Messages in this thread | | | Date | Tue, 22 Jul 2003 21:25:38 +0300 | From | Mika Penttilä <> | Subject | Re: pivot_root seems to be broken in 2.4.21-ac4 |
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Alan Cox wrote:
>On Maw, 2003-07-22 at 18:37, Jason Baron wrote: > > >>>I tell init to re-execute itself (after pivot_root and thus from the new >>>root fs), which causes init to close its old fds and open new ones from >>>the new root fs with. This is necessary because init already runs as pid >>>1 when I start the root fs switching. Maybe something changed with the >>>kernel process fds from 2.4.21-rc2 to 2.4.21-ac4 ? >>> >>> >>> >>yes, see the addition of the unshare_files function in kernel/fork.c >> >> > >Shouldnt really have changed anything except for security exploits and >threaded apps doing weird stuff. In normal situations the files count is >one so we should actually be executing nothing more exciting that an >atomic_inc/atomic_dec. > >I wonder what is going on here. > >- > > But kernel threads may be incrementing init's files->count before user space init execs, so unshare_files() after execve("/sbin/init") ends up copying files.
--Mika
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