[PATCH V2 5/5] selftests: arm64: add test for unaligned/inexact watchpoint handling
Pratyush Anand
panand at redhat.com
Wed Oct 19 22:48:17 PDT 2016
ARM64 hardware expects 64bit aligned address for watchpoint invocation.
However, it provides byte selection method to select any number of
consecutive byte set within the range of 1-8.
This patch adds support to test all such byte selection option for
different memory write sizes.
Patch also adds a test for handling the case when the cpu does not
report an address which exactly matches one of the regions we have
been watching (which is a situation permitted by the spec if an
instruction accesses both watched and unwatched regions). The test
was failing on a MSM8996pro before this patch series and is
passing now.
Signed-off-by: Pavel Labath <labath at google.com>
Signed-off-by: Pratyush Anand <panand at redhat.com>
---
tools/testing/selftests/breakpoints/Makefile | 5 +-
.../selftests/breakpoints/breakpoint_test_arm64.c | 236 +++++++++++++++++++++
2 files changed, 240 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/breakpoints/breakpoint_test_arm64.c
diff --git a/tools/testing/selftests/breakpoints/Makefile b/tools/testing/selftests/breakpoints/Makefile
index 74e533fd4bc5..61b79e8df1f4 100644
--- a/tools/testing/selftests/breakpoints/Makefile
+++ b/tools/testing/selftests/breakpoints/Makefile
@@ -5,6 +5,9 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)
ifeq ($(ARCH),x86)
TEST_PROGS := breakpoint_test
endif
+ifeq ($(ARCH),aarch64)
+TEST_PROGS := breakpoint_test_arm64
+endif
TEST_PROGS += step_after_suspend_test
@@ -13,4 +16,4 @@ all: $(TEST_PROGS)
include ../lib.mk
clean:
- rm -fr breakpoint_test step_after_suspend_test
+ rm -fr breakpoint_test breakpoint_test_arm64 step_after_suspend_test
diff --git a/tools/testing/selftests/breakpoints/breakpoint_test_arm64.c b/tools/testing/selftests/breakpoints/breakpoint_test_arm64.c
new file mode 100644
index 000000000000..3897e996541e
--- /dev/null
+++ b/tools/testing/selftests/breakpoints/breakpoint_test_arm64.c
@@ -0,0 +1,236 @@
+/*
+ * Copyright (C) 2016 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Original Code by Pavel Labath <labath at google.com>
+ *
+ * Code modified by Pratyush Anand <panand at redhat.com>
+ * for testing different byte select for each access size.
+ *
+ */
+
+#define _GNU_SOURCE
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/ptrace.h>
+#include <sys/param.h>
+#include <sys/uio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <elf.h>
+#include <errno.h>
+#include <signal.h>
+
+#include "../kselftest.h"
+
+static volatile uint8_t var[96] __attribute__((__aligned__(32)));
+
+static void child(int size, int wr)
+{
+ volatile uint8_t *addr = &var[32 + wr];
+
+ if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
+ perror("ptrace(PTRACE_TRACEME) failed");
+ _exit(1);
+ }
+
+ if (raise(SIGSTOP) != 0) {
+ perror("raise(SIGSTOP) failed");
+ _exit(1);
+ }
+
+ if ((uintptr_t) addr % size) {
+ perror("Wrong address write for the given size\n");
+ _exit(1);
+ }
+ switch (size) {
+ case 1:
+ *addr = 47;
+ break;
+ case 2:
+ *(uint16_t *)addr = 47;
+ break;
+ case 4:
+ *(uint32_t *)addr = 47;
+ break;
+ case 8:
+ *(uint64_t *)addr = 47;
+ break;
+ case 16:
+ __asm__ volatile ("stp x29, x30, %0" : "=m" (addr[0]));
+ break;
+ case 32:
+ __asm__ volatile ("stp q29, q30, %0" : "=m" (addr[0]));
+ break;
+ }
+
+ _exit(0);
+}
+
+static bool set_watchpoint(pid_t pid, int size, int wp)
+{
+ const volatile uint8_t *addr = &var[32 + wp];
+ const int offset = (uintptr_t)addr % 8;
+ const unsigned int byte_mask = ((1 << size) - 1) << offset;
