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| author | Borislav Petkov <bp@suse.de> | 2016-06-16 19:13:49 +0200 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2016-08-27 11:40:23 +0200 |
| commit | 583e3ee15bf87946667d30f238bcd78585b208da (patch) | |
| tree | 43f9d37ce130745ddb64cc445d70b312c5a27323 | |
| parent | b92e992e592b68fa7a7b3e3ba19c473d3d396292 (diff) | |
| download | lwn-583e3ee15bf87946667d30f238bcd78585b208da.tar.gz lwn-583e3ee15bf87946667d30f238bcd78585b208da.zip | |
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: <stable@vger.kernel.org>
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: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | arch/x86/kernel/amd_nb.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c index 59554dca96ec..e6a3b1e35fae 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) |