[PATCH 3/3] selftest/arm64/ptrace: add tests for PTRACE_O_ARM64_RAW_REGS

Andrei Vagin
2021-02-01T19:43:29Z

Test output:
TAP version 13
1..2
# selftests: arm64/ptrace: ptrace_syscall_raw_regs_test
# 1..2
# ok 1 x7: 686920776f726c64
# ok 2 The child exited with code 0.
# # Totals: pass:2 fail:0 xfail:0 xpass:0 skip:0 error:0
ok 1 selftests: arm64/ptrace: ptrace_syscall_raw_regs_test
# selftests: arm64/ptrace: ptrace_syscall_regs_test
# 1..3
# ok 1 x7: 0
# ok 2 x7: 1
# ok 3 The child exited with code 0.
# # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0
ok 2 selftests: arm64/ptrace: ptrace_syscall_regs_test

Signed-off-by: Andrei Vagin <avagin@gmail.com>
---
tools/testing/selftests/arm64/Makefile | 2 +-
tools/testing/selftests/arm64/ptrace/Makefile | 6 +
.../ptrace/ptrace_syscall_raw_regs_test.c | 142 +++++++++++++++++
.../arm64/ptrace/ptrace_syscall_regs_test.c | 150 ++++++++++++++++++
4 files changed, 299 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/arm64/ptrace/Makefile
create mode 100644 tools/testing/selftests/arm64/ptrace/ptrace_syscall_raw_regs_test.c
create mode 100644 tools/testing/selftests/arm64/ptrace/ptrace_syscall_regs_test.c

diff --git a/tools/testing/selftests/arm64/Makefile b/tools/testing/selftests/arm64/Makefile
index 2c9d012797a7..704770a60ece 100644
--- a/tools/testing/selftests/arm64/Makefile
+++ b/tools/testing/selftests/arm64/Makefile
@@ -4,7 +4,7 @@
ARCH ?= $(shell uname -m 2>/dev/null || echo not)

