[Xen-devel] [PATCH v2 2/7] x86/ucode/intel: Adjust microcode_sanity_check() to not take void *

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

microcode_sanity_check()'s callers actually call it with a mixture of
microcode_intel(/patch) and microcode_header_intel pointers, which is fragile.

Rework it to take struct microcode_patch *, which in turn requires
microcode_update_match()'s type to be altered.

No functional change - compiled binary is identical.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
CC: Wei Liu <wl@xxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>

v2:
 * Rebase over struct microcode_patch re-work
---
 xen/arch/x86/cpu/microcode/intel.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/cpu/microcode/intel.c 
b/xen/arch/x86/cpu/microcode/intel.c
index a69f7fe1de..77539a00be 100644
--- a/xen/arch/x86/cpu/microcode/intel.c
+++ b/xen/arch/x86/cpu/microcode/intel.c
@@ -118,9 +118,9 @@ static int collect_cpu_info(struct cpu_signature *csig)
     return 0;
 }
 
-static int microcode_sanity_check(const void *mc)
+static int microcode_sanity_check(const struct microcode_patch *mc)
 {
-    const struct microcode_header_intel *mc_header = mc;
+    const struct microcode_header_intel *mc_header = &mc->hdr;
     const struct extended_sigtable *ext_header = NULL;
     const struct extended_signature *ext_sig;
     unsigned long total_size, data_size, ext_table_size;
@@ -152,7 +152,7 @@ static int microcode_sanity_check(const void *mc)
                    "Small exttable size in microcode data file\n");
             return -EINVAL;
         }
-        ext_header = mc + MC_HEADER_SIZE + data_size;
+        ext_header = (void *)mc + MC_HEADER_SIZE + data_size;
         if ( ext_table_size != exttable_size(ext_header) )
         {
             printk(KERN_ERR "microcode: error! "
@@ -210,8 +210,9 @@ static int microcode_sanity_check(const void *mc)
 
 /* Check an update against the CPU signature and current update revision */
 static enum microcode_match_result microcode_update_match(
-    const struct microcode_header_intel *mc_header)
+    const struct microcode_patch *mc)
 {
+    const struct microcode_header_intel *mc_header = &mc->hdr;
     const struct extended_sigtable *ext_header;
     const struct extended_signature *ext_sig;
     unsigned int i;
@@ -222,7 +223,7 @@ static enum microcode_match_result microcode_update_match(
     unsigned long data_size = get_datasize(mc_header);
     const void *end = (const void *)mc_header + get_totalsize(mc_header);
 
-    ASSERT(!microcode_sanity_check(mc_header));
+    ASSERT(!microcode_sanity_check(mc));
     if ( sigmatch(sig, mc_header->sig, pf, mc_header->pf) )
         return (mc_header->rev > rev) ? NEW_UCODE : OLD_UCODE;
 
@@ -248,7 +249,7 @@ static bool match_cpu(const struct microcode_patch *patch)
     if ( !patch )
         return false;
 
-    return microcode_update_match(&patch->hdr) == NEW_UCODE;
+    return microcode_update_match(patch) == NEW_UCODE;
 }
 
 static void free_patch(struct microcode_patch *patch)
@@ -263,8 +264,8 @@ static enum microcode_match_result compare_patch(
      * Both patches to compare are supposed to be applicable to local CPU.
      * Just compare the revision number.
      */
-    ASSERT(microcode_update_match(&old->hdr) != MIS_UCODE);
-    ASSERT(microcode_update_match(&new->hdr) != MIS_UCODE);
+    ASSERT(microcode_update_match(old) != MIS_UCODE);
+    ASSERT(microcode_update_match(new) != MIS_UCODE);
 
     return (new->hdr.rev > old->hdr.rev) ? NEW_UCODE : OLD_UCODE;
 }
@@ -361,7 +362,7 @@ static struct microcode_patch *cpu_request_microcode(const 
void *buf,
          * If the new update covers current CPU, compare updates and store the
          * one with higher revision.
          */
-        if ( (microcode_update_match(&mc->hdr) != MIS_UCODE) &&
+        if ( (microcode_update_match(mc) != MIS_UCODE) &&
              (!saved || (mc->hdr.rev > saved->hdr.rev)) )
         {
             xfree(saved);
-- 
2.11.0