From 651be3cb085341a21847e47c694c249c3e1e4e5b Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Mon, 14 Nov 2016 19:32:42 +0530 Subject: hw_breakpoint: Allow watchpoint of length 3,5,6 and 7 We only support breakpoint/watchpoint of length 1, 2, 4 and 8. If we can support other length as well, then user may watch more data with less number of watchpoints (provided hardware supports it). For example: if we have to watch only 4th, 5th and 6th byte from a 64 bit aligned address, we will have to use two slots to implement it currently. One slot will watch a half word at offset 4 and other a byte at offset 6. If we can have a watchpoint of length 3 then we can watch it with single slot as well. ARM64 hardware does support such functionality, therefore adding these new definitions in generic layer. Signed-off-by: Pratyush Anand Signed-off-by: Will Deacon --- tools/include/uapi/linux/hw_breakpoint.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'tools') diff --git a/tools/include/uapi/linux/hw_breakpoint.h b/tools/include/uapi/linux/hw_breakpoint.h index b04000a2296a..2b65efd19a46 100644 --- a/tools/include/uapi/linux/hw_breakpoint.h +++ b/tools/include/uapi/linux/hw_breakpoint.h @@ -4,7 +4,11 @@ enum { HW_BREAKPOINT_LEN_1 = 1, HW_BREAKPOINT_LEN_2 = 2, + HW_BREAKPOINT_LEN_3 = 3, HW_BREAKPOINT_LEN_4 = 4, + HW_BREAKPOINT_LEN_5 = 5, + HW_BREAKPOINT_LEN_6 = 6, + HW_BREAKPOINT_LEN_7 = 7, HW_BREAKPOINT_LEN_8 = 8, }; -- cgit v1.2.3-58-ga151 From f43365ee17f8d22b1f887d2b26faa0837ca85138 Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Mon, 14 Nov 2016 19:32:46 +0530 Subject: 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: Pavel Labath Signed-off-by: Pratyush Anand Signed-off-by: Will Deacon --- 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 (limited to 'tools') 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 + * + * Code modified by Pratyush Anand + * for testing different byte select for each access size. + * + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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(); +} -- cgit v1.2.3-58-ga151