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Borislav Petkov dac6ca243c x86/microcode/AMD: Change load_microcode_amd()'s param to bool to fix preemptibility bug
With CONFIG_DEBUG_PREEMPT enabled, I get:

  BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
  caller is debug_smp_processor_id
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2+ #2
  Call Trace:
   dump_stack
   check_preemption_disabled
   debug_smp_processor_id
   save_microcode_in_initrd_amd
   ? microcode_init
   save_microcode_in_initrd
   ...

because, well, it says it above, we're using smp_processor_id() in
preemptible code.

But passing the CPU number is not really needed. It is only used to
determine whether we're on the BSP, and, if so, to save the microcode
patch for early loading.

 [ We don't absolutely need to do it on the BSP but we do that
   customarily there. ]

Instead, convert that function parameter to a boolean which denotes
whether the patch should be saved or not, thereby avoiding the use of
smp_processor_id() in preemptible code.

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/20170528200414.31305-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-29 08:22:48 +02:00
Documentation Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2017-05-26 16:45:13 -07:00
arch x86/microcode/AMD: Change load_microcode_amd()'s param to bool to fix preemptibility bug 2017-05-29 08:22:48 +02:00
block Merge branch 'nvme-4.12' of git://git.infradead.org/nvme into for-linus 2017-05-26 09:11:19 -06:00
certs scripts/spelling.txt: add "intialise(d)" pattern and fix typo instances 2017-05-08 17:15:13 -07:00
crypto crypto: skcipher - Add missing API setkey checks 2017-05-18 13:04:05 +08:00
drivers Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal 2017-05-28 16:18:27 -07:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs Changed since last update: 2017-05-26 12:13:08 -07:00
include TTY/Serial fixes for 4.12-rc3 2017-05-27 09:39:09 -07:00
init Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-10 10:30:46 -07:00
ipc mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
kernel Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-27 09:14:24 -07:00
lib test_bpf: Add a couple of tests for BPF_JSGE. 2017-05-25 14:37:56 -04:00
mm mm: vmscan: scan until it finds eligible pages 2017-05-12 15:57:16 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-05-26 13:51:01 -07:00
samples samples/bpf: run cleanup routines when receiving SIGTERM 2017-05-11 21:43:30 -04:00
scripts DeviceTree fixes for 4.12-rc: 2017-05-19 15:03:24 -07:00
security Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-09 09:12:53 -07:00
sound sound fixes for 4.12-rc3 2017-05-26 09:03:09 -07:00
tools powerpc fixes for 4.12 #4 2017-05-27 09:28:34 -07:00
usr initramfs: provide a way to ignore image provided by bootloader 2017-05-08 17:15:12 -07:00
virt KVM: arm/arm64: Hold slots_lock when unregistering kvm io bus devices 2017-05-18 11:18:16 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS TTY/Serial fixes for 4.12-rc3 2017-05-27 09:39:09 -07:00
Makefile Linux 4.12-rc3 2017-05-28 17:20:53 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.