Messages in this thread | | | Date | Thu, 16 Jun 2022 06:40:21 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [ammarfaizi2-block:paulmck/linux-rcu/pmladek.2022.06.15a 133/140] vmlinux.o: warning: objtool: __ct_user_exit+0x41: call to __kasan_check_read() leaves .noinstr.text section |
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On Thu, Jun 16, 2022 at 10:19:18AM +0200, Marco Elver wrote: > On Wed, 15 Jun 2022 at 23:17, Paul E. McKenney <paulmck@kernel.org> wrote: > > > > On Wed, Jun 15, 2022 at 01:40:39PM -0700, Paul E. McKenney wrote: > > > On Thu, Jun 16, 2022 at 04:26:16AM +0800, kernel test robot wrote: > > > > tree: https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/pmladek.2022.06.15a > > > > head: 0ba7324b44282870af740a5a121add62c7f5f730 > > > > commit: db21b02f8044e812f8a5e3811f602409290e3ede [133/140] context_tracking: Convert state to atomic_t > > > > config: x86_64-randconfig-r003-20220516 (https://download.01.org/0day-ci/archive/20220616/202206160411.v3iL3YC0-lkp@intel.com/config) > > > > compiler: gcc-11 (Debian 11.3.0-3) 11.3.0 > > > > reproduce (this is a W=1 build): > > > > # https://github.com/ammarfaizi2/linux-block/commit/db21b02f8044e812f8a5e3811f602409290e3ede > > > > git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block > > > > git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/pmladek.2022.06.15a > > > > git checkout db21b02f8044e812f8a5e3811f602409290e3ede > > > > # save the config file > > > > mkdir build_dir && cp config build_dir/.config > > > > make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash > > > > > > > > If you fix the issue, kindly add following tag where applicable > > > > Reported-by: kernel test robot <lkp@intel.com> > > > > > > > > All warnings (new ones prefixed by >>): > > > > > > > > >> vmlinux.o: warning: objtool: __ct_user_exit+0x41: call to __kasan_check_read() leaves .noinstr.text section > > > > >> vmlinux.o: warning: objtool: __ct_user_enter+0x7f: call to __kasan_check_read() leaves .noinstr.text section > > > > > > Marco, Dmitry, my guess is that this is due to the ct->active check in > > > both functions. Are we supposed to do something to make this sort of > > > thing safe for KASAN? > > > > This time actually CCing Marco and Dmitry... > > It's due to the atomic_read()s within the noinstr function. Within > noinstr you can use arch_atomic_read() to avoid the instrumentation.
Thank you, will fix!
Thanx, Paul
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