Merge tag 'microcode_fixes_for_3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/urgent

Pull two fixes for early microcode loader on 32-bit from Borislav Petkov:

 - access the dis_ucode_ldr chicken bit properly
 - fix patch stashing on AMD on 32-bit

Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 15 insertions, 11 deletions

diff --git a/arch/x86/kernel/cpu/microcode/amd_early.c b/arch/x86/kernel/cpu/microcode/amd_early.c
index 8b75f7050129..06674473b0e6 100644
--- a/arch/x86/kernel/cpu/microcode/amd_early.c
+++ b/arch/x86/kernel/cpu/microcode/amd_early.c
@@ -108,12 +108,13 @@ static size_t compute_container_size(u8 *data, u32 total_size)
  * load_microcode_amd() to save equivalent cpu table and microcode patches in
  * kernel heap memory.
  */
-static void apply_ucode_in_initrd(void *ucode, size_t size)
+static void apply_ucode_in_initrd(void *ucode, size_t size, bool save_patch)
 {
         struct equiv_cpu_entry *eq;
         size_t *cont_sz;
         u32 *header;
         u8  *data, **cont;
+        u8 (*patch)[PATCH_MAX_SIZE];
         u16 eq_id = 0;
         int offset, left;
         u32 rev, eax, ebx, ecx, edx;
@@ -123,10 +124,12 @@ static void apply_ucode_in_initrd(void *ucode, size_t size)
         new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
         cont_sz = (size_t *)__pa_nodebug(&container_size);
         cont    = (u8 **)__pa_nodebug(&container);
+        patch   = (u8 (*)[PATCH_MAX_SIZE])__pa_nodebug(&amd_ucode_patch);
 #else
         new_rev = &ucode_new_rev;
         cont_sz = &container_size;
         cont    = &container;
+        patch   = &amd_ucode_patch;
 #endif
 
         data   = ucode;
@@ -213,9 +216,9 @@ static void apply_ucode_in_initrd(void *ucode, size_t size)
                                 rev = mc->hdr.patch_id;
                                 *new_rev = rev;
 
-                                /* save ucode patch */
-                                memcpy(amd_ucode_patch, mc,
-                                       min_t(u32, header[1], PATCH_MAX_SIZE));
+                                if (save_patch)
+                                        memcpy(patch, mc,
+                                               min_t(u32, header[1], PATCH_MAX_SIZE));
                         }
                 }
 
@@ -246,7 +249,7 @@ void __init load_ucode_amd_bsp(void)
         *data = cp.data;
         *size = cp.size;
 
-        apply_ucode_in_initrd(cp.data, cp.size);
+        apply_ucode_in_initrd(cp.data, cp.size, true);
 }
 
 #ifdef CONFIG_X86_32
@@ -263,7 +266,7 @@ void load_ucode_amd_ap(void)
         size_t *usize;
         void **ucode;
 
-        mc = (struct microcode_amd *)__pa(amd_ucode_patch);
+        mc = (struct microcode_amd *)__pa_nodebug(amd_ucode_patch);
         if (mc->hdr.patch_id && mc->hdr.processor_rev_id) {
                 __apply_microcode_amd(mc);
                 return;
@@ -275,7 +278,7 @@ void load_ucode_amd_ap(void)
         if (!*ucode || !*usize)
                 return;
 
-        apply_ucode_in_initrd(*ucode, *usize);
+        apply_ucode_in_initrd(*ucode, *usize, false);
 }
 
 static void __init collect_cpu_sig_on_bsp(void *arg)
@@ -339,7 +342,7 @@ void load_ucode_amd_ap(void)
                  * AP has a different equivalence ID than BSP, looks like
                  * mixed-steppings silicon so go through the ucode blob anew.
                  */
-                apply_ucode_in_initrd(ucode_cpio.data, ucode_cpio.size);
+                apply_ucode_in_initrd(ucode_cpio.data, ucode_cpio.size, false);
         }
 }
 #endif
@@ -347,6 +350,7 @@ void load_ucode_amd_ap(void)
 int __init save_microcode_in_initrd_amd(void)
 {
         unsigned long cont;
+        int retval = 0;
         enum ucode_state ret;
         u8 *cont_va;
         u32 eax;
@@ -387,7 +391,7 @@ int __init save_microcode_in_initrd_amd(void)
 
         ret = load_microcode_amd(eax, container, container_size);
         if (ret != UCODE_OK)
-                return -EINVAL;
+                retval = -EINVAL;
 
         /*
          * This will be freed any msec now, stash patches for the current
@@ -396,5 +400,5 @@ int __init save_microcode_in_initrd_amd(void)
         container = NULL;
         container_size = 0;
 
-        return 0;
+        return retval;
 }
diff --git a/arch/x86/kernel/cpu/microcode/core_early.c b/arch/x86/kernel/cpu/microcode/core_early.c
index 5f28a64e71ea..2c017f242a78 100644
--- a/arch/x86/kernel/cpu/microcode/core_early.c
+++ b/arch/x86/kernel/cpu/microcode/core_early.c
@@ -124,7 +124,7 @@ void __init load_ucode_bsp(void)
 static bool check_loader_disabled_ap(void)
 {
 #ifdef CONFIG_X86_32
-        return __pa_nodebug(dis_ucode_ldr);
+        return *((bool *)__pa_nodebug(&dis_ucode_ldr));
 #else
         return dis_ucode_ldr;
 #endif