[PATCH v2 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
From: Charlie Jenkins
This test checks that orig_a0 allows a syscall argument to be modified,
and that changing a0 does not change the syscall argument.
Cc: sta...@vger.kernel.org
Co-developed-by: Quan Zhou
Signed-off-by: Quan Zhou
Co-developed-by: Celeste Liu
Signed-off-by: Celeste Liu
Signed-off-by: Charlie Jenkins
---
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
..d192764b428d1f1c442f3957c6fedeb01a48d556
--- /dev/null
+++ b/tools/testing/selftests/riscv/abi/ptrace.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#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;
+
[PATCH v2 0/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is no way to add it without breaking UAPI. (See Link tag below) Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to access original a0 register from userspace via ptrace API. Link: https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/ Signed-off-by: Celeste Liu --- Changes in v2: - Fix integer width. - Add selftest. - Link to v1: https://lore.kernel.org/r/20241201-riscv-new-regset-v1-1-c83c58abc...@coelacanthus.name --- Celeste Liu (1): riscv/ptrace: add new regset to access original a0 register Charlie Jenkins (1): riscv: selftests: Add a ptrace test to verify syscall parameter modification arch/riscv/kernel/ptrace.c | 32 +++ include/uapi/linux/elf.h | 1 + tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 5 +- tools/testing/selftests/riscv/abi/ptrace.c | 134 +++ 5 files changed, 172 insertions(+), 1 deletion(-) --- base-commit: 0e287d31b62bb53ad81d5e59778384a40f8b6f56 change-id: 20241201-riscv-new-regset-d529b952ad0d Best regards, -- Celeste Liu
[PATCH v2 1/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is
no way to add it without breaking UAPI. (See Link tag below)
Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to
access original a0 register from userspace via ptrace API.
Link:
https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/
Cc: sta...@vger.kernel.org
Signed-off-by: Celeste Liu
---
arch/riscv/kernel/ptrace.c | 32
include/uapi/linux/elf.h | 1 +
2 files changed, 33 insertions(+)
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index
ea67e9fb7a583683b922fe2c017ea61f3bc848db..18ce07ffb27bb1180667769eed800f6fdf96c083
100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -31,6 +31,7 @@ enum riscv_regset {
#ifdef CONFIG_RISCV_ISA_SUPM
REGSET_TAGGED_ADDR_CTRL,
#endif
+ REGSET_ORIG_A0,
};
static int riscv_gpr_get(struct task_struct *target,
@@ -184,6 +185,29 @@ static int tagged_addr_ctrl_set(struct task_struct *target,
}
#endif
+static int riscv_orig_a0_get(struct task_struct *target,
+const struct user_regset *regset,
+struct membuf to)
+{
+ return membuf_store(&to, task_pt_regs(target)->orig_a0);
+}
+
+static int riscv_orig_a0_set(struct task_struct *target,
+const struct user_regset *regset,
+unsigned int pos, unsigned int count,
+const void *kbuf, const void __user *ubuf)
+{
+ unsigned long orig_a0 = task_pt_regs(target)->orig_a0;
+ int ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &orig_a0, 0, -1);
+ if (ret)
+ return ret;
+
+ task_pt_regs(target)->orig_a0 = orig_a0;
+ return ret;
+}
+
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
@@ -224,6 +248,14 @@ static const struct user_regset riscv_user_regset[] = {
.set = tagged_addr_ctrl_set,
},
#endif
+ [REGSET_ORIG_A0] = {
+ .core_note_type = NT_RISCV_ORIG_A0,
+ .n = 1,
+ .size = sizeof(elf_greg_t),
+ .align = sizeof(elf_greg_t),
+ .regset_get = riscv_orig_a0_get,
+ .set = riscv_orig_a0_set,
+ },
};
static const struct user_regset_view riscv_user_native_view = {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index
b44069d29cecc0f9de90ee66bfffd2137f4275a8..390060229601631da2fb27030d9fa2142e676c14
100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -452,6 +452,7 @@ typedef struct elf64_shdr {
#define NT_RISCV_CSR 0x900 /* RISC-V Control and Status Registers
*/
#define NT_RISCV_VECTOR0x901 /* RISC-V vector registers */
#define NT_RISCV_TAGGED_ADDR_CTRL 0x902/* RISC-V tagged address
control (prctl()) */
+#define NT_RISCV_ORIG_A0 0x903 /* RISC-V original a0 register */
#define NT_LOONGARCH_CPUCFG0xa00 /* LoongArch CPU config registers */
#define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status
registers */
#define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension
registers */
--
2.47.0
[PATCH v3 1/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is
no way to add it without breaking UAPI. (See Link tag below)
Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to
access original a0 register from userspace via ptrace API.
Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Link:
https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/
Cc: sta...@vger.kernel.org
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
arch/riscv/kernel/ptrace.c | 32
include/uapi/linux/elf.h | 1 +
2 files changed, 33 insertions(+)
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index
ea67e9fb7a583683b922fe2c017ea61f3bc848db..ef9ab74c8575a5c440155973b1c625c06a867c97
100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -31,6 +31,7 @@ enum riscv_regset {
#ifdef CONFIG_RISCV_ISA_SUPM
REGSET_TAGGED_ADDR_CTRL,
#endif
+ REGSET_ORIG_A0,
};
static int riscv_gpr_get(struct task_struct *target,
@@ -184,6 +185,29 @@ static int tagged_addr_ctrl_set(struct task_struct *target,
}
#endif
+static int riscv_orig_a0_get(struct task_struct *target,
+const struct user_regset *regset,
+struct membuf to)
+{
+ return membuf_store(&to, task_pt_regs(target)->orig_a0);
+}
+
+static int riscv_orig_a0_set(struct task_struct *target,
+const struct user_regset *regset,
+unsigned int pos, unsigned int count,
+const void *kbuf, const void __user *ubuf)
+{
+ unsigned long orig_a0 = task_pt_regs(target)->orig_a0;
+ int ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &orig_a0, 0, -1);
+ if (ret)
+ return ret;
+
+ task_pt_regs(target)->orig_a0 = orig_a0;
+ return 0;
+}
+
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
@@ -224,6 +248,14 @@ static const struct user_regset riscv_user_regset[] = {
.set = tagged_addr_ctrl_set,
},
#endif
+ [REGSET_ORIG_A0] = {
+ .core_note_type = NT_RISCV_ORIG_A0,
+ .n = 1,
+ .size = sizeof(elf_greg_t),
+ .align = sizeof(elf_greg_t),
+ .regset_get = riscv_orig_a0_get,
+ .set = riscv_orig_a0_set,
+ },
};
static const struct user_regset_view riscv_user_native_view = {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index
b44069d29cecc0f9de90ee66bfffd2137f4275a8..390060229601631da2fb27030d9fa2142e676c14
100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -452,6 +452,7 @@ typedef struct elf64_shdr {
#define NT_RISCV_CSR 0x900 /* RISC-V Control and Status Registers
*/
#define NT_RISCV_VECTOR0x901 /* RISC-V vector registers */
#define NT_RISCV_TAGGED_ADDR_CTRL 0x902/* RISC-V tagged address
control (prctl()) */
+#define NT_RISCV_ORIG_A0 0x903 /* RISC-V original a0 register */
#define NT_LOONGARCH_CPUCFG0xa00 /* LoongArch CPU config registers */
#define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status
registers */
#define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension
registers */
--
2.47.1
[PATCH v3 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
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
Signed-off-by: Quan Zhou
Co-developed-by: Charlie Jenkins
Signed-off-by: Charlie Jenkins
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
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
..c89343cb4abc7da57f83879ecce619f503c438bb
--- /dev/null
+++ b/tools/testing/selftests/riscv/abi/ptrace.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#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:
+
Re: [PATCH v2 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
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
>>>>>
>>>>> This test checks that orig_a0 allows a syscall argument to be modified,
>>>>> and that changing a0 does not change the syscall argument.
>>>>>
>>>>> Cc: sta...@vger.kernel.org
>>>>> Co-developed-by: Quan Zhou
>>>>> Signed-off-by: Quan Zhou
>>>>> Co-developed-by: Celeste Liu
>>>>> Signed-off-by: Celeste Liu
>>>>> Signed-off-by: Charlie Jenkins
>>>>> ---
>>>>> 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
>>>>> ..d192764b428d1f1c442f3957c6fedeb01a48d556
>>>>> --- /dev/null
>>>>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c
>>>>> @@ -0,0 +1,134 @@
>>>>> +// SPDX-License-Identifier: GPL-2.0-only
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +#include
>>>>> +
>>>>> +#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", \
Re: [PATCH v4 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
On 2024-12-26 21:35, Dmitry V. Levin wrote:
> On Thu, Dec 26, 2024 at 06:52:52PM +0800, 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
>> Signed-off-by: Quan Zhou
>> Co-developed-by: Charlie Jenkins
>> Signed-off-by: Charlie Jenkins
>> Reviewed-by: Björn Töpel
>> Signed-off-by: Celeste Liu
> [...]
>> diff --git a/tools/testing/selftests/riscv/abi/ptrace.c
>> b/tools/testing/selftests/riscv/abi/ptrace.c
>> new file mode 100644
>> index
>> ..023695352215bb5de3f91c1a6f5ea3b4f9373ff9
>> --- /dev/null
>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c
> [...]
>> +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;
>
> I'm sorry but this is not how PTRACE_GET_SYSCALL_INFO should be used.
>
> PTRACE_GET_SYSCALL_INFO operation takes a pointer and a size,
> and in this example instead of size you pass constants 1 and 2, which
> essentially means that both syscall_info_entry->entry.args[0] and
> syscall_info_exit->exit.rval are not going to be assigned
> and would just contain some garbage from the stack.
>
> Also, PTRACE_GET_SYSCALL_INFO operation returns the number of bytes
> available to be written by the kernel, which is always nonzero on any
> PTRACE_GET_SYSCALL_INFO-capable kernel. In other words, this example
> will always end up with perr_and_exit() call.
>
> I wonder how this test was tested before the submission.
Oops... It seems I forget sync the code to test board so it runs with the old
code...
The code is completely not tested...
I'm so sorry for my mistake.
I will correct it and test it carefully later...
