On Thu, Feb 3, 2022 at 9:22 PM Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > On Thu, Feb 3, 2022 at 8:20 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote: > > > > 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@xxxxxxxxxxxxx> > > --- > > 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..400a4f002f77 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 > > +#define PT_REGS_SYSCALL(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx)) > > +#endif > > maybe PT_REGS_SYSCALL_REGS? It returns regs, not the "syscall". > PT_REGS prefix is for consistency with all other pt_regs macros, but > "SYSCALL_REGS" is specifying what is actually returned by the macro > Oh, and instead of casting to `struct pt_regs *` directly, maybe use __PT_REGS_CAST() instead? For some architectures it probably should stay user_pt_regs (or whatever it is there). > > + > > #ifndef ___bpf_concat > > #define ___bpf_concat(a, b) a ## b > > #endif > > -- > > 2.34.1 > >
