mirror/libbpf
1
0
Fork 0
mirror of https://github.com/netdata/libbpf.git synced 2026-04-04 23:59:07 +08:00
Code Issues Packages Projects Releases Wiki Activity

libbpf: Access first syscall argument with CO-RE direct read on arm64

Browse Source 
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 <andrii@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/bpf/20240831041934.1629216-3-pulehui@huaweicloud.com
This commit is contained in:
Pu Lehui
2024-08-31 04:19:32 +00:00
committed by Andrii Nakryiko
parent 6d01681b02
commit 53a645402f
1 changed files with 2 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/bpf_tracing.h
View File

@@ -222,7 +222,7 @@ struct pt_regs___s390 {
struct pt_regs___arm64 { struct pt_regs___arm64 {
unsigned long orig_x0; unsigned long orig_x0;
}; } __attribute__((preserve_access_index));
/* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */ /* 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_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_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG #define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_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) \ #define PT_REGS_PARM1_CORE_SYSCALL(x) \
BPF_CORE_READ((const struct pt_regs___arm64 *)(x), __PT_PARM1_SYSCALL_REG) BPF_CORE_READ((const struct pt_regs___arm64 *)(x), __PT_PARM1_SYSCALL_REG)