Re: ftrace syscalls, PowerPC: Fixes and PowerPC raw syscall tracepoint implementation

[Steven Rostedt <rostedt@goodmis.org>]

Frederic,

I'm fine with these patches, but since you mainly did the syscall work,
I'll let you take them.

The patches that touch the PowerPC code needs an acked-by from Ben or
Paul.

-- Steve


On Thu, 2010-05-13 at 17:43 +1000, Ian Munsie wrote:
> This patch series implements raw system call tracepoints on PowerPC that can be
> used with ftrace and perf. Some problems with the generic ftrace syscall
> tracepoint code have also been addressed.
> 
> The patches are based upon Ben's powerpc/next tree merged with tip/tracing/core
> 
> Patch #1 removes all ftrace syscall events that fail to map the system call
> name from the system call metadata with the system call's number, preventing
> the events which will not work from showing up in perf list and removing them
> from /sys/kernel/debug/tracing/events/syscalls.
> 
> Patches #2 and #3 allow for archs with unusual system call tables (#2) or
> unusual symbol names (#3) to override the appropriate functions so that they
> can still work with ftrace syscalls.
> 
> Patch #4 implements the actual raw system call tracepoints that ftrace syscalls
> builds upon, allowing all of the system calls to be used with the raw_syscalls
> events category and most to be used with the syscalls category.
> 
> 
> Not all the raw_syscalls are currently mapped to ftrace syscalls - the syscalls
> defined in /arch/powerpc/include/asm/syscalls.h do not use the SYSCALL_DEFINE
> class of macros and as such have no meta data, likewise some of the ppc_*
> syscalls have assembly wrappers. These are on their way, but I wanted to put
> the work I have done so far out first.
> 
> Some of those syscalls have different return types than the __SYSCALL_DEFINE
> macro uses (unsigned long, int, time_t) and some have different prefixes (ppc,
> ppc64) - I didn't particularly want to change them straight over without asking
> the list first, and I certainly don't want to change the return types. I see
> that Jason Baron ran into similar issues, but his "add compat syscall support"
> patches have yet to be merged, and do not tackle the differing return types.
>