This is a note to let you know that I've just added the patch titled
x86/cpu: Switch to arch_cpu_finalize_init()
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-cpu-switch-to-arch_cpu_finalize_init.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b3454eb2d26a6cecada04b38e72e255ae702ccdb Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Wed, 14 Jun 2023 01:39:24 +0200
Subject: x86/cpu: Switch to arch_cpu_finalize_init()
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
commit 7c7077a72674402654f3291354720cd73cdf649e upstream
check_bugs() is a dumping ground for finalizing the CPU bringup. Only parts of
it has to do with actual CPU bugs.
Split it apart into arch_cpu_finalize_init() and cpu_select_mitigations().
Fixup the bogus 32bit comments while at it.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230613224545.019583869@xxxxxxxxxxxxx
Signed-off-by: Daniel Sneddon <daniel.sneddon@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 1
arch/x86/include/asm/bugs.h | 2 -
arch/x86/kernel/cpu/bugs.c | 51 ---------------------------------------
arch/x86/kernel/cpu/common.c | 55 +++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/cpu.h | 1
5 files changed, 58 insertions(+), 52 deletions(-)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -47,6 +47,7 @@ config X86
select ARCH_CLOCKSOURCE_DATA
select ARCH_DISCARD_MEMBLOCK
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
+ select ARCH_HAS_CPU_FINALIZE_INIT
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
--- a/arch/x86/include/asm/bugs.h
+++ b/arch/x86/include/asm/bugs.h
@@ -4,8 +4,6 @@
#include <asm/processor.h>
-extern void check_bugs(void);
-
#if defined(CONFIG_CPU_SUP_INTEL)
void check_mpx_erratum(struct cpuinfo_x86 *c);
#else
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -9,7 +9,6 @@
* - Andrew D. Balsa (code cleanup).
*/
#include <linux/init.h>
-#include <linux/utsname.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/nospec.h>
@@ -25,10 +24,8 @@
#include <asm/msr.h>
#include <asm/vmx.h>
#include <asm/paravirt.h>
-#include <asm/alternative.h>
#include <asm/hypervisor.h>
#include <asm/pgtable.h>
-#include <asm/set_memory.h>
#include <asm/intel-family.h>
#include <asm/e820/api.h>
#include <linux/bpf.h>
@@ -115,21 +112,8 @@ EXPORT_SYMBOL_GPL(mds_idle_clear);
DEFINE_STATIC_KEY_FALSE(mmio_stale_data_clear);
EXPORT_SYMBOL_GPL(mmio_stale_data_clear);
-void __init check_bugs(void)
+void __init cpu_select_mitigations(void)
{
- identify_boot_cpu();
-
- /*
- * identify_boot_cpu() initialized SMT support information, let the
- * core code know.
- */
- cpu_smt_check_topology();
-
- if (!IS_ENABLED(CONFIG_SMP)) {
- pr_info("CPU: ");
- print_cpu_info(&boot_cpu_data);
- }
-
/*
* Read the SPEC_CTRL MSR to account for reserved bits which may
* have unknown values. AMD64_LS_CFG MSR is cached in the early AMD
@@ -165,39 +149,6 @@ void __init check_bugs(void)
l1tf_select_mitigation();
md_clear_select_mitigation();
srbds_select_mitigation();
-
- arch_smt_update();
-
-#ifdef CONFIG_X86_32
- /*
- * Check whether we are able to run this kernel safely on SMP.
- *
- * - i386 is no longer supported.
- * - In order to run on anything without a TSC, we need to be
- * compiled for a i486.
- */
- if (boot_cpu_data.x86 < 4)
- panic("Kernel requires i486+ for 'invlpg' and other features");
-
- init_utsname()->machine[1] =
- '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
- alternative_instructions();
-
- fpu__init_check_bugs();
-#else /* CONFIG_X86_64 */
- alternative_instructions();
-
- /*
- * Make sure the first 2MB area is not mapped by huge pages
- * There are typically fixed size MTRRs in there and overlapping
- * MTRRs into large pages causes slow downs.
