From: Nick Piggin Date: Fri, 6 Jun 2008 05:45:57 +0000 (-0700) Subject: hugetlb: fix lockdep error X-Git-Tag: v2.6.26-rc6~86 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4647875819aa210115d926242aa18e034517cece;p=linux-2.6 hugetlb: fix lockdep error ============================================= [ INFO: possible recursive locking detected ] 2.6.26-rc4 #30 --------------------------------------------- heap-overflow/2250 is trying to acquire lock: (&mm->page_table_lock){--..}, at: [] .copy_hugetlb_page_range+0x108/0x280 but task is already holding lock: (&mm->page_table_lock){--..}, at: [] .copy_hugetlb_page_range+0xfc/0x280 other info that might help us debug this: 3 locks held by heap-overflow/2250: #0: (&mm->mmap_sem){----}, at: [] .dup_mm+0x134/0x410 #1: (&mm->mmap_sem/1){--..}, at: [] .dup_mm+0x144/0x410 #2: (&mm->page_table_lock){--..}, at: [] .copy_hugetlb_page_range+0xfc/0x280 stack backtrace: Call Trace: [c00000003b2774e0] [c000000000010ce4] .show_stack+0x74/0x1f0 (unreliable) [c00000003b2775a0] [c0000000003f10e0] .dump_stack+0x20/0x34 [c00000003b277620] [c0000000000889bc] .__lock_acquire+0xaac/0x1080 [c00000003b277740] [c000000000089000] .lock_acquire+0x70/0xb0 [c00000003b2777d0] [c0000000003ee15c] ._spin_lock+0x4c/0x80 [c00000003b277870] [c0000000000cf2e8] .copy_hugetlb_page_range+0x108/0x280 [c00000003b277950] [c0000000000bcaa8] .copy_page_range+0x558/0x790 [c00000003b277ac0] [c000000000050fe0] .dup_mm+0x2d0/0x410 [c00000003b277ba0] [c000000000051d24] .copy_process+0xb94/0x1020 [c00000003b277ca0] [c000000000052244] .do_fork+0x94/0x310 [c00000003b277db0] [c000000000011240] .sys_clone+0x60/0x80 [c00000003b277e30] [c0000000000078c4] .ppc_clone+0x8/0xc Fix is the same way that mm/memory.c copy_page_range does the lockdep annotation. Acked-by: KOSAKI Motohiro Acked-by: Adam Litke Acked-by: Nishanth Aravamudan Signed-off-by: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/hugetlb.c b/mm/hugetlb.c index bbf953eeb5..ab171274ef 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -785,7 +785,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, continue; spin_lock(&dst->page_table_lock); - spin_lock(&src->page_table_lock); + spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); if (!huge_pte_none(huge_ptep_get(src_pte))) { if (cow) huge_ptep_set_wrprotect(src, addr, src_pte);