On Thu, 30 Oct 2014 07:10:39 -0400 Steven Rostedt <[email protected]> wrote:
> On Thu, 30 Oct 2014 10:18:08 +0000 > Russell King - ARM Linux <[email protected]> wrote: > > > On Thu, Oct 30, 2014 at 01:26:06AM -0700, Christoph Hellwig wrote: > > > On Wed, Oct 29, 2014 at 11:06:58PM +0100, Rabin Vincent wrote: > > > > ARM has some private syscalls (for example, set_tls(2)) which lie > > > > outside the range of NR_syscalls. If any of these are called while > > > > syscall tracing is being performed, out-of-bounds array access will > > > > occur in the ftrace and perf sys_{enter,exit} handlers. > > > > > > While this patch looks like good caution, having syscalls outside of > > > NR_syscalls seems like a receipe for a disaster. Can you try to fix > > > that issue as ell, please? > > > > No. We've had them since the inception of Linux on ARM. They predate > > this tracing crap by more than a decade. We're not changing them > > because that would be a massive user API breakage. > > > > Since syscall tracing is only broken on ARM, then the fix needs to be > ARM specific, and not remove the check for all other architectures that > have a sane NR_syscalls variable. Bah, I misread the patch. I shouldn't read patches before having my morning coffee :-/ I read it backwards. I thought it was removing the checks for NR_syscalls, and not adding them. I'm fine with the patch as is, and will take it. But I agree that the syscall tracing code needs a rewrite to handle these types of issues. It has problems with compat calls as well, which we simply ignore. Sorry for the confusion. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
