| Message ID | 20201210121110.10094-7-will@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tlb: Fix (soft-)dirty bit management clean up API | expand |
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
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. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Will Deacon <will@kernel.org> --- arch/x86/kernel/ldt.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)