gentoo-overlay/sys-kernel/hardened-kernel/files/linux-5.4/9127_0127-x86-microcode-For...

144 lines
4.2 KiB
Diff
Raw Normal View History

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Ashok Raj <ashok.raj@intel.com>
Date: Sat, 20 Jul 2019 14:14:47 +0000
Subject: [PATCH] x86/microcode: Force update a uCode even if the rev is the
same
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
---
arch/x86/kernel/cpu/microcode/core.c | 1 +
arch/x86/kernel/cpu/microcode/intel.c | 57 +++++++++++++++++++++++++--
2 files changed, 55 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index cb0fdcaf1415..d44fe3e5c028 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -601,6 +601,7 @@ static int microcode_reload_late(void)
atomic_set(&late_cpus_in, 0);
atomic_set(&late_cpus_out, 0);
+ printk ("Going to do stop_machine\n");
ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask);
if (ret > 0)
microcode_check();
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index ce799cfe9434..9e85d785b226 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -30,6 +30,7 @@
#include <linux/uio.h>
#include <linux/mm.h>
+#include <asm/cmdline.h>
#include <asm/microcode_intel.h>
#include <asm/intel-family.h>
#include <asm/processor.h>
@@ -38,6 +39,7 @@
#include <asm/msr.h>
static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";
+static bool force_ucode_load = false;
/* Current microcode patch used in early patching on the APs. */
static struct microcode_intel *intel_ucode_patch;
@@ -94,8 +96,18 @@ static int has_newer_microcode(void *mc, unsigned int csig, int cpf, int new_rev
{
struct microcode_header_intel *mc_hdr = mc;
- if (mc_hdr->rev <= new_rev)
+ //if (mc_hdr->rev <= new_rev)
+ if (mc_hdr->rev < new_rev) {
+ printk ("Returning NO_NEW old = 0x%x new = 0x%x\n",
+ mc_hdr->rev, new_rev);
return 0;
+ }
+ if ((mc_hdr->rev == new_rev) && !force_ucode_load) {
+ printk ("SAME REV: no_force Returning NO_NEW old = 0x%x new = 0x%x\n",
+ mc_hdr->rev, new_rev);
+ return 0;
+ }
+ printk ("ucode: force loading same rev\n");
return find_matching_signature(mc, csig, cpf);
}
@@ -593,11 +605,20 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
* already.
*/
rev = intel_get_microcode_revision();
- if (rev >= mc->hdr.rev) {
+ if (rev > mc->hdr.rev) {
uci->cpu_sig.rev = rev;
return UCODE_OK;
}
+ if (rev == mc->hdr.rev) {
+ if (!force_ucode_load) {
+ printk ("Matching ucode rev, no update\n");
+ return UCODE_OK;
+ } else {
+ printk ("Matching ucode rev.. force updating\n");
+ }
+ }
+
/*
* Writeback and invalidate caches before updating microcode to avoid
* internal issues depending on what the microcode is updating.
@@ -649,6 +670,29 @@ int __init save_microcode_in_initrd_intel(void)
return 0;
}
+static bool check_force_ucode_bsp(void)
+{
+ static const char *__force_ucode_str = "force_ucode_load";
+
+#ifdef CONFIG_X86_32
+ const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
+ const char *option = (const char *)__pa_nodebug(__force_ucode_str);
+ bool *res = (bool *)__pa_nodebug(&force_ucode_load);
+
+#else /* CONFIG_X86_64 */
+ const char *cmdline = boot_command_line;
+ const char *option = __force_ucode_str;
+ bool *res = &force_ucode_load;
+#endif
+
+ if (cmdline_find_option_bool(cmdline, option)) {
+ printk("cmdline forcing ucode update for same rev\n");
+ *res = true;
+ }
+
+ return *res;
+}
+
/*
* @res_patch, output: a pointer to the patch we found.
*/
@@ -682,6 +726,9 @@ void __init load_ucode_intel_bsp(void)
{
struct microcode_intel *patch;
struct ucode_cpu_info uci;
+ bool force_bsp;
+
+ force_bsp = check_force_ucode_bsp();
patch = __load_ucode_intel(&uci);
if (!patch)
@@ -730,8 +777,12 @@ static struct microcode_intel *find_patch(struct ucode_cpu_info *uci)
phdr = (struct microcode_header_intel *)iter->data;
- if (phdr->rev <= uci->cpu_sig.rev)
+ if (phdr->rev < uci->cpu_sig.rev)
continue;
+ if (phdr->rev == uci->cpu_sig.rev && !force_ucode_load)
+ continue;
+ else
+ printk ("same rev forcing ucode\n");
if (!find_matching_signature(phdr,
uci->cpu_sig.sig,
--
https://clearlinux.org