>
>
Re: [PATCH v3 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
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
> Signed-off-by: Quan Zhou
> Co-developed-by: Charlie Jenkins
> Signed-off-by: Charlie Jenkins
> Reviewed-by: Björn Töpel
> Signed-off-by: Celeste Liu
> ---
> 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
> ..c89343cb4abc7da57f83879ecce619f503c438bb
> --- /dev/null
> +++ b/tools/testing/selftests/riscv/abi/ptrace.c
> @@ -0,0 +1,151 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +#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);
> +
[PATCH v4 0/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is no way to add it without breaking UAPI. (See Link tag below) Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to access original a0 register from userspace via ptrace API. Link: https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/ Signed-off-by: Celeste Liu --- Changes in v4: - Fix a copy paste error in selftest. (Forget to commit...) - Link to v3: https://lore.kernel.org/r/20241226-riscv-new-regset-v3-0-f5b964658...@coelacanthus.name Changes in v3: - Use return 0 directly for readability. - Fix test for modify a0. - Add Fixes: tag - Remove useless Cc: stable. - Selftest will check both a0 and orig_a0, but depends on the correctness of PTRACE_GET_SYSCALL_INFO. - Link to v2: https://lore.kernel.org/r/20241203-riscv-new-regset-v2-0-d37da8c0c...@coelacanthus.name Changes in v2: - Fix integer width. - Add selftest. - Link to v1: https://lore.kernel.org/r/20241201-riscv-new-regset-v1-1-c83c58abc...@coelacanthus.name --- Celeste Liu (2): riscv/ptrace: add new regset to access original a0 register riscv: selftests: Add a ptrace test to verify syscall parameter modification arch/riscv/kernel/ptrace.c | 32 ++ include/uapi/linux/elf.h | 1 + tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 5 +- tools/testing/selftests/riscv/abi/ptrace.c | 151 +++ 5 files changed, 189 insertions(+), 1 deletion(-) --- base-commit: 0e287d31b62bb53ad81d5e59778384a40f8b6f56 change-id: 20241201-riscv-new-regset-d529b952ad0d Best regards, -- Celeste Liu
[PATCH v3 0/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is no way to add it without breaking UAPI. (See Link tag below) Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to access original a0 register from userspace via ptrace API. Link: https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/ Signed-off-by: Celeste Liu --- Changes in v3: - Use return 0 directly for readability. - Fix test for modify a0. - Add Fixes: tag - Remove useless Cc: stable. - Selftest will check both a0 and orig_a0, but depends on the correctness of PTRACE_GET_SYSCALL_INFO. - Link to v2: https://lore.kernel.org/r/20241203-riscv-new-regset-v2-0-d37da8c0c...@coelacanthus.name Changes in v2: - Fix integer width. - Add selftest. - Link to v1: https://lore.kernel.org/r/20241201-riscv-new-regset-v1-1-c83c58abc...@coelacanthus.name --- Celeste Liu (2): riscv/ptrace: add new regset to access original a0 register riscv: selftests: Add a ptrace test to verify syscall parameter modification arch/riscv/kernel/ptrace.c | 32 ++ include/uapi/linux/elf.h | 1 + tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 5 +- tools/testing/selftests/riscv/abi/ptrace.c | 151 +++ 5 files changed, 189 insertions(+), 1 deletion(-) --- base-commit: 0e287d31b62bb53ad81d5e59778384a40f8b6f56 change-id: 20241201-riscv-new-regset-d529b952ad0d Best regards, -- Celeste Liu
[PATCH v4 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
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
Signed-off-by: Quan Zhou
Co-developed-by: Charlie Jenkins
Signed-off-by: Charlie Jenkins
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
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
..023695352215bb5de3f91c1a6f5ea3b4f9373ff9
--- /dev/null
+++ b/tools/testing/selftests/riscv/abi/ptrace.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#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:
+
[PATCH v4 1/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is
no way to add it without breaking UAPI. (See Link tag below)
Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to
access original a0 register from userspace via ptrace API.
Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Link:
https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/
Cc: sta...@vger.kernel.org
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
arch/riscv/kernel/ptrace.c | 32
include/uapi/linux/elf.h | 1 +
2 files changed, 33 insertions(+)
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index
ea67e9fb7a583683b922fe2c017ea61f3bc848db..ef9ab74c8575a5c440155973b1c625c06a867c97
100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -31,6 +31,7 @@ enum riscv_regset {
#ifdef CONFIG_RISCV_ISA_SUPM
REGSET_TAGGED_ADDR_CTRL,
#endif
+ REGSET_ORIG_A0,
};
static int riscv_gpr_get(struct task_struct *target,
@@ -184,6 +185,29 @@ static int tagged_addr_ctrl_set(struct task_struct *target,
}
#endif
+static int riscv_orig_a0_get(struct task_struct *target,
+const struct user_regset *regset,
+struct membuf to)
+{
+ return membuf_store(&to, task_pt_regs(target)->orig_a0);
+}
+
+static int riscv_orig_a0_set(struct task_struct *target,
+const struct user_regset *regset,
+unsigned int pos, unsigned int count,
+const void *kbuf, const void __user *ubuf)
+{
+ unsigned long orig_a0 = task_pt_regs(target)->orig_a0;
+ int ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &orig_a0, 0, -1);
+ if (ret)
+ return ret;
+
+ task_pt_regs(target)->orig_a0 = orig_a0;
+ return 0;
+}
+
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
@@ -224,6 +248,14 @@ static const struct user_regset riscv_user_regset[] = {
.set = tagged_addr_ctrl_set,
},
#endif
+ [REGSET_ORIG_A0] = {
+ .core_note_type = NT_RISCV_ORIG_A0,
+ .n = 1,
+ .size = sizeof(elf_greg_t),
+ .align = sizeof(elf_greg_t),
+ .regset_get = riscv_orig_a0_get,
+ .set = riscv_orig_a0_set,
+ },
};
static const struct user_regset_view riscv_user_native_view = {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index
b44069d29cecc0f9de90ee66bfffd2137f4275a8..390060229601631da2fb27030d9fa2142e676c14
100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -452,6 +452,7 @@ typedef struct elf64_shdr {
#define NT_RISCV_CSR 0x900 /* RISC-V Control and Status Registers
*/
#define NT_RISCV_VECTOR0x901 /* RISC-V vector registers */
#define NT_RISCV_TAGGED_ADDR_CTRL 0x902/* RISC-V tagged address
control (prctl()) */
+#define NT_RISCV_ORIG_A0 0x903 /* RISC-V original a0 register */
#define NT_LOONGARCH_CPUCFG0xa00 /* LoongArch CPU config registers */
#define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status
registers */
#define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension
registers */
--
2.47.1
Re: [PATCH v2 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
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
>>>
>>> This test checks that orig_a0 allows a syscall argument to be modified,
>>> and that changing a0 does not change the syscall argument.
>>>
>>> Cc: sta...@vger.kernel.org
>>> Co-developed-by: Quan Zhou
>>> Signed-off-by: Quan Zhou
>>> Co-developed-by: Celeste Liu
>>> Signed-off-by: Celeste Liu
>>> Signed-off-by: Charlie Jenkins
>>> ---
>>> 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
>>> ..d192764b428d1f1c442f3957c6fedeb01a48d556
>>> --- /dev/null
>>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c
>>> @@ -0,0 +1,134 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +#include
>>> +
>>> +#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) !=
Re: [PATCH v4 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
On 2025-01-10 11:34, Charlie Jenkins wrote:
> On Thu, Dec 26, 2024 at 11:21:59PM +0800, Celeste Liu wrote:
>>
>> On 2024-12-26 21:35, Dmitry V. Levin wrote:
>>> On Thu, Dec 26, 2024 at 06:52:52PM +0800, 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
>>>> Signed-off-by: Quan Zhou
>>>> Co-developed-by: Charlie Jenkins
>>>> Signed-off-by: Charlie Jenkins
>>>> Reviewed-by: Björn Töpel
>>>> Signed-off-by: Celeste Liu
>>> [...]
>>>> diff --git a/tools/testing/selftests/riscv/abi/ptrace.c
>>>> b/tools/testing/selftests/riscv/abi/ptrace.c
>>>> new file mode 100644
>>>> index
>>>> ..023695352215bb5de3f91c1a6f5ea3b4f9373ff9
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c
>>> [...]
>>>> + 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;
>>>
>>> I'm sorry but this is not how PTRACE_GET_SYSCALL_INFO should be used.
>>>
>>> PTRACE_GET_SYSCALL_INFO operation takes a pointer and a size,
>>> and in this example instead of size you pass constants 1 and 2, which
>>> essentially means that both syscall_info_entry->entry.args[0] and
>>> syscall_info_exit->exit.rval are not going to be assigned
>>> and would just contain some garbage from the stack.
>>>
>>> Also, PTRACE_GET_SYSCALL_INFO operation returns the number of bytes
>>> available to be written by the kernel, which is always nonzero on any
>>> PTRACE_GET_SYSCALL_INFO-capable kernel. In other words, this example
>>> will always end up with perr_and_exit() call.
>>>
>>> I wonder how this test was tested before the submission.
>>
>> Oops... It seems I forget sync the code to test board so it runs with the
>> old code...
>> The code is completely not tested...
>> I'm so sorry for my mistake.
>>
>> I will correct it and test it carefully later...
>
> It would be great to get this into 6.14. Let me know if you would like
> any help!
Sorry, delayed due to personal reasons. I have returned to this job recently.
The update patchset will be sent tomorrow.
>
> - Charlie
>
>>
>>>
>>>
>>
Re: [PATCH v4 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification
On 2025-01-10 11:34, Charlie Jenkins wrote:
> On Thu, Dec 26, 2024 at 11:21:59PM +0800, Celeste Liu wrote:
>>
>> On 2024-12-26 21:35, Dmitry V. Levin wrote:
>>> On Thu, Dec 26, 2024 at 06:52:52PM +0800, 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
>>>> Signed-off-by: Quan Zhou
>>>> Co-developed-by: Charlie Jenkins
>>>> Signed-off-by: Charlie Jenkins
>>>> Reviewed-by: Björn Töpel
>>>> Signed-off-by: Celeste Liu
>>> [...]
>>>> diff --git a/tools/testing/selftests/riscv/abi/ptrace.c
>>>> b/tools/testing/selftests/riscv/abi/ptrace.c
>>>> new file mode 100644
>>>> index
>>>> ..023695352215bb5de3f91c1a6f5ea3b4f9373ff9
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c
>>> [...]
