x86, microcode, AMD: Simplify install_equiv_cpu_table

There's no need to memcpy the ucode header in order to look at it only
in this function - use the original buffer instead. Also, fix return
type semantics by returning a negative value on error and a positive
otherwise.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Andreas Herrmann <Andreas.Herrmann3@amd.com>

diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c
index ef91df0fb64d1b2b21576b0f4f5a4635e198dbf8..9a451d7182f0d5edecca199b61e64ad2a1a75a97 100644 (file)
--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -188,27 +188,22 @@ get_next_ucode(const u8 *buf, unsigned int size, unsigned int *mc_size)
 
 static int install_equiv_cpu_table(const u8 *buf)
 {
-       u8 *container_hdr[UCODE_CONTAINER_HEADER_SIZE];
-       unsigned int *buf_pos = (unsigned int *)container_hdr;
-       unsigned long size;
+       unsigned int *ibuf = (unsigned int *)buf;
+       unsigned int type = ibuf[1];
+       unsigned int size = ibuf[2];
 
-       get_ucode_data(&container_hdr, buf, UCODE_CONTAINER_HEADER_SIZE);
-
-       size = buf_pos[2];
-
-       if (buf_pos[1] != UCODE_EQUIV_CPU_TABLE_TYPE || !size) {
+       if (type != UCODE_EQUIV_CPU_TABLE_TYPE || !size) {
                pr_err("error: invalid type field in container file section header\n");
-               return 0;
+               return -EINVAL;
        }
 
        equiv_cpu_table = vmalloc(size);
        if (!equiv_cpu_table) {
                pr_err("failed to allocate equivalent CPU table\n");
-               return 0;
+               return -ENOMEM;
        }
 
-       buf += UCODE_CONTAINER_HEADER_SIZE;
-       get_ucode_data(equiv_cpu_table, buf, size);
+       get_ucode_data(equiv_cpu_table, buf + UCODE_CONTAINER_HEADER_SIZE, size);
 
        return size + UCODE_CONTAINER_HEADER_SIZE; /* add header length */
 }
@@ -232,7 +227,7 @@ generic_load_microcode(int cpu, const u8 *data, size_t size)
        enum ucode_state state = UCODE_OK;
 
        offset = install_equiv_cpu_table(ucode_ptr);
-       if (!offset) {
+       if (offset < 0) {
                pr_err("failed to create equivalent cpu table\n");
                return UCODE_ERROR;
        }