ifneq (,$(filter $(ARCH),aarch64 arm64))
-ARM64_SUBTARGETS ?= tags signal pauth fp mte
+ARM64_SUBTARGETS ?= tags signal pauth fp mte ptrace
else
ARM64_SUBTARGETS :=
endif
diff --git a/tools/testing/selftests/arm64/ptrace/Makefile b/tools/testing/selftests/arm64/ptrace/Makefile
new file mode 100644
index 000000000000..84b27449f3d1
--- /dev/null
+++ b/tools/testing/selftests/arm64/ptrace/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CFLAGS += -g -I../../../../../usr/include/
+TEST_GEN_PROGS := ptrace_syscall_raw_regs_test ptrace_syscall_regs_test
+
+include ../../lib.mk
diff --git a/tools/testing/selftests/arm64/ptrace/ptrace_syscall_raw_regs_test.c b/tools/testing/selftests/arm64/ptrace/ptrace_syscall_raw_regs_test.c
new file mode 100644
index 000000000000..78f913303a99
--- /dev/null
+++ b/tools/testing/selftests/arm64/ptrace/ptrace_syscall_raw_regs_test.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/ptrace.h>
+#include <sys/user.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
+#include <linux/elf.h>
+#include <linux/unistd.h>
+
+#include "../../kselftest.h"
+
+#define TEST_VAL 0x686920776f726c64UL
+
+#define pr_p(func, fmt, ...) func(fmt ": %m", ##__VA_ARGS__)
+
+#define pr_err(fmt, ...) \
+ ({ \
+ ksft_test_result_error(fmt "\n", ##__VA_ARGS__); \
+ -1; \
+ })
+
+#define pr_fail(fmt, ...) \
+ ({ \
+ ksft_test_result_fail(fmt "\n", ##__VA_ARGS__); \
+ -1; \
+ })
+
+#define pr_perror(fmt, ...) pr_p(pr_err, fmt, ##__VA_ARGS__)
+
+static long loop(void *val)
+{
+ register long x0 __asm__("x0");
+ register void *x1 __asm__("x1") = val;
+ register long x8 __asm__("x8") = 555;
+
+ __asm__ (
+ "again:\n"
+ "ldr x7, [x1, 0]\n"
+ "svc 0\n"
+ "str x7, [x1, 0]\n"
+ : "=r"(x0)
+ : "r"(x1), "r"(x8)
+ :
+ );
+ return 0;
+}
+
+static int child(void)
+{
+ long val = TEST_VAL;
+
+ loop(&val);
+ if (val != ~TEST_VAL) {
+ ksft_print_msg("Unexpected x7: %lx\n", val);
+ return 1;
+ }
+
+ return 0;
+}
+
+#ifndef PTRACE_SYSEMU
+#define PTRACE_SYSEMU 31
+#endif
+
+#ifndef PTRACE_O_ARM64_RAW_REGS
+#define PTRACE_O_ARM64_RAW_REGS (1 << 28)
+#endif
+
+int main(int argc, void **argv)
+{
+ struct user_regs_struct regs = {};
+ struct iovec iov = {
+ .iov_base = &regs,
+ .iov_len = sizeof(struct user_regs_struct),
+ };
+ int status;
+ pid_t pid;
+
+ ksft_set_plan(2);
+
+ pid = fork();
+ if (pid == 0) {
+ kill(getpid(), SIGSTOP);
+ child();
+ _exit(0);
+ }
+ if (pid < 0)
+ return 1;
+
+ if (ptrace(PTRACE_ATTACH, pid, 0, 0))
+ return pr_perror("Can't attach to the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+ if (ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_ARM64_RAW_REGS))
+ return pr_perror("Can't set PTRACE_O_ARM64_RAW_REGS");
+ /* skip SIGSTOP */
+ if (ptrace(PTRACE_CONT, pid, 0, 0))
+ return pr_perror("Can't resume the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+
+ /* Resume the child to the next system call. */
+ if (ptrace(PTRACE_SYSEMU, pid, 0, 0))
+ return pr_perror("Can't resume the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+ if (!WIFSTOPPED(status) || WSTOPSIG(status) != SIGTRAP)
+ return pr_err("Unexpected status: %d", status);
+
+ /* Check that x7 isnt't clobbered if PTRACE_O_ARM64_RAW_REGS is set. */
+ if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov))
+ return pr_perror("Can't get child registers");
+ if (regs.regs[7] != TEST_VAL)
+ return pr_fail("unexpected x7: %lx", regs.regs[7]);
+ ksft_test_result_pass("x7: %llx\n", regs.regs[7]);
+
+ /* Check that the child will see a new value of x7. */
+ regs.regs[0] = 0;
+ regs.regs[7] = ~TEST_VAL;
+ if (ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov))
+ return pr_perror("Can't set child registers");
+
+ if (ptrace(PTRACE_CONT, pid, 0, 0))
+ return pr_perror("Can't resume the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+
+ if (status != 0)
+ return pr_fail("Child exited with code %d.", status);
