Messages in this thread | | | Date | Sat, 23 Aug 2014 15:30:01 +0200 | From | Oleg Nesterov <> | Subject | Re: + prctl-pr_set_mm-introduce-pr_set_mm_map-operation-v3.patch added to -mm tree |
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forgot to mention,
On 08/23, Oleg Nesterov wrote: > > On 08/23, Cyrill Gorcunov wrote: > > > Looks like I need > > to use cred_guard_mutex instead of task_lock here, no? > > Please don't. First of all, it can't help because proc_pid_auxv() doesn't hold > this lock. It does mm_access() which drops this lock after return. And to remind, > we are going to remove mm_access/lock_trace from sys_read() paths in proc.
Besides, it can't help anyway. cred_guard_mutex is per-process (not per-thread), suppose that a vfork()'ed child does prctl() while another thread reads the parent's /proc/pid/auxv.
Cyrill, I am sorry, but I am starting to think that this patch should be dropped and replaced by another version. Or do you think it would be better to send the fixes on top?
Oleg.
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