* [PATCH bpf-next v3 01/11] arm64/bpf: Add orig_x0 to user_pt_regs
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 02/11] s390/bpf: Add orig_gpr2 " Ilya Leoshkevich
` (10 subsequent siblings)
11 siblings, 0 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
orig_x0 is needed in order to access the first syscall argument from
eBPF programs.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
arch/arm64/include/asm/ptrace.h | 2 +-
arch/arm64/include/uapi/asm/ptrace.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 41b332c054ab..1be22f7870f8 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -183,9 +183,9 @@ struct pt_regs {
u64 sp;
u64 pc;
u64 pstate;
+ u64 orig_x0;
};
};
- u64 orig_x0;
#ifdef __AARCH64EB__
u32 unused2;
s32 syscallno;
diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h
index 758ae984ff97..3c118c5b0893 100644
--- a/arch/arm64/include/uapi/asm/ptrace.h
+++ b/arch/arm64/include/uapi/asm/ptrace.h
@@ -90,6 +90,7 @@ struct user_pt_regs {
__u64 sp;
__u64 pc;
__u64 pstate;
+ __u64 orig_x0;
};
struct user_fpsimd_state {
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* [PATCH bpf-next v3 02/11] s390/bpf: Add orig_gpr2 to user_pt_regs
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 01/11] arm64/bpf: Add orig_x0 to user_pt_regs Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-05 0:36 ` Heiko Carstens
2022-02-05 12:37 ` Vasily Gorbik
2022-02-04 14:50 ` [PATCH bpf-next v3 03/11] selftests/bpf: Fix an endianness issue in bpf_syscall_macro test Ilya Leoshkevich
` (9 subsequent siblings)
11 siblings, 2 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
user_pt_regs is used by eBPF in order to access userspace registers -
see commit 466698e654e8 ("s390/bpf: correct broken uapi for
BPF_PROG_TYPE_PERF_EVENT program type"). In order to access the first
syscall argument from eBPF programs, we need to export orig_gpr2.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
arch/s390/include/asm/ptrace.h | 2 +-
arch/s390/include/uapi/asm/ptrace.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index 4ffa8e7f0ed3..c8698e643904 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -83,9 +83,9 @@ struct pt_regs {
unsigned long args[1];
psw_t psw;
unsigned long gprs[NUM_GPRS];
+ unsigned long orig_gpr2;
};
};
- unsigned long orig_gpr2;
union {
struct {
unsigned int int_code;
diff --git a/arch/s390/include/uapi/asm/ptrace.h b/arch/s390/include/uapi/asm/ptrace.h
index ad64d673b5e6..b3dec603f507 100644
--- a/arch/s390/include/uapi/asm/ptrace.h
+++ b/arch/s390/include/uapi/asm/ptrace.h
@@ -295,6 +295,7 @@ typedef struct {
unsigned long args[1];
psw_t psw;
unsigned long gprs[NUM_GPRS];
+ unsigned long orig_gpr2;
} user_pt_regs;
/*
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* Re: [PATCH bpf-next v3 02/11] s390/bpf: Add orig_gpr2 to user_pt_regs
2022-02-04 14:50 ` [PATCH bpf-next v3 02/11] s390/bpf: Add orig_gpr2 " Ilya Leoshkevich
@ 2022-02-05 0:36 ` Heiko Carstens
2022-02-05 12:37 ` Vasily Gorbik
1 sibling, 0 replies; 21+ messages in thread
From: Heiko Carstens @ 2022-02-05 0:36 UTC (permalink / raw)
To: Ilya Leoshkevich
Cc: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Vasily Gorbik, Christian Borntraeger, Alexander Gordeev,
Catalin Marinas, Michael Ellerman, Paul Walmsley, Naveen N . Rao,
bpf
On Fri, Feb 04, 2022 at 03:50:09PM +0100, Ilya Leoshkevich wrote:
> user_pt_regs is used by eBPF in order to access userspace registers -
> see commit 466698e654e8 ("s390/bpf: correct broken uapi for
> BPF_PROG_TYPE_PERF_EVENT program type"). In order to access the first
> syscall argument from eBPF programs, we need to export orig_gpr2.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
> arch/s390/include/asm/ptrace.h | 2 +-
> arch/s390/include/uapi/asm/ptrace.h | 1 +
> 2 files changed, 2 insertions(+), 1 deletion(-)
Acked-by: Heiko Carstens <hca@linux.ibm.com>
^ permalink raw reply [flat|nested] 21+ messages in thread* Re: [PATCH bpf-next v3 02/11] s390/bpf: Add orig_gpr2 to user_pt_regs
2022-02-04 14:50 ` [PATCH bpf-next v3 02/11] s390/bpf: Add orig_gpr2 " Ilya Leoshkevich
2022-02-05 0:36 ` Heiko Carstens
@ 2022-02-05 12:37 ` Vasily Gorbik
1 sibling, 0 replies; 21+ messages in thread
From: Vasily Gorbik @ 2022-02-05 12:37 UTC (permalink / raw)
To: Ilya Leoshkevich
Cc: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Christian Borntraeger, Alexander Gordeev,
Catalin Marinas, Michael Ellerman, Paul Walmsley, Naveen N . Rao,
bpf
On Fri, Feb 04, 2022 at 03:50:09PM +0100, Ilya Leoshkevich wrote:
> user_pt_regs is used by eBPF in order to access userspace registers -
> see commit 466698e654e8 ("s390/bpf: correct broken uapi for
> BPF_PROG_TYPE_PERF_EVENT program type"). In order to access the first
> syscall argument from eBPF programs, we need to export orig_gpr2.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
> arch/s390/include/asm/ptrace.h | 2 +-
> arch/s390/include/uapi/asm/ptrace.h | 1 +
> 2 files changed, 2 insertions(+), 1 deletion(-)
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH bpf-next v3 03/11] selftests/bpf: Fix an endianness issue in bpf_syscall_macro test
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 01/11] arm64/bpf: Add orig_x0 to user_pt_regs Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 02/11] s390/bpf: Add orig_gpr2 " Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 04/11] libbpf: Add __PT_PARM1_REG_SYSCALL macro Ilya Leoshkevich
` (8 subsequent siblings)
11 siblings, 0 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
bpf_syscall_macro reads a long argument into an int variable, which
produces a wrong value on big-endian systems. Fix by reading the
argument into an intermediate long variable first.
