From ccdd57f8985d51700e222c0fbe6de3517fa6d7e6 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 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 Orabug: 25999953 Signed-off-by: Pavel Tatashin Reviewed-by: Bob Picco Reviewed-by: Steven Sistare Signed-off-by: David S. Miller (cherry picked from commit 588974857359861891f478a070b1dc7ae04a3880) Signed-off-by: Pavel Tatashin Reviewed-by: Steven Sistare Signed-off-by: Allen Pais --- 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 0e42c840cb32..c29074e31236 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -903,6 +903,8 @@ 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: -- 2.50.1