* Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > On Wed, Oct 11, 2023 at 09:46:16AM +0200, Peter Zijlstra wrote: > > On Wed, Oct 11, 2023 at 09:58:49AM +0300, Kirill A. Shutemov wrote: > > > Fei has reported that KASAN triggers during apply_alternatives() on > > > 5-level paging machine: > > > > > > > Urgh @ KASAN splat, can't we summarize that? > > What about this? > > BUG: KASAN: out-of-bounds in rcu_is_watching > Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0 > ... > __asan_load4 > rcu_is_watching > ? text_poke_early > trace_hardirqs_on > ? __asan_load4 > text_poke_early > apply_alternatives > ... > > Is it enough details or I overdid summarization? No, that's perfect IMO. I'd even leave out the unreliable '?' entries: > BUG: KASAN: out-of-bounds in rcu_is_watching > Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0 > ... > __asan_load4 > rcu_is_watching > trace_hardirqs_on > text_poke_early > apply_alternatives > ... ... or so. > /* > * In the case CONFIG_X86_5LEVEL=y, KASAN_SHADOW_START is defined using > * cpu_feature_enabled(X86_FEATURE_LA57) and is therefore patched here. > * During the process, KASAN becomes confused seeing partial LA57 > * conversion and triggers a false-positive out-of-bound report. > * > * Disable KASAN until the patching is complete. > */ > > Looks good? LGTM. Thanks, Ingo