Fixes: 77fc0330dfe5 ("selftests/bpf: Add a test to confirm PT_REGS_PARM4_SYSCALL")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/testing/selftests/bpf/progs/bpf_syscall_macro.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
index c8e60220cda8..f5c6ef2ff6d1 100644
--- a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
+++ b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
@@ -28,6 +28,7 @@ int BPF_KPROBE(handle_sys_prctl)
{
struct pt_regs *real_regs;
pid_t pid = bpf_get_current_pid_tgid() >> 32;
+ unsigned long tmp;
if (pid != filter_pid)
return 0;
@@ -35,7 +36,9 @@ int BPF_KPROBE(handle_sys_prctl)
real_regs = (struct pt_regs *)PT_REGS_PARM1(ctx);
/* test for PT_REGS_PARM */
- bpf_probe_read_kernel(&arg1, sizeof(arg1), &PT_REGS_PARM1_SYSCALL(real_regs));
+
+ bpf_probe_read_kernel(&tmp, sizeof(tmp), &PT_REGS_PARM1_SYSCALL(real_regs));
+ arg1 = tmp;
bpf_probe_read_kernel(&arg2, sizeof(arg2), &PT_REGS_PARM2_SYSCALL(real_regs));
bpf_probe_read_kernel(&arg3, sizeof(arg3), &PT_REGS_PARM3_SYSCALL(real_regs));
bpf_probe_read_kernel(&arg4_cx, sizeof(arg4_cx), &PT_REGS_PARM4(real_regs));
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* [PATCH bpf-next v3 04/11] libbpf: Add __PT_PARM1_REG_SYSCALL macro
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (2 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 03/11] selftests/bpf: Fix an endianness issue in bpf_syscall_macro test Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 16:15 ` Naveen N. Rao
2022-02-04 14:50 ` [PATCH bpf-next v3 05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro Ilya Leoshkevich
` (7 subsequent siblings)
11 siblings, 1 reply; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
Some architectures have a special way to access the first syscall
argument. There already exists __PT_PARM4_REG_SYSCALL for the
fourth argument, so define a similar macro for the first one.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 032ba809f3e5..30f0964f8c9e 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -265,7 +265,11 @@ struct pt_regs;
#endif
+#ifdef __PT_PARM1_REG_SYSCALL
+#define PT_REGS_PARM1_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM1_REG_SYSCALL)
+#else /* __PT_PARM1_REG_SYSCALL */
#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1(x)
+#endif
#define PT_REGS_PARM2_SYSCALL(x) PT_REGS_PARM2(x)
#define PT_REGS_PARM3_SYSCALL(x) PT_REGS_PARM3(x)
#ifdef __PT_PARM4_REG_SYSCALL
@@ -275,7 +279,11 @@ struct pt_regs;
#endif
#define PT_REGS_PARM5_SYSCALL(x) PT_REGS_PARM5(x)
+#ifdef __PT_PARM1_REG_SYSCALL
+#define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM1_REG_SYSCALL)
+#else /* __PT_PARM1_REG_SYSCALL */
#define PT_REGS_PARM1_CORE_SYSCALL(x) PT_REGS_PARM1_CORE(x)
+#endif
#define PT_REGS_PARM2_CORE_SYSCALL(x) PT_REGS_PARM2_CORE(x)
#define PT_REGS_PARM3_CORE_SYSCALL(x) PT_REGS_PARM3_CORE(x)
#ifdef __PT_PARM4_REG_SYSCALL
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* Re: [PATCH bpf-next v3 04/11] libbpf: Add __PT_PARM1_REG_SYSCALL macro
2022-02-04 14:50 ` [PATCH bpf-next v3 04/11] libbpf: Add __PT_PARM1_REG_SYSCALL macro Ilya Leoshkevich
@ 2022-02-04 16:15 ` Naveen N. Rao
0 siblings, 0 replies; 21+ messages in thread
From: Naveen N. Rao @ 2022-02-04 16:15 UTC (permalink / raw)
To: Alexander Gordeev, Andrii Nakryiko, Alexei Starovoitov,
Christian Borntraeger, Catalin Marinas, Daniel Borkmann,
Vasily Gorbik, Heiko Carstens, Ilya Leoshkevich,
Michael Ellerman, Paul Walmsley
Cc: bpf
Ilya Leoshkevich wrote:
> Some architectures have a special way to access the first syscall
> argument. There already exists __PT_PARM4_REG_SYSCALL for the
> fourth argument, so define a similar macro for the first one.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
> tools/lib/bpf/bpf_tracing.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
> index 032ba809f3e5..30f0964f8c9e 100644
> --- a/tools/lib/bpf/bpf_tracing.h
> +++ b/tools/lib/bpf/bpf_tracing.h
> @@ -265,7 +265,11 @@ struct pt_regs;
>
> #endif
>
> +#ifdef __PT_PARM1_REG_SYSCALL
> +#define PT_REGS_PARM1_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM1_REG_SYSCALL)
> +#else /* __PT_PARM1_REG_SYSCALL */
> #define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1(x)
> +#endif
> #define PT_REGS_PARM2_SYSCALL(x) PT_REGS_PARM2(x)
> #define PT_REGS_PARM3_SYSCALL(x) PT_REGS_PARM3(x)
> #ifdef __PT_PARM4_REG_SYSCALL
> @@ -275,7 +279,11 @@ struct pt_regs;
> #endif
> #define PT_REGS_PARM5_SYSCALL(x) PT_REGS_PARM5(x)
>
> +#ifdef __PT_PARM1_REG_SYSCALL
> +#define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM1_REG_SYSCALL)
> +#else /* __PT_PARM1_REG_SYSCALL */
> #define PT_REGS_PARM1_CORE_SYSCALL(x) PT_REGS_PARM1_CORE(x)
> +#endif
> #define PT_REGS_PARM2_CORE_SYSCALL(x) PT_REGS_PARM2_CORE(x)
> #define PT_REGS_PARM3_CORE_SYSCALL(x) PT_REGS_PARM3_CORE(x)
> #ifdef __PT_PARM4_REG_SYSCALL
When I was contemplating implementing this for powerpc, I came up with
the below patch which looked cleaner to me, and also makes it easy for
architectures to over-ride any other syscall parameter in future. Feel
free to include this in your series if it makes sense.
