Re: [PATCH] slab: fix a crash by reading /proc/slab_allocators
From: Christopher Lameter
Date: Mon Apr 08 2019 - 11:15:16 EST
On Sun, 7 Apr 2019, Linus Torvalds wrote:
> On Sat, Apr 6, 2019 at 12:59 PM Qian Cai <cai@xxxxxx> wrote:
> > The commit 510ded33e075 ("slab: implement slab_root_caches list")
> > changes the name of the list node within "struct kmem_cache" from
> > "list" to "root_caches_node", but leaks_show() still use the "list"
> > which causes a crash when reading /proc/slab_allocators.
> The patch does seem to be correct, and I have applied it.
> However, it does strike me that apparently this wasn't caught for two
> years. Which makes me wonder whether we should (once again) discuss
> just removing SLAB entirely, or at least removing the
> /proc/slab_allocators file. Apparently it has never been used in the
> last two years. At some point a "this can't have worked if anybody
> ever tried to use it" situation means that the code should likely be
This is only occurring with specially build kernels so that memory leaks
can be investigated. The same is done with other tools (kasan and friends)
today I guess and also the SLUB debugging tools are much more user
friendly. So this means that some esoteric debugging feature of SLAB was