On Wed, 4 Mar 2020 at 17:57, Marco Elver <elver@xxxxxxxxxx> wrote: > > On Wed, 4 Mar 2020 at 17:44, Qian Cai <cai@xxxxxx> wrote: > > > > On Wed, 2020-03-04 at 17:25 +0100, 'Marco Elver' via kasan-dev wrote: > > > Selective analysis > > > ~~~~~~~~~~~~~~~~~~ > > > @@ -111,8 +107,8 @@ the below options are available: > > > > > > * Disabling data race detection for entire functions can be accomplished by > > > using the function attribute ``__no_kcsan`` (or ``__no_kcsan_or_inline`` for > > > - ``__always_inline`` functions). To dynamically control for which functions > > > - data races are reported, see the `debugfs`_ blacklist/whitelist feature. > > > + ``__always_inline`` functions). To dynamically limit for which functions to > > > + generate reports, see the `DebugFS interface`_ blacklist/whitelist feature. > > > > As mentioned in [1], do it worth mentioning "using __no_kcsan_or_inline for > > inline functions as well when CONFIG_OPTIMIZE_INLINING=y" ? > > > > [1] https://lore.kernel.org/lkml/E9162CDC-BBC5-4D69-87FB-C93AB8B3D581@xxxxxx/ > > Strictly speaking it shouldn't be necessary. Only __always_inline is > incompatible with __no_kcsan. > > AFAIK what you noticed is a bug with some versions of GCC. I think > with GCC >=9 and Clang there is no problem. > > The bigger problem is turning a bunch of 'inline' functions into > '__always_inline' accidentally, that's why the text only mentions > '__no_kcsan_or_inline' for '__always_inline'. For extremely small > functions, that's probably ok, but it's not general advice we should > give for that reason. > > I will try to write something about this here, but sadly there is no > clear rule for this until the misbehaving compilers are no longer > supported. I've sent v2 of the comment/documentation update series: http://lkml.kernel.org/r/20200305142109.50945-1-elver@xxxxxxxxxx (only this patch changed) Please check it captures the current caveat around "__no_kcsan inline" with old compilers. Thank you, -- Marco