- Naveen
--
libbpf: Generalize overriding syscall parameter access macros
Instead of conditionally overriding PT_REGS_PARM4_SYSCALL, provide
default fallback for all _REG_SYSCALL macros so that architectures can
simply override a specific syscall parameter macro.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 40 ++++++++++++++++++++++---------------
1 file changed, 24 insertions(+), 16 deletions(-)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 032ba809f3e57a..2e2f057c7ec7c5 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -265,25 +265,33 @@ struct pt_regs;
#endif
-#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1(x)
-#define PT_REGS_PARM2_SYSCALL(x) PT_REGS_PARM2(x)
-#define PT_REGS_PARM3_SYSCALL(x) PT_REGS_PARM3(x)
-#ifdef __PT_PARM4_REG_SYSCALL
-#define PT_REGS_PARM4_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM4_REG_SYSCALL)
-#else /* __PT_PARM4_REG_SYSCALL */
-#define PT_REGS_PARM4_SYSCALL(x) PT_REGS_PARM4(x)
+#ifndef __PT_PARM1_REG_SYSCALL
+#define __PT_PARM1_REG_SYSCALL __PT_PARM1_REG
+#endif
+#ifndef __PT_PARM2_REG_SYSCALL
+#define __PT_PARM2_REG_SYSCALL __PT_PARM2_REG
+#endif
+#ifndef __PT_PARM3_REG_SYSCALL
+#define __PT_PARM3_REG_SYSCALL __PT_PARM3_REG
+#endif
+#ifndef __PT_PARM4_REG_SYSCALL
+#define __PT_PARM4_REG_SYSCALL __PT_PARM4_REG
#endif
-#define PT_REGS_PARM5_SYSCALL(x) PT_REGS_PARM5(x)
+#ifndef __PT_PARM5_REG_SYSCALL
+#define __PT_PARM5_REG_SYSCALL __PT_PARM5_REG
+#endif
+
+#define PT_REGS_PARM1_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM1_REG_SYSCALL)
+#define PT_REGS_PARM2_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM2_REG_SYSCALL)
+#define PT_REGS_PARM3_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM3_REG_SYSCALL)
+#define PT_REGS_PARM4_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM4_REG_SYSCALL)
+#define PT_REGS_PARM5_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM5_REG_SYSCALL)
-#define PT_REGS_PARM1_CORE_SYSCALL(x) PT_REGS_PARM1_CORE(x)
-#define PT_REGS_PARM2_CORE_SYSCALL(x) PT_REGS_PARM2_CORE(x)
-#define PT_REGS_PARM3_CORE_SYSCALL(x) PT_REGS_PARM3_CORE(x)
-#ifdef __PT_PARM4_REG_SYSCALL
+#define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM1_REG_SYSCALL)
+#define PT_REGS_PARM2_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM2_REG_SYSCALL)
+#define PT_REGS_PARM3_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM3_REG_SYSCALL)
#define PT_REGS_PARM4_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM4_REG_SYSCALL)
-#else /* __PT_PARM4_REG_SYSCALL */
-#define PT_REGS_PARM4_CORE_SYSCALL(x) PT_REGS_PARM4_CORE(x)
-#endif
-#define PT_REGS_PARM5_CORE_SYSCALL(x) PT_REGS_PARM5_CORE(x)
+#define PT_REGS_PARM5_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM5_REG_SYSCALL)
#else /* defined(bpf_target_defined) */
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH bpf-next v3 05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (3 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 04/11] libbpf: Add __PT_PARM1_REG_SYSCALL macro Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 16:46 ` Naveen N. Rao
2022-02-04 14:50 ` [PATCH bpf-next v3 06/11] selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro Ilya Leoshkevich
` (6 subsequent siblings)
11 siblings, 1 reply; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
Some architectures pass a pointer to struct pt_regs to syscall
handlers, others unpack it into individual function parameters.
Introduce a macro to describe what a particular arch does, using
`passing pt_regs *` as a default.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 30f0964f8c9e..08d2990c006f 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -334,6 +334,15 @@ struct pt_regs;
#endif /* defined(bpf_target_defined) */
+/*
+ * When invoked from a syscall handler kprobe, returns a pointer to a
+ * struct pt_regs containing syscall arguments and suitable for passing to
+ * PT_REGS_PARMn_SYSCALL() and PT_REGS_PARMn_CORE_SYSCALL().
