| Message ID | 20241203-riscv-new-regset-v2-2-d37da8c0cba6@coelacanthus.name (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv/ptrace: add new regset to access original a0 register | expand |
Celeste Liu <uwu@coelacanthus.name> writes: > From: Charlie Jenkins <charlie@rivosinc.com> > > This test checks that orig_a0 allows a syscall argument to be modified, > and that changing a0 does not change the syscall argument. > > Cc: stable@vger.kernel.org > Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn> > Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> > Co-developed-by: Celeste Liu <uwu@coelacanthus.name> > Signed-off-by: Celeste Liu <uwu@coelacanthus.name> > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Nice with a selftest! (Don't think the Cc: stable applies... ;-)) Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
On Tue, Dec 03, 2024 at 05:30:05PM +0800, Celeste Liu wrote: > From: Charlie Jenkins <charlie@rivosinc.com> > > This test checks that orig_a0 allows a syscall argument to be modified, > and that changing a0 does not change the syscall argument. > > Cc: stable@vger.kernel.org > Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn> > Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> > Co-developed-by: Celeste Liu <uwu@coelacanthus.name> > Signed-off-by: Celeste Liu <uwu@coelacanthus.name> > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> > --- > tools/testing/selftests/riscv/abi/.gitignore | 1 + > tools/testing/selftests/riscv/abi/Makefile | 5 +- > tools/testing/selftests/riscv/abi/ptrace.c | 134 +++++++++++++++++++++++++++ > 3 files changed, 139 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..d192764b428d1f1c442f3957c6fedeb01a48d556 > --- /dev/null > +++ b/tools/testing/selftests/riscv/abi/ptrace.c > @@ -0,0 +1,134 @@ > +// 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 Shouldn't A0_OLD and A0_NEW set more bits, since 3 and 4 aren't very unique (we could have those values by accident)? And should we include setting bits over 31 for 64-bit targets? > + > +#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); \ > + }) Can we use e.g. ksft_exit_fail_perror() instead? I'd prefer we try to consolidate testing/selftests/riscv/* tests on a common format for errors and exit codes and we're already using other kselftest stuff. > + > +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), > + }; > + > + unsigned long orig_a0; > + struct iovec a0_iov = { > + .iov_base = &orig_a0, > + .iov_len = sizeof(orig_a0), > + }; > + > + 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); This unexpected error condition deserves a message, so I'd use ksft_exit_fail_perror() here. > + > + 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_RISCV_ORIG_A0, &a0_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); What about checking that we actually set regs.a0 to A0_NEW? We'd need A0_NEW to be more unique than 4, though. > +} > + > +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 */ If we run ptrace_modify_a0 first then we've already set regs.a0 to A0_NEW and can't check with this test that we don't set it to A0_NEW. We should probably have two different test values, one for regs.a0 and one for orig_a0 and ensure on both tests that we aren't writing both. > + EXPECT_EQ(A0_NEW, result); > +} > + > +TEST_HARNESS_MAIN > > -- > 2.47.0 > Thanks, drew
On Tue, Dec 03, 2024 at 01:55:07PM +0100, Andrew Jones wrote: > On Tue, Dec 03, 2024 at 05:30:05PM +0800, Celeste Liu wrote: > > From: Charlie Jenkins <charlie@rivosinc.com> > > > > This test checks that orig_a0 allows a syscall argument to be modified, > > and that changing a0 does not change the syscall argument. > > > > Cc: stable@vger.kernel.org > > Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn> > > Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> > > Co-developed-by: Celeste Liu <uwu@coelacanthus.name> > > Signed-off-by: Celeste Liu <uwu@coelacanthus.name> > > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> > > --- > > tools/testing/selftests/riscv/abi/.gitignore | 1 + > > tools/testing/selftests/riscv/abi/Makefile | 5 +- > > tools/testing/selftests/riscv/abi/ptrace.c | 134 +++++++++++++++++++++++++++ > > 3 files changed, 139 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..d192764b428d1f1c442f3957c6fedeb01a48d556 > > --- /dev/null > > +++ b/tools/testing/selftests/riscv/abi/ptrace.c > > @@ -0,0 +1,134 @@ > > +// 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 > > Shouldn't A0_OLD and A0_NEW set more bits, since 3 and 4 aren't very > unique (we could have those values by accident)? And should we include > setting bits over 31 for 64-bit targets? > > > + > > +#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); \ > > + }) > > Can we use e.g. ksft_exit_fail_perror() instead? I'd prefer we try to > consolidate testing/selftests/riscv/* tests on a common format for > errors and exit codes and we're already using other kselftest stuff. > > > + > > +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), > > + }; > > + > > + unsigned long orig_a0; > > + struct iovec a0_iov = { > > + .iov_base = &orig_a0, > > + .iov_len = sizeof(orig_a0), > > + }; > > + > > + 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); > > This unexpected error condition deserves a message, so I'd use > ksft_exit_fail_perror() here. > > > + > > + 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_RISCV_ORIG_A0, &a0_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); > > What about checking that we actually set regs.a0 to A0_NEW? We'd need > A0_NEW to be more unique than 4, though. > > > +} > > + > > +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 */ > > If we run ptrace_modify_a0 first then we've already set regs.a0 to A0_NEW > and can't check with this test that we don't set it to A0_NEW. We should > probably have two different test values, one for regs.a0 and one for > orig_a0 and ensure on both tests that we aren't writing both. > Celeste, do you want to fix this up or are you waiting for me to? - Charlie > > + EXPECT_EQ(A0_NEW, result); > > +} > > + > > +TEST_HARNESS_MAIN > > > > -- > > 2.47.0 > > > > Thanks, > drew
On 2024-12-20 02:26, Charlie Jenkins wrote: > On Tue, Dec 03, 2024 at 01:55:07PM +0100, Andrew Jones wrote: >> On Tue, Dec 03, 2024 at 05:30:05PM +0800, Celeste Liu wrote: >>> From: Charlie Jenkins <charlie@rivosinc.com> >>> >>> This test checks that orig_a0 allows a syscall argument to be modified, >>> and that changing a0 does not change the syscall argument. >>> >>> Cc: stable@vger.kernel.org >>> Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn> >>> Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> >>> Co-developed-by: Celeste Liu <uwu@coelacanthus.name> >>> Signed-off-by: Celeste Liu <uwu@coelacanthus.name> >>> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> >>> --- >>> tools/testing/selftests/riscv/abi/.gitignore | 1 + >>> tools/testing/selftests/riscv/abi/Makefile | 5 +- >>> tools/testing/selftests/riscv/abi/ptrace.c | 134 +++++++++++++++++++++++++++ >>> 3 files changed, 139 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..d192764b428d1f1c442f3957c6fedeb01a48d556 >>> --- /dev/null >>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c >>> @@ -0,0 +1,134 @@ >>> +// 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 >> >> Shouldn't A0_OLD and A0_NEW set more bits, since 3 and 4 aren't very >> unique (we could have those values by accident)? And should we include >> setting bits over 31 for 64-bit targets? >> >>> + >>> +#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); \ >>> + }) >> >> Can we use e.g. ksft_exit_fail_perror() instead? I'd prefer we try to >> consolidate testing/selftests/riscv/* tests on a common format for >> errors and exit codes and we're already using other kselftest stuff. >> >>> + >>> +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), >>> + }; >>> + >>> + unsigned long orig_a0; >>> + struct iovec a0_iov = { >>> + .iov_base = &orig_a0, >>> + .iov_len = sizeof(orig_a0), >>> + }; >>> + >>> + 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); >> >> This unexpected error condition deserves a message, so I'd use >> ksft_exit_fail_perror() here. >> >>> + >>> + 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_RISCV_ORIG_A0, &a0_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); >> >> What