[PATCH] x86/tlb: Revert: Align TLB invalidation info

From: Peter Zijlstra
Date: Tue Apr 16 2019 - 04:03:54 EST



It was found that under some .config options (notably L1_CACHE_SHIFT=7)
and compiler combinations this on-stack alignment leads to a 320 byte
stack usage, which then triggers a KASAN stack warning elsewhere.

Using 320 bytes of stack space for a 40 byte structure is ludicrous and
clearly not right.

Fixes: 515ab7c41306 ("x86/mm: Align TLB invalidation info")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
Index: linux-2.6/arch/x86/mm/tlb.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/tlb.c
+++ linux-2.6/arch/x86/mm/tlb.c
@@ -728,7 +728,7 @@ void flush_tlb_mm_range(struct mm_struct
{
int cpu;

- struct flush_tlb_info info __aligned(SMP_CACHE_BYTES) = {
+ struct flush_tlb_info info = {
.mm = mm,
.stride_shift = stride_shift,
.freed_tables = freed_tables,