>>>> + 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;
>>>
>>> I'm sorry but this is not how PTRACE_GET_SYSCALL_INFO should be used.
>>>
>>> PTRACE_GET_SYSCALL_INFO operation takes a pointer and a size,
>>> and in this example instead of size you pass constants 1 and 2, which
>>> essentially means that both syscall_info_entry->entry.args[0] and
>>> syscall_info_exit->exit.rval are not going to be assigned
>>> and would just contain some garbage from the stack.
>>>
>>> Also, PTRACE_GET_SYSCALL_INFO operation returns the number of bytes
>>> available to be written by the kernel, which is always nonzero on any
>>> PTRACE_GET_SYSCALL_INFO-capable kernel. In other words, this example
>>> will always end up with perr_and_exit() call.
>>>
>>> I wonder how this test was tested before the submission.
>>
>> Oops... It seems I forget sync the code to test board so it runs with the
>> old code...
>> The code is completely not tested...
>> I'm so sorry for my mistake.
>>
>> I will correct it and test it carefully later...
>
> It would be great to get this into 6.14. Let me know if you would like
> any help!
v5 has been sent.
Sorry for delay. My test environment was broken yesterday so I have to
spend time to repair it first...
https://lore.kernel.org/lkml/20250115-riscv-new-regset-v5-0-d0e6ec031...@coelacanthus.name/T/
>
> - Charlie
>
>>
>>>
>>>
>>
Re: [PATCH v5 2/2] riscv: selftests: Add a ptrace test to verify a0 and orig_a0 access
On 2025-01-15 17:14, Andrew Jones wrote:
> On Wed, Jan 15, 2025 at 04:24:59AM +0800, Celeste Liu wrote:
>> This test checks that orig_a0 and a0 can be modified and accessed
>> independently.
>>
>> Co-developed-by: Quan Zhou
>> Signed-off-by: Quan Zhou
>> Co-developed-by: Charlie Jenkins
>> Signed-off-by: Charlie Jenkins
>> Reviewed-by: Björn Töpel
>> Signed-off-by: Celeste Liu
>> ---
>> tools/testing/selftests/riscv/abi/.gitignore | 1 +
>> tools/testing/selftests/riscv/abi/Makefile | 6 +-
>> tools/testing/selftests/riscv/abi/ptrace.c | 201
>> +++
>> 3 files changed, 207 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..359a082c88a401883fb3776b35e4dacf69be
>> 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
>> ..f1a0458adccdd040bfaa350e2e8d98b1ef34c0ad
>> --- /dev/null
>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c
>> @@ -0,0 +1,201 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +#include
>> +
>> +#include "../../kselftest_harness.h"
>> +
>> +#ifndef sizeof_field
>> +#define sizeof_field(TYPE, MEMBER) sizeofTYPE *)0)->MEMBER))
>> +#endif
>> +#ifndef offsetofend
>> +#define offsetofend(TYPE, MEMBER) \
>> +(offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
>> +#endif
>
> I think this is the sixth test to define these. We should copy
> include/linux/stddef.h into tools/include. We already have
> tools/include/uapi/linux/stddef.h with __struct_group and
> __DECLARE_FLEX_ARRAY, so I think it should just work.
Agreed. But it may be better to be a separate patchset
so we can change those definition in different selftests
one pass.
>
>> +
>> +
>> +#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,
>> +
[PATCH v6 2/3] tools: copy include/linux/stddef.h to tools/include
Some macro defined in stddef.h are useful and have been used in many code in selftests. Copy them to tools/include so developers needn't create their copy in every files. Remove some definitions like NULL and true/false to be suitable to non-kernel environment. Signed-off-by: Celeste Liu --- tools/include/linux/stddef.h | 85 +++ tools/include/uapi/linux/stddef.h | 6 +-- 2 files changed, 87 insertions(+), 4 deletions(-) diff --git a/tools/include/linux/stddef.h b/tools/include/linux/stddef.h new file mode 100644 index ..55f3964d9a3d9f9f9345a75248eec027c56faef9 --- /dev/null +++ b/tools/include/linux/stddef.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_STDDEF_H +#define _LINUX_STDDEF_H + +#include + +/** + * sizeof_field() - Report the size of a struct field in bytes + * + * @TYPE: The structure containing the field of interest + * @MEMBER: The field to return the size of + */ +#define sizeof_field(TYPE, MEMBER) sizeofTYPE *)0)->MEMBER)) + +/** + * offsetofend() - Report the offset of a struct field within the struct + * + * @TYPE: The type of the structure + * @MEMBER: The member within the structure to get the end offset of + */ +#define offsetofend(TYPE, MEMBER) \ + (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) + +/** + * struct_group() - Wrap a set of declarations in a mirrored struct + * + * @NAME: The identifier name of the mirrored sub-struct + * @MEMBERS: The member declarations for the mirrored structs + * + * Used to create an anonymous union of two structs with identical + * layout and size: one anonymous and one named. The former can be + * used normally without sub-struct naming, and the latter can be + * used to reason about the start, end, and size of the group of + * struct members. + */ +#define struct_group(NAME, MEMBERS...) \ + __struct_group(/* no tag */, NAME, /* no attrs */, MEMBERS) + +/** + * struct_group_attr() - Create a struct_group() with trailing attributes + * + * @NAME: The identifier name of the mirrored sub-struct + * @ATTRS: Any struct attributes to apply + * @MEMBERS: The member declarations for the mirrored structs + * + * Used to create an anonymous union of two structs with identical + * layout and size: one anonymous and one named. The former can be + * used normally without sub-struct naming, and the latter