about checking that we actually set regs.a0 to A0_NEW? We'd need >> A0_NEW to be more unique than 4, though. >> >>> +} >>> + >>> +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 */ >> >> If we run ptrace_modify_a0 first then we've already set regs.a0 to A0_NEW >> and can't check with this test that we don't set it to A0_NEW. We should >> probably have two different test values, one for regs.a0 and one for >> orig_a0 and ensure on both tests that we aren't writing both. >> > > Celeste, do you want to fix this up or are you waiting for me to? Sorry for delay. I was busy with household affairs in the past few weeks. v3 will be sent tomorrow or the day after tomorrow. I am deeply sorry for this. > > - Charlie > >>> + EXPECT_EQ(A0_NEW, result); >>> +} >>> + >>> +TEST_HARNESS_MAIN >>> >>> -- >>> 2.47.0 >>> >> >> Thanks, >> drew
On Fri, Dec 20, 2024 at 05:29:45AM +0800, Celeste Liu wrote: > > On 2024-12-20 02:26, Charlie Jenkins wrote: > > On Tue, Dec 03, 2024 at 01:55:07PM +0100, Andrew Jones wrote: > >> On Tue, Dec 03, 2024 at 05:30:05PM +0800, Celeste Liu wrote: > >>> From: Charlie Jenkins <charlie@rivosinc.com> > >>> > >>> This test checks that orig_a0 allows a syscall argument to be modified, > >>> and that changing a0 does not change the syscall argument. > >>> > >>> Cc: stable@vger.kernel.org > >>> Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn> > >>> Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> > >>> Co-developed-by: Celeste Liu <uwu@coelacanthus.name> > >>> Signed-off-by: Celeste Liu <uwu@coelacanthus.name> > >>> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> > >>> --- > >>> tools/testing/selftests/riscv/abi/.gitignore | 1 + > >>> tools/testing/selftests/riscv/abi/Makefile | 5 +- > >>> tools/testing/selftests/riscv/abi/ptrace.c | 134 +++++++++++++++++++++++++++ > >>> 3 files changed, 139 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..d192764b428d1f1c442f3957c6fedeb01a48d556 > >>> --- /dev/null > >>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c > >>> @@ -0,0 +1,134 @@ > >>> +// 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 > >> > >> Shouldn't A0_OLD and A0_NEW set more bits, since 3 and 4 aren't very > >> unique (we could have those values by accident)? And should we include > >> setting bits over 31 for 64-bit targets? > >> > >>> + > >>> +#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); \ > >>> + }) > >> > >> Can we use e.g. ksft_exit_fail_perror() instead? I'd prefer we try to > >> consolidate testing/selftests/riscv/* tests on a common format for > >> errors and exit codes and we're already using other kselftest stuff. > >> > >>> + > >>> +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), > >>> + }; > >>> + > >>> + unsigned long orig_a0; > >>> + struct iovec a0_iov = { > >>> + .iov_base = &orig_a0, > >>> + .iov_len = sizeof(orig_a0), > >>> + }; > >>> + > >>> + 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); > >> > >> This unexpected error condition deserves a message, so I'd use > >> ksft_exit_fail_perror() here. > >> > >>> + > >>> + 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_RISCV_ORIG_A0, &a0_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); > >> > >> What about checking that we actually set regs.a0 to A0_NEW? We'd need > >> A0_NEW to be more unique than 4, though. > >> > >>> +} > >>> + > >>> +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 */ > >> > >> If we run ptrace_modify_a0 first then we've already set regs.a0 to A0_NEW > >> and can't check with this test that we don't set it to A0_NEW. We should > >> probably have two different test values, one for regs.a0 and one for > >> orig_a0 and ensure on both tests that we aren't writing both. > >> > > > > Celeste, do you want to fix this up or are you waiting for me to? > > Sorry for delay. I was busy with household affairs in the past few weeks. > v3 will be sent tomorrow or the day after tomorrow. > > I am deeply sorry for this. No need to apologize! Just wanted to make sure you weren't expected me to update the test :) - Charlie > > > > > - Charlie > > > >>> + EXPECT_EQ(A0_NEW, result); > >>> +} > >>> + > >>> +TEST_HARNESS_MAIN > >>> > >>> -- > >>> 2.47.0 > >>> > >> > >> Thanks, > >> drew >