+ */
+#ifndef PT_REGS_SYSCALL_REGS
+#define PT_REGS_SYSCALL_REGS(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
+#endif
+
#ifndef ___bpf_concat
#define ___bpf_concat(a, b) a ## b
#endif
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* Re: [PATCH bpf-next v3 05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro
2022-02-04 14:50 ` [PATCH bpf-next v3 05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro Ilya Leoshkevich
@ 2022-02-04 16:46 ` Naveen N. Rao
2022-02-04 18:15 ` Andrii Nakryiko
0 siblings, 1 reply; 21+ messages in thread
From: Naveen N. Rao @ 2022-02-04 16:46 UTC (permalink / raw)
To: Alexander Gordeev, Andrii Nakryiko, Alexei Starovoitov,
Christian Borntraeger, Catalin Marinas, Daniel Borkmann,
Vasily Gorbik, Heiko Carstens, Ilya Leoshkevich,
Michael Ellerman, Paul Walmsley
Cc: bpf
Ilya Leoshkevich wrote:
> Some architectures pass a pointer to struct pt_regs to syscall
> handlers, others unpack it into individual function parameters.
I think that is just dependent on ARCH_HAS_SYSCALL_WRAPPER, so only x86,
arm64 and s390 pass pointers to pt_regs to syscall entry points.
> Introduce a macro to describe what a particular arch does, using
> `passing pt_regs *` as a default.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
> tools/lib/bpf/bpf_tracing.h | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
> index 30f0964f8c9e..08d2990c006f 100644
> --- a/tools/lib/bpf/bpf_tracing.h
> +++ b/tools/lib/bpf/bpf_tracing.h
> @@ -334,6 +334,15 @@ struct pt_regs;
>
> #endif /* defined(bpf_target_defined) */
>
> +/*
> + * When invoked from a syscall handler kprobe, returns a pointer to a
> + * struct pt_regs containing syscall arguments and suitable for passing to
> + * PT_REGS_PARMn_SYSCALL() and PT_REGS_PARMn_CORE_SYSCALL().
> + */
> +#ifndef PT_REGS_SYSCALL_REGS
> +#define PT_REGS_SYSCALL_REGS(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
> +#endif
> +
I think that name is misleading if an architecture doesn't implement syscall
wrappers, since you are simply getting access to the kprobe pt_regs, rather
than the syscall pt_regs. This can perhaps be named PT_REGS_SYSCALL_UNWRAP() or
such to make that clear.
Also, should this just be keyed off a simpler HAS_SYSCALL_WRAPPER or such,
rather than the other way around?
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 032ba809f3e57a..c72f285578d3fc 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -110,6 +110,8 @@
#endif /* __i386__ */
+#define HAS_SYSCALL_WRAPPER
+
#endif /* __KERNEL__ || __VMLINUX_H__ */
#elif defined(bpf_target_s390)
@@ -126,6 +128,7 @@
#define __PT_RC_REG gprs[2]
#define __PT_SP_REG gprs[15]
#define __PT_IP_REG psw.addr
+#define HAS_SYSCALL_WRAPPER
#elif defined(bpf_target_arm)
@@ -154,6 +157,7 @@
#define __PT_RC_REG regs[0]
#define __PT_SP_REG sp
#define __PT_IP_REG pc
+#define HAS_SYSCALL_WRAPPER
#elif defined(bpf_target_mips)
We can then simply do:
#ifdef HAS_SYSCALL_WRAPPER
#define PT_REGS_SYSCALL_UNWRAP(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
#else
#define PT_REGS_SYSCALL_unwRAP(ctx) ((struct pt_regs *)(ctx))
#endif
Taking this a bit further, it would be nice if we can fold in progs/bpf_misc.h
into bpf_traching.h by also including SYS_PREFIX.
- Naveen
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [PATCH bpf-next v3 05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro
2022-02-04 16:46 ` Naveen N. Rao
@ 2022-02-04 18:15 ` Andrii Nakryiko
2022-02-05 7:04 ` Naveen N. Rao
0 siblings, 1 reply; 21+ messages in thread
From: Andrii Nakryiko @ 2022-02-04 18:15 UTC (permalink / raw)
To: Naveen N. Rao
Cc: Alexander Gordeev, Alexei Starovoitov, Christian Borntraeger,
Catalin Marinas, Daniel Borkmann, Vasily Gorbik, Heiko Carstens,
Ilya Leoshkevich, Michael Ellerman, Paul Walmsley, bpf
On Fri, Feb 4, 2022 at 8:46 AM Naveen N. Rao
<naveen.n.rao@linux.vnet.ibm.com> wrote:
>
> Ilya Leoshkevich wrote:
> > Some architectures pass a pointer to struct pt_regs to syscall
> > handlers, others unpack it into individual function parameters.
>
> I think that is just dependent on ARCH_HAS_SYSCALL_WRAPPER, so only x86,
> arm64 and s390 pass pointers to pt_regs to syscall entry points.
>
> > Introduce a macro to describe what a particular arch does, using
> > `passing pt_regs *` as a default.
> >
> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > ---
> > tools/lib/bpf/bpf_tracing.h | 9 +++++++++
> > 1 file changed, 9 insertions(+)
> >
> > diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
> > index 30f0964f8c9e..08d2990c006f 100644
> > --- a/tools/lib/bpf/bpf_tracing.h
> > +++ b/tools/lib/bpf/bpf_tracing.h
> > @@ -334,6 +334,15 @@ struct pt_regs;
> >
> > #endif /* defined(bpf_target_defined) */
> >
> > +/*
> > + * When invoked from a syscall handler kprobe, returns a pointer to a
> > + * struct pt_regs containing syscall arguments and suitable for passing to
> > + * PT_REGS_PARMn_SYSCALL() and PT_REGS_PARMn_CORE_SYSCALL().
