Messages in this thread | | | Date | Thu, 8 May 2014 10:26:46 +0100 | From | Catalin Marinas <> | Subject | Re: [BUG] kmemleak on __radix_tree_preload |
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On Thu, May 08, 2014 at 06:16:51PM +0900, Jaegeuk Kim wrote: > 2014-05-07 (수), 12:39 +0100, Catalin Marinas: > > On Wed, May 07, 2014 at 03:58:08AM +0100, Jaegeuk Kim wrote: > > > unreferenced object 0xffff880004226da0 (size 576): > > > comm "fsstress", pid 14590, jiffies 4295191259 (age 706.308s) > > > hex dump (first 32 bytes): > > > 01 00 00 00 81 ff ff ff 00 00 00 00 00 00 00 00 ................ > > > 50 89 34 81 ff ff ff ff b8 6d 22 04 00 88 ff ff P.4......m"..... > > > backtrace: > > > [<ffffffff816c02e8>] kmemleak_update_trace+0x58/0x80 > > > [<ffffffff81349517>] radix_tree_node_alloc+0x77/0xa0 > > > [<ffffffff81349718>] __radix_tree_create+0x1d8/0x230 > > > [<ffffffff8113286c>] __add_to_page_cache_locked+0x9c/0x1b0 > > > [<ffffffff811329a8>] add_to_page_cache_lru+0x28/0x80 > > > [<ffffffff81132f58>] grab_cache_page_write_begin+0x98/0xf0 > > > [<ffffffffa02e4bf4>] f2fs_write_begin+0xb4/0x3c0 [f2fs] > > > [<ffffffff81131b77>] generic_perform_write+0xc7/0x1c0 > > > [<ffffffff81133b7d>] __generic_file_aio_write+0x1cd/0x3f0 > > > [<ffffffff81133dfe>] generic_file_aio_write+0x5e/0xe0 > > > [<ffffffff81195c5a>] do_sync_write+0x5a/0x90 > > > [<ffffffff811968d2>] vfs_write+0xc2/0x1d0 > > > [<ffffffff81196daf>] SyS_write+0x4f/0xb0 > > > [<ffffffff816dead2>] system_call_fastpath+0x16/0x1b > > > [<ffffffffffffffff>] 0xffffffffffffffff > > > > OK, it shows that the allocation happens via add_to_page_cache_locked() > > and I guess it's page_cache_tree_insert() which calls > > __radix_tree_create() (the latter reusing the preloaded node). I'm not > > familiar enough to this code (radix-tree.c and filemap.c) to tell where > > the node should have been freed, who keeps track of it. > > > > At a quick look at the hex dump (assuming that the above leak is struct > > radix_tree_node): > > > > .path = 1 > > .count = -0x7f (or 0xffffff81 as unsigned int) > > union { > > { > > .parent = NULL > > .private_data = 0xffffffff81348950 > > } > > { > > .rcu_head.next = NULL > > .rcu_head.func = 0xffffffff81348950 > > } > > } > > > > The count is a bit suspicious. > > > > From the union, it looks most likely like rcu_head information. Is > > radix_tree_node_rcu_free() function at the above rcu_head.func?
Thanks for the config. Could you please confirm that 0xffffffff81348950 address corresponds to the radix_tree_node_rcu_free() function in your System.map (or something else)?
> > Also, if you run echo scan > /sys/kernel/debug/kmemleak a few times, do > > any of the above leaks disappear (in case the above are some transient > > rcu freeing reports; normally this shouldn't happen as the objects are > > still referred but I'll look at the relevant code once I have your > > .config). > > Once I run the echo, the leaks are still remained.
OK, so they aren't just transient.
Thanks.
-- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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