[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 fa98dae3cd986dc323132a0ad2f0bd205ea7c9a4..eb20c3afff585b965a0bf3c2f1eace56b909aacb 100644 (file)
--- 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