On Thu, Apr 05, 2012 at 01:29:04PM -0700, Matt Helsley wrote: ... > > > Doesn't that break the semantics of the kernel ABI? > > > > Which one? exe_file can be changed iif there is no MAP_EXECUTABLE left. > > Still, once assigned (via this prctl) the mm_struct::exe_file can't be changed > > again, until program exit. > > The prctl() interface itself is fine as it stands now. > > As far as I can tell Konstantin is proposing that we remove the unusual > counter that tracks the number of mappings of the exe_file and require > userspace use the prctl() to drop the last reference. That's what I think > will break the ABI because after that change you *must* change userspace > code to use the prctl(). It's an ABI change because the same sequence of > system calls with the same input bits produces different behavior. Hi Matt, I see what you mean (I misread your email at first, sorry). Sure it's impossible to patch already existing programs (and btw, this prctl code actually won't help a program to drop symlink completely and live without it then, because old one will gone but new one will be assigned) so personally I can't answer here on Konstantin's behalf, but I guess the main question is -- which programs use this 'drop-all-MAP_EXECUTABLE' feature? Cyrill -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>