From 24e2c32c847ab496bd79d417265534ff3da7b009 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Mon, 28 Aug 2006 00:40:40 -0700 Subject: [PATCH] SPARC64: Fix X server crashes on sparc64 [SPARC64]: Fix X server hangs due to large pages. This problem was introduced by changeset 14778d9072e53d2171f66ffd9657daff41acfaed Unlike the hugetlb code paths, the normal fault code is not setup to propagate PTE changes for large page sizes correctly like the ones we make for I/O mappings in io_remap_pfn_range(). It is absolutely necessary to update all sub-ptes of a largepage mapping on a fault. Adding special handling for this would add considerably complexity to tlb_batch_add(). So let's just side-step the issue and forcefully dirty any writable PTEs created by io_remap_pfn_range(). The only other real option would be to disable to large PTE code of io_remap_pfn_range() and we really don't want to do that. Much thanks to Mikael Pettersson for tracking down this problem and testing debug patches. Signed-off-by: David S. Miller --- arch/sparc64/mm/generic.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/sparc64/mm/generic.c b/arch/sparc64/mm/generic.c index 8cb06205d265..af9d81db0b38 100644 --- a/arch/sparc64/mm/generic.c +++ b/arch/sparc64/mm/generic.c @@ -69,6 +69,8 @@ static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte, } else offset += PAGE_SIZE; + if (pte_write(entry)) + entry = pte_mkdirty(entry); do { BUG_ON(!pte_none(*pte)); set_pte_at(mm, address, pte, entry);