x86/microcode/intel: Reuse microcode_sanity_check()

IFS test image carries the same microcode header as regular Intel
microcode blobs.

Reuse microcode_sanity_check() in the IFS driver to perform sanity check
of the IFS test images too.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-8-jithu.joseph@intel.com

1 files changed, 2 insertions, 100 deletions

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index e48f05ec15aa..fb6ff71a5ff5 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -135,104 +135,6 @@ static void save_microcode_patch(struct ucode_cpu_info *uci, void *data, unsigne
 		intel_ucode_patch = p->data;
 }
 
-static int microcode_sanity_check(void *mc, bool print_err)
-{
-	unsigned long total_size, data_size, ext_table_size;
-	struct microcode_header_intel *mc_header = mc;
-	struct extended_sigtable *ext_header = NULL;
-	u32 sum, orig_sum, ext_sigcount = 0, i;
-	struct extended_signature *ext_sig;
-
-	total_size = get_totalsize(mc_header);
-	data_size = get_datasize(mc_header);
-
-	if (data_size + MC_HEADER_SIZE > total_size) {
-		if (print_err)
-			pr_err("Error: bad microcode data file size.\n");
-		return -EINVAL;
-	}
-
-	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
-		if (print_err)
-			pr_err("Error: invalid/unknown microcode update format.\n");
-		return -EINVAL;
-	}
-
-	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
-	if (ext_table_size) {
-		u32 ext_table_sum = 0;
-		u32 *ext_tablep;
-
-		if ((ext_table_size < EXT_HEADER_SIZE)
-		 || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
-			if (print_err)
-				pr_err("Error: truncated extended signature table.\n");
-			return -EINVAL;
-		}
-
-		ext_header = mc + MC_HEADER_SIZE + data_size;
-		if (ext_table_size != exttable_size(ext_header)) {
-			if (print_err)
-				pr_err("Error: extended signature table size mismatch.\n");
-			return -EFAULT;
-		}
-
-		ext_sigcount = ext_header->count;
-
-		/*
-		 * Check extended table checksum: the sum of all dwords that
-		 * comprise a valid table must be 0.
-		 */
-		ext_tablep = (u32 *)ext_header;
-
-		i = ext_table_size / sizeof(u32);
-		while (i--)
-			ext_table_sum += ext_tablep[i];
-
-		if (ext_table_sum) {
-			if (print_err)
-				pr_warn("Bad extended signature table checksum, aborting.\n");
-			return -EINVAL;
-		}
-	}
-
-	/*
-	 * Calculate the checksum of update data and header. The checksum of
-	 * valid update data and header including the extended signature table
-	 * must be 0.
-	 */
-	orig_sum = 0;
-	i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
-	while (i--)
-		orig_sum += ((u32 *)mc)[i];
-
-	if (orig_sum) {
-		if (print_err)
-			pr_err("Bad microcode data checksum, aborting.\n");
-		return -EINVAL;
-	}
-
-	if (!ext_table_size)
-		return 0;
-
-	/*
-	 * Check extended signature checksum: 0 => valid.
-	 */
-	for (i = 0; i < ext_sigcount; i++) {
-		ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
-			  EXT_SIGNATURE_SIZE * i;
-
-		sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
-		      (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
-		if (sum) {
-			if (print_err)
-				pr_err("Bad extended signature checksum, aborting.\n");
-			return -EINVAL;
-		}
-	}
-	return 0;
-}
-
 /*
  * Get microcode matching with BSP's model. Only CPUs with the same model as
  * BSP can stay in the platform.
@@ -253,7 +155,7 @@ scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
 		mc_size = get_totalsize(mc_header);
 		if (!mc_size ||
 		    mc_size > size ||
-		    microcode_sanity_check(data, false) < 0)
+		    intel_microcode_sanity_check(data, false) < 0)
 			break;
 
 		size -= mc_size;
@@ -792,7 +694,7 @@ static enum ucode_state generic_load_microcode(int cpu, struct iov_iter *iter)
 		memcpy(mc, &mc_header, sizeof(mc_header));
 		data = mc + sizeof(mc_header);
 		if (!copy_from_iter_full(data, data_size, iter) ||
-		    microcode_sanity_check(mc, true) < 0) {
+		    intel_microcode_sanity_check(mc, true) < 0) {
 			break;
 		}