+ const unsigned int type = 2; /* Write */
+ const unsigned int enable = 1;
+ const unsigned int control = byte_mask << 5 | type << 3 | enable;
+ struct user_hwdebug_state dreg_state;
+ struct iovec iov;
+
+ memset(&dreg_state, 0, sizeof(dreg_state));
+ dreg_state.dbg_regs[0].addr = (uintptr_t)(addr - offset);
+ dreg_state.dbg_regs[0].ctrl = control;
+ iov.iov_base = &dreg_state;
+ iov.iov_len = offsetof(struct user_hwdebug_state, dbg_regs) +
+ sizeof(dreg_state.dbg_regs[0]);
+ if (ptrace(PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov) == 0)
+ return true;
+
+ if (errno == EIO) {
+ printf("ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) "
+ "not supported on this hardware\n");
+ ksft_exit_skip();
+ }
+ perror("ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) failed");
+ return false;
+}
+
+static bool run_test(int wr_size, int wp_size, int wr, int wp)
+{
+ int status;
+ siginfo_t siginfo;
+ pid_t pid = fork();
+ pid_t wpid;
+
+ if (pid < 0) {
+ perror("fork() failed");
+ return false;
+ }
+ if (pid == 0)
+ child(wr_size, wr);
+
+ wpid = waitpid(pid, &status, __WALL);
+ if (wpid != pid) {
+ perror("waitpid() failed");
+ return false;
+ }
+ if (!WIFSTOPPED(status)) {
+ printf("child did not stop\n");
+ return false;
+ }
+ if (WSTOPSIG(status) != SIGSTOP) {
+ printf("child did not stop with SIGSTOP\n");
+ return false;
+ }
+
+ if (!set_watchpoint(pid, wp_size, wp))
+ return false;
+
+ if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
+ perror("ptrace(PTRACE_SINGLESTEP) failed");
+ return false;
+ }
+
+ alarm(3);
+ wpid = waitpid(pid, &status, __WALL);
+ if (wpid != pid) {
+ perror("waitpid() failed");
+ return false;
+ }
+ alarm(0);
+ if (WIFEXITED(status)) {
+ printf("child did not single-step\t");
+ return false;
+ }
+ if (!WIFSTOPPED(status)) {
+ printf("child did not stop\n");
+ return false;
+ }
+ if (WSTOPSIG(status) != SIGTRAP) {
+ printf("child did not stop with SIGTRAP\n");
+ return false;
+ }
+ if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0) {
+ perror("ptrace(PTRACE_GETSIGINFO)");
+ return false;
+ }
+ if (siginfo.si_code != TRAP_HWBKPT) {
+ printf("Unexpected si_code %d\n", siginfo.si_code);
+ return false;
+ }
+
+ kill(pid, SIGKILL);
+ wpid = waitpid(pid, &status, 0);
+ if (wpid != pid) {
+ perror("waitpid() failed");
+ return false;
+ }
+ return true;
+}
+
+static void sigalrm(int sig)
+{
+}
+
+int main(int argc, char **argv)
+{
+ int opt;
+ bool succeeded = true;
+ struct sigaction act;
+ int wr, wp, size;
+ bool result;
+
+ act.sa_handler = sigalrm;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = 0;
+ sigaction(SIGALRM, &act, NULL);
+ for (size = 1; size <= 32; size = size*2) {
+ for (wr = 0; wr <= 32; wr = wr + size) {
+ for (wp = wr - size; wp <= wr + size; wp = wp + size) {
+ printf("Test size = %d write offset = %d watchpoint offset = %d\t", size, wr, wp);
+ result = run_test(size, MIN(size, 8), wr, wp);
+ if ((result && wr == wp) || (!result && wr != wp)) {
+ printf("[OK]\n");
+ ksft_inc_pass_cnt();
+ } else {
+ printf("[FAILED]\n");
+ ksft_inc_fail_cnt();
+ succeeded = false;
+ }
+ }
+ }
+ }
+
+ for (size = 1; size <= 32; size = size*2) {
+ printf("Test size = %d write offset = %d watchpoint offset = -8\t", size, -size);
+
+ if (run_test(size, 8, -size, -8)) {
+ printf("[OK]\n");
+ ksft_inc_pass_cnt();
+ } else {
+ printf("[FAILED]\n");
+ ksft_inc_fail_cnt();
+ succeeded = false;
+ }
+ }
+
+ ksft_print_cnts();
+ if (succeeded)
+ ksft_exit_pass();
+ else
+ ksft_exit_fail();
+}
--
2.7.4
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