Messages in this thread | | | Date | Fri, 16 Mar 2018 12:39:18 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH 5/8] trace_uprobe: Support SDT markers having reference count (semaphore) |
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On 03/16, Ravi Bangoria wrote: > > On 03/15/2018 08:00 PM, Oleg Nesterov wrote: > > Note to mention that sdt_find_vma() can return NULL but the callers do > > vma_offset_to_vaddr(vma) without any check. > > If the "mm" we are passing to sdt_find_vma() is returned by > uprobe_build_map_info(ref_ctr_offset), sdt_find_vma() must > _not_ return NULL.
Not at all.
Once build_map_info() returns any mapping can go away. Otherwise, why do you think the caller has to take ->mmap_sem and use find_vma()? If you were right, build_map_info() could just return the list of vma's instead of list of mm's.
Oleg.
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