can be + * used to reason about the start, end, and size of the group of + * struct members. Includes structure attributes argument. + */ +#define struct_group_attr(NAME, ATTRS, MEMBERS...) \ + __struct_group(/* no tag */, NAME, ATTRS, MEMBERS) + +/** + * struct_group_tagged() - Create a struct_group with a reusable tag + * + * @TAG: The tag name for the named sub-struct + * @NAME: The identifier name of the mirrored sub-struct + * @MEMBERS: The member declarations for the mirrored structs + * + * Used to create an anonymous union of two structs with identical + * layout and size: one anonymous and one named. The former can be + * used normally without sub-struct naming, and the latter can be + * used to reason about the start, end, and size of the group of + * struct members. Includes struct tag argument for the named copy, + * so the specified layout can be reused later. + */ +#define struct_group_tagged(TAG, NAME, MEMBERS...) \ + __struct_group(TAG, NAME, /* no attrs */, MEMBERS) + +/** + * DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union + * + * @TYPE: The type of each flexible array element + * @NAME: The name of the flexible array member + * + * In order to have a flexible array member in a union or alone in a + * struct, it needs to be wrapped in an anonymous struct with at least 1 + * named member, but that member can be empty. + */ +#define DECLARE_FLEX_ARRAY(TYPE, NAME) \ + __DECLARE_FLEX_ARRAY(TYPE, NAME) + +#endif diff --git a/tools/include/uapi/linux/stddef.h b/tools/include/uapi/linux/stddef.h index bb6ea517efb51177a7983fadad9b590b12b786e5..f2548fd95f6e1d8cb218d52918bb81a3317d10b1 100644 --- a/tools/include/uapi/linux/stddef.h +++ b/tools/include/uapi/linux/stddef.h @@ -1,8 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ -#ifndef _LINUX_STDDEF_H -#define _LINUX_STDDEF_H - - +#ifndef _UAPI_LINUX_STDDEF_H +#define _UAPI_LINUX_STDDEF_H #ifndef __always_inline #define __always_inline __inline__ -- 2.48.0
[PATCH v6 3/3] riscv: selftests: Add a ptrace test to verify a0 and orig_a0 access
This test checks that orig_a0 and a0 can be modified and accessed
independently.
Co-developed-by: Quan Zhou
Signed-off-by: Quan Zhou
Co-developed-by: Charlie Jenkins
Signed-off-by: Charlie Jenkins
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
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..359a082c88a401883fb3776b35e4dacf69be
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
..cbd60462021165ca2bcc38be24b8423c96047b93
--- /dev/null
+++ b/tools/testing/selftests/riscv/abi/ptrace.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#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,
&am
[PATCH v6 1/3] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is
no way to add it without breaking UAPI. (See Link tag below)
Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to
access original a0 register from userspace via ptrace API.
Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Link:
https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/
Cc: sta...@vger.kernel.org
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
arch/riscv/kernel/ptrace.c | 32
include/uapi/linux/elf.h | 1 +
2 files changed, 33 insertions(+)
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index
ea67e9fb7a583683b922fe2c017ea61f3bc848db..ef9ab74c8575a5c440155973b1c625c06a867c97
100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -31,6 +31,7 @@ enum riscv_regset {
#ifdef CONFIG_RISCV_ISA_SUPM
REGSET_TAGGED_ADDR_CTRL,
#endif
+ REGSET_ORIG_A0,
};
static int riscv_gpr_get(struct task_struct *target,
@@ -184,6 +185,29 @@ static int tagged_addr_ctrl_set(struct task_struct *target,
}
#endif
+static int riscv_orig_a0_get(struct task_struct *target,
+const struct user_regset *regset,
+struct membuf to)
+{
+ return membuf_store(&to, task_pt_regs(target)->orig_a0);
+}
+
+static int riscv_orig_a0_set(struct task_struct *target,
+const struct user_regset *regset,
+unsigned int pos, unsigned int count,
+const void *kbuf, const void __user *ubuf)
+{
+ unsigned long orig_a0 = task_pt_regs(target)->orig_a0;
+ int ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &orig_a0, 0, -1);
+ if (ret)
+ return ret;
+
+ task_pt_regs(target)->orig_a0 = orig_a0;
+ return 0;
+}
+
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
@@ -224,6 +248,14 @@ static const struct user_regset riscv_user_regset[] = {
.set = tagged_addr_ctrl_set,
},
#endif
+ [REGSET_ORIG_A0] = {
+ .core_note_type = NT_RISCV_ORIG_A0,
+ .n = 1,
+ .size = sizeof(elf_greg_t),
+ .align = sizeof(elf_greg_t),
+ .regset_get = riscv_orig_a0_get,
+ .set = riscv_orig_a0_set,
+ },
};
static const struct user_regset_view riscv_user_native_view = {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index
b44069d29cecc0f9de90ee66bfffd2137f4275a8..390060229601631da2fb27030d9fa2142e676c14
100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -452,6 +452,7 @@ typedef struct elf64_shdr {
#define NT_RISCV_CSR 0x900 /* RISC-V Control and Status Registers
*/
#define NT_RISCV_VECTOR0x901 /* RISC-V vector registers */
#define NT_RISCV_TAGGED_ADDR_CTRL 0x902/* RISC-V tagged address
control (prctl()) */
+#define NT_RISCV_ORIG_A0 0x903 /* RISC-V original a0 register */
#define NT_LOONGARCH_CPUCFG0xa00 /* LoongArch CPU config registers */
#define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status
registers */
#define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension
registers */
--
2.48.0
