From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Date: Fri, 23 Sep 2005 04:43:57 +0000 (-0700)
Subject: [PATCH] alpha: fix kernel panic during SysRq-b
X-Git-Tag: v2.6.14-rc3~51^2~56
X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=4b3c86a7452df8608c32a1c1f19c0cc0723c145f;p=linux-2.6-omap-h63xx.git

[PATCH] alpha: fix kernel panic during SysRq-b

acquire_console_sem() does BUG() in interrupt context now, as in the case
of SysRq-b.

Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index fa98dae3cd9..eb20c3afff5 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -127,6 +127,10 @@ common_shutdown_1(void *generic_ptr)
 	/* If booted from SRM, reset some of the original environment. */
 	if (alpha_using_srm) {
 #ifdef CONFIG_DUMMY_CONSOLE
+		/* If we've gotten here after SysRq-b, leave interrupt
+		   context before taking over the console. */
+		if (in_interrupt())
+			irq_exit();
 		/* This has the effect of resetting the VGA video origin.  */
 		take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
 #endif