970360c4..b448d36186f3 100644
--- a/tools/testing/selftests/xsave/.gitignore
+++ b/tools/testing/selftests/xsave/.gitignore
@@ -1,2 +1,3 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 xsave_instruction
+xsave_signal_handle
diff --git a/tools/testing/selftests/xsave/Makefile b/tools/testing/selftests/xsave/Makefile
index dafdb0abdeb3..fedae2778297 100644
--- a/tools/testing/selftests/xsave/Makefile
+++ b/tools/testing/selftests/xsave/Makefile
@@ -1,6 +1,6 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 CFLAGS := -g -Wall -mxsave -O2
 
-TEST_GEN_PROGS := xsave_instruction
+TEST_GEN_PROGS := xsave_instruction xsave_signal_handle
 
 include ../lib.mk
diff --git a/tools/testing/selftests/xsave/xsave_signal_handle.c b/tools/testing/selftests/xsave/xsave_signal_handle.c
new file mode 100644
index 000000000000..0afcba3a1bd5
--- /dev/null
+++ b/tools/testing/selftests/xsave/xsave_signal_handle.c
@@ -0,0 +1,184 @@ 
+// 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"
+
+static unsigned char *xsave_buf0, *xsave_buf1, *xsave_buf2, *xsave_buf3;
+static int result[2];
+
+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 *test_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();
+	XSAVE(xsave_buf2, SAVE_MASK);
+	raise(SIGUSR2);
+	XSAVE(xsave_buf3, SAVE_MASK);
+	result[0] = check_xsave_buf(xsave_buf2, xsave_buf2, xsave_size, test_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, xsave_size;
+	const char *sig_test_name0 = "Child XSAVE was same in nested signal test";
+	const char *sig_test_name1 = "Child XSAVE content was same after signal";
+
+	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");
+
+	srand(time(NULL));
+	result[0] = RESULT_PASS;
+	result[1] = RESULT_PASS;
+
+	XSAVE(xsave_buf0, SAVE_MASK);
+	for (i = 1; i <= loop_times; i++) {
+		raise(SIGUSR1);
+		XSAVE(xsave_buf1, SAVE_MASK);
+		result[1] = check_xsave_buf(xsave_buf0, xsave_buf1, xsave_size,
+						sig_test_name1, NO_CHANGE);
+		if (result[1] != RESULT_PASS)
+			break;
+	}
+
+	check_result(result[0], sig_test_name0);
+	check_result(result[1], sig_test_name1);
+}
+
+static void test_xsave_sig_handle(void)
+{
+	const char *test_name0 = "xsave in child nested signal handling test";
+	const char *test_name1 = "xsave after child signal handling test";
+	pid_t child;
+	int status, fd[2], readbuf[2];
+
+	set_signal_handle();
+
+	/* Use pipe to transfer test result of child process to parent process */
+	if (pipe(fd) < 0)
+		execution_failed("FAIL: create pipe failed\n");
+
+	/* 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) {
+		populate_fpu_regs();
+		sig_handle_xsave_test();
+		close(fd[0]);
+		write(fd[1], &result, sizeof(result));
+	} else {
+		if (waitpid(child, &status, 0) != child ||
+			!WIFEXITED(status))
+			execution_failed("FAIL: Child died unexpectedly\n");
+		else {
+			close(fd[1]);
+			read(fd[0], &readbuf, sizeof(readbuf));
+
+			check_result(readbuf[0], test_name0);
+			check_result(readbuf[1], test_name1);
+		}
+	}
+}
+
+int main(void)
+{
+	ksft_print_header();
+	ksft_set_plan(2);
+
+	test_xsave_sig_handle();
+
+	ksft_exit(!ksft_get_fail_cnt());
+}