On Mon, 2007-09-10 at 15:49 +0800, Andrew Morton wrote: > On Mon, 20 Aug 2007 23:50:05 +0800 Zhang Rui <rui.zhang@xxxxxxxxx> > wrote: > > > Hi, Oliver, > > Thanks for your comments, > > > > On Mon, 2007-08-20 at 18:45 +0800, Oliver Neukum wrote: > > > Am Montag 20 August 2007 schrieb Zhang Rui: > > > > Files name must be unique in the same directory. > > > > > > > > Bug is reported here: > > > > http://bugzilla.kernel.org/show_bug.cgi?id=8798 > > > > > > Then I'd say fix the callers. > > But at least the callers need to be told that something is wrong > first. > > > > > This will paper over bugs. > > Hmm, what kind of bugs? > > callers always need to check the return value when calling > > proc_mkdir/create_proc_entry, don't they? > > > > Yes, but there's some risk that such a change will cause a > presently-working system to stop working. It's quite likely, if that > system is checking the procfs-creation return value. Yes, that's true. I checked several systems and didn't find any similar problems. I think this situation is rare. Besides, duplicate names are totally unusable for user space. We should fix this kind of bugs ASAP if there are any. > So I think it'd be best if we were to detect the duplication and print > a > warning (which should include, if possible, the full pathname and a > dump_stack()) and then the code should proceed as normal: permit the > duplicated entry and return success. > Then, when such duplicates are reported, we can work out what to do > about > them on a case-by-case basis. Please review the patch below. :) dump_stack is enough to debug the problem, so only the current duplicate file names are printed out instead of the full pathname. From: Zhang Rui <rui.zhang@xxxxxxxxx> File name should be unique in the same directory. In order to keep the back-compatibility, only a warning is given currently, but actions must be taken to fix it when such duplicates are detected. Bug report and a simple fix can be found here: http://bugzilla.kernel.org/show_bug.cgi?id=8798 Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> --- fs/proc/generic.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) Index: linux-2.6/fs/proc/generic.c =================================================================== --- linux-2.6.orig/fs/proc/generic.c +++ linux-2.6/fs/proc/generic.c @@ -523,6 +523,7 @@ static const struct inode_operations pro static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp) { + struct proc_dir_entry *tmp = NULL; unsigned int i; i = get_inode_number(); @@ -547,11 +548,22 @@ static int proc_register(struct proc_dir } spin_lock(&proc_subdir_lock); + + for (tmp = dir->subdir, i = 0; tmp && !i; tmp = tmp->next) + if (!strcmp(dp->name, tmp->name)) + i = 1; + dp->next = dir->subdir; dp->parent = dir; dir->subdir = dp; spin_unlock(&proc_subdir_lock); + if (i) { + printk(KERN_WARNING + "Duplicate file names \"%s\" detected.", dp->name); + dump_stack(); + } + return 0; } - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