> > + */
> > +#ifndef PT_REGS_SYSCALL_REGS
> > +#define PT_REGS_SYSCALL_REGS(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
> > +#endif
> > +
>
> I think that name is misleading if an architecture doesn't implement syscall
> wrappers, since you are simply getting access to the kprobe pt_regs, rather
> than the syscall pt_regs. This can perhaps be named PT_REGS_SYSCALL_UNWRAP() or
> such to make that clear.
UNWRAP implies that there is something to unwrap, always. In case of
s390x, for example, there is nothing to unwrap. So I think
PT_REGS_SYSCALL_REGS() makes more sense, it just fetches correct
pt_regs to work with to get syscall input arguments (and it might be
exactly the same pt_regs that are passed in).
I think in practice most users won't ever have to use this, as we'll
add BPF_KPROBE_SYSCALL() macro, similar to BPF_KPROBE that we have
now, but specific to syscall kprobe.
>
> Also, should this just be keyed off a simpler HAS_SYSCALL_WRAPPER or such,
> rather than the other way around?
I think the way Ilya did it is totally fine.
>
> diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
> index 032ba809f3e57a..c72f285578d3fc 100644
> --- a/tools/lib/bpf/bpf_tracing.h
> +++ b/tools/lib/bpf/bpf_tracing.h
> @@ -110,6 +110,8 @@
>
> #endif /* __i386__ */
>
> +#define HAS_SYSCALL_WRAPPER
> +
> #endif /* __KERNEL__ || __VMLINUX_H__ */
>
> #elif defined(bpf_target_s390)
> @@ -126,6 +128,7 @@
> #define __PT_RC_REG gprs[2]
> #define __PT_SP_REG gprs[15]
> #define __PT_IP_REG psw.addr
> +#define HAS_SYSCALL_WRAPPER
>
> #elif defined(bpf_target_arm)
>
> @@ -154,6 +157,7 @@
> #define __PT_RC_REG regs[0]
> #define __PT_SP_REG sp
> #define __PT_IP_REG pc
> +#define HAS_SYSCALL_WRAPPER
>
> #elif defined(bpf_target_mips)
>
>
> We can then simply do:
>
> #ifdef HAS_SYSCALL_WRAPPER
> #define PT_REGS_SYSCALL_UNWRAP(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
> #else
> #define PT_REGS_SYSCALL_unwRAP(ctx) ((struct pt_regs *)(ctx))
> #endif
>
>
> Taking this a bit further, it would be nice if we can fold in progs/bpf_misc.h
> into bpf_traching.h by also including SYS_PREFIX.
As far as I know, SYS_PREFIX depends not just on architecture but also
on kernel version (older versions of x86-64 kernels didn't need that
prefix). For selftests, given they follow the latest version of kernel
it's ok to always append SYS_PREFIX, but generally speaking for user
BPF apps, they would need to be more careful and check whether they
need SYS_PREFIX or not. So I don't want to add SYS_PREFIX to
bpf_tracing.h because it's misleading.
>
>
> - Naveen
>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH bpf-next v3 05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro
2022-02-04 18:15 ` Andrii Nakryiko
@ 2022-02-05 7:04 ` Naveen N. Rao
0 siblings, 0 replies; 21+ messages in thread
From: Naveen N. Rao @ 2022-02-05 7:04 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: Alexander Gordeev, Alexei Starovoitov, Christian Borntraeger,
bpf, Catalin Marinas, Daniel Borkmann, Vasily Gorbik,
Heiko Carstens, Ilya Leoshkevich, Michael Ellerman,
Paul Walmsley
Andrii Nakryiko wrote:
> On Fri, Feb 4, 2022 at 8:46 AM Naveen N. Rao
> <naveen.n.rao@linux.vnet.ibm.com> wrote:
>>
>> Ilya Leoshkevich wrote:
>> > Some architectures pass a pointer to struct pt_regs to syscall
>> > handlers, others unpack it into individual function parameters.
>>
>> I think that is just dependent on ARCH_HAS_SYSCALL_WRAPPER, so only x86,
>> arm64 and s390 pass pointers to pt_regs to syscall entry points.
>>
>> > Introduce a macro to describe what a particular arch does, using
>> > `passing pt_regs *` as a default.
>> >
>> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
>> > ---
>> > tools/lib/bpf/bpf_tracing.h | 9 +++++++++
>> > 1 file changed, 9 insertions(+)
>> >
>> > diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
>> > index 30f0964f8c9e..08d2990c006f 100644
>> > --- a/tools/lib/bpf/bpf_tracing.h
>> > +++ b/tools/lib/bpf/bpf_tracing.h
>> > @@ -334,6 +334,15 @@ struct pt_regs;
>> >
>> > #endif /* defined(bpf_target_defined) */
>> >
>> > +/*
>> > + * When invoked from a syscall handler kprobe, returns a pointer to a
>> > + * struct pt_regs containing syscall arguments and suitable for passing to
>> > + * PT_REGS_PARMn_SYSCALL() and PT_REGS_PARMn_CORE_SYSCALL().
>> > + */
>> > +#ifndef PT_REGS_SYSCALL_REGS
>> > +#define PT_REGS_SYSCALL_REGS(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
>> > +#endif
>> > +
>>
>> I think that name is misleading if an architecture doesn't implement syscall
>> wrappers, since you are simply getting access to the kprobe pt_regs, rather
>> than the syscall pt_regs. This can perhaps be named PT_REGS_SYSCALL_UNWRAP() or
>> such to make that clear.
>
> UNWRAP implies that there is something to unwrap, always. In case of
> s390x, for example, there is nothing to unwrap. So I think
> PT_REGS_SYSCALL_REGS() makes more sense, it just fetches correct
> pt_regs to work with to get syscall input arguments (and it might be
> exactly the same pt_regs that are passed in).
