4.15-stable review patch. If anyone has any objections, please let me know.
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From: Borislav Petkov bp@suse.de
commit 1008c52c09dcb23d93f8e0ea83a6246265d2cce0 upstream.
Add a callback function which the microcode loader calls when microcode has been updated to a newer revision. Do the callback only when no error was encountered during loading.
Tested-by: Ashok Raj ashok.raj@intel.com Signed-off-by: Borislav Petkov bp@suse.de Reviewed-by: Ashok Raj ashok.raj@intel.com Cc: Andy Lutomirski luto@kernel.org Cc: Arjan van de Ven arjan@linux.intel.com Cc: Borislav Petkov bp@alien8.de Cc: Dan Williams dan.j.williams@intel.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: David Woodhouse dwmw2@infradead.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Josh Poimboeuf jpoimboe@redhat.com 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/20180216112640.11554-3-bp@alien8.de Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/include/asm/processor.h | 1 + arch/x86/kernel/cpu/common.c | 10 ++++++++++ arch/x86/kernel/cpu/microcode/core.c | 8 ++++++-- 3 files changed, 17 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -969,4 +969,5 @@ bool xen_set_default_idle(void);
void stop_this_cpu(void *dummy); void df_debug(struct pt_regs *regs, long error_code); +void microcode_check(void); #endif /* _ASM_X86_PROCESSOR_H */ --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1749,3 +1749,13 @@ static int __init init_cpu_syscore(void) return 0; } core_initcall(init_cpu_syscore); + +/* + * The microcode loader calls this upon late microcode load to recheck features, + * only when microcode has been updated. Caller holds microcode_mutex and CPU + * hotplug lock. + */ +void microcode_check(void) +{ + perf_check_microcode(); +} --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -509,6 +509,7 @@ static ssize_t reload_store(struct devic const char *buf, size_t size) { enum ucode_state tmp_ret = UCODE_OK; + bool do_callback = false; unsigned long val; ssize_t ret = 0; int cpu; @@ -531,10 +532,13 @@ static ssize_t reload_store(struct devic if (!ret) ret = -EINVAL; } + + if (tmp_ret == UCODE_UPDATED) + do_callback = true; }
- if (!ret && tmp_ret == UCODE_UPDATED) - perf_check_microcode(); + if (!ret && do_callback) + microcode_check();
mutex_unlock(µcode_mutex); put_online_cpus();