selftests/powerpc: Add uaccess flush test (da650ada) · Commits · EulixOS / Software / Kernel

tools/testing/selftests/powerpc/security/Makefile

+2 −1

Original line number	Diff line number	Diff line
		# SPDX-License-Identifier: GPL-2.0+

		TEST_GEN_PROGS := rfi_flush entry_flush spectre_v2
		TEST_GEN_PROGS := rfi_flush entry_flush uaccess_flush spectre_v2
		top_srcdir = ../../../../..

		CFLAGS += -I../../../../../usr/include
		@@ -13,3 +13,4 @@ $(OUTPUT)/spectre_v2: CFLAGS += -m64
		$(OUTPUT)/spectre_v2: ../pmu/event.c branch_loops.S
		$(OUTPUT)/rfi_flush: flush_utils.c
		$(OUTPUT)/entry_flush: flush_utils.c
		$(OUTPUT)/uaccess_flush: flush_utils.c

tools/testing/selftests/powerpc/security/flush_utils.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -13,6 +13,7 @@
		#include <stdlib.h>
		#include <string.h>
		#include <stdio.h>
		#include <sys/utsname.h>
		#include "utils.h"
		#include "flush_utils.h"

		@@ -35,6 +36,18 @@ void syscall_loop(char *p, unsigned long iterations,
		}
		}

		void syscall_loop_uaccess(char *p, unsigned long iterations,
		unsigned long zero_size)
		{
		struct utsname utsname;

		for (unsigned long i = 0; i < iterations; i++) {
		for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
		load(p + j);
		uname(&utsname);
		}
		}

		static void sigill_handler(int signr, siginfo_t info, void unused)
		{
		static int warned;

tools/testing/selftests/powerpc/security/flush_utils.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,9 @@
		void syscall_loop(char *p, unsigned long iterations,
		unsigned long zero_size);

		void syscall_loop_uaccess(char *p, unsigned long iterations,
		unsigned long zero_size);

		void set_dscr(unsigned long val);

		#endif /* _SELFTESTS_POWERPC_SECURITY_FLUSH_UTILS_H */

tools/testing/selftests/powerpc/security/uaccess_flush.c

0 → 100644

+158 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0+

		/*
		* Copyright 2018 IBM Corporation.
		* Copyright 2020 Canonical Ltd.
		*/

		#define __SANE_USERSPACE_TYPES__

		#include <sys/types.h>
		#include <stdint.h>
		#include <malloc.h>
		#include <unistd.h>
		#include <signal.h>
		#include <stdlib.h>
		#include <string.h>
		#include <stdio.h>
		#include "utils.h"
		#include "flush_utils.h"

		int uaccess_flush_test(void)
		{
		char *p;
		int repetitions = 10;
		int fd, passes = 0, iter, rc = 0;
		struct perf_event_read v;
		__u64 l1d_misses_total = 0;
		unsigned long iterations = 100000, zero_size = 24 * 1024;
		unsigned long l1d_misses_expected;
		int rfi_flush_orig;
		int entry_flush_orig;
		int uaccess_flush, uaccess_flush_orig;

		SKIP_IF(geteuid() != 0);

		// The PMU event we use only works on Power7 or later
		SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));

		if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
		perror("Unable to read powerpc/rfi_flush debugfs file");
		SKIP_IF(1);
		}

		if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
		perror("Unable to read powerpc/entry_flush debugfs file");
		SKIP_IF(1);
		}

		if (read_debugfs_file("powerpc/uaccess_flush", &uaccess_flush_orig) < 0) {
		perror("Unable to read powerpc/entry_flush debugfs file");
		SKIP_IF(1);
		}

		if (rfi_flush_orig != 0) {
		if (write_debugfs_file("powerpc/rfi_flush", 0) < 0) {
		perror("error writing to powerpc/rfi_flush debugfs file");
		FAIL_IF(1);
		}
		}

		if (entry_flush_orig != 0) {
		if (write_debugfs_file("powerpc/entry_flush", 0) < 0) {
		perror("error writing to powerpc/entry_flush debugfs file");
		FAIL_IF(1);
		}
		}

		uaccess_flush = uaccess_flush_orig;

		fd = perf_event_open_counter(PERF_TYPE_HW_CACHE, PERF_L1D_READ_MISS_CONFIG, -1);
		FAIL_IF(fd < 0);

		p = (char *)memalign(zero_size, CACHELINE_SIZE);

		FAIL_IF(perf_event_enable(fd));

		// disable L1 prefetching
		set_dscr(1);

		iter = repetitions;

		/*
		* We expect to see l1d miss for each cacheline access when entry_flush
		* is set. Allow a small variation on this.
		*/
		l1d_misses_expected = iterations * (zero_size / CACHELINE_SIZE - 2);

		again:
		FAIL_IF(perf_event_reset(fd));

		syscall_loop_uaccess(p, iterations, zero_size);

		FAIL_IF(read(fd, &v, sizeof(v)) != sizeof(v));

		if (uaccess_flush && v.l1d_misses >= l1d_misses_expected)
		passes++;
		else if (!uaccess_flush && v.l1d_misses < (l1d_misses_expected / 2))
		passes++;

		l1d_misses_total += v.l1d_misses;

		while (--iter)
		goto again;

		if (passes < repetitions) {
		printf("FAIL (L1D misses with uaccess_flush=%d: %llu %c %lu) [%d/%d failures]\n",
		uaccess_flush, l1d_misses_total, uaccess_flush ? '<' : '>',
		uaccess_flush ? repetitions * l1d_misses_expected :
		repetitions * l1d_misses_expected / 2,
		repetitions - passes, repetitions);
		rc = 1;
		} else {
		printf("PASS (L1D misses with uaccess_flush=%d: %llu %c %lu) [%d/%d pass]\n",
		uaccess_flush, l1d_misses_total, uaccess_flush ? '>' : '<',
		uaccess_flush ? repetitions * l1d_misses_expected :
		repetitions * l1d_misses_expected / 2,
		passes, repetitions);
		}

		if (uaccess_flush == uaccess_flush_orig) {
		uaccess_flush = !uaccess_flush_orig;
		if (write_debugfs_file("powerpc/uaccess_flush", uaccess_flush) < 0) {
		perror("error writing to powerpc/uaccess_flush debugfs file");
		return 1;
		}
		iter = repetitions;
		l1d_misses_total = 0;
		passes = 0;
		goto again;
		}

		perf_event_disable(fd);
		close(fd);

		set_dscr(0);

		if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
		perror("unable to restore original value of powerpc/rfi_flush debugfs file");
		return 1;
		}

		if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
		perror("unable to restore original value of powerpc/entry_flush debugfs file");
		return 1;
		}

		if (write_debugfs_file("powerpc/uaccess_flush", uaccess_flush_orig) < 0) {
		perror("unable to restore original value of powerpc/uaccess_flush debugfs file");
		return 1;
		}

		return rc;
		}

		int main(int argc, char *argv[])
		{
		return test_harness(uaccess_flush_test, "uaccess_flush_test");
		}