Merge tag 'x86_microcode_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x75 microcode loader updates from Borislav Petkov:

 - Get rid of a single ksize() usage

 - By popular demand, print the previous microcode revision an update
   was done over

 - Remove more code related to the now gone MICROCODE_OLD_INTERFACE

 - Document the problems stemming from microcode late loading

* tag 'x86_microcode_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/AMD: Track patch allocation size explicitly
  x86/microcode: Print previous version of microcode after reload
  x86/microcode: Remove ->request_microcode_user()
  x86/microcode: Document the whole late loading problem

4 files changed, 6 insertions, 30 deletions

diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index 0c3d3440fe27..74ecc2bd6cd0 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -9,6 +9,7 @@
 struct ucode_patch {
 	struct list_head plist;
 	void *data;		/* Intel uses only this one */
+	unsigned int size;
 	u32 patch_id;
 	u16 equiv_cpu;
 };
@@ -32,9 +33,6 @@ enum ucode_state {
 };
 
 struct microcode_ops {
-	enum ucode_state (*request_microcode_user) (int cpu,
-				const void __user *buf, size_t size);
-
 	enum ucode_state (*request_microcode_fw) (int cpu, struct device *,
 						  bool refresh_fw);
 
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 8b2fcdfa6d31..e7410e98fc1f 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -788,6 +788,7 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover,
 		kfree(patch);
 		return -EINVAL;
 	}
+	patch->size = *patch_size;
 
 	mc_hdr      = (struct microcode_header_amd *)(fw + SECTION_HDR_SIZE);
 	proc_id     = mc_hdr->processor_rev_id;
@@ -869,7 +870,7 @@ load_microcode_amd(bool save, u8 family, const u8 *data, size_t size)
 		return ret;
 
 	memset(amd_ucode_patch, 0, PATCH_MAX_SIZE);
-	memcpy(amd_ucode_patch, p->data, min_t(u32, ksize(p->data), PATCH_MAX_SIZE));
+	memcpy(amd_ucode_patch, p->data, min_t(u32, p->size, PATCH_MAX_SIZE));
 
 	return ret;
 }
@@ -924,12 +925,6 @@ static enum ucode_state request_microcode_amd(int cpu, struct device *device,
 	return ret;
 }
 
-static enum ucode_state
-request_microcode_user(int cpu, const void __user *buf, size_t size)
-{
-	return UCODE_ERROR;
-}
-
 static void microcode_fini_cpu_amd(int cpu)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -938,7 +933,6 @@ static void microcode_fini_cpu_amd(int cpu)
 }
 
 static struct microcode_ops microcode_amd_ops = {
-	.request_microcode_user           = request_microcode_user,
 	.request_microcode_fw             = request_microcode_amd,
 	.collect_cpu_info                 = collect_cpu_info_amd,
 	.apply_microcode                  = apply_microcode_amd,
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index ad57e0e4d674..6a41cee242f6 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -491,7 +491,7 @@ wait_for_siblings:
  */
 static int microcode_reload_late(void)
 {
-	int ret;
+	int old = boot_cpu_data.microcode, ret;
 
 	pr_err("Attempting late microcode loading - it is dangerous and taints the kernel.\n");
 	pr_err("You should switch to early loading, if possible.\n");
@@ -503,7 +503,8 @@ static int microcode_reload_late(void)
 	if (ret == 0)
 		microcode_check();
 
-	pr_info("Reload completed, microcode revision: 0x%x\n", boot_cpu_data.microcode);
+	pr_info("Reload completed, microcode revision: 0x%x -> 0x%x\n",
+		old, boot_cpu_data.microcode);
 
 	return ret;
 }
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 025c8f0cd948..1fcbd671f1df 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -916,24 +916,7 @@ static enum ucode_state request_microcode_fw(int cpu, struct device *device,
 	return ret;
 }
 
-static enum ucode_state
-request_microcode_user(int cpu, const void __user *buf, size_t size)
-{
-	struct iov_iter iter;
-	struct iovec iov;
-
-	if (is_blacklisted(cpu))
-		return UCODE_NFOUND;
-
-	iov.iov_base = (void __user *)buf;
-	iov.iov_len = size;
-	iov_iter_init(&iter, WRITE, &iov, 1, size);
-
-	return generic_load_microcode(cpu, &iter);
-}
-
 static struct microcode_ops microcode_intel_ops = {
-	.request_microcode_user		  = request_microcode_user,
 	.request_microcode_fw             = request_microcode_fw,
 	.collect_cpu_info                 = collect_cpu_info,
 	.apply_microcode                  = apply_microcode_intel,