Messages in this thread | | | Date | Thu, 3 Jun 2021 15:15:24 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH v3 4/4] slub: Force on no_hash_pointers when slub_debug is enabled |
| |
On Tue 2021-06-01 11:22:02, Stephen Boyd wrote: > Obscuring the pointers that slub shows when debugging makes for some > confusing slub debug messages: > > Padding overwritten. 0x0000000079f0674a-0x000000000d4dce17 > > Those addresses are hashed for kernel security reasons. If we're trying > to be secure with slub_debug on the commandline we have some big > problems given that we dump whole chunks of kernel memory to the kernel > logs. Let's force on the no_hash_pointers commandline flag when > slub_debug is on the commandline. This makes slub debug messages more > meaningful and if by chance a kernel address is in some slub debug > object dump we will have a better chance of figuring out what went > wrong. > > Note that we don't use %px in the slub code because we want to reduce > the number of places that %px is used in the kernel. This also nicely > prints a big fat warning at kernel boot if slub_debug is on the > commandline so that we know that this kernel shouldn't be used on > production systems. > > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Best Regards, Petr
| |