From: Peter Zijlstra peterz@infradead.org
[ Upstream commit 780e0106d468a2962b16b52fdf42898f2639e0a0 ]
Revert the following commit:
515ab7c41306: ("x86/mm: Align TLB invalidation info")
I found out (the hard way) 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.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: Linus Torvalds torvalds@linux-foundation.org Acked-by: Nadav Amit namit@vmware.com Cc: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@intel.com Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Fixes: 515ab7c41306 ("x86/mm: Align TLB invalidation info") Link: http://lkml.kernel.org/r/20190416080335.GM7905@worktop.programming.kicks-ass... [ Minor changelog edits. ] Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/mm/tlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index a6d1b0241aea..a6836ab0fcc7 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -694,7 +694,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, { int cpu;
- struct flush_tlb_info info __aligned(SMP_CACHE_BYTES) = { + struct flush_tlb_info info = { .mm = mm, };