libbpf: Add PT_REGS_SYSCALL_REGS macro

Architectures that select ARCH_HAS_SYSCALL_WRAPPER 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.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-3-iii@linux.ibm.com
This commit is contained in:
Ilya Leoshkevich 2022-02-09 03:17:37 +01:00 committed by Andrii Nakryiko
parent 4fc49b51ab
commit c5a1ffa0da

View file

@ -326,6 +326,16 @@ 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
/* By default, assume that the arch selects ARCH_HAS_SYSCALL_WRAPPER. */
#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