Messages in this thread |  | | Subject | Re: [BUG] mm: truncate: a possible sleep-in-atomic-context bug in truncate_exceptional_pvec_entries() | From | Jia-Ju Bai <> | Date | Mon, 13 Aug 2018 17:30:55 +0800 |
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On 2018/8/13 16:56, Jan Kara wrote: > Hi, > > On Mon 13-08-18 11:10:23, Jia-Ju Bai wrote: >> The kernel may sleep with holding a spinlock. >> >> The function call paths (from bottom to top) in Linux-4.16 are: >> >> [FUNC] schedule >> fs/dax.c, 259: schedule in get_unlocked_mapping_entry >> fs/dax.c, 450: get_unlocked_mapping_entry in __dax_invalidate_mapping_entry >> fs/dax.c, 471: __dax_invalidate_mapping_entry in dax_delete_mapping_entry >> mm/truncate.c, 97: dax_delete_mapping_entry in >> truncate_exceptional_pvec_entries >> mm/truncate.c, 82: spin_lock_irq in truncate_exceptional_pvec_entries >> >> I do not find a good way to fix, so I only report. >> This is found by my static analysis tool (DSAC). > Thanks for report but this is a false positive. Note that the lock is > acquired only if we are not operating on DAX mapping but we can get to > dax_delete_mapping_entry() only if we are operating on DAX mapping.
Thanks for your reply :) My tool does not well check the path condition here... Sorry for this false report.
Best wishes, Jia-Ju Bai
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