From: Thomas Gleixner tglx@linutronix.de
mainline inclusion from mainline-v6.5-rc1 commit 7c7077a72674402654f3291354720cd73cdf649e category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7XLNT CVE: CVE-2022-40982
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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@linutronix.de Reviewed-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/r/20230613224545.019583869@linutronix.de Signed-off-by: Daniel Sneddon daniel.sneddon@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org conflict: arch/x86/kernel/cpu/bugs.c arch/x86/kernel/cpu/common.c Signed-off-by: Zeng Heng zengheng4@huawei.com --- arch/x86/Kconfig | 1 + arch/x86/include/asm/bugs.h | 2 -- arch/x86/kernel/cpu/bugs.c | 51 +--------------------------------- arch/x86/kernel/cpu/common.c | 53 ++++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/cpu.h | 1 + 5 files changed, 56 insertions(+), 52 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5bdf36c0d789..9eadce534c74 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -61,6 +61,7 @@ config X86 select ARCH_32BIT_OFF_T if X86_32 select ARCH_CLOCKSOURCE_INIT select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI + select ARCH_HAS_CPU_FINALIZE_INIT select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE select ARCH_HAS_DEVMEM_IS_ALLOWED diff --git a/arch/x86/include/asm/bugs.h b/arch/x86/include/asm/bugs.h index 92ae28389940..f25ca2d709d4 100644 --- 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) && defined(CONFIG_X86_32) int ppro_with_ram_bug(void); #else diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 812ac979c871..89b22439620c 100644 --- 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> @@ -27,8 +26,6 @@ #include <asm/msr.h> #include <asm/vmx.h> #include <asm/paravirt.h> -#include <asm/alternative.h> -#include <asm/set_memory.h> #include <asm/intel-family.h> #include <asm/e820/api.h> #include <asm/hypervisor.h> @@ -117,21 +114,8 @@ 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 @@ -160,39 +144,6 @@ void __init check_bugs(void) md_clear_select_mitigation(); srbds_select_mitigation(); gds_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 }
/* diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index abba125765e4..cb5dd020ee24 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -19,10 +19,13 @@ #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 <linux/pgtable.h> +#include <linux/utsname.h>
+#include <asm/alternative.h> #include <asm/cmdline.h> #include <asm/stackprotector.h> #include <asm/perf_event.h> @@ -59,6 +62,7 @@ #include <asm/cpu_device_id.h> #include <asm/uv/uv.h> #include <asm/sigframe.h> +#include <asm/set_memory.h>
#include "cpu.h"
@@ -2202,3 +2206,52 @@ void arch_smt_update(void) /* Check whether IPI broadcasting can be enabled */ apic_smt_update(); } + +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(); + } +} diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index 4e1da316879a..66e19380a899 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -78,6 +78,7 @@ extern void detect_ht(struct cpuinfo_x86 *c); extern void check_null_seg_clears_base(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);