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-d4b2055eeaac@gmail.com/
Signed-off-by: Celeste Liu uwu@coelacanthus.name --- 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-d0e6ec031a23@coelac...
Changes in v5: - Fix wrong usage in selftests. - Link to v4: https://lore.kernel.org/r/20241226-riscv-new-regset-v4-0-4496a29d0436@coelac...
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-f5b96465826b@coelac...
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-d37da8c0cba6@coelac...
Changes in v2: - Fix integer width. - Add selftest. - Link to v1: https://lore.kernel.org/r/20241201-riscv-new-regset-v1-1-c83c58abcc7b@coelac...
--- 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,
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-d4b2055eeaac@gmail.com/ Cc: stable@vger.kernel.org Reviewed-by: Björn Töpel bjorn@rivosinc.com Signed-off-by: Celeste Liu uwu@coelacanthus.name --- 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_VECTOR 0x901 /* 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_CPUCFG 0xa00 /* LoongArch CPU config registers */ #define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status registers */ #define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension registers */
On Wed, Jan 15, 2025 at 07:13:27PM +0800, Celeste Liu wrote:
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-d4b2055eeaac@gmail.com/ Cc: stable@vger.kernel.org Reviewed-by: Björn Töpel bjorn@rivosinc.com Signed-off-by: Celeste Liu uwu@coelacanthus.name
Thank you!
Reviewed-by: Charlie Jenkins charlie@rivosinc.com Tested-by: Charlie Jenkins charlie@rivosinc.com
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_VECTOR 0x901 /* 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_CPUCFG 0xa00 /* 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
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 uwu@coelacanthus.name --- 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 0000000000000000000000000000000000000000..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 <uapi/linux/stddef.h> + +/** + * 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) sizeof((((TYPE *)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__
On Wed, Jan 15, 2025 at 07:13:28PM +0800, Celeste Liu wrote:
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 uwu@coelacanthus.name
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 0000000000000000000000000000000000000000..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 <uapi/linux/stddef.h>
+/**
- 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) sizeof((((TYPE *)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
Reviewed-by: Andrew Jones ajones@ventanamicro.com
On Wed, Jan 15, 2025 at 07:13:28PM +0800, Celeste Liu wrote:
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 uwu@coelacanthus.name
Reviewed-by: Charlie Jenkins charlie@rivosinc.com Tested-by: Charlie Jenkins charlie@rivosinc.com
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 0000000000000000000000000000000000000000..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 <uapi/linux/stddef.h>
+/**
- 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) sizeof((((TYPE *)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
This test checks that orig_a0 and a0 can be modified and accessed independently.
