From: Borislav Petkov <bp@xxxxxxx> 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@xxxxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1466097230-5333-2-git-send-email-bp@xxxxxxxxx Link: https://lkml.kernel.org/r/5761BEB0.9000807@xxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Willy Tarreau <w@xxxxxx> --- arch/x86/kernel/amd_nb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c index 59554dc..e6a3b1e 100644 --- a/arch/x86/kernel/amd_nb.c +++ b/arch/x86/kernel/amd_nb.c @@ -67,8 +67,8 @@ 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) -- 2.8.0.rc2.1.gbe9624a -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html