Stefan Reinauer (stefan.reinauer@coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2990
-gerrit
commit 51d0cc0581f93ef85552b2ce73e8aee1f8d6ba58 Author: Vladimir Serbinenko phcoder@gmail.com Date: Sat Mar 30 12:04:23 2013 +0100
Intel: Return on missing microcode file to fix null pointer dereference
Selecting `CPU_MICROCODE_IN_CBFS` in Kconfig but not having the microcode blob `cpu_microcode_blob.bin` in CBFS results in a null pointer dereference later on resulting in a crash.
for(c = microcode_updates; m->hdrver; m = (const struct microcode *)c) {
Fix this by returning if `microcode_updates` is `NULL`, that means no file is found.
This patch is successfully tested on the Lenovo X201.
Change-Id: I6e18fd37256910bf047061e4633a66cf29ad7b69 Signed-off-by: Vladimir Serbinenko phcoder@gmail.com Signed-off-by: Paul Menzel paulepanter@users.sourceforge.net --- src/cpu/intel/microcode/microcode.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/cpu/intel/microcode/microcode.c b/src/cpu/intel/microcode/microcode.c index d908c25..7735e0d 100644 --- a/src/cpu/intel/microcode/microcode.c +++ b/src/cpu/intel/microcode/microcode.c @@ -131,7 +131,7 @@ const void *intel_microcode_find(void) #endif
if (!microcode_updates) - return microcode_updates; + return NULL;
/* CPUID sets MSR 0x8B iff a microcode update has been loaded. */ msr.lo = 0; @@ -202,6 +202,13 @@ void intel_update_microcode(const void *microcode_updates) const char *c; msr_t msr;
+ if (!microcode_updates) { +#if !defined(__ROMCC__) + printk(BIOS_WARNING, "No microcode updates found.\n"); +#endif + return; + } + /* CPUID sets MSR 0x8B iff a microcode update has been loaded. */ msr.lo = 0; msr.hi = 0;