This is a note to let you know that I've just added the patch titled
kaiser: Set _PAGE_NX only if supported
to the 4.4-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:
kaiser-set-_page_nx-only-if-supported.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ytht.net@xxxxxxxxx Sat Jan 13 15:46:36 2018
From: Lepton Wu <ytht.net@xxxxxxxxx>
Date: Fri, 12 Jan 2018 13:42:56 -0800
Subject: kaiser: Set _PAGE_NX only if supported
To: stable@xxxxxxxxxxxxxxx
Cc: gregkh@xxxxxxxxxxxxxxxxxxx, groeck@xxxxxxxxxxxx, hshan@xxxxxxxxxx, Lepton Wu <ytht.net@xxxxxxxxx>
Message-ID: <20180112214256.257463-1-ytht.net@xxxxxxxxx>
From: Lepton Wu <ytht.net@xxxxxxxxx>
This finally resolve crash if loaded under qemu + haxm. Haitao Shan pointed
out that the reason of that crash is that NX bit get set for page tables.
It seems we missed checking if _PAGE_NX is supported in kaiser_add_user_map
Link: https://www.spinics.net/lists/kernel/msg2689835.html
Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx>
Signed-off-by: Lepton Wu <ytht.net@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/kaiser.c | 2 ++
1 file changed, 2 insertions(+)
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -198,6 +198,8 @@ static int kaiser_add_user_map(const voi
* requires that not to be #defined to 0): so mask it off here.
*/
flags &= ~_PAGE_GLOBAL;
+ if (!(__supported_pte_mask & _PAGE_NX))
+ flags &= ~_PAGE_NX;
for (; address < end_addr; address += PAGE_SIZE) {
target_address = get_pa_from_mapping(address);
Patches currently in stable-queue which might be from ytht.net@xxxxxxxxx are
queue-4.4/kaiser-set-_page_nx-only-if-supported.patch