The following commit has been merged into the x86/mm branch of tip: Commit-ID: bfe3d8f6313d1e10806062ba22c5f660dddecbcc Gitweb: https://git.kernel.org/tip/bfe3d8f6313d1e10806062ba22c5f660dddecbcc Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Tue, 21 Apr 2020 11:20:43 +02:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Sun, 26 Apr 2020 18:52:33 +02:00 x86/tlb: Restrict access to tlbstate Hide tlbstate, flush_tlb_info and related helpers when tlbflush.h is included from a module. Modules have absolutely no business with these internals. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200421092600.328438734@xxxxxxxxxxxxx --- arch/x86/include/asm/tlbflush.h | 96 ++++++++++++++++---------------- arch/x86/mm/init.c | 1 +- 2 files changed, 49 insertions(+), 48 deletions(-) diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index f973121..8c87a2e 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -13,19 +13,46 @@ #include <asm/pti.h> #include <asm/processor-flags.h> -struct flush_tlb_info; - void __flush_tlb_all(void); -void flush_tlb_local(void); -void flush_tlb_one_user(unsigned long addr); -void flush_tlb_one_kernel(unsigned long addr); -void flush_tlb_others(const struct cpumask *cpumask, - const struct flush_tlb_info *info); -#ifdef CONFIG_PARAVIRT -#include <asm/paravirt.h> -#endif +#define TLB_FLUSH_ALL -1UL + +void cr4_update_irqsoff(unsigned long set, unsigned long clear); +unsigned long cr4_read_shadow(void); + +/* Set in this cpu's CR4. */ +static inline void cr4_set_bits_irqsoff(unsigned long mask) +{ + cr4_update_irqsoff(mask, 0); +} +/* Clear in this cpu's CR4. */ +static inline void cr4_clear_bits_irqsoff(unsigned long mask) +{ + cr4_update_irqsoff(0, mask); +} + +/* Set in this cpu's CR4. */ +static inline void cr4_set_bits(unsigned long mask) +{ + unsigned long flags; + + local_irq_save(flags); + cr4_set_bits_irqsoff(mask); + local_irq_restore(flags); +} + +/* Clear in this cpu's CR4. */ +static inline void cr4_clear_bits(unsigned long mask) +{ + unsigned long flags; + + local_irq_save(flags); + cr4_clear_bits_irqsoff(mask); + local_irq_restore(flags); +} + +#ifndef MODULE /* * 6 because 6 should be plenty and struct tlb_state will fit in two cache * lines. @@ -129,54 +156,17 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate); bool nmi_uaccess_okay(void); #define nmi_uaccess_okay nmi_uaccess_okay -void cr4_update_irqsoff(unsigned long set, unsigned long clear); -unsigned long cr4_read_shadow(void); - /* Initialize cr4 shadow for this CPU. */ static inline void cr4_init_shadow(void) { this_cpu_write(cpu_tlbstate.cr4, __read_cr4()); } -/* Set in this cpu's CR4. */ -static inline void cr4_set_bits_irqsoff(unsigned long mask) -{ - cr4_update_irqsoff(mask, 0); -} - -/* Clear in this cpu's CR4. */ -static inline void cr4_clear_bits_irqsoff(unsigned long mask) -{ - cr4_update_irqsoff(0, mask); -} - -/* Set in this cpu's CR4. */ -static inline void cr4_set_bits(unsigned long mask) -{ - unsigned long flags; - - local_irq_save(flags); - cr4_set_bits_irqsoff(mask); - local_irq_restore(flags); -} - -/* Clear in this cpu's CR4. */ -static inline void cr4_clear_bits(unsigned long mask) -{ - unsigned long flags; - - local_irq_save(flags); - cr4_clear_bits_irqsoff(mask); - local_irq_restore(flags); -} - extern unsigned long mmu_cr4_features; extern u32 *trampoline_cr4_features; extern void initialize_tlbstate_and_flush(void); -#define TLB_FLUSH_ALL -1UL - /* * TLB flushing: * @@ -215,6 +205,16 @@ struct flush_tlb_info { bool freed_tables; }; +void flush_tlb_local(void); +void flush_tlb_one_user(unsigned long addr); +void flush_tlb_one_kernel(unsigned long addr); +void flush_tlb_others(const struct cpumask *cpumask, + const struct flush_tlb_info *info); + +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#endif + #define flush_tlb_mm(mm) \ flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true) @@ -255,4 +255,6 @@ static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch, extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch); +#endif /* !MODULE */ + #endif /* _ASM_X86_TLBFLUSH_H */ diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index d37e816..248dc8f 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -992,7 +992,6 @@ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate) = { .next_asid = 1, .cr4 = ~0UL, /* fail hard if we screw up cr4 shadow initialization */ }; -EXPORT_PER_CPU_SYMBOL(cpu_tlbstate); void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache) {
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