From e7590a1b15c816db318d941eee24111798d655fd Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Wed, 31 May 2017 11:25:20 -0400 Subject: [PATCH] sparc64: reset mm cpumask after wrap [ Upstream commit 588974857359861891f478a070b1dc7ae04a3880 ] After a wrap (getting a new context version) a process must get a new context id, which means that we would need to flush the context id from the TLB before running for the first time with this ID on every CPU. But, we use mm_cpumask to determine if this process has been running on this CPU before, and this mask is not reset after a wrap. So, there are two possible fixes for this issue: 1. Clear mm cpumask whenever mm gets a new context id 2. Unconditionally flush context every time process is running on a CPU This patch implements the first solution Signed-off-by: Pavel Tatashin Reviewed-by: Bob Picco Reviewed-by: Steven Sistare Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- arch/sparc/mm/init_64.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index bd7e2aa86c45..f9c0eee9577d 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -710,6 +710,8 @@ void get_new_mmu_context(struct mm_struct *mm) goto out; } } + if (mm->context.sparc64_ctx_val) + cpumask_clear(mm_cpumask(mm)); mmu_context_bmap[new_ctx>>6] |= (1UL << (new_ctx & 63)); new_ctx |= (tlb_context_cache & CTX_VERSION_MASK); out: -- 2.11.0