Patch "x86/amd_nb: Fix boot crash on non-AMD systems" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

x86/amd_nb: Fix boot crash on non-AMD systems

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:
x86-amd_nb-fix-boot-crash-on-non-amd-systems.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 <[email protected]> know about it.

From: Borislav Petkov <[email protected]>
Date: Thu, 16 Jun 2016 19:13:49 +0200
Subject: x86/amd_nb: Fix boot crash on non-AMD systems

From: Borislav Petkov <[email protected]>

commit 1ead852dd88779eda12cb09cc894a03d9abfe1ec upstream.

Fix boot crash that triggers if this driver is built into a kernel and run on non-AMD systems.

AMD northbridges users call amd_cache_northbridges() and it returns a negative value to signal that we weren't able to cache/detect any northbridges on the system.

At least, it should do so as all its callers expect it to do so. But it does return a negative value only when kmalloc() fails.

Fix it to return -ENODEV if there are no NBs cached as otherwise, amd_nb users like amd64_edac, for example, which relies on it to know whether it should load or not, gets loaded on systems like Intel Xeons where it shouldn't.

---
 arch/x86/kernel/amd_nb.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -71,8 +71,8 @@ int amd_cache_northbridges(void)
 	while ((misc = next_northbridge(misc, amd_nb_misc_ids)) != NULL)
 		i++;
 
-	if (i == 0)
-		return 0;
+	if (!i)
+		return -ENODEV;
 
 	nb = kzalloc(i * sizeof(struct amd_northbridge), GFP_KERNEL);
 	if (!nb)

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/x86-amd_nb-fix-boot-crash-on-non-amd-systems.patch queue-4.4/edac-sb_edac-fix-rank-lookup-on-broadwell.patch