| Message ID | 1e9cbab1b0badc05592fce46717418930076a6ae.1719408040.git.zhouquan@iscas.ac.cn (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: Expose orig_a0 to userspace for ptrace to set the actual a0 | expand |
On Thu, Jun 27, 2024 at 11:02:54AM +0800, zhouquan@iscas.ac.cn wrote: > From: Quan Zhou <zhouquan@iscas.ac.cn> > > This test checks that orig_a0 allows a syscall argument to be modified, > and that changing a0 does not change the syscall argument. > > Suggested-by: Charlie Jenkins <charlie@rivosinc.com> > Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> > --- > tools/testing/selftests/riscv/Makefile | 2 +- > tools/testing/selftests/riscv/abi/.gitignore | 1 + > tools/testing/selftests/riscv/abi/Makefile | 12 ++ > tools/testing/selftests/riscv/abi/ptrace.c | 124 +++++++++++++++++++ > 4 files changed, 138 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/riscv/abi/.gitignore > create mode 100644 tools/testing/selftests/riscv/abi/Makefile > create mode 100644 tools/testing/selftests/riscv/abi/ptrace.c > > diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile > index 7ce03d832b64..98541dc2f164 100644 > --- a/tools/testing/selftests/riscv/Makefile > +++ b/tools/testing/selftests/riscv/Makefile > @@ -5,7 +5,7 @@ > ARCH ?= $(shell uname -m 2>/dev/null || echo not) > > ifneq (,$(filter $(ARCH),riscv)) > -RISCV_SUBTARGETS ?= hwprobe vector mm sigreturn > +RISCV_SUBTARGETS ?= hwprobe vector mm sigreturn abi > else > RISCV_SUBTARGETS := > endif > diff --git a/tools/testing/selftests/riscv/abi/.gitignore b/tools/testing/selftests/riscv/abi/.gitignore > new file mode 100644 > index 000000000000..d61c51358965 > --- /dev/null > +++ b/tools/testing/selftests/riscv/abi/.gitignore > @@ -0,0 +1 @@ > +ptrace > diff --git a/tools/testing/selftests/riscv/abi/Makefile b/tools/testing/selftests/riscv/abi/Makefile > new file mode 100644 > index 000000000000..808d48a91ad7 > --- /dev/null > +++ b/tools/testing/selftests/riscv/abi/Makefile > @@ -0,0 +1,12 @@ > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (C) 2021 ARM Limited > +# Originally tools/testing/arm64/abi/Makefile > + > +CFLAGS += -I$(top_srcdir)/tools/include > + > +TEST_GEN_PROGS := ptrace > + > +include ../../lib.mk > + > +$(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 000000000000..f85f927cd685 > --- /dev/null > +++ b/tools/testing/selftests/riscv/abi/ptrace.c > @@ -0,0 +1,124 @@ > +// 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 <asm/ptrace.h> > + > +#include "../../kselftest_harness.h" > + > +#define ORIG_A0_MODIFY 0x01 > +#define A0_MODIFY 0x02 > +#define A0_OLD 0x03 > +#define A0_NEW 0x04 > + > +#define perr_and_exit(fmt, ...) \ > + ({ \ > + char buf[256]; \ Apologies, I missed this in the last review. In the above line there is a space in the middle of the tabs before `char buf[256];`. > + snprintf(buf, sizeof(buf), "%s:%d: " fmt ": %m\n", \ > + __func__, __LINE__, ##__VA_ARGS__); \ > + perror(buf); \ > + exit(-1); \ > + }) > + > +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, int *result) > +{ > + int status; > + pid_t pid; > + struct user_regs_struct regs; > + struct iovec iov = { > + .iov_base = ®s, > + .iov_len = sizeof(regs), > + }; > + > + 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) > + exit(1); > + > + 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 orig_a0 before the syscall */ > + if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov)) > + perr_and_exit("failed to get tracee registers\n"); > + if (regs.orig_a0 != A0_OLD) > + perr_and_exit("unexpected orig_a0: 0x%lx\n", regs.orig_a0); > + > + /* Modify a0/orig_a0 for the syscall */ > + switch (opt) { > + case A0_MODIFY: > + regs.a0 = A0_NEW; > + break; > + case ORIG_A0_MODIFY: > + regs.orig_a0 = A0_NEW; > + break; > + } > + > + if (ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov)) > + perr_and_exit("failed to set tracee registers\n"); > + > + /* 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"); > + > + *result = WEXITSTATUS(status); > +} > + > +TEST(ptrace_modify_a0) > +{ > + int result; > + > + ptrace_test(A0_MODIFY, &result); > + > + /* The modification of a0 cannot affect the first argument of the syscall */ > + EXPECT_EQ(A0_OLD, result); > +} > + > +TEST(ptrace_modify_orig_a0) > +{ > + int result; > + > + ptrace_test(ORIG_A0_MODIFY, &result); > + > + /* Only modify orig_a0 to change the first argument of the syscall */ > + EXPECT_EQ(A0_NEW, result); > +} > + > +TEST_HARNESS_MAIN > -- > 2.34.1 > Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile index 7ce03d832b64..98541dc2f164 100644 --- a/tools/testing/selftests/riscv/Makefile +++ b/tools/testing/selftests/riscv/Makefile @@ -5,7 +5,7 @@ ARCH ?= $(shell uname -m 2>/dev/null || echo not) ifneq (,$(filter $(ARCH),riscv)) -RISCV_SUBTARGETS ?= hwprobe vector mm sigreturn +RISCV_SUBTARGETS ?= hwprobe vector mm sigreturn abi else RISCV_SUBTARGETS := endif diff --git a/tools/testing/selftests/riscv/abi/.gitignore b/tools/testing/selftests/riscv/abi/.gitignore new file mode 100644 index 000000000000..d61c51358965 --- /dev/null +++ b/tools/testing/selftests/riscv/abi/.gitignore @@ -0,0 +1 @@ +ptrace diff --git a/tools/testing/selftests/riscv/abi/Makefile b/tools/testing/selftests/riscv/abi/Makefile new file mode 100644 index 000000000000..808d48a91ad7 --- /dev/null +++ b/tools/testing/selftests/riscv/abi/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2021 ARM Limited +# Originally tools/testing/arm64/abi/Makefile + +CFLAGS += -I$(top_srcdir)/tools/include + +TEST_GEN_PROGS := ptrace + +include ../../lib.mk + +$(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 000000000000..f85f927cd685 --- /dev/null +++ b/tools/testing/selftests/riscv/abi/ptrace.c @@ -0,0 +1,124 @@ +// 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 <asm/ptrace.h> + +#include "../../kselftest_harness.h" + +#define ORIG_A0_MODIFY 0x01 +#define A0_MODIFY 0x02 +#define A0_OLD 0x03 +#define A0_NEW 0x04 + +#define perr_and_exit(fmt, ...) \ + ({ \ + char buf[256]; \ + snprintf(buf, sizeof(buf), "%s:%d: " fmt ": %m\n", \ + __func__, __LINE__, ##__VA_ARGS__); \ + perror(buf); \ + exit(-1); \ + }) + +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, int *result) +{ + int status; + pid_t pid; + struct user_regs_struct regs; + struct iovec iov = { + .iov_base = ®s, + .iov_len = sizeof(regs), + }; + + 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) + exit(1); + + 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 orig_a0 before the syscall */ + if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov)) + perr_and_exit("failed to get tracee registers\n"); + if (regs.orig_a0 != A0_OLD) + perr_and_exit("unexpected orig_a0: 0x%lx\n", regs.orig_a0); + + /* Modify a0/orig_a0 for the syscall */ + switch (opt) { + case A0_MODIFY: + regs.a0 = A0_NEW; + break; + case ORIG_A0_MODIFY: + regs.orig_a0 = A0_NEW; + break; + } + + if (ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov)) + perr_and_exit("failed to set tracee registers\n"); + + /* 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"); + + *result = WEXITSTATUS(status); +} + +TEST(ptrace_modify_a0) +{ + int result; + + ptrace_test(A0_MODIFY, &result); + + /* The modification of a0 cannot affect the first argument of the syscall */ + EXPECT_EQ(A0_OLD, result); +} + +TEST(ptrace_modify_orig_a0) +{ + int result; + + ptrace_test(ORIG_A0_MODIFY, &result); + + /* Only modify orig_a0 to change the first argument of the syscall */ + EXPECT_EQ(A0_NEW, result); +} + +TEST_HARNESS_MAIN