powerpc: fix double syscall restarts
Make sigreturn zero regs->trap, make do_signal() do the same on all
paths. As it is, signal interrupting e.g. read() from fd 512 (==
ERESTARTSYS) with another signal getting unblocked when the first
handler finishes will lead to restart one insn earlier than it ought
to. Same for multiple signals with in-kernel handlers interrupting
that sucker at the same time. Same for multiple signals of any kind
interrupting that sucker on 64bit...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 2666101..b96a3a0 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -511,6 +511,7 @@
if (!sig)
save_r2 = (unsigned int)regs->gpr[2];
err = restore_general_regs(regs, sr);
+ regs->trap = 0;
err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
if (!sig)
regs->gpr[2] = (unsigned long) save_r2;
@@ -884,7 +885,6 @@
regs->nip = (unsigned long) ka->sa.sa_handler;
/* enter the signal handler in big-endian mode */
regs->msr &= ~MSR_LE;
- regs->trap = 0;
return 1;
badframe:
@@ -1228,7 +1228,6 @@
regs->nip = (unsigned long) ka->sa.sa_handler;
/* enter the signal handler in big-endian mode */
regs->msr &= ~MSR_LE;
- regs->trap = 0;
return 1;