[PATCH 10/17] x86/microcode/intel: Move the BUG_ON up and turn it into WARN_ON

[Borislav Petkov]

From: Borislav Petkov <bp@xxxxxxx>

If we're going to BUG_ON() because we're running on the wrong CPU, we
better do it as the first thing we do when entering that function. And
also, turn it into a WARN_ON() because it is not worth to panic the
system if we apply the microcode on the wrong CPU - we're simply going
to exit early.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
 arch/x86/kernel/cpu/microcode/intel.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index d1b2f583f543..c029c2bb2a29 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -843,12 +843,12 @@ static int apply_microcode_intel(int cpu)
 	int cpu_num = raw_smp_processor_id();
 	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
 
-	uci = ucode_cpu_info + cpu;
-	mc = uci->mc;
-
 	/* We should bind the task to the CPU */
-	BUG_ON(cpu_num != cpu);
+	if (WARN_ON(cpu_num != cpu))
+		return -1;
 
+	uci = ucode_cpu_info + cpu;
+	mc = uci->mc;
 	if (!mc)
 		return 0;
 
-- 
2.3.5