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 <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 8 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 27a0228c9cae..b816971f5da4 100644
--- 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);