[PATCH AUTOSEL 5.1 45/51] arm64: tlbflush: Ensure start/end of address range are aligned to stride

Sasha Levin
2019-06-26T03:49:59Z

From: Will Deacon <will.deacon@arm.com>

[ Upstream commit 01d57485fcdb9f9101a10a18e32d5f8b023cab86 ]

Since commit 3d65b6bbc01e ("arm64: tlbi: Set MAX_TLBI_OPS to
PTRS_PER_PTE"), we resort to per-ASID invalidation when attempting to
perform more than PTRS_PER_PTE invalidation instructions in a single
call to __flush_tlb_range(). Whilst this is beneficial, the mmu_gather
code does not ensure that the end address of the range is rounded-up
to the stride when freeing intermediate page tables in pXX_free_tlb(),
which defeats our range checking.

Align the bounds passed into __flush_tlb_range().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reported-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/include/asm/tlbflush.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index 3a1870228946..dff8f9ea5754 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -195,6 +195,9 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
unsigned long asid = ASID(vma->vm_mm);
unsigned long addr;

+ start = round_down(start, stride);
+ end = round_up(end, stride);
+
if ((end - start) >= (MAX_TLBI_OPS * stride)) {
flush_tlb_mm(vma->vm_mm);
return;
--
2.20.1