linux/arch/x86
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
..
boot x86/boot: Use CROSS_COMPILE prefix for readelf 2017-05-21 13:04:27 +02:00
configs Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-01 20:51:12 -07:00
crypto crypto: glue_helper - remove the le128_gf128mul_x_ble function 2017-04-05 21:58:37 +08:00
entry Revert "x86/entry: Fix the end of the stack for newly forked tasks" 2017-05-24 09:05:16 +02:00
events perf/core improvements and fixes: 2017-05-03 19:28:27 +02:00
hyperv char/misc patches for 4.12-rc1 2017-05-04 19:15:35 -07:00
ia32 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
include Merge branch 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-27 09:06:43 -07:00
kernel x86/microcode/AMD: Change load_microcode_amd()'s param to bool to fix preemptibility bug 2017-05-29 08:22:48 +02:00
kvm KVM: x86: prevent uninitialized variable warning in check_svme() 2017-05-19 19:59:28 +02:00
lguest Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-01 20:51:12 -07:00
lib x86/mm/kaslr: Use the _ASM_MUL macro for multiplication to work around Clang incompatibility 2017-05-05 08:31:05 +02:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-27 09:17:58 -07:00
net x86: use set_memory.h header 2017-05-08 17:15:13 -07:00
oprofile x86/oprofile/nmi: Convert to hotplug state machine 2016-11-22 23:34:43 +01:00
pci pci-v4.12-changes 2017-05-08 19:03:25 -07:00
platform x86: use set_memory.h header 2017-05-08 17:15:13 -07:00
power x86/mm: Add support for gbpages to kernel_ident_mapping_init() 2017-05-08 08:28:40 +02:00
purgatory kasan: do not sanitize kexec purgatory 2017-03-31 17:13:30 -07:00
ras RAS: Add a Corrected Errors Collector 2017-03-28 08:54:48 +02:00
realmode x86: use set_memory.h header 2017-05-08 17:15:13 -07:00
tools x86/tools: Fix gcc-7 warning in relocs.c 2016-12-19 11:50:24 +01:00
um Merge branch 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-05-13 10:20:02 -07:00
video
xen xen: make xen_flush_tlb_all() static 2017-05-19 08:04:25 +02:00
.gitignore
Kbuild Drivers: hv vmbus: Move Hypercall page setup out of common code 2017-01-19 11:42:07 +01:00
Kconfig x86/watchdog: Fix Kconfig help text file path reference to lockup watchdog documentation 2017-05-24 09:06:32 +02:00
Kconfig.cpu
Kconfig.debug usb/early: Add driver for xhci debug capability 2017-03-21 12:30:05 +01:00
Makefile x86/build: Permit building with old make versions 2017-05-24 09:05:17 +02:00
Makefile_32.cpu x86/build: Mostly disable '-maccumulate-outgoing-args' 2017-03-30 11:53:04 +02:00
Makefile.um