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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-04-21 11:20:32 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-04-26 11:00:05 +0200 |
| commit | 2faf153bb7346b7dfc895f916edf93a86297ec0a (patch) | |
| tree | 763c31123cdf2cb76222cc28ffdb6c9df795f377 /arch/x86/mm/tlb.c | |
| parent | 9020d3956317d052cdddd43e55acdd2970344192 (diff) | |
| download | linux-2faf153bb7346b7dfc895f916edf93a86297ec0a.tar.bz2 | |
x86/tlb: Move __flush_tlb() out of line
cpu_tlbstate is exported because various TLB-related functions need
access to it, but cpu_tlbstate is sensitive information which should
only be accessed by well-contained kernel functions and not be directly
exposed to modules.
As a first step, move __flush_tlb() out of line and hide the native
function. The latter can be static when CONFIG_PARAVIRT is disabled.
Consolidate the namespace while at it and remove the pointless extra
wrapper in the paravirt code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200421092559.246130908@linutronix.de
Diffstat (limited to 'arch/x86/mm/tlb.c')
| -rw-r--r-- | arch/x86/mm/tlb.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 3d9d81951962..06116480c343 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -18,6 +18,13 @@ #include "mm_internal.h" +#ifdef CONFIG_PARAVIRT +# define STATIC_NOPV +#else +# define STATIC_NOPV static +# define __flush_tlb_local native_flush_tlb_local +#endif + /* * TLB flushing, formerly SMP-only * c/o Linus Torvalds. @@ -645,7 +652,7 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f, trace_tlb_flush(reason, nr_invalidate); } else { /* Full flush. */ - local_flush_tlb(); + flush_tlb_local(); if (local) count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); trace_tlb_flush(reason, TLB_FLUSH_ALL); @@ -884,6 +891,30 @@ unsigned long __get_current_cr3_fast(void) EXPORT_SYMBOL_GPL(__get_current_cr3_fast); /* + * Flush the entire current user mapping + */ +STATIC_NOPV void native_flush_tlb_local(void) +{ + /* + * Preemption or interrupts must be disabled to protect the access + * to the per CPU variable and to prevent being preempted between + * read_cr3() and write_cr3(). + */ + WARN_ON_ONCE(preemptible()); + + invalidate_user_asid(this_cpu_read(cpu_tlbstate.loaded_mm_asid)); + + /* If current->mm == NULL then the read_cr3() "borrows" an mm */ + native_write_cr3(__native_read_cr3()); +} + +void flush_tlb_local(void) +{ + __flush_tlb_local(); +} +EXPORT_SYMBOL_GPL(flush_tlb_local); + +/* * arch_tlbbatch_flush() performs a full TLB flush regardless of the active mm. * This means that the 'struct flush_tlb_info' that describes which mappings to * flush is actually fixed. We therefore set a single fixed struct and use it in |