powerpc/kdump: Fix timeout in crash_kexec_wait_realmode

commit 63f21a56f1cc0b800a4c00349c59448f82473d19 upstream.

The existing code it pretty ugly.  How about we clean it up even more
like this?

From: Anton Blanchard <anton@samba.org>

We check for timeout expiry in the outer loop, but we also need to
check it in the inner loop or we can lock up forever waiting for a
CPU to hit real mode.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
index 50091984685d6ce111adb14385599baf15075cf3..d3749742d2a58b6bdfa34f09ceed6f500f6e1364 100644 (file)
--- a/arch/powerpc/kernel/crash.c
+++ b/arch/powerpc/kernel/crash.c
@@ -176,12 +176,8 @@ static void crash_kexec_wait_realmode(int cpu)
 
                while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
                        barrier();
-                       if (!cpu_possible(i)) {
+                       if (!cpu_possible(i) || !cpu_online(i) || (msecs <= 0))
                                break;
-                       }
-                       if (!cpu_online(i)) {
-                               break;
-                       }
                        msecs--;
                        mdelay(1);
                }