>
> I think in practice most users won't ever have to use this, as we'll
> add BPF_KPROBE_SYSCALL() macro, similar to BPF_KPROBE that we have
> now, but specific to syscall kprobe.
That will be very nice.
>
>>
>> Also, should this just be keyed off a simpler HAS_SYSCALL_WRAPPER or such,
>> rather than the other way around?
>
> I think the way Ilya did it is totally fine.
>
>>
>> diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
>> index 032ba809f3e57a..c72f285578d3fc 100644
>> --- a/tools/lib/bpf/bpf_tracing.h
>> +++ b/tools/lib/bpf/bpf_tracing.h
>> @@ -110,6 +110,8 @@
>>
>> #endif /* __i386__ */
>>
>> +#define HAS_SYSCALL_WRAPPER
>> +
>> #endif /* __KERNEL__ || __VMLINUX_H__ */
>>
>> #elif defined(bpf_target_s390)
>> @@ -126,6 +128,7 @@
>> #define __PT_RC_REG gprs[2]
>> #define __PT_SP_REG gprs[15]
>> #define __PT_IP_REG psw.addr
>> +#define HAS_SYSCALL_WRAPPER
>>
>> #elif defined(bpf_target_arm)
>>
>> @@ -154,6 +157,7 @@
>> #define __PT_RC_REG regs[0]
>> #define __PT_SP_REG sp
>> #define __PT_IP_REG pc
>> +#define HAS_SYSCALL_WRAPPER
>>
>> #elif defined(bpf_target_mips)
>>
>>
>> We can then simply do:
>>
>> #ifdef HAS_SYSCALL_WRAPPER
>> #define PT_REGS_SYSCALL_UNWRAP(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
>> #else
>> #define PT_REGS_SYSCALL_unwRAP(ctx) ((struct pt_regs *)(ctx))
>> #endif
>>
>>
>> Taking this a bit further, it would be nice if we can fold in progs/bpf_misc.h
>> into bpf_traching.h by also including SYS_PREFIX.
>
> As far as I know, SYS_PREFIX depends not just on architecture but also
> on kernel version (older versions of x86-64 kernels didn't need that
> prefix). For selftests, given they follow the latest version of kernel
> it's ok to always append SYS_PREFIX, but generally speaking for user
> BPF apps, they would need to be more careful and check whether they
> need SYS_PREFIX or not. So I don't want to add SYS_PREFIX to
> bpf_tracing.h because it's misleading.
That makes sense, thanks.
- Naveen
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH bpf-next v3 06/11] selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (4 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 07/11] libbpf: Fix accessing the first syscall argument on arm64 Ilya Leoshkevich
` (5 subsequent siblings)
11 siblings, 0 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
Ensure that PT_REGS_SYSCALL_REGS works correctly.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/testing/selftests/bpf/progs/bpf_syscall_macro.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
index f5c6ef2ff6d1..e7c622cb6a39 100644
--- a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
+++ b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
@@ -33,7 +33,7 @@ int BPF_KPROBE(handle_sys_prctl)
if (pid != filter_pid)
return 0;
- real_regs = (struct pt_regs *)PT_REGS_PARM1(ctx);
+ real_regs = PT_REGS_SYSCALL_REGS(ctx);
/* test for PT_REGS_PARM */
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* [PATCH bpf-next v3 07/11] libbpf: Fix accessing the first syscall argument on arm64
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (5 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 06/11] selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 08/11] libbpf: Fix accessing syscall arguments on powerpc Ilya Leoshkevich
` (4 subsequent siblings)
11 siblings, 0 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
On arm64, the first syscall argument should be accessed via orig_x0
(see arch/arm64/include/asm/syscall.h). Currently regs[0] is used
instead, leading to bpf_syscall_macro test failure.
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 08d2990c006f..317bee0fd8e4 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -145,6 +145,7 @@
/* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */
#define __PT_REGS_CAST(x) ((const struct user_pt_regs *)(x))
#define __PT_PARM1_REG regs[0]
+#define __PT_PARM1_REG_SYSCALL orig_x0
#define __PT_PARM2_REG regs[1]
#define __PT_PARM3_REG regs[2]
#define __PT_PARM4_REG regs[3]
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* [PATCH bpf-next v3 08/11] libbpf: Fix accessing syscall arguments on powerpc
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (6 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 07/11] libbpf: Fix accessing the first syscall argument on arm64 Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-05 7:05 ` Naveen N. Rao
2022-02-04 14:50 ` [PATCH bpf-next v3 09/11] libbpf: Fix accessing program counter on riscv Ilya Leoshkevich
` (3 subsequent siblings)
11 siblings, 1 reply; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
powerpc's syscall handlers get "unpacked" arguments instead of a
struct pt_regs pointer. Indicate this to libbpf using
PT_REGS_SYSCALL_REGS macro.
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 317bee0fd8e4..f9d22ea0af97 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -181,6 +181,7 @@
#define __PT_RC_REG gpr[3]
#define __PT_SP_REG sp
#define __PT_IP_REG nip
+#define PT_REGS_SYSCALL_REGS(ctx) ctx
#elif defined(bpf_target_sparc)
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* Re: [PATCH bpf-next v3 08/11] libbpf: Fix accessing syscall arguments on powerpc
2022-02-04 14:50 ` [PATCH bpf-next v3 08/11] libbpf: Fix accessing syscall arguments on powerpc Ilya Leoshkevich
@ 2022-02-05 7:05 ` Naveen N. Rao
0 siblings, 0 replies; 21+ messages in thread
From: Naveen N. Rao @ 2022-02-05 7:05 UTC (permalink / raw)
To: Alexander Gordeev, Andrii Nakryiko, Alexei Starovoitov,
Christian Borntraeger, Catalin Marinas, Daniel Borkmann,
Vasily Gorbik, Heiko Carstens, Ilya Leoshkevich,
Michael Ellerman, Paul Walmsley
Cc: bpf
Ilya Leoshkevich wrote:
> powerpc's syscall handlers get "unpacked" arguments instead of a
> struct pt_regs pointer. Indicate this to libbpf using
> PT_REGS_SYSCALL_REGS macro.