Co-developed-by: Quan Zhou zhouquan@iscas.ac.cn Signed-off-by: Quan Zhou zhouquan@iscas.ac.cn Co-developed-by: Charlie Jenkins charlie@rivosinc.com Signed-off-by: Charlie Jenkins charlie@rivosinc.com Reviewed-by: Björn Töpel bjorn@rivosinc.com Signed-off-by: Celeste Liu uwu@coelacanthus.name --- tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 6 +- tools/testing/selftests/riscv/abi/ptrace.c | 193 +++++++++++++++++++++++++++ 3 files changed, 199 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/riscv/abi/.gitignore b/tools/testing/selftests/riscv/abi/.gitignore index b38358f91c4d2240ae64892871d9ca98bda1ae58..378c605919a3b3d58eec2701eb7af430cfe315d6 100644 --- a/tools/testing/selftests/riscv/abi/.gitignore +++ b/tools/testing/selftests/riscv/abi/.gitignore @@ -1 +1,2 @@ pointer_masking +ptrace diff --git a/tools/testing/selftests/riscv/abi/Makefile b/tools/testing/selftests/riscv/abi/Makefile index ed82ff9c664e7eb3f760cbab81fb957ff72579c5..359a082c88a401883fb3776b35e4dacf69beaaaa 100644 --- a/tools/testing/selftests/riscv/abi/Makefile +++ b/tools/testing/selftests/riscv/abi/Makefile @@ -1,10 +1,14 @@ # SPDX-License-Identifier: GPL-2.0
CFLAGS += -I$(top_srcdir)/tools/include +CFLAGS += $(KHDR_INCLUDES)
-TEST_GEN_PROGS := pointer_masking +TEST_GEN_PROGS := pointer_masking ptrace
include ../../lib.mk
$(OUTPUT)/pointer_masking: pointer_masking.c $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^ + +$(OUTPUT)/ptrace: ptrace.c + $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^ diff --git a/tools/testing/selftests/riscv/abi/ptrace.c b/tools/testing/selftests/riscv/abi/ptrace.c new file mode 100644 index 0000000000000000000000000000000000000000..cbd60462021165ca2bcc38be24b8423c96047b93 --- /dev/null +++ b/tools/testing/selftests/riscv/abi/ptrace.c @@ -0,0 +1,193 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <signal.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/ptrace.h> +#include <sys/stat.h> +#include <sys/user.h> +#include <sys/wait.h> +#include <sys/uio.h> +#include <linux/elf.h> +#include <linux/unistd.h> +#include <linux/ptrace.h> +#include <linux/stddef.h> +#include <asm/ptrace.h> + +#include "../../kselftest_harness.h" + +#define ORIG_A0_MODIFY 0x01 +#define A0_MODIFY 0x02 +#define A0_OLD 0xbadbeefbeeff +#define A0_NEW 0xffeebfeebdab + + +struct a0_regs { + __s64 orig_a0; + __u64 a0; +}; + +#define perr_and_exit(fmt, ...) \ + ({ \ + char buf[256]; \ + snprintf(buf, sizeof(buf), "%s:%d:" fmt ": %m\n", \ + __func__, __LINE__, ##__VA_ARGS__); \ + ksft_exit_fail_perror(buf); \ + }) + +static void ptrace_test(int opt, struct a0_regs result[]) +{ + int status; + long rc; + pid_t pid; + struct user_regs_struct regs; + struct iovec iov = { + .iov_base = ®s, + .iov_len = sizeof(regs), + }; + + unsigned long orig_a0; + struct iovec a0_iov = { + .iov_base = &orig_a0, + .iov_len = sizeof(orig_a0), + }; + struct ptrace_syscall_info syscall_info = { + .op = 0xff, + }; + const unsigned int expected_sci_entry_size = + offsetofend(struct ptrace_syscall_info, entry.args); + const unsigned int expected_sci_exit_size = + offsetofend(struct ptrace_syscall_info, exit.is_error); + + pid = fork(); + if (pid == 0) { + /* Mark oneself being traced */ + long val = ptrace(PTRACE_TRACEME, 0, 0, 0); + + if (val < 0) + perr_and_exit("failed to request for tracer to trace me: %ld", val); + + kill(getpid(), SIGSTOP); + + /* Perform chdir syscall that will be intercepted */ + syscall(__NR_chdir, A0_OLD); + + exit(0); + } + + if (pid < 0) + ksft_exit_fail_perror("failed to fork"); + + for (int i = 0; i < 3; i++) { + if (waitpid(pid, &status, 0) != pid) + perr_and_exit("failed to wait for the tracee %d", pid); + if (WIFSTOPPED(status)) { + switch (WSTOPSIG(status)) { + case SIGSTOP: + if (ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACESYSGOOD) < 0) + perr_and_exit("failed to set PTRACE_O_TRACESYSGOOD"); + break; + case SIGTRAP|0x80: + /* Modify twice so GET_SYSCALL_INFO get modified a0 and orig_a0 */ + if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov)) + perr_and_exit("failed to get tracee registers"); + if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov)) + perr_and_exit("failed to get tracee registers"); + + /* Modify a0/orig_a0 for the syscall */ + switch (opt) { + case A0_MODIFY: + regs.a0 = A0_NEW; + break; + case ORIG_A0_MODIFY: + orig_a0 = A0_NEW; + break; + } + + if (ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov)) + perr_and_exit("failed to set tracee registers"); + if (ptrace(PTRACE_SETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov)) + perr_and_exit("failed to set tracee registers"); + switch (i) { + case 1: + /* Stop at the beginning of syscall */ + rc = ptrace(PTRACE_GET_SYSCALL_INFO, pid, + sizeof(syscall_info), &syscall_info); + if (rc < 0) + perr_and_exit("failed to get syscall info of entry"); + if (rc < expected_sci_entry_size + || syscall_info.op != PTRACE_SYSCALL_INFO_ENTRY) + perr_and_exit("stop position of entry mismatched"); + result[0].orig_a0 = syscall_info.entry.args[0]; + break; + + case 2: + /* Stop at the end of syscall */ + rc = ptrace(PTRACE_GET_SYSCALL_INFO, pid, + sizeof(syscall_info), &syscall_info); + if (rc < 0) + perr_and_exit("failed to get syscall info of entry"); + if (rc < expected_sci_exit_size + || syscall_info.op != PTRACE_SYSCALL_INFO_EXIT) + perr_and_exit("stop position of exit mismatched"); + result[0].a0 = syscall_info.exit.rval; + + if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov)) + perr_and_exit("failed to get tracee registers"); + result[1].a0 = regs.a0; + if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0, + &a0_iov)) + perr_and_exit("failed to get tracee registers"); + result[1].orig_a0 = orig_a0; + } + } + if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) + perr_and_exit("failed to resume tracee"); + } + } + + /* Resume the tracee */ + ptrace(PTRACE_CONT, pid, 0, 0); + if (waitpid(pid, &status, 0) != pid) + perr_and_exit("failed to wait for the tracee"); + +} + +TEST(ptrace_access_a0) +{ + struct a0_regs result[2]; + + ptrace_test(A0_MODIFY, result); + + /* Verify PTRACE_SETREGSET */ + /* The modification of a0 cannot affect the first argument of the syscall */ + EXPECT_EQ(A0_OLD, result[0].orig_a0); + EXPECT_EQ(A0_NEW, result[0].a0); + + /* Verify PTRACE_GETREGSET */ + EXPECT_EQ(result[1].orig_a0, result[0].orig_a0); + EXPECT_EQ(result[1].a0, result[0].a0); +} + +TEST(ptrace_access_orig_a0) +{ + struct a0_regs result[2]; + + ptrace_test(ORIG_A0_MODIFY, result); + + /* Verify PTRACE_SETREGSET */ + /* Only modify orig_a0 to change the first argument of the syscall */ + EXPECT_EQ(A0_NEW, result[0].orig_a0); + /* a0 will not be affected */ + EXPECT_NE(A0_NEW, result[0].a0); + + /* Verify PTRACE_GETREGSET */ + EXPECT_EQ(result[1].orig_a0, result[0].orig_a0); + EXPECT_EQ(result[1].a0, result[0].a0); +} + +TEST_HARNESS_MAIN
On Wed, Jan 15, 2025 at 07:13:29PM +0800, Celeste Liu wrote:
This test checks that orig_a0 and a0 can be modified and accessed independently.
