On Sun, Apr 29, 2012 at 02:40:01AM -0400, Jon Masters wrote: > > > -------- Original Message -------- > Subject: [PATCH] ARM: Fix restoration of IP scratch register when > auditing syscalls > Date: Sun, 29 Apr 2012 02:38:24 -0400 > From: Jon Masters <jcm@xxxxxxxxxxxxxx> > To: Linux ARM Kernel <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx> > CC: Jon Masters <jcm@xxxxxxxxxx>, Al Viro <viro@xxxxxxxxxxxxxxxxxx>, > Eric Paris <eparis@xxxxxxxxxx>, Jon Masters <jcm@xxxxxxxxxxxxxx> > > The audit subsystem builds upon ptrace to record system calls. This is done > in a couple of places (on return from fork into a new task, on exit from > the SWI vector), using calls to syscall_trace. The latter function abuses > the userspace intra-procedure scratch register (regs->ARM_ip, aka r12), > and intends to restore it prior to return to userspace. Unfortunately, > there are cases where we will return to userspace without restoring. > > If we are in fact not ptracing but are merely auditing calls, we will > happily trash the content of ip but will exit to userspace without > restoring the value. It just so happens that GLIBC uses ip as a > storage for the TLS thread pointer info, and bad things result. > > The fix is simply to have an additional out when not ptracing. > > Signed-off-by: Jon Masters <jcm@xxxxxxxxxxxxxx> > --- Going to assume you forwarded this here because you want it applied to the Fedora kernel. Likely F17/rawhide? I'm guessing we probably want to follow http://lists.infradead.org/pipermail/linux-arm-kernel/2012-April/096951.html for a bit to see if there are any more iterations of this? Since it's CC'd to stable, it should get picked up rather quickly if RMK applies it. josh _______________________________________________ kernel mailing list kernel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/kernel