>
> Reported-by: Heiko Carstens <hca@linux.ibm.com>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
> tools/lib/bpf/bpf_tracing.h | 1 +
> 1 file changed, 1 insertion(+)
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
>
> diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
> index 317bee0fd8e4..f9d22ea0af97 100644
> --- a/tools/lib/bpf/bpf_tracing.h
> +++ b/tools/lib/bpf/bpf_tracing.h
> @@ -181,6 +181,7 @@
> #define __PT_RC_REG gpr[3]
> #define __PT_SP_REG sp
> #define __PT_IP_REG nip
> +#define PT_REGS_SYSCALL_REGS(ctx) ctx
>
> #elif defined(bpf_target_sparc)
>
> --
> 2.34.1
>
>
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH bpf-next v3 09/11] libbpf: Fix accessing program counter on riscv
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (7 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 08/11] libbpf: Fix accessing syscall arguments on powerpc Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 10/11] libbpf: Fix accessing syscall arguments " Ilya Leoshkevich
` (2 subsequent siblings)
11 siblings, 0 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
riscv registers are accessed via struct user_regs_struct, not struct
pt_regs. The program counter member in this struct is called pc, not
epc.
Fixes: 3cc31d794097 ("libbpf: Normalize PT_REGS_xxx() macro definitions")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index f9d22ea0af97..8629441304df 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -213,7 +213,7 @@
#define __PT_FP_REG fp
#define __PT_RC_REG a5
#define __PT_SP_REG sp
-#define __PT_IP_REG epc
+#define __PT_IP_REG pc
#endif
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* [PATCH bpf-next v3 10/11] libbpf: Fix accessing syscall arguments on riscv
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (8 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 09/11] libbpf: Fix accessing program counter on riscv Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-04 14:50 ` [PATCH bpf-next v3 11/11] libbpf: Fix accessing the first syscall argument on s390 Ilya Leoshkevich
2022-02-05 20:30 ` [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments patchwork-bot+netdevbpf
11 siblings, 0 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich
riscv's syscall handlers get "unpacked" arguments instead of a
struct pt_regs pointer. Indicate this to libbpf using
PT_REGS_SYSCALL_REGS macro.
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 8629441304df..169d47aa0a79 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -214,6 +214,7 @@
#define __PT_RC_REG a5
#define __PT_SP_REG sp
#define __PT_IP_REG pc
+#define PT_REGS_SYSCALL_REGS(ctx) ctx
#endif
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* [PATCH bpf-next v3 11/11] libbpf: Fix accessing the first syscall argument on s390
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (9 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 10/11] libbpf: Fix accessing syscall arguments " Ilya Leoshkevich
@ 2022-02-04 14:50 ` Ilya Leoshkevich
2022-02-05 20:30 ` [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments patchwork-bot+netdevbpf
11 siblings, 0 replies; 21+ messages in thread
From: Ilya Leoshkevich @ 2022-02-04 14:50 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N . Rao
Cc: bpf, Ilya Leoshkevich, Andrii Nakryiko
On s390, the first syscall argument should be accessed via orig_gpr2
(see arch/s390/include/asm/syscall.h). Currently gpr[2] is used
instead, leading to bpf_syscall_macro test failure.
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_tracing.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index 169d47aa0a79..cf980e54d331 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -117,6 +117,7 @@
/* s390 provides user_pt_regs instead of struct pt_regs to userspace */
#define __PT_REGS_CAST(x) ((const user_pt_regs *)(x))
#define __PT_PARM1_REG gprs[2]
+#define __PT_PARM1_REG_SYSCALL orig_gpr2
#define __PT_PARM2_REG gprs[3]
#define __PT_PARM3_REG gprs[4]
#define __PT_PARM4_REG gprs[5]
--
2.34.1
^ permalink raw reply related [flat|nested] 21+ messages in thread* Re: [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments
2022-02-04 14:50 [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments Ilya Leoshkevich
` (10 preceding siblings ...)
2022-02-04 14:50 ` [PATCH bpf-next v3 11/11] libbpf: Fix accessing the first syscall argument on s390 Ilya Leoshkevich
@ 2022-02-05 20:30 ` patchwork-bot+netdevbpf
2022-02-07 16:10 ` Andrii Nakryiko
11 siblings, 1 reply; 21+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-02-05 20:30 UTC (permalink / raw)
To: Ilya Leoshkevich
Cc: ast, daniel, andrii.nakryiko, hca, gor, borntraeger, agordeev,
catalin.marinas, mpe, paul.walmsley, naveen.n.rao, bpf
Hello:
This series was applied to bpf/bpf-next.git (master)
by Andrii Nakryiko <andrii@kernel.org>:
On Fri, 4 Feb 2022 15:50:07 +0100 you wrote:
> libbpf now has macros to access syscall arguments in an
> architecture-agnostic manner, but unfortunately they have a number of
> issues on non-Intel arches, which this series aims to fix.
>
> v1: https://lore.kernel.org/bpf/20220201234200.1836443-1-iii@linux.ibm.com/
> v1 -> v2:
> * Put orig_gpr2 in place of args[1] on s390 (Vasily).
> * Fix arm64, powerpc and riscv (Heiko).
>
> [...]
