[PATCH] ARM: entry: fix tracing of ARM-private syscalls

[will.deacon@arm.com (Will Deacon)]

On Wed, Sep 18, 2013 at 10:09:11PM +0100, Jason Gunthorpe wrote:
> On Wed, Sep 18, 2013 at 05:12:45PM +0100, Will Deacon wrote:
> > Commit 377747c40657 ("ARM: entry: allow ARM-private syscalls to be
> > restarted") reworked the low-level syscall dispatcher to allow
> > restarting of ARM-private syscalls. Unfortunately, this relocated the
> > label used to dispatch a private syscall from the trace path, so that
> > the invocation would be bypassed altogether!
> > 
> > This causes applications to fail under strace as soon as they rely on
> > a private syscall (e.g. set_tls):
> > 
> >   set_tls(0xb6fad4c0, 0xb6fadb98, 0xb6fb1050, 0xb6fad4c0, 0xb6fb1050)
> >       = -1 ENOSYS (Function not implemented)
> > 
> > This patch fixes the label so that we correctly dispatch private
> > syscalls from the trace path.
> > 
> > Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
> > Signed-off-by: Will Deacon <will.deacon@arm.com>
> 
> Worked here
> 
> Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>

Thanks Jason, I'll send this to Russell.

> This should probably go into the 3.11 stable series too?

This problem was introduced during the merge window, so 3.11 shouldn't be
affected.

Will