+
+ ksft_test_result_pass("The child exited with code 0.\n");
+ ksft_exit_pass();
+ return 0;
+}
+
diff --git a/tools/testing/selftests/arm64/ptrace/ptrace_syscall_regs_test.c b/tools/testing/selftests/arm64/ptrace/ptrace_syscall_regs_test.c
new file mode 100644
index 000000000000..d1534525ef26
--- /dev/null
+++ b/tools/testing/selftests/arm64/ptrace/ptrace_syscall_regs_test.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/ptrace.h>
+#include <sys/user.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
+#include <linux/elf.h>
+#include <linux/unistd.h>
+
+#include "../../kselftest.h"
+
+#define TEST_VAL 0x686920776f726c64UL
+
+#define pr_p(func, fmt, ...) func(fmt ": %m", ##__VA_ARGS__)
+
+#define pr_err(fmt, ...) \
+ ({ \
+ ksft_test_result_error(fmt "\n", ##__VA_ARGS__); \
+ -1; \
+ })
+
+#define pr_fail(fmt, ...) \
+ ({ \
+ ksft_test_result_fail(fmt "\n", ##__VA_ARGS__); \
+ -1; \
+ })
+
+#define pr_perror(fmt, ...) pr_p(pr_err, fmt, ##__VA_ARGS__)
+
+static long loop(void *val)
+{
+ register long x0 __asm__("x0");
+ register void *x1 __asm__("x1") = val;
+ register long x8 __asm__("x8") = 555;
+
+ __asm__ (
+ "again:\n"
+ "ldr x7, [x1, 0]\n"
+ "svc 0\n"
+ "str x7, [x1, 0]\n"
+ : "=r"(x0)
+ : "r"(x1), "r"(x8)
+ :
+ );
+ return 0;
+}
+
+static int child(void)
+{
+ long val = TEST_VAL;
+
+ loop(&val);
+ if (val != TEST_VAL) {
+ ksft_print_msg("Unexpected x7: %lx\n", val);
+ return 1;
+ }
+
+ return 0;
+}
+
+#ifndef PTRACE_O_ARM64_RAW_REGS
+#define PTRACE_O_ARM64_RAW_REGS (1 << 28)
+#endif
+
+int main(int argc, void **argv)
+{
+ struct user_regs_struct regs = {};
+ struct iovec iov = {
+ .iov_base = &regs,
+ .iov_len = sizeof(struct user_regs_struct),
+ };
+ int status;
+ pid_t pid;
+
+ ksft_set_plan(3);
+
+ pid = fork();
+ if (pid == 0) {
+ kill(getpid(), SIGSTOP);
+ child();
+ _exit(0);
+ }
+ if (pid < 0)
+ return 1;
+
+ if (ptrace(PTRACE_ATTACH, pid, 0, 0))
+ return pr_perror("Can't attach to the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+ /* skip SIGSTOP */
+ if (ptrace(PTRACE_CONT, pid, 0, 0))
+ return pr_perror("Can't resume the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+
+ /* Resume the child to the next system call. */
+ if (ptrace(PTRACE_SYSCALL, pid, 0, 0))
+ return pr_perror("Can't resume the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+ if (!WIFSTOPPED(status) || WSTOPSIG(status) != SIGTRAP)
+ return pr_err("Unexpected status: %d", status);
+
+ /* Check that x7 is 0 on syscall-enter. */
+ if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov))
+ return pr_perror("Can't get child registers");
+ if (regs.regs[7] != 0)
+ return pr_fail("Unexpected x7: %lx", regs.regs[7]);
+ ksft_test_result_pass("x7: %llx\n", regs.regs[7]);
+
+ if (ptrace(PTRACE_SYSCALL, pid, 0, 0))
+ return pr_perror("Can't resume the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+ if (!WIFSTOPPED(status) || WSTOPSIG(status) != SIGTRAP)
+ return pr_err("Unexpected status: %d", status);
+
+ /* Check that x7 is 1 on syscall-exit. */
+ if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov))
+ return pr_perror("Can't get child registers");
+ if (regs.regs[7] != 1)
+ return pr_fail("Unexpected x7: %lx", regs.regs[7]);
+ ksft_test_result_pass("x7: %llx\n", regs.regs[7]);
+
+ /* Check that the child will not a new value of x7. */
+ regs.regs[0] = 0;
+ regs.regs[7] = ~TEST_VAL;
+ if (ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov))
+ return pr_perror("Can't set child registers");
+
+ if (ptrace(PTRACE_CONT, pid, 0, 0))
+ return pr_perror("Can't resume the child %d", pid);
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Can't wait for the child %d", pid);
+
+ if (status != 0)
+ return pr_fail("Child exited with code %d.", status);
+
+ ksft_test_result_pass("The child exited with code 0.\n");
+ ksft_exit_pass();
+ return 0;
+}
+
--
2.29.2