- *
- * Right now we don't do that with gbpages because there seems
- * very little benefit for that case.
- */
- if (!direct_gbpages)
- set_memory_4k((unsigned long)__va(0), 1);
-#endif
}
/*
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -10,14 +10,19 @@
#include <linux/sched/mm.h>
#include <linux/sched/clock.h>
#include <linux/sched/task.h>
+#include <linux/sched/smt.h>
#include <linux/init.h>
#include <linux/kprobes.h>
#include <linux/kgdb.h>
#include <linux/smp.h>
+#include <linux/cpu.h>
#include <linux/io.h>
#include <linux/syscore_ops.h>
#include <asm/stackprotector.h>
+#include <linux/utsname.h>
+
+#include <asm/alternative.h>
#include <asm/perf_event.h>
#include <asm/mmu_context.h>
#include <asm/archrandom.h>
@@ -53,6 +58,7 @@
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/uv/uv.h>
#endif
+#include <asm/set_memory.h>
#include "cpu.h"
@@ -1995,3 +2001,52 @@ void microcode_check(void)
pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
pr_warn("x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
}
+
+void __init arch_cpu_finalize_init(void)
+{
+ identify_boot_cpu();
+
+ /*
+ * identify_boot_cpu() initialized SMT support information, let the
+ * core code know.
+ */
+ cpu_smt_check_topology();
+
+ if (!IS_ENABLED(CONFIG_SMP)) {
+ pr_info("CPU: ");
+ print_cpu_info(&boot_cpu_data);
+ }
+
+ cpu_select_mitigations();
+
+ arch_smt_update();
+
+ if (IS_ENABLED(CONFIG_X86_32)) {
+ /*
+ * Check whether this is a real i386 which is not longer
+ * supported and fixup the utsname.
+ */
+ if (boot_cpu_data.x86 < 4)
+ panic("Kernel requires i486+ for 'invlpg' and other features");
+
+ init_utsname()->machine[1] =
+ '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
+ }
+
+ alternative_instructions();
+
+ if (IS_ENABLED(CONFIG_X86_64)) {
+ /*
+ * Make sure the first 2MB area is not mapped by huge pages
+ * There are typically fixed size MTRRs in there and overlapping
+ * MTRRs into large pages causes slow downs.
+ *
+ * Right now we don't do that with gbpages because there seems
+ * very little benefit for that case.
+ */
+ if (!direct_gbpages)
+ set_memory_4k((unsigned long)__va(0), 1);
+ } else {
+ fpu__init_check_bugs();
+ }
+}
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -67,6 +67,7 @@ extern int detect_extended_topology_earl
extern int detect_ht_early(struct cpuinfo_x86 *c);
unsigned int aperfmperf_get_khz(int cpu);
+void cpu_select_mitigations(void);
extern void x86_spec_ctrl_setup_ap(void);
extern void update_srbds_msr(void);
Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are
queue-4.14/x86-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/arm-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/um-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/mips-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/init-x86-move-mem_encrypt_init-into-arch_cpu_finalize_init.patch
queue-4.14/sh-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/init-invoke-arch_cpu_finalize_init-earlier.patch
queue-4.14/x86-xen-fix-secondary-processors-fpu-initialization.patch
queue-4.14/x86-fpu-move-fpu-initialization-into-arch_cpu_finalize_init.patch
queue-4.14/init-remove-check_bugs-leftovers.patch
queue-4.14/init-provide-arch_cpu_finalize_init.patch
queue-4.14/m68k-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/sparc-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/x86-fpu-mark-init-functions-__init.patch
queue-4.14/ia64-cpu-switch-to-arch_cpu_finalize_init.patch
queue-4.14/x86-fpu-remove-cpuinfo-argument-from-init-functions.patch
