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charset="UTF-8" X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 176C2160008 X-Stat-Signature: wngbnzxjioejz7hfg4em51ofuuw3kmq9 Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=lxXkzKjF; spf=pass (imf08.hostedemail.com: domain of andreyknvl@gmail.com designates 209.85.166.180 as permitted sender) smtp.mailfrom=andreyknvl@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-HE-Tag: 1640891500-86072 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Dec 21, 2021 at 3:43 PM Alexander Potapenko wrote: > > > > > + switch (kasan_arg_vmalloc) { > > + case KASAN_ARG_VMALLOC_DEFAULT: > > + /* Default to enabling vmalloc tagging. */ > > + fallthrough; > > + case KASAN_ARG_VMALLOC_ON: > > + static_branch_enable(&kasan_flag_vmalloc); > > + break; > > + case KASAN_ARG_VMALLOC_OFF: > > + /* Do nothing, kasan_flag_vmalloc keeps its default value. */ > > + break; > > + } > > I think we should be setting the default when defining the static key > (e.g. in this case it should be DEFINE_STATIC_KEY_TRUE), so that: > - the _DEFAULT case is always empty; > - the _ON case explicitly enables the static branch > - the _OFF case explicitly disables the branch > This way we'll only need to change DEFINE_STATIC_KEY_TRUE to > DEFINE_STATIC_KEY_FALSE if we want to change the default, but we don't > have to mess up with the rest of the code. > Right now the switch statement is confusing, because the _OFF case > refers to some "default" value, whereas the _DEFAULT one actively > changes the state. > > I see that this code is copied from kasan_flag_stacktrace > implementation, and my comment also applies there (but I don't insist > on fixing that one right now). Will do in v5. Thanks!