linux-kernel - [tip:x86/urgent] x86/microcode/AMD: Make find_proper

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Date:   Mon, 19 Dec 2016 01:55:13 -0800
From:   tip-bot for Borislav Petkov <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, jgross@...e.com, mingo@...nel.org,
        bp@...e.de, tglx@...utronix.de, boris.ostrovsky@...cle.com,
        hpa@...or.com
Subject: [tip:x86/urgent] x86/microcode/AMD: Make find_proper_container()
 sane again

Commit-ID:  8feaa64a9a69652fdff87205f8a8cfe1bfd5b522
Gitweb:     http://git.kernel.org/tip/8feaa64a9a69652fdff87205f8a8cfe1bfd5b522
Author:     Borislav Petkov <bp@...e.de>
AuthorDate: Sun, 18 Dec 2016 17:44:11 +0100
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Mon, 19 Dec 2016 10:46:19 +0100

x86/microcode/AMD: Make find_proper_container() sane again

Fixup signature and retvals, return the container struct through the
passed in pointer, not as a function return value.

Signed-off-by: Borislav Petkov <bp@...e.de>
Cc: Jürgen Gross <jgross@...e.com>
Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Link: http://lkml.kernel.org/r/20161218164414.9649-2-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>

---
 arch/x86/kernel/cpu/microcode/amd.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 6f353bd..31f4e3f 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -116,10 +116,11 @@ static inline u16 find_equiv_id(struct equiv_cpu_entry *equiv_cpu_table,
 
 /*
  * This scans the ucode blob for the proper container as we can have multiple
- * containers glued together.
+ * containers glued together. Returns the equivalence ID from the equivalence
+ * table or 0 if none found.
  */
-static struct container
-find_proper_container(u8 *ucode, size_t size, u16 *ret_id)
+static u16
+find_proper_container(u8 *ucode, size_t size, struct container *ret_cont)
 {
 	struct container ret = { NULL, 0 };
 	u32 eax, ebx, ecx, edx;
@@ -138,7 +139,7 @@ find_proper_container(u8 *ucode, size_t size, u16 *ret_id)
 	if (header[0] != UCODE_MAGIC ||
 	    header[1] != UCODE_EQUIV_CPU_TABLE_TYPE || /* type */
 	    header[2] == 0)                            /* size */
-		return ret;
+		return eq_id;
 
 	eax = 0x00000001;
 	ecx = 0;
@@ -163,8 +164,9 @@ find_proper_container(u8 *ucode, size_t size, u16 *ret_id)
 			 * ucode update loop below
 			 */
 			left = ret.size - offset;
-			*ret_id = eq_id;
-			return ret;
+
+			*ret_cont = ret;
+			return eq_id;
 		}
 
 		/*
@@ -189,7 +191,7 @@ find_proper_container(u8 *ucode, size_t size, u16 *ret_id)
 		ucode     = data;
 	}
 
-	return ret;
+	return eq_id;
 }
 
 static int __apply_microcode_amd(struct microcode_amd *mc_amd)
@@ -237,7 +239,7 @@ apply_microcode_early_amd(void *ucode, size_t size, bool save_patch)
 	if (check_current_patch_level(&rev, true))
 		return (struct container){ NULL, 0 };
 
-	ret = find_proper_container(ucode, size, &eq_id);
+	eq_id = find_proper_container(ucode, size, &ret);
 	if (!eq_id)
 		return (struct container){ NULL, 0 };
 
@@ -443,7 +445,7 @@ int __init save_microcode_in_initrd_amd(unsigned int fam)
 				return -EINVAL;
 			}
 
-			cont = find_proper_container(cp.data, cp.size, &eq_id);
+			eq_id = find_proper_container(cp.data, cp.size, &cont);
 			if (!eq_id) {
 				cont.size = -1;
 				return -EINVAL;