On 2024-12-20 05:36, Charlie Jenkins wrote: > On Fri, Dec 20, 2024 at 05:29:45AM +0800, Celeste Liu wrote: >> >> On 2024-12-20 02:26, Charlie Jenkins wrote: >>> On Tue, Dec 03, 2024 at 01:55:07PM +0100, Andrew Jones wrote: >>>> On Tue, Dec 03, 2024 at 05:30:05PM +0800, Celeste Liu wrote: >>>>> From: Charlie Jenkins <charlie@rivosinc.com> >>>>> >>>>> This test checks that orig_a0 allows a syscall argument to be modified, >>>>> and that changing a0 does not change the syscall argument. >>>>> >>>>> Cc: stable@vger.kernel.org >>>>> Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn> >>>>> Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> >>>>> Co-developed-by: Celeste Liu <uwu@coelacanthus.name> >>>>> Signed-off-by: Celeste Liu <uwu@coelacanthus.name> >>>>> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> >>>>> --- >>>>> tools/testing/selftests/riscv/abi/.gitignore | 1 + >>>>> tools/testing/selftests/riscv/abi/Makefile | 5 +- >>>>> tools/testing/selftests/riscv/abi/ptrace.c | 134 +++++++++++++++++++++++++++ >>>>> 3 files changed, 139 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..d192764b428d1f1c442f3957c6fedeb01a48d556 >>>>> --- /dev/null >>>>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c >>>>> @@ -0,0 +1,134 @@ >>>>> +// 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 >>>> >>>> Shouldn't A0_OLD and A0_NEW set more bits, since 3 and 4 aren't very >>>> unique (we could have those values by accident)? And should we include >>>> setting bits over 31 for 64-bit targets? >>>> >>>>> + >>>>> +#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); \ >>>>> + }) >>>> >>>> Can we use e.g. ksft_exit_fail_perror() instead? I'd prefer we try to >>>> consolidate testing/selftests/riscv/* tests on a common format for >>>> errors and exit codes and we're already using other kselftest stuff. >>>> >>>>> + >>>>> +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), >>>>> + }; >>>>> + >>>>> + unsigned long orig_a0; >>>>> + struct iovec a0_iov = { >>>>> + .iov_base = &orig_a0, >>>>> + .iov_len = sizeof(orig_a0), >>>>> + }; >>>>> + >>>>> + 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); >>>> >>>> This unexpected error condition deserves a message, so I'd use >>>> ksft_exit_fail_perror() here. >>>> >>>>> + >>>>> + 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_RISCV_ORIG_A0, &a0_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); >>>> >>>> What about checking that we actually set regs.a0 to A0_NEW? We'd need >>>> A0_NEW to be more unique than 4, though. >>>> >>>>> +} >>>>> + >>>>> +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 */ >>>> >>>> If we run ptrace_modify_a0 first then we've already set regs.a0 to A0_NEW >>>> and can't check with this test that we don't set it to A0_NEW. We should >>>> probably have two different test values, one for regs.a0 and one for >>>> orig_a0 and ensure on both tests that we aren't writing both. >>>> >>> >>> Celeste, do you want to fix this up or are you waiting for me to? >> >> Sorry for delay. I was busy with household affairs in the past few weeks. >> v3 will be sent tomorrow or the day after tomorrow. >> >> I am deeply sorry for this. > > No need to apologize! Just wanted to make sure you weren't expected me > to update the test :) > > - Charlie > >> >>> >>> - Charlie >>> >>>>> + EXPECT_EQ(A0_NEW, result); >>>>> +} >>>>> + >>>>> +TEST_HARNESS_MAIN >>>>> >>>>> -- >>>>> 2.47.0 >>>>> >>>> >>>> Thanks, >>>> drew >> v4 has been sent.
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..d192764b428d1f1c442f3957c6fedeb01a48d556 --- /dev/null +++ b/tools/testing/selftests/riscv/abi/ptrace.c @@ -0,0 +1,134 @@ +// 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), + }; + + unsigned long orig_a0; + struct iovec a0_iov = { + .iov_base = &orig_a0, + .iov_len = sizeof(orig_a0), + }; + + 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 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_RISCV_ORIG_A0, &a0_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