Here is the summary with links:
- [bpf-next,v3,01/11] arm64/bpf: Add orig_x0 to user_pt_regs
https://git.kernel.org/bpf/bpf-next/c/d473f4062165
- [bpf-next,v3,02/11] s390/bpf: Add orig_gpr2 to user_pt_regs
https://git.kernel.org/bpf/bpf-next/c/61f88e88f263
- [bpf-next,v3,03/11] selftests/bpf: Fix an endianness issue in bpf_syscall_macro test
https://git.kernel.org/bpf/bpf-next/c/a936c141cbe4
- [bpf-next,v3,04/11] libbpf: Add __PT_PARM1_REG_SYSCALL macro
https://git.kernel.org/bpf/bpf-next/c/3a9d84aafb8c
- [bpf-next,v3,05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro
https://git.kernel.org/bpf/bpf-next/c/b62a862d42f5
- [bpf-next,v3,06/11] selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro
https://git.kernel.org/bpf/bpf-next/c/730809c15ac2
- [bpf-next,v3,07/11] libbpf: Fix accessing the first syscall argument on arm64
https://git.kernel.org/bpf/bpf-next/c/8b9b06ad4726
- [bpf-next,v3,08/11] libbpf: Fix accessing syscall arguments on powerpc
https://git.kernel.org/bpf/bpf-next/c/f5af16d0ae28
- [bpf-next,v3,09/11] libbpf: Fix accessing program counter on riscv
https://git.kernel.org/bpf/bpf-next/c/27870c91b5c7
- [bpf-next,v3,10/11] libbpf: Fix accessing syscall arguments on riscv
https://git.kernel.org/bpf/bpf-next/c/5860b82236c6
- [bpf-next,v3,11/11] libbpf: Fix accessing the first syscall argument on s390
https://git.kernel.org/bpf/bpf-next/c/088d6aafd5bb
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 21+ messages in thread* Re: [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments
2022-02-05 20:30 ` [PATCH bpf-next v3 00/11] libbpf: Fix accessing syscall arguments patchwork-bot+netdevbpf
@ 2022-02-07 16:10 ` Andrii Nakryiko
0 siblings, 0 replies; 21+ messages in thread
From: Andrii Nakryiko @ 2022-02-07 16:10 UTC (permalink / raw)
To: patchwork-bot+netdevbpf
Cc: Ilya Leoshkevich, Alexei Starovoitov, Daniel Borkmann,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger,
Alexander Gordeev, Catalin Marinas, Michael Ellerman,
Paul Walmsley, Naveen N. Rao, bpf
On Sat, Feb 5, 2022 at 12:30 PM <patchwork-bot+netdevbpf@kernel.org> wrote:
>
> Hello:
>
> This series was applied to bpf/bpf-next.git (master)
> by Andrii Nakryiko <andrii@kernel.org>:
>
> On Fri, 4 Feb 2022 15:50:07 +0100 you wrote:
> > libbpf now has macros to access syscall arguments in an
> > architecture-agnostic manner, but unfortunately they have a number of
> > issues on non-Intel arches, which this series aims to fix.
> >
> > v1: https://lore.kernel.org/bpf/20220201234200.1836443-1-iii@linux.ibm.com/
> > v1 -> v2:
> > * Put orig_gpr2 in place of args[1] on s390 (Vasily).
> > * Fix arm64, powerpc and riscv (Heiko).
> >
> > [...]
>
> Here is the summary with links:
> - [bpf-next,v3,01/11] arm64/bpf: Add orig_x0 to user_pt_regs
> https://git.kernel.org/bpf/bpf-next/c/d473f4062165
> - [bpf-next,v3,02/11] s390/bpf: Add orig_gpr2 to user_pt_regs
> https://git.kernel.org/bpf/bpf-next/c/61f88e88f263
> - [bpf-next,v3,03/11] selftests/bpf: Fix an endianness issue in bpf_syscall_macro test
> https://git.kernel.org/bpf/bpf-next/c/a936c141cbe4
> - [bpf-next,v3,04/11] libbpf: Add __PT_PARM1_REG_SYSCALL macro
> https://git.kernel.org/bpf/bpf-next/c/3a9d84aafb8c
> - [bpf-next,v3,05/11] libbpf: Add PT_REGS_SYSCALL_REGS macro
> https://git.kernel.org/bpf/bpf-next/c/b62a862d42f5
> - [bpf-next,v3,06/11] selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro
> https://git.kernel.org/bpf/bpf-next/c/730809c15ac2
> - [bpf-next,v3,07/11] libbpf: Fix accessing the first syscall argument on arm64
> https://git.kernel.org/bpf/bpf-next/c/8b9b06ad4726
> - [bpf-next,v3,08/11] libbpf: Fix accessing syscall arguments on powerpc
> https://git.kernel.org/bpf/bpf-next/c/f5af16d0ae28
> - [bpf-next,v3,09/11] libbpf: Fix accessing program counter on riscv
> https://git.kernel.org/bpf/bpf-next/c/27870c91b5c7
> - [bpf-next,v3,10/11] libbpf: Fix accessing syscall arguments on riscv
> https://git.kernel.org/bpf/bpf-next/c/5860b82236c6
> - [bpf-next,v3,11/11] libbpf: Fix accessing the first syscall argument on s390
> https://git.kernel.org/bpf/bpf-next/c/088d6aafd5bb
>
I've backed out this patch set from bpf-next for now while we are
deciding the best way to deal with s390x and arm64 arches without
breaking UAPIs.
> You are awesome, thank you!
> --
> Deet-doot-dot, I am a bot.
> https://korg.docs.kernel.org/patchwork/pwbot.html
>
>
^ permalink raw reply [flat|nested] 21+ messages in thread