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

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index e853440b5c65d4736397621ddad7b5792d7c0bd2..9e3ac95acf2d9d2995c4371e8ced8ca677a6a2d4 100644 (file)
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -96,5 +96,6 @@ static inline bool intel_cpu_signatures_match(unsigned int s1, unsigned int p1,
 
 extern u64 x86_read_arch_cap_msr(void);
 int intel_find_matching_signature(void *mc, unsigned int csig, int cpf);
+int intel_microcode_sanity_check(void *mc, bool print_err);
 
 #endif /* _ASM_X86_CPU_H */

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index c7331eced21f5edf80304a65d99a1e47e5cffa19..bef06a1fafe98f67f58731d46232916b545fc7b7 100644 (file)
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -244,6 +244,105 @@ int intel_find_matching_signature(void *mc, unsigned int csig, int cpf)
 }
 EXPORT_SYMBOL_GPL(intel_find_matching_signature);
 
+int intel_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;
+}
+EXPORT_SYMBOL_GPL(intel_microcode_sanity_check);
+
 static void early_init_intel(struct cpuinfo_x86 *c)
 {
        u64 misc_enable;

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index e48f05ec15aad356f50c689f0f496539bfaf201b..fb6ff71a5ff5cea935a94d5aaa0309eec2273042 100644 (file)
--- 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;
                }