@@ -52,11 +52,11 @@ struct microcode_patch {
};
#define UCODE_MAGIC 0x00414d44
-#define UCODE_EQUIV_CPU_TABLE_TYPE 0x00000000
+#define UCODE_EQUIV_TYPE 0x00000000
#define UCODE_UCODE_TYPE 0x00000001
struct container_equiv_table {
- uint32_t type; /* UCODE_EQUIV_CPU_TABLE_TYPE */
+ uint32_t type; /* UCODE_EQUIV_TYPE */
uint32_t len;
struct equiv_cpu_entry eq[];
};
@@ -335,10 +335,10 @@ static struct microcode_patch *cf_check cpu_request_microcode(
buf += 4;
size -= 4;
- if ( size < sizeof(*et) ||
- (et = buf)->type != UCODE_EQUIV_CPU_TABLE_TYPE ||
- size - sizeof(*et) < et->len ||
- et->len % sizeof(et->eq[0]) )
+ if ( size < sizeof(*et) || /* Insufficient space for header? */
+ (et = buf)->type != UCODE_EQUIV_TYPE || /* Not an Equivalence Table? */
+ size - sizeof(*et) < et->len || /* Insufficient space for table? */
+ et->len % sizeof(et->eq[0]) ) /* Not a multiple of equiv_cpu_entry? */
{
printk(XENLOG_ERR "microcode: Bad equivalent cpu table\n");
error = -EINVAL;
@@ -351,7 +351,12 @@ static struct microcode_patch *cf_check cpu_request_microcode(
error = scan_equiv_cpu_table(et);
- /* -ESRCH means no applicable microcode in this container. */
+ /*
+ * -ESRCH means no applicable microcode in this container. But, there
+ * might be subsequent containers in the blob. Skipping to the end of
+ * this container still requires us to follow the UCODE_UCODE_TYPE/len
+ * metadata because there's no overall container length given.
+ */
if ( error && error != -ESRCH )
break;
skip_ucode = error;
@@ -361,10 +366,10 @@ static struct microcode_patch *cf_check cpu_request_microcode(
{
const struct container_microcode *mc;
- if ( size < sizeof(*mc) ||
- (mc = buf)->type != UCODE_UCODE_TYPE ||
- size - sizeof(*mc) < mc->len ||
- mc->len < sizeof(struct microcode_patch) )
+ if ( size < sizeof(*mc) || /* Insufficient space for container header? */
+ (mc = buf)->type != UCODE_UCODE_TYPE || /* Not an ucode blob? */
+ size - sizeof(*mc) < mc->len || /* Insufficient space for blob? */
+ mc->len < sizeof(struct microcode_patch) ) /* Insufficient space for patch header? */
{
printk(XENLOG_ERR "microcode: Bad microcode data\n");
error = -EINVAL;
Despite writing this code, it's not the easiest logic to follow. Shorten the UCODE_EQUIV_TYPE name, and provide more of an explanation of what's going on. No functional change. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Roger Pau Monné <roger.pau@citrix.com> --- xen/arch/x86/cpu/microcode/amd.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-)