On 2024-12-26 18:45, Celeste Liu wrote:
This test checks that orig_a0 allows a syscall argument to be modified, and that changing a0 does not change the syscall argument.
Co-developed-by: Quan Zhou zhouquan@iscas.ac.cn Signed-off-by: Quan Zhou zhouquan@iscas.ac.cn Co-developed-by: Charlie Jenkins charlie@rivosinc.com Signed-off-by: Charlie Jenkins charlie@rivosinc.com Reviewed-by: Björn Töpel bjorn@rivosinc.com Signed-off-by: Celeste Liu uwu@coelacanthus.name
tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 5 +- tools/testing/selftests/riscv/abi/ptrace.c | 151 +++++++++++++++++++++++++++ 3 files changed, 156 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/riscv/abi/.gitignore b/tools/testing/selftests/riscv/abi/.gitignore index b38358f91c4d2240ae64892871d9ca98bda1ae58..378c605919a3b3d58eec2701eb7af430cfe315d6 100644 --- a/tools/testing/selftests/riscv/abi/.gitignore +++ b/tools/testing/selftests/riscv/abi/.gitignore @@ -1 +1,2 @@ pointer_masking +ptrace diff --git a/tools/testing/selftests/riscv/abi/Makefile b/tools/testing/selftests/riscv/abi/Makefile index ed82ff9c664e7eb3f760cbab81fb957ff72579c5..3f74d059dfdcbce4d45d8ff618781ccea1419061 100644 --- a/tools/testing/selftests/riscv/abi/Makefile +++ b/tools/testing/selftests/riscv/abi/Makefile @@ -2,9 +2,12 @@ CFLAGS += -I$(top_srcdir)/tools/include -TEST_GEN_PROGS := pointer_masking +TEST_GEN_PROGS := pointer_masking ptrace include ../../lib.mk $(OUTPUT)/pointer_masking: pointer_masking.c $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
+$(OUTPUT)/ptrace: ptrace.c
- $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
diff --git a/tools/testing/selftests/riscv/abi/ptrace.c b/tools/testing/selftests/riscv/abi/ptrace.c new file mode 100644 index 0000000000000000000000000000000000000000..c89343cb4abc7da57f83879ecce619f503c438bb --- /dev/null +++ b/tools/testing/selftests/riscv/abi/ptrace.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <signal.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/ptrace.h> +#include <sys/stat.h> +#include <sys/user.h> +#include <sys/wait.h> +#include <sys/uio.h> +#include <linux/elf.h> +#include <linux/unistd.h> +#include <linux/ptrace.h> +#include <asm/ptrace.h>
+#include "../../kselftest_harness.h"
+#define ORIG_A0_MODIFY 0x01 +#define A0_MODIFY 0x02 +#define A0_OLD 0x03 +#define A0_NEW 0x04
+struct a0_regs {
- __s64 orig_a0;
- __u64 a0;
+};
+#define perr_and_exit(fmt, ...) \
- ({ \
char buf[256]; \snprintf(buf, sizeof(buf), "%s:%d:" fmt ": %m\n", \__func__, __LINE__, ##__VA_ARGS__); \ksft_exit_fail_perror(buf); \- })
+static inline void resume_and_wait_tracee(pid_t pid, int flag) +{
- int status;
- if (ptrace(flag, pid, 0, 0))
perr_and_exit("failed to resume the tracee %d\n", pid);- if (waitpid(pid, &status, 0) != pid)
perr_and_exit("failed to wait for the tracee %d\n", pid);+}
+static void ptrace_test(int opt, struct a0_regs *result) +{
- int status;
- pid_t pid;
- struct user_regs_struct regs;
- struct iovec iov = {
.iov_base = ®s,.iov_len = sizeof(regs),- };
- unsigned long orig_a0;
- struct iovec a0_iov = {
.iov_base = &orig_a0,.iov_len = sizeof(orig_a0),- };
- struct ptrace_syscall_info syscall_info_entry, syscall_info_exit;
- pid = fork();
- if (pid == 0) {
/* Mark oneself being traced */long val = ptrace(PTRACE_TRACEME, 0, 0, 0);if (val)perr_and_exit("failed to request for tracer to trace me: %ld\n", val);kill(getpid(), SIGSTOP);/* Perform exit syscall that will be intercepted */exit(A0_OLD);- }
- if (pid < 0)
ksft_exit_fail_perror("failed to fork");- if (waitpid(pid, &status, 0) != pid)
perr_and_exit("failed to wait for the tracee %d\n", pid);- /* Stop at the entry point of the syscall */
- resume_and_wait_tracee(pid, PTRACE_SYSCALL);
- /* Check tracee regs before the syscall */
- if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov))
perr_and_exit("failed to get tracee registers\n");- if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov))
perr_and_exit("failed to get tracee registers\n");- if (orig_a0 != A0_OLD)
perr_and_exit("unexpected orig_a0: 0x%lx\n", orig_a0);- /* Modify a0/orig_a0 for the syscall */
- switch (opt) {
- case A0_MODIFY:
regs.a0 = A0_NEW;break;- case ORIG_A0_MODIFY:
orig_a0 = A0_NEW;break;- }
- if (ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &a0_iov))
perr_and_exit("failed to set tracee registers\n");
v4 has been sent because I found a uncommited fix for this...
- if (ptrace(PTRACE_SETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov))
perr_and_exit("failed to set tracee registers\n");- if (ptrace(PTRACE_GET_SYSCALL_INFO, pid, PTRACE_SYSCALL_INFO_ENTRY, &syscall_info_entry))
perr_and_exit("failed to get syscall info of entry\n");- result->orig_a0 = syscall_info_entry->entry.args[0];
- if (ptrace(PTRACE_GET_SYSCALL_INFO, pid, PTRACE_SYSCALL_INFO_EXIT, &syscall_info_exit))
perr_and_exit("failed to get syscall info of exit\n");- result->a0 = syscall_info_exit->exit.rval;
- /* Resume the tracee */
- ptrace(PTRACE_CONT, pid, 0, 0);
- if (waitpid(pid, &status, 0) != pid)
perr_and_exit("failed to wait for the tracee\n");+}
+TEST(ptrace_modify_a0) +{
- struct a0_regs result;
- ptrace_test(A0_MODIFY, &result);
- /* The modification of a0 cannot affect the first argument of the syscall */
- EXPECT_EQ(A0_OLD, result.orig_a0);
- EXPECT_EQ(A0_NEW, result.a0);
+}
+TEST(ptrace_modify_orig_a0) +{
- struct a0_regs result;
- ptrace_test(ORIG_A0_MODIFY, &result);
- /* Only modify orig_a0 to change the first argument of the syscall */
- EXPECT_EQ(A0_NEW, result.orig_a0);
- /* a0 will keep default value, orig_a0 or -ENOSYS, depends on internal. */
- EXPECT_NE(A0_NEW, result.a0);
+}
+TEST_HARNESS_MAIN