Co-developed-by: Quan Zhou zhouquan@iscas.ac.cn Signed-off-by: Quan Zhou zhouquan@iscas.ac.cn Co-developed-by: Charlie Jenkins charlie@rivosinc.com Signed-off-by: Charlie Jenkins charlie@rivosinc.com Reviewed-by: Björn Töpel bjorn@rivosinc.com Signed-off-by: Celeste Liu uwu@coelacanthus.name
tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 6 +- tools/testing/selftests/riscv/abi/ptrace.c | 193 +++++++++++++++++++++++++++ 3 files changed, 199 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/riscv/abi/.gitignore b/tools/testing/selftests/riscv/abi/.gitignore index b38358f91c4d2240ae64892871d9ca98bda1ae58..378c605919a3b3d58eec2701eb7af430cfe315d6 100644 --- a/tools/testing/selftests/riscv/abi/.gitignore +++ b/tools/testing/selftests/riscv/abi/.gitignore @@ -1 +1,2 @@ pointer_masking +ptrace diff --git a/tools/testing/selftests/riscv/abi/Makefile b/tools/testing/selftests/riscv/abi/Makefile index ed82ff9c664e7eb3f760cbab81fb957ff72579c5..359a082c88a401883fb3776b35e4dacf69beaaaa 100644 --- a/tools/testing/selftests/riscv/abi/Makefile +++ b/tools/testing/selftests/riscv/abi/Makefile @@ -1,10 +1,14 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS += -I$(top_srcdir)/tools/include +CFLAGS += $(KHDR_INCLUDES) -TEST_GEN_PROGS := pointer_masking +TEST_GEN_PROGS := pointer_masking ptrace include ../../lib.mk $(OUTPUT)/pointer_masking: pointer_masking.c $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
+$(OUTPUT)/ptrace: ptrace.c
- $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
diff --git a/tools/testing/selftests/riscv/abi/ptrace.c b/tools/testing/selftests/riscv/abi/ptrace.c new file mode 100644 index 0000000000000000000000000000000000000000..cbd60462021165ca2bcc38be24b8423c96047b93 --- /dev/null +++ b/tools/testing/selftests/riscv/abi/ptrace.c @@ -0,0 +1,193 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <signal.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/ptrace.h> +#include <sys/stat.h> +#include <sys/user.h> +#include <sys/wait.h> +#include <sys/uio.h> +#include <linux/elf.h> +#include <linux/unistd.h> +#include <linux/ptrace.h> +#include <linux/stddef.h> +#include <asm/ptrace.h>
+#include "../../kselftest_harness.h"
+#define ORIG_A0_MODIFY 0x01 +#define A0_MODIFY 0x02 +#define A0_OLD 0xbadbeefbeeff +#define A0_NEW 0xffeebfeebdab
+struct a0_regs {
- __s64 orig_a0;
- __u64 a0;
+};
+#define perr_and_exit(fmt, ...) \
- ({ \
char buf[256]; \snprintf(buf, sizeof(buf), "%s:%d:" fmt ": %m\n", \__func__, __LINE__, ##__VA_ARGS__); \ksft_exit_fail_perror(buf); \- })
+static void ptrace_test(int opt, struct a0_regs result[]) +{
- int status;
- long rc;
- pid_t pid;
- struct user_regs_struct regs;
- struct iovec iov = {
.iov_base = ®s,.iov_len = sizeof(regs),- };
- unsigned long orig_a0;
- struct iovec a0_iov = {
.iov_base = &orig_a0,.iov_len = sizeof(orig_a0),- };
- struct ptrace_syscall_info syscall_info = {
.op = 0xff,- };
- const unsigned int expected_sci_entry_size =
offsetofend(struct ptrace_syscall_info, entry.args);- const unsigned int expected_sci_exit_size =
offsetofend(struct ptrace_syscall_info, exit.is_error);- pid = fork();
- if (pid == 0) {
/* Mark oneself being traced */long val = ptrace(PTRACE_TRACEME, 0, 0, 0);if (val < 0)perr_and_exit("failed to request for tracer to trace me: %ld", val);kill(getpid(), SIGSTOP);/* Perform chdir syscall that will be intercepted */syscall(__NR_chdir, A0_OLD);exit(0);- }
- if (pid < 0)
ksft_exit_fail_perror("failed to fork");- for (int i = 0; i < 3; i++) {
