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McKenney" , Alexander Potapenko , kasan-dev , LKML , the arch/x86 maintainers , Andrew Morton , Josh Poimboeuf Subject: Re: [PATCH -tip v3 1/2] kcov: Make runtime functions noinstr-compatible Message-ID: <20200615145448.GV2531@hirez.programming.kicks-ass.net> References: <20200608110108.GB2497@hirez.programming.kicks-ass.net> <20200611215538.GE4496@worktop.programming.kicks-ass.net> <20200612114900.GA187027@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 15, 2020 at 09:53:06AM +0200, Marco Elver wrote: > For KCSAN the crash still happens in check_preemption_disabled, in the > inlined native_save_fl function (apparently on its 'pushf'). If I turn > fixup_bad_iret's __this_cpu_read into a raw_cpu_read (to bypass > check_preemption_disabled), no more crash with KCSAN. Yeah, I can't see anything weird there with KCSAN + KCOV + NOP :-(