Messages in this thread | | | Date | Mon, 16 Mar 2009 08:34:57 +0000 | From | Al Viro <> | Subject | Re: [PATCH] filp->f_pos not correctly updated in proc_task_readdir |
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On Mon, Mar 16, 2009 at 02:44:31PM +0800, Zhang Le wrote: > filp->f_pos only get updated at the end of the function. Thus d_off of those > dirents who are in the middle will be 0, and this will cause a problem in > glibc's readdir implementation, specifically endless loop. Because when overflow > occurs, f_pos will be set to next dirent to read, however it will be 0, unless > the next one is the last one. So it will start over again and again.
Eh... Here's what's really going on:
proc_..._fill_cache() API is rather kludgy and far too convoluted. In particular, it calls filldir() and passes file->f_pos to it, expecting the caller to update file->f_pos between the calls. proc_task_readdir() uses that sucker, but doesn't update ->f_pos until the very end. As the result, d_off of direntries produced by it gets screwed. Broken-by: commit 61a28784028e6d55755e4d0f39bee8d9bf2ee8d9 Author: Eric W. Biederman <ebiederm@xmission.com> Date: Mon Oct 2 02:18:49 2006 -0700
[PATCH] proc: Remove the hard coded inode numbers
Patch is fine, but I'd rather rip the layers of ..._fill_cache() abstractions out and see what falls out. Anyway, for -rc your variant is definitely the way to go.
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