[PATCH 3.2 77/94] x86/amd_nb: Fix boot crash on non-AMD systems

From	Ben Hutchings <ben@decadent.org.uk>
Newsgroups	linux.kernel
Subject	[PATCH 3.2 77/94] x86/amd_nb: Fix boot crash on non-AMD systems
Date	2016-08-14 20:10 +0200
Message-ID	<s681c-31c-37@gated-at.bofh.it> (permalink)
References	<s5LnX-4sk-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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3.2.82-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Borislav Petkov <bp@suse.de>

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)

Thread

[PATCH 3.2 00/94] 3.2.82-rc1 review Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 13:50 +0200
  [PATCH 3.2 26/94] fs/cifs: correctly to anonymous authentication  for the LANMAN authentication Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 13:50 +0200
  [PATCH 3.2 23/94] x86/PCI: Mark Broadwell-EP Home Agent 1 as  having non-compliant BARs Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 13:50 +0200
  [PATCH 3.2 93/94] tcp: make challenge acks less predictable Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 13:50 +0200
  [PATCH 3.2 62/94] UBIFS: Implement ->migratepage() Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:00 +0200
  [PATCH 3.2 42/94] x86, build: copy ldlinux.c32 to image.iso Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:00 +0200
  [PATCH 3.2 54/94] kvm: Fix irq route entries exceeding  KVM_MAX_IRQ_ROUTES Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:00 +0200
  [PATCH 3.2 13/94] USB: serial: option: add even more ZTE device ids Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:00 +0200
  [PATCH 3.2 35/94] Input: xpad - prevent spurious input from wired  Xbox 360 controllers Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:00 +0200
  [PATCH 3.2 43/94] fix d_walk()/non-delayed __d_free() race Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:00 +0200
  [PATCH 3.2 18/94] powerpc/mm/hash64: Factor out hash preload  psize check Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:00 +0200
  [PATCH 3.2 86/94] proc: prevent stacking filesystems on top Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 34/94] RDMA/cxgb3: device driver frees DMA memory with  different size Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 22/94] net/mlx4_core: Fix access to uninitialized index Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 82/94] xenbus: don't BUG() on user mode induced condition Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 69/94] ALSA: dummy: Fix a use-after-free at closing Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 74/94] NFS: Fix another OPEN_DOWNGRADE bug Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 73/94] ALSA: echoaudio: Fix memory allocation Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 61/94] mm: Export migrate_page_move_mapping and  migrate_page_copy Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  [PATCH 3.2 02/94] ath5k: Change led pin configuration for compaq  c700 laptop Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 14:10 +0200
  Re: [PATCH 3.2 00/94] 3.2.82-rc1 review Guenter Roeck <linux@roeck-us.net> - 2016-08-14 17:10 +0200
  [PATCH 3.2 39/94] ARM: fix PTRACE_SETVFPREGS on SMP systems Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 85/94] fs: limit filesystem stacking depth Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 11/94] tty: vt, return error when con_startup fails Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 91/94] tipc: fix an infoleak in tipc_nl_compat_link_dump Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 15/94] MIPS: Adjust set_pte() SMP fix to handle  R10000_LLSC_WAR Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 60/94] ubi: Make recover_peb power cut aware Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 03/94] crypto: s5p-sss - Fix missed interrupts when  working with 8 kB blocks Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 64/94] xen/pciback: Fix conf_space read/write overlap  check. Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 25/94] fs/cifs: correctly to anonymous authentication  via NTLMSSP Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:00 +0200
  [PATCH 3.2 37/94] Input: pwm-beeper - fix - scheduling while atomic Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 21/94] mmc: mmc: Fix partition switch timeout for some  eMMCs Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 88/94] ALSA: timer: Fix leak in SNDRV_TIMER_IOCTL_PARAMS Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 01/94] regmap: cache: Fix typo in cache_bypass  parameter description Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 63/94] can: fix oops caused by wrong rtnl dellink usage Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 77/94] x86/amd_nb: Fix boot crash on non-AMD systems Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 79/94] bonding: prevent out of bound accesses Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 06/94] crypto: s5p-sss - fix incorrect usage of  scatterlists api Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 59/94] can: at91_can: RX queue could get stuck at high  bus load Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 70/94] fs/nilfs2: fix potential underflow in call to  crc32_le Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 71/94] staging: iio: accel: fix error check Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 84/94] cifs: dynamic allocation of ntlmssp blob Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 52/94] kernel/sysrq, watchdog, sched/core: Reset  watchdog on all CPUs while processing sysrq-w Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 40/94] KVM: x86: fix OOPS after invalid KVM_SET_DEBUGREGS Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 53/94] base: make module_create_drivers_dir race-free Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:10 +0200
  [PATCH 3.2 87/94] USB: usbfs: fix potential infoleak in devio Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:20 +0200
  [PATCH 3.2 48/94] staging:iio: trigger fixes for repeat request  of same trigger and allocation failure Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:20 +0200
  [PATCH 3.2 09/94] ext4: fix hang when processing corrupted  orphaned inode list Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:20 +0200
  [PATCH 3.2 75/94] batman-adv: Fix use-after-free/double-free of  tt_req_node Ben Hutchings <ben@decadent.org.uk> - 2016-08-14 20:20 +0200

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