This is a note to let you know that I've just added the patch titled
x86: Don't clear olpc_ofw_header when sentinel is detected
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-don-t-clear-olpc_ofw_header-when-sentinel-is-detected.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d55e37bb0f51316e552376ddc0a3fff34ca7108b Mon Sep 17 00:00:00 2001
From: Daniel Drake <dsd@xxxxxxxxxx>
Date: Fri, 9 Aug 2013 18:14:20 -0400
Subject: x86: Don't clear olpc_ofw_header when sentinel is detected
From: Daniel Drake <dsd@xxxxxxxxxx>
commit d55e37bb0f51316e552376ddc0a3fff34ca7108b upstream.
OpenFirmware wasn't quite following the protocol described in boot.txt
and the kernel has detected this through use of the sentinel value
in boot_params. OFW does zero out almost all of the stuff that it should
do, but not the sentinel.
This causes the kernel to clear olpc_ofw_header, which breaks x86 OLPC
support.
OpenFirmware has now been fixed. However, it would be nice if we could
maintain Linux compatibility with old firmware versions. To do that, we just
have to avoid zeroing out olpc_ofw_header.
OFW does not write to any other parts of the header that are being zapped
by the sentinel-detection code, and all users of olpc_ofw_header are
somewhat protected through checking for the OLPC_OFW_SIG magic value
before using it. So this should not cause any problems for anyone.
Signed-off-by: Daniel Drake <dsd@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20130809221420.618E6FAB03@xxxxxxxxxxxxxx
Acked-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/bootparam_utils.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/bootparam_utils.h
+++ b/arch/x86/include/asm/bootparam_utils.h
@@ -35,9 +35,9 @@ static void sanitize_boot_params(struct
*/
if (boot_params->sentinel) {
/* fields in boot_params are left uninitialized, clear them */
- memset(&boot_params->olpc_ofw_header, 0,
+ memset(&boot_params->ext_ramdisk_image, 0,
(char *)&boot_params->efi_info -
- (char *)&boot_params->olpc_ofw_header);
+ (char *)&boot_params->ext_ramdisk_image);
memset(&boot_params->kbd_status, 0,
(char *)&boot_params->hdr -
(char *)&boot_params->kbd_status);
Patches currently in stable-queue which might be from dsd@xxxxxxxxxx are
queue-3.10/x86-don-t-clear-olpc_ofw_header-when-sentinel-is-detected.patch
queue-3.10/drivers-platform-olpc-olpc-ec.c-initialise-earlier.patch
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