diff options
| author | Borislav Petkov <bp@suse.de> | 2018-02-19 11:13:28 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-25 11:05:56 +0100 |
| commit | 1acf767c213a0be16a9e1bacb140dd5bf0bb644a (patch) | |
| tree | 24b96c49253e42b1af102034ce87e70df7e86be2 /arch/x86/include | |
| parent | 353727e3b4565aaf0eeff57278fac3e1d01547f8 (diff) | |
x86/microcode/AMD: Change load_microcode_amd()'s param to bool to fix preemptibility bug
commit dac6ca243c4c49a9ca7507d3d66140ebfac8b04b upstream.
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>
[arnd: rebased to 4.9, after running into warning:
arch/x86/kernel/cpu/microcode/amd.c:881:30: self-comparison always evaluates to true]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/microcode_amd.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h index 15eb75484cc0..98ccbd1dbb01 100644 --- a/arch/x86/include/asm/microcode_amd.h +++ b/arch/x86/include/asm/microcode_amd.h @@ -59,7 +59,6 @@ static inline u16 find_equiv_id(struct equiv_cpu_entry *equiv_cpu_table, extern int __apply_microcode_amd(struct microcode_amd *mc_amd); extern int apply_microcode_amd(int cpu); -extern enum ucode_state load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size); #define PATCH_MAX_SIZE PAGE_SIZE |