This test checks that orig_a0 and a0 can be modified and accessed independently.
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 | 6 +- tools/testing/selftests/riscv/abi/ptrace.c | 193 +++++++++++++++++++++++++++ 3 files changed, 199 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..359a082c88a401883fb3776b35e4dacf69beaaaa 100644 --- a/tools/testing/selftests/riscv/abi/Makefile +++ b/tools/testing/selftests/riscv/abi/Makefile @@ -1,10 +1,14 @@ # SPDX-License-Identifier: GPL-2.0
CFLAGS += -I$(top_srcdir)/tools/include +CFLAGS += $(KHDR_INCLUDES)
-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..cbd60462021165ca2bcc38be24b8423c96047b93 --- /dev/null +++ b/tools/testing/selftests/riscv/abi/ptrace.c @@ -0,0 +1,193 @@ +// 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 <linux/stddef.h> +#include <asm/ptrace.h> + +#include "../../kselftest_harness.h" + +#define ORIG_A0_MODIFY 0x01 +#define A0_MODIFY 0x02 +#define A0_OLD 0xbadbeefbeeff +#define A0_NEW 0xffeebfeebdab + + +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 void ptrace_test(int opt, struct a0_regs result[]) +{ + int status; + long rc; + 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 = { + .op = 0xff, + }; + const unsigned int expected_sci_entry_size = + offsetofend(struct ptrace_syscall_info, entry.args); + const unsigned int expected_sci_exit_size = + offsetofend(struct ptrace_syscall_info, exit.is_error); + + pid = fork(); + if (pid == 0) { + /* Mark oneself being traced */ + long val = ptrace(PTRACE_TRACEME, 0, 0, 0); + + if (val < 0) + perr_and_exit("failed to request for tracer to trace me: %ld", val); + + kill(getpid(), SIGSTOP); + + /* Perform chdir syscall that will be intercepted */ + syscall(__NR_chdir, A0_OLD); + + exit(0); + } + + if (pid < 0) + ksft_exit_fail_perror("failed to fork"); + + for (int i = 0; i < 3; i++) { + if (waitpid(pid, &status, 0) != pid) + perr_and_exit("failed to wait for the tracee %d", pid); + if (WIFSTOPPED(status)) { + switch (WSTOPSIG(status)) { + case SIGSTOP: + if (ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACESYSGOOD) < 0) + perr_and_exit("failed to set PTRACE_O_TRACESYSGOOD"); + break; + case SIGTRAP|0x80: + /* Modify twice so GET_SYSCALL_INFO get modified a0 and orig_a0 */ + if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov)) + perr_and_exit("failed to get tracee registers"); + if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov)) + perr_and_exit("failed to get tracee registers"); + + /* 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, &iov)) + perr_and_exit("failed to set tracee registers"); + if (ptrace(PTRACE_SETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov)) + perr_and_exit("failed to set tracee registers"); + switch (i) { + case 1: + /* Stop at the beginning of syscall */ + rc = ptrace(PTRACE_GET_SYSCALL_INFO, pid, + sizeof(syscall_info), &syscall_info); + if (rc < 0) + perr_and_exit("failed to get syscall info of entry"); + if (rc < expected_sci_entry_size + || syscall_info.op != PTRACE_SYSCALL_INFO_ENTRY) + perr_and_exit("stop position of entry mismatched"); + result[0].orig_a0 = syscall_info.entry.args[0]; + break; + + case 2: + /* Stop at the end of syscall */ + rc = ptrace(PTRACE_GET_SYSCALL_INFO, pid, + sizeof(syscall_info), &syscall_info); + if (rc < 0) + perr_and_exit("failed to get syscall info of entry"); + if (rc < expected_sci_exit_size + || syscall_info.op != PTRACE_SYSCALL_INFO_EXIT) + perr_and_exit("stop position of exit mismatched"); + result[0].a0 = syscall_info.exit.rval; + + if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov)) + perr_and_exit("failed to get tracee registers"); + result[1].a0 = regs.a0; + if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0, + &a0_iov)) + perr_and_exit("failed to get tracee registers"); + result[1].orig_a0 = orig_a0; + } + } + if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) + perr_and_exit("failed to resume tracee"); + } + } + + /* Resume the tracee */ + ptrace(PTRACE_CONT, pid, 0, 0); + if (waitpid(pid, &status, 0) != pid) + perr_and_exit("failed to wait for the tracee"); + +} + +TEST(ptrace_access_a0) +{ + struct a0_regs result[2]; + + ptrace_test(A0_MODIFY, result); + + /* Verify PTRACE_SETREGSET */ + /* The modification of a0 cannot affect the first argument of the syscall */ + EXPECT_EQ(A0_OLD, result[0].orig_a0); + EXPECT_EQ(A0_NEW, result[0].a0); + + /* Verify PTRACE_GETREGSET */ + EXPECT_EQ(result[1].orig_a0, result[0].orig_a0); + EXPECT_EQ(result[1].a0, result[0].a0); +} + +TEST(ptrace_access_orig_a0) +{ + struct a0_regs result[2]; + + ptrace_test(ORIG_A0_MODIFY, result); + + /* Verify PTRACE_SETREGSET */ + /* Only modify orig_a0 to change the first argument of the syscall */ + EXPECT_EQ(A0_NEW, result[0].orig_a0); + /* a0 will not be affected */ + EXPECT_NE(A0_NEW, result[0].a0); + + /* Verify PTRACE_GETREGSET */ + EXPECT_EQ(result[1].orig_a0, result[0].orig_a0); + EXPECT_EQ(result[1].a0, result[0].a0); +} + +TEST_HARNESS_MAIN