[PATCH v6 0/3] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is no way to add it without breaking UAPI. (See Link tag below) Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to access original a0 register from userspace via ptrace API. Link: https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/ Signed-off-by: Celeste Liu --- Changes in v6: - Fix obsolute comment. - Copy include/linux/stddef.h to tools/include to use offsetofend in selftests. - Link to v5: https://lore.kernel.org/r/20250115-riscv-new-regset-v5-0-d0e6ec031...@coelacanthus.name Changes in v5: - Fix wrong usage in selftests. - Link to v4: https://lore.kernel.org/r/20241226-riscv-new-regset-v4-0-4496a29d0...@coelacanthus.name Changes in v4: - Fix a copy paste error in selftest. (Forget to commit...) - Link to v3: https://lore.kernel.org/r/20241226-riscv-new-regset-v3-0-f5b964658...@coelacanthus.name Changes in v3: - Use return 0 directly for readability. - Fix test for modify a0. - Add Fixes: tag - Remove useless Cc: stable. - Selftest will check both a0 and orig_a0, but depends on the correctness of PTRACE_GET_SYSCALL_INFO. - Link to v2: https://lore.kernel.org/r/20241203-riscv-new-regset-v2-0-d37da8c0c...@coelacanthus.name Changes in v2: - Fix integer width. - Add selftest. - Link to v1: https://lore.kernel.org/r/20241201-riscv-new-regset-v1-1-c83c58abc...@coelacanthus.name --- Celeste Liu (3): riscv/ptrace: add new regset to access original a0 register tools: copy include/linux/stddef.h to tools/include riscv: selftests: Add a ptrace test to verify a0 and orig_a0 access arch/riscv/kernel/ptrace.c | 32 + include/uapi/linux/elf.h | 1 + tools/include/linux/stddef.h | 85 tools/include/uapi/linux/stddef.h| 6 +- tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 6 +- tools/testing/selftests/riscv/abi/ptrace.c | 193 +++ 7 files changed, 319 insertions(+), 5 deletions(-) --- base-commit: 0e287d31b62bb53ad81d5e59778384a40f8b6f56 change-id: 20241201-riscv-new-regset-d529b952ad0d Best regards, -- Celeste Liu
Re: [PATCH v5 2/2] riscv: selftests: Add a ptrace test to verify a0 and orig_a0 access
On 2025-01-15 17:56, Andrew Jones wrote: > On Wed, Jan 15, 2025 at 05:41:57PM +0800, Celeste Liu wrote: >> On 2025-01-15 17:14, Andrew Jones wrote: >>> On Wed, Jan 15, 2025 at 04:24:59AM +0800, Celeste Liu wrote: > ... >>>> +#ifndef sizeof_field >>>> +#define sizeof_field(TYPE, MEMBER) sizeofTYPE *)0)->MEMBER)) >>>> +#endif >>>> +#ifndef offsetofend >>>> +#define offsetofend(TYPE, MEMBER) \ >>>> + (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) >>>> +#endif >>> >>> I think this is the sixth test to define these. We should copy >>> include/linux/stddef.h into tools/include. We already have >>> tools/include/uapi/linux/stddef.h with __struct_group and >>> __DECLARE_FLEX_ARRAY, so I think it should just work. >> >> Agreed. But it may be better to be a separate patchset >> so we can change those definition in different selftests >> one pass. >> > > I think a separate "copy stddef.h" patch could be in this series to > avoid having to add the defines here. Then, another series can be > sent with one patch for each conversion. That said, I'm OK with > adding the defines for now and doing the conversion later. I just > hope it will actually happen. v6 has been sent. The "copy stddef.h" patch has been included. Once this patchset land, I will send another patchset to deal with other usages. https://lore.kernel.org/lkml/20250115-riscv-new-regset-v6-0-59bfddd33...@coelacanthus.name/T/ > > Thanks, > drew
[PATCH v5 0/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is no way to add it without breaking UAPI. (See Link tag below) Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to access original a0 register from userspace via ptrace API. Link: https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/ Signed-off-by: Celeste Liu --- Changes in v5: - Fix wrong usage in selftests. - Link to v4: https://lore.kernel.org/r/20241226-riscv-new-regset-v4-0-4496a29d0...@coelacanthus.name Changes in v4: - Fix a copy paste error in selftest. (Forget to commit...) - Link to v3: https://lore.kernel.org/r/20241226-riscv-new-regset-v3-0-f5b964658...@coelacanthus.name Changes in v3: - Use return 0 directly for readability. - Fix test for modify a0. - Add Fixes: tag - Remove useless Cc: stable. - Selftest will check both a0 and orig_a0, but depends on the correctness of PTRACE_GET_SYSCALL_INFO. - Link to v2: https://lore.kernel.org/r/20241203-riscv-new-regset-v2-0-d37da8c0c...@coelacanthus.name Changes in v2: - Fix integer width. - Add selftest. - Link to v1: https://lore.kernel.org/r/20241201-riscv-new-regset-v1-1-c83c58abc...@coelacanthus.name --- Celeste Liu (2): riscv/ptrace: add new regset to access original a0 register riscv: selftests: Add a ptrace test to verify a0 and orig_a0 access arch/riscv/kernel/ptrace.c | 32 + include/uapi/linux/elf.h | 1 + tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 6 +- tools/testing/selftests/riscv/abi/ptrace.c | 201 +++ 5 files changed, 240 insertions(+), 1 deletion(-) --- base-commit: 0e287d31b62bb53ad81d5e59778384a40f8b6f56 change-id: 20241201-riscv-new-regset-d529b952ad0d Best regards, -- Celeste Liu
[PATCH v5 1/2] riscv/ptrace: add new regset to access original a0 register
The orig_a0 is missing in struct user_regs_struct of riscv, and there is
no way to add it without breaking UAPI. (See Link tag below)
Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to
access original a0 register from userspace via ptrace API.
Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Link:
https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055ee...@gmail.com/
Cc: sta...@vger.kernel.org
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
arch/riscv/kernel/ptrace.c | 32
include/uapi/linux/elf.h | 1 +
2 files changed, 33 insertions(+)
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index
ea67e9fb7a583683b922fe2c017ea61f3bc848db..ef9ab74c8575a5c440155973b1c625c06a867c97
100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -31,6 +31,7 @@ enum riscv_regset {
#ifdef CONFIG_RISCV_ISA_SUPM
REGSET_TAGGED_ADDR_CTRL,
#endif
+ REGSET_ORIG_A0,
};
static int riscv_gpr_get(struct task_struct *target,
@@ -184,6 +185,29 @@ static int tagged_addr_ctrl_set(struct task_struct *target,
}
#endif
+static int riscv_orig_a0_get(struct task_struct *target,
+const struct user_regset *regset,
+struct membuf to)
+{
+ return membuf_store(&to, task_pt_regs(target)->orig_a0);
+}
+
+static int riscv_orig_a0_set(struct task_struct *target,
+const struct user_regset *regset,
+unsigned int pos, unsigned int count,
+const void *kbuf, const void __user *ubuf)
+{
+ unsigned long orig_a0 = task_pt_regs(target)->orig_a0;
+ int ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &orig_a0, 0, -1);
+ if (ret)
+ return ret;
+
+ task_pt_regs(target)->orig_a0 = orig_a0;
+ return 0;
+}
+
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
@@ -224,6 +248,14 @@ static const struct user_regset riscv_user_regset[] = {
.set = tagged_addr_ctrl_set,
},
#endif
+ [REGSET_ORIG_A0] = {
+ .core_note_type = NT_RISCV_ORIG_A0,
+ .n = 1,
+ .size = sizeof(elf_greg_t),
+ .align = sizeof(elf_greg_t),
+ .regset_get = riscv_orig_a0_get,
+ .set = riscv_orig_a0_set,
+ },
};
static const struct user_regset_view riscv_user_native_view = {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index
b44069d29cecc0f9de90ee66bfffd2137f4275a8..390060229601631da2fb27030d9fa2142e676c14
100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -452,6 +452,7 @@ typedef struct elf64_shdr {
#define NT_RISCV_CSR 0x900 /* RISC-V Control and Status Registers
*/
#define NT_RISCV_VECTOR0x901 /* RISC-V vector registers */
#define NT_RISCV_TAGGED_ADDR_CTRL 0x902/* RISC-V tagged address
control (prctl()) */
+#define NT_RISCV_ORIG_A0 0x903 /* RISC-V original a0 register */
#define NT_LOONGARCH_CPUCFG0xa00 /* LoongArch CPU config registers */
#define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status
registers */
#define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension
registers */
--
2.48.0
[PATCH v5 2/2] riscv: selftests: Add a ptrace test to verify a0 and orig_a0 access
This test checks that orig_a0 and a0 can be modified and accessed
independently.
Co-developed-by: Quan Zhou
Signed-off-by: Quan Zhou
Co-developed-by: Charlie Jenkins
Signed-off-by: Charlie Jenkins
Reviewed-by: Björn Töpel
Signed-off-by: Celeste Liu
---
tools/testing/selftests/riscv/abi/.gitignore | 1 +
tools/testing/selftests/riscv/abi/Makefile | 6 +-
tools/testing/selftests/riscv/abi/ptrace.c | 201 +++
3 files changed, 207 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..359a082c88a401883fb3776b35e4dacf69be
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
..f1a0458adccdd040bfaa350e2e8d98b1ef34c0ad
--- /dev/null
+++ b/tools/testing/selftests/riscv/abi/ptrace.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include "../../kselftest_harness.h"
+
+#ifndef sizeof_field
+#define sizeof_field(TYPE, MEMBER) sizeofTYPE *)0)->MEMBER))
+#endif
+#ifndef offsetofend
+#define offsetofend(TYPE, MEMBER) \
+ (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
+#endif
+
+
+#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;
