On Mon, Apr 14, 2008 at 09:42:46PM +0200, Jan Kara wrote: > > Why would you want to? You can already set the filepointer explicitly > > to any value you want if you have the filehandle. > > > > If you had a file with some security checks for whether the user could > > read from it implemented based on locations then you would check it when > > you read/write not when you seek, since after all you could just keep > > reading until you get to the desired position. > Yes and no - for example if you manage to corrupt f_pos so that it > becomes negative, you have won because it is checked only in seek, pread, > pwrite, but not in read or write which rely on the check in seek... The only file that could possibly implement any such silly security based on position would be in /proc or /sys or similar, in which case whatever driver implements it can check the position during any read/write operation, and it would have to if it wants to implement such a silly security system. Any sane system would put the secured data in a seperate file from the unsecured data obviously. Trying to read from a negative position on a normal file should clearly fail, and if it doesn't then that is a seperate issue to fix and has nothing to do with the file position being set atomicly. -- Len Sorensen -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
