libbpf: Fix the incorrect register read for syscalls on x86_64

Currently, rcx is read as the fourth parameter of syscall on x86_64.
But x86_64 Linux System Call convention uses r10 actually.
This commit adds the wrapper for users who want to access to
syscall params to analyze the user space.

Signed-off-by: Kenta Tada <Kenta.Tada@sony.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220124141622.4378-3-Kenta.Tada@sony.com
This commit is contained in:
Kenta Tada 2022-01-24 23:16:21 +09:00 committed by Andrii Nakryiko
parent 78a2054156
commit d084df3b7a
1 changed files with 34 additions and 0 deletions

View File

@ -70,6 +70,7 @@
#define __PT_PARM2_REG si
#define __PT_PARM3_REG dx
#define __PT_PARM4_REG cx
#define __PT_PARM4_REG_SYSCALL r10 /* syscall uses r10 */
#define __PT_PARM5_REG r8
#define __PT_RET_REG sp
#define __PT_FP_REG bp
@ -99,6 +100,7 @@
#define __PT_PARM2_REG rsi
#define __PT_PARM3_REG rdx
#define __PT_PARM4_REG rcx
#define __PT_PARM4_REG_SYSCALL r10 /* syscall uses r10 */
#define __PT_PARM5_REG r8
#define __PT_RET_REG rsp
#define __PT_FP_REG rbp
@ -263,6 +265,26 @@ 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)
#endif
#define PT_REGS_PARM5_SYSCALL(x) PT_REGS_PARM5(x)
#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_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)
#else /* defined(bpf_target_defined) */
#define PT_REGS_PARM1(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
@ -290,6 +312,18 @@ struct pt_regs;
#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define BPF_KRETPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM2_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM3_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM4_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM5_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM1_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM2_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM3_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM4_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM5_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#endif /* defined(bpf_target_defined) */
#ifndef ___bpf_concat