commit 34a89d26bdc4ba46a406fa3842239e921c493d44
author Chris Metcalf <cmetcalf@tilera.com> Thu Oct 28 15:03:30 2010 -0400
committer Chris Metcalf <cmetcalf@tilera.com> Mon Nov 01 15:31:04 2010 -0400
tree bbfc0dcd4376f6f6337cc199fa785f53243b36cb
parent d59e609d6568ba5ab23c256f412ac5ec360722c1

arch/tile: correct double syscall restart for nested signals

This change is modelled on similar fixes for other architectures.
The pt_regs "faultnum" member is set to the trap (fault) number that
caused us to enter the kernel, and is INT_SWINT_1 for the syscall software
interrupt.  We already supported a pseudo value, INT_SWINT_1_SIGRETURN,
that we used for the rt_sigreturn syscall; it avoided the case where
one signal was handled, then we "tail-called" to another handler.

This change avoids the similar case where we start to call one handler,
then are preempted into another handler when we start trying to run
the first handler.  We clear ->faultnum after calling handle_signal(),
and to be paranoid also in the case where there was no signal to deliver.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>