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authorDan Williams <dan.j.williams@intel.com>2018-12-04 22:37:21 +0100
committerIngo Molnar <mingo@kernel.org>2018-12-05 09:03:06 +0100
commit0a9fe8ca844d43f3f547f0e166122b6048121c8f (patch)
tree2560d196ef1166c200d2be0a6509a9098b005a66 /include/asm-generic/pgtable-nop4d-hack.h
parentgeneric/pgtable: Introduce set_pte_safe() (diff)
downloadlinux-0a9fe8ca844d43f3f547f0e166122b6048121c8f.tar.xz
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x86/mm: Validate kernel_physical_mapping_init() PTE population
The usage of __flush_tlb_all() in the kernel_physical_mapping_init() path is not necessary. In general flushing the TLB is not required when updating an entry from the !present state. However, to give confidence in the future removal of TLB flushing in this path, use the new set_pte_safe() family of helpers to assert that the !present assumption is true in this path. [ mingo: Minor readability edits. ] Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/154395944177.32119.8524957429632012270.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/asm-generic/pgtable-nop4d-hack.h')
-rw-r--r--include/asm-generic/pgtable-nop4d-hack.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/asm-generic/pgtable-nop4d-hack.h b/include/asm-generic/pgtable-nop4d-hack.h
index 1d6dd38c0e5e..829bdb0d6327 100644
--- a/include/asm-generic/pgtable-nop4d-hack.h
+++ b/include/asm-generic/pgtable-nop4d-hack.h
@@ -31,6 +31,7 @@ static inline void pgd_clear(pgd_t *pgd) { }
#define pud_ERROR(pud) (pgd_ERROR((pud).pgd))
#define pgd_populate(mm, pgd, pud) do { } while (0)
+#define pgd_populate_safe(mm, pgd, pud) do { } while (0)
/*
* (puds are folded into pgds so this doesn't get actually called,
* but the define is needed for a generic inline function.)