x86/microcode/AMD: Fix initrd loading with CONFIG_RANDOMIZE_MEMORY=y

Similar to:

  efaad554b4ff ("x86/microcode/intel: Fix initrd loading with CONFIG_RANDOMIZE_MEMORY=y")

... fix microcode loading from the initrd on AMD by adding the
randomization offset to the microcode patch container within the initrd.

Reported-and-tested-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-tip-commits@vger.kernel.org
Link: http://lkml.kernel.org/r/20160817113314.GA19221@nazgul.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 27a0228c9cae0dd32d2d5aff092a5b39162d6593..b816971f5da4cd45d1461831283aafb39578f296 100644 (file)
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -355,6 +355,7 @@ void load_ucode_amd_ap(void)
        unsigned int cpu = smp_processor_id();
        struct equiv_cpu_entry *eq;
        struct microcode_amd *mc;
+       u8 *cont = container;
        u32 rev, eax;
        u16 eq_id;
 
@@ -371,8 +372,11 @@ void load_ucode_amd_ap(void)
        if (check_current_patch_level(&rev, false))
                return;
 
+       /* Add CONFIG_RANDOMIZE_MEMORY offset. */
+       cont += PAGE_OFFSET - __PAGE_OFFSET_BASE;
+
        eax = cpuid_eax(0x00000001);
-       eq  = (struct equiv_cpu_entry *)(container + CONTAINER_HDR_SZ);
+       eq  = (struct equiv_cpu_entry *)(cont + CONTAINER_HDR_SZ);
 
        eq_id = find_equiv_id(eq, eax);
        if (!eq_id)
@@ -434,6 +438,9 @@ int __init save_microcode_in_initrd_amd(void)
        else
                container = cont_va;
 
+       /* Add CONFIG_RANDOMIZE_MEMORY offset. */
+       container += PAGE_OFFSET - __PAGE_OFFSET_BASE;
+
        eax   = cpuid_eax(0x00000001);
        eax   = ((eax >> 8) & 0xf) + ((eax >> 20) & 0xff);