On 4/16/2019 8:50 PM, Thomas Gleixner wrote: > On Tue, 16 Apr 2019, Vlastimil Babka wrote: > >> On 4/16/19 4:22 PM, Qian Cai wrote: >>> store_stackinfo() does not seem used in actual SLAB debugging. >>> Potentially, it could be added to check_poison_obj() to provide more >>> information, but this seems like an overkill due to the declining >>> popularity of the SLAB, so just remove it instead. >>> >>> Signed-off-by: Qian Cai <cai@xxxxxx> >> >> I've acked Thomas' version already which was narrower, but no objection >> to remove more stuff on top of that. Linus (and I later in another >> thread) already pointed out /proc/slab_allocators. It only takes a look >> at add_caller() there to not regret removing that one. > > The issue why I was looking at this was a krobot complaint about the kernel > crashing in that stack store function with my stackguard series applied. It > was broken before the stackguard pages already, it just went unnoticed. > > As you explained, nobody is caring about DEBUG_SLAB + DEBUG_PAGEALLOC > anyway, so I'm happy to not care about krobot tripping over it either. > > So we have 3 options: > > 1) I ignore it and merge the stack guard series w/o it > > 2) I can carry the minimal fix or Qian's version in the stackguard > branch > > 3) We ship that minimal fix to Linus right now and then everyone can > base their stuff on top independently. I think #3 is overkill for something that was broken for who knows how long and nobody noticed. I'd go with 2) and perhaps Qian's version as nobody AFAIK uses the caller+cpu as well as the stack trace. For Qian's version also: Acked-by: Vlastimil Babka <vbabka@xxxxxxx> > #3 is probably the right thing to do. > > Thanks, > > tglx >
