From 9ab94078e868a45cbd23828b8377600b83a41fac Mon Sep 17 00:00:00 2001 From: Pu Lehui Date: Sat, 31 Aug 2024 04:19:32 +0000 Subject: libbpf: Access first syscall argument with CO-RE direct read on arm64 Currently PT_REGS_PARM1 SYSCALL(x) is consistent with PT_REGS_PARM1_CORE SYSCALL(x), which will introduce the overhead of BPF_CORE_READ(), taking into account the read pt_regs comes directly from the context, let's use CO-RE direct read to access the first system call argument. Suggested-by: Andrii Nakryiko Signed-off-by: Pu Lehui Signed-off-by: Andrii Nakryiko Acked-by: Xu Kuohai Link: https://lore.kernel.org/bpf/20240831041934.1629216-3-pulehui@huaweicloud.com --- tools/lib/bpf/bpf_tracing.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h index 1297d8d297d1..c15831c98990 100644 --- a/tools/lib/bpf/bpf_tracing.h +++ b/tools/lib/bpf/bpf_tracing.h @@ -222,7 +222,7 @@ struct pt_regs___s390 { struct pt_regs___arm64 { unsigned long orig_x0; -}; +} __attribute__((preserve_access_index)); /* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */ #define __PT_REGS_CAST(x) ((const struct user_pt_regs *)(x)) @@ -241,7 +241,7 @@ struct pt_regs___arm64 { #define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG #define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG #define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG -#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1_CORE_SYSCALL(x) +#define PT_REGS_PARM1_SYSCALL(x) (((const struct pt_regs___arm64 *)(x))->__PT_PARM1_SYSCALL_REG) #define PT_REGS_PARM1_CORE_SYSCALL(x) \ BPF_CORE_READ((const struct pt_regs___arm64 *)(x), __PT_PARM1_SYSCALL_REG) -- cgit v1.2.3-58-ga151