[PATCH 01/13] x86/microcode/intel: Check if microcode was found before applying

From: Borislav Petkov
Date: Tue Feb 24 2015 - 05:41:50 EST


From: Borislav Petkov <bp@xxxxxxx>

We should check the return value of the routines fishing out the proper
microcode and not try to apply if we haven't found a suitable blob.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/kernel/cpu/microcode/intel_early.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c
index 420eb933189c..b3cb1568cd9a 100644
--- a/arch/x86/kernel/cpu/microcode/intel_early.c
+++ b/arch/x86/kernel/cpu/microcode/intel_early.c
@@ -729,9 +729,10 @@ _load_ucode_intel_bsp(struct mc_saved_data *mc_saved_data,

ret = load_microcode(mc_saved_data, mc_saved_in_initrd,
initrd_start_early, uci);
+ if (ret != UCODE_OK)
+ return;

- if (ret == UCODE_OK)
- apply_microcode_early(uci, true);
+ apply_microcode_early(uci, true);
}

void __init
@@ -771,6 +772,7 @@ void load_ucode_intel_ap(void)
struct ucode_cpu_info uci;
unsigned long *mc_saved_in_initrd_p;
unsigned long initrd_start_addr;
+ enum ucode_state ret;
#ifdef CONFIG_X86_32
unsigned long *initrd_start_p;

@@ -793,8 +795,12 @@ void load_ucode_intel_ap(void)
return;

collect_cpu_info_early(&uci);
- load_microcode(mc_saved_data_p, mc_saved_in_initrd_p,
- initrd_start_addr, &uci);
+ ret = load_microcode(mc_saved_data_p, mc_saved_in_initrd_p,
+ initrd_start_addr, &uci);
+
+ if (ret != UCODE_OK)
+ return;
+
apply_microcode_early(&uci, true);
}

--
2.2.0.33.gc18b867

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