3.2.82-rc1 review patch. If anyone has any objections, please let me know.
------------------ 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. Reported-and-tested-by: Tony Battersby <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- 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)
