[Precise][PATCH 1/2] kexec: remove KMSG_DUMP_KEXEC

[joseph.salisbury at canonical.com]

From: WANG Cong <xiyou.wangcong at gmail.com>

BugLink: http://bugs.launchpad.net/bugs/944772

KMSG_DUMP_KEXEC is useless because we already save kernel messages inside
/proc/vmcore, and it is unsafe to allow modules to do other stuffs in a
crash dump scenario.

[akpm at linux-foundation.org: fix powerpc build]
Signed-off-by: WANG Cong <xiyou.wangcong at gmail.com>
Reported-by: Vivek Goyal <vgoyal at redhat.com>
Acked-by: Vivek Goyal <vgoyal at redhat.com>
Acked-by: Jarod Wilson <jarod at redhat.com>
Cc: "Eric W. Biederman" <ebiederm at xmission.com>
Cc: KOSAKI Motohiro <kosaki.motohiro at jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
(cherry picked from commit a3dd3323058d281abd584b15ad4c5b65064d7a61)

Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 arch/powerpc/platforms/pseries/nvram.c |    1 -
 drivers/char/ramoops.c                 |    3 +--
 drivers/mtd/mtdoops.c                  |    3 +--
 include/linux/kmsg_dump.h              |    1 -
 kernel/kexec.c                         |    3 ---
 5 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index a76b228..bd4861b 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -636,7 +636,6 @@ static void oops_to_nvram(struct kmsg_dumper *dumper,
 		/* These are almost always orderly shutdowns. */
 		return;
 	case KMSG_DUMP_OOPS:
-	case KMSG_DUMP_KEXEC:
 		break;
 	case KMSG_DUMP_PANIC:
 		panicking = true;
diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c
index 7c7f42a1f8..feda90c 100644
--- a/drivers/char/ramoops.c
+++ b/drivers/char/ramoops.c
@@ -83,8 +83,7 @@ static void ramoops_do_dump(struct kmsg_dumper *dumper,
 	struct timeval timestamp;
 
 	if (reason != KMSG_DUMP_OOPS &&
-	    reason != KMSG_DUMP_PANIC &&
-	    reason != KMSG_DUMP_KEXEC)
+	    reason != KMSG_DUMP_PANIC)
 		return;
 
 	/* Only dump oopses if dump_oops is set */
diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c
index f3cdce9..b7883e5 100644
--- a/drivers/mtd/mtdoops.c
+++ b/drivers/mtd/mtdoops.c
@@ -311,8 +311,7 @@ static void mtdoops_do_dump(struct kmsg_dumper *dumper,
 	char *dst;
 
 	if (reason != KMSG_DUMP_OOPS &&
-	    reason != KMSG_DUMP_PANIC &&
-	    reason != KMSG_DUMP_KEXEC)
+	    reason != KMSG_DUMP_PANIC)
 		return;
 
 	/* Only dump oopses if dump_oops is set */
diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
index ee0c952..fee6631 100644
--- a/include/linux/kmsg_dump.h
+++ b/include/linux/kmsg_dump.h
@@ -18,7 +18,6 @@
 enum kmsg_dump_reason {
 	KMSG_DUMP_OOPS,
 	KMSG_DUMP_PANIC,
-	KMSG_DUMP_KEXEC,
 	KMSG_DUMP_RESTART,
 	KMSG_DUMP_HALT,
 	KMSG_DUMP_POWEROFF,
diff --git a/kernel/kexec.c b/kernel/kexec.c
index dc7bc08..dc535d7 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -32,7 +32,6 @@
 #include <linux/console.h>
 #include <linux/vmalloc.h>
 #include <linux/swap.h>
-#include <linux/kmsg_dump.h>
 #include <linux/syscore_ops.h>
 
 #include <asm/page.h>
@@ -1094,8 +1093,6 @@ void crash_kexec(struct pt_regs *regs)
 		if (kexec_crash_image) {
 			struct pt_regs fixed_regs;
 
-			kmsg_dump(KMSG_DUMP_KEXEC);
-
 			crash_setup_regs(&fixed_regs, regs);
 			crash_save_vmcoreinfo();
 			machine_crash_shutdown(&fixed_regs);
-- 
1.7.9.1