Commit f43365ee authored by Pratyush Anand's avatar Pratyush Anand Committed by Will Deacon

selftests: arm64: add test for unaligned/inexact watchpoint handling

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: default avatarPavel Labath <labath@google.com>
Signed-off-by: default avatarPratyush Anand <panand@redhat.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 0ddb8e0b
......@@ -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
/*
* 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@google.com>
*
* Code modified by Pratyush Anand <panand@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();
}
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