Re: [PATCH 2/2] convert to syscall tracepoints

[Ingo Molnar <mingo@elte.hu>]

* Jason Baron <jbaron@redhat.com> wrote:

> 
> Implements syscall tracer via tracepoints and TRACE_EVENT(). Introduces
> a new tracing flag 'trace_syscalls', which must be toggled to enable this
> feature.
> 
> 
> Signed-off-by: Jason Baron <jbaron@redhat.com>
> 
> ---
>  arch/x86/kernel/ptrace.c        |    8 +-
>  include/asm-generic/syscall.h   |    3 +
>  include/trace/events/syscalls.h | 4202 +++++++++++++++++++++++++++++++++++++++
>  include/trace/syscall.h         |    6 +
>  kernel/trace/Makefile           |    1 -
>  kernel/trace/trace.c            |  101 +
>  kernel/trace/trace_syscalls.c   |  250 ---
>  7 files changed, 4317 insertions(+), 254 deletions(-)
>  create mode 100644 include/trace/events/syscalls.h
>  delete mode 100644 kernel/trace/trace_syscalls.c

the functionality is fine and very desired IMO, but the 
implementation is pretty large and ugly, isnt it?

Wouldnt it be possible to compress this:

> +#ifdef __NR_setgroups
> +trace_event_syscall_enter(2, setgroups, int, gidsetsize, gid_t __user *, grouplist);
> +trace_event_syscall_exit(setgroups);
> +#define ENTERCASEsetgroups create_syscall_enter(2, setgroups, int, gid_t __user *);
> +#define EXITCASEsetgroups create_syscall_exit(setgroups);
> +#else
> +#define ENTERCASEsetgroups
> +#define EXITCASEsetgroups
> +#endif

down to some sane syntax? Do we really want to replicate all the 
DEFINE_SYSCALL() information again in a separate header? Is there no 
way to somehow define the tracepoint in-situ, where the 
DEFINE_SYSCALL macro is present? That would eliminate 
include/trace/events/syscalls.h altogether.

	Ingo