if (waitpid(pid, &status, 0) != pid)perr_and_exit("failed to wait for the tracee %d", pid);if (WIFSTOPPED(status)) {switch (WSTOPSIG(status)) {case SIGSTOP:if (ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACESYSGOOD) < 0)perr_and_exit("failed to set PTRACE_O_TRACESYSGOOD");break;case SIGTRAP|0x80:/* Modify twice so GET_SYSCALL_INFO get modified a0 and orig_a0 */if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov))perr_and_exit("failed to get tracee registers");if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov))perr_and_exit("failed to get tracee registers");/* Modify a0/orig_a0 for the syscall */switch (opt) {case A0_MODIFY:regs.a0 = A0_NEW;break;case ORIG_A0_MODIFY:orig_a0 = A0_NEW;break;}if (ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov))perr_and_exit("failed to set tracee registers");if (ptrace(PTRACE_SETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov))perr_and_exit("failed to set tracee registers");switch (i) {case 1:/* Stop at the beginning of syscall */rc = ptrace(PTRACE_GET_SYSCALL_INFO, pid,sizeof(syscall_info), &syscall_info);if (rc < 0)perr_and_exit("failed to get syscall info of entry");if (rc < expected_sci_entry_size|| syscall_info.op != PTRACE_SYSCALL_INFO_ENTRY)perr_and_exit("stop position of entry mismatched");result[0].orig_a0 = syscall_info.entry.args[0];break;case 2:/* Stop at the end of syscall */rc = ptrace(PTRACE_GET_SYSCALL_INFO, pid,sizeof(syscall_info), &syscall_info);if (rc < 0)perr_and_exit("failed to get syscall info of entry");if (rc < expected_sci_exit_size|| syscall_info.op != PTRACE_SYSCALL_INFO_EXIT)perr_and_exit("stop position of exit mismatched");result[0].a0 = syscall_info.exit.rval;if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov))perr_and_exit("failed to get tracee registers");result[1].a0 = regs.a0;if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0,&a0_iov))perr_and_exit("failed to get tracee registers");result[1].orig_a0 = orig_a0;}}if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)perr_and_exit("failed to resume tracee");}- }
- /* Resume the tracee */
- ptrace(PTRACE_CONT, pid, 0, 0);
- if (waitpid(pid, &status, 0) != pid)
perr_and_exit("failed to wait for the tracee");+}
+TEST(ptrace_access_a0) +{
- struct a0_regs result[2];
- ptrace_test(A0_MODIFY, result);
- /* Verify PTRACE_SETREGSET */
- /* The modification of a0 cannot affect the first argument of the syscall */
- EXPECT_EQ(A0_OLD, result[0].orig_a0);
- EXPECT_EQ(A0_NEW, result[0].a0);
- /* Verify PTRACE_GETREGSET */
- EXPECT_EQ(result[1].orig_a0, result[0].orig_a0);
- EXPECT_EQ(result[1].a0, result[0].a0);
+}
+TEST(ptrace_access_orig_a0) +{
- struct a0_regs result[2];
- ptrace_test(ORIG_A0_MODIFY, result);
- /* Verify PTRACE_SETREGSET */
- /* Only modify orig_a0 to change the first argument of the syscall */
- EXPECT_EQ(A0_NEW, result[0].orig_a0);
- /* a0 will not be affected */
- EXPECT_NE(A0_NEW, result[0].a0);
- /* Verify PTRACE_GETREGSET */
- EXPECT_EQ(result[1].orig_a0, result[0].orig_a0);
- EXPECT_EQ(result[1].a0, result[0].a0);
+}
+TEST_HARNESS_MAIN
-- 2.48.0
Reviewed-by: Andrew Jones ajones@ventanamicro.com
On Wed, Jan 15, 2025 at 07:13:26PM +0800, Celeste Liu wrote:
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-d4b2055eeaac@gmail.com/
Signed-off-by: Celeste Liu uwu@coelacanthus.name
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-d0e6ec031a23@coelac...
Changes in v5:
- Fix wrong usage in selftests.
- Link to v4: https://lore.kernel.org/r/20241226-riscv-new-regset-v4-0-4496a29d0436@coelac...
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-f5b96465826b@coelac...
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-d37da8c0cba6@coelac...
Changes in v2:
- Fix integer width.
- Add selftest.
- Link to v1: https://lore.kernel.org/r/20241201-riscv-new-regset-v1-1-c83c58abcc7b@coelac...
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 uwu@coelacanthus.name
There is also this series that looks like it will solve this problem by providing an architecture agnostic way of changing syscall args with PTRACE_SET_SYSCALL_INFO [1].
- Charlie
[1] https://lore.kernel.org/lkml/20250113170925.GA392@altlinux.org/
linux-kselftest-mirror@lists.linaro.org
-
Andrew Jones -
Celeste Liu -
Charlie Jenkins