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x86/tlb: Move __flush_tlb() out of line

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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
This commit is contained in:
Thomas Gleixner
2020-04-21 11:20:32 +02:00
committed by Borislav Petkov
parent 9020d39563
commit 2faf153bb7
7 changed files with 45 additions and 36 deletions
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29
arch/x86/include/asm/tlbflush.h
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@@ -140,12 +140,13 @@ static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid)
return __sme_pa(pgd) | kern_pcid(asid) | CR3_NOFLUSH;
}
void flush_tlb_local(void);
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else
#define __flush_tlb() __native_flush_tlb()
#define __flush_tlb_global() __native_flush_tlb_global()
#define __flush_tlb_one_user(addr) __native_flush_tlb_one_user(addr)
#define __flush_tlb_global() __native_flush_tlb_global()
#define __flush_tlb_one_user(addr) __native_flush_tlb_one_user(addr)
#endif
struct tlb_context {
@@ -370,24 +371,6 @@ static inline void invalidate_user_asid(u16 asid)
(unsigned long *)this_cpu_ptr(&cpu_tlbstate.user_pcid_flush_mask));
}
/*
* flush the entire current user mapping
*/
static inline void __native_flush_tlb(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());
}
/*
* flush everything
*/
@@ -461,7 +444,7 @@ static inline void __flush_tlb_all(void)
/*
* !PGE -> !PCID (setup_pcid()), thus every flush is total.
*/
__flush_tlb();
flush_tlb_local();
}
}
@@ -537,8 +520,6 @@ struct flush_tlb_info {
bool freed_tables;
};
#define local_flush_tlb() __flush_tlb()
#define flush_tlb_mm(mm) \
flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true)