blob: 05ad4fee1fe3df0ae66ae28e9eaab04d72fa1fad [file] [log] [blame]
From: Borislav Petkov <bp@suse.de>
Date: Thu, 16 Jun 2016 19:13:49 +0200
Subject: x86/amd_nb: Fix boot crash on non-AMD systems
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.
Reported-and-tested-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1466097230-5333-2-git-send-email-bp@alien8.de
Link: https://lkml.kernel.org/r/5761BEB0.9000807@cybernetics.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/kernel/amd_nb.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -59,8 +59,8 @@ 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)