diff options
| author | Will Deacon <will@kernel.org> | 2021-01-27 23:53:47 +0000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-01-29 20:02:29 +0100 |
| commit | 8cf55f24ce6cf90eb8828421e15e9efcd508bd2c (patch) | |
| tree | b56b879d2eaf1356eea82db964751a985d36951f | |
| parent | c7bd8010a335260927e3643e79360272f9aca266 (diff) | |
x86/ldt: Use tlb_gather_mmu_fullmm() when freeing LDT page-tables
free_ldt_pgtables() uses the MMU gather API for batching TLB flushes
over the call to free_pgd_range(). However, tlb_gather_mmu() expects
to operate on user addresses and so passing LDT_{BASE,END}_ADDR will
confuse the range setting logic in __tlb_adjust_range(), causing the
gather to identify a range starting at TASK_SIZE. Such a large range
will be converted into a 'fullmm' flush by the low-level invalidation
code, so change the caller to invoke tlb_gather_mmu_fullmm() directly.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20210127235347.1402-7-will@kernel.org
| -rw-r--r-- | arch/x86/kernel/ldt.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index 7ad9834e0d95..aa15132228da 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -398,7 +398,13 @@ static void free_ldt_pgtables(struct mm_struct *mm) if (!boot_cpu_has(X86_FEATURE_PTI)) return; - tlb_gather_mmu(&tlb, mm); + /* + * Although free_pgd_range() is intended for freeing user + * page-tables, it also works out for kernel mappings on x86. + * We use tlb_gather_mmu_fullmm() to avoid confusing the + * range-tracking logic in __tlb_adjust_range(). + */ + tlb_gather_mmu_fullmm(&tlb, mm); free_pgd_range(&tlb, start, end, start, end); tlb_finish_mmu(&tlb); #endif |