linux-kernel - Re: [PATCH 2/9] rcu: Fixup noinstr warnings

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200615155513.GG2554@hirez.programming.kicks-ass.net>
Date:   Mon, 15 Jun 2020 17:55:13 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     tglx@...utronix.de
Cc:     x86@...nel.org, elver@...gle.com, paulmck@...nel.org,
        kasan-dev@...glegroups.com, linux-kernel@...r.kernel.org,
        will@...nel.org, dvyukov@...gle.com, glider@...gle.com,
        andreyknvl@...gle.com
Subject: Re: [PATCH 2/9] rcu: Fixup noinstr warnings

On Mon, Jun 15, 2020 at 05:49:05PM +0200, Peter Zijlstra wrote:
> @@ -983,13 +993,17 @@ noinstr void rcu_nmi_enter(void)
>  		if (!in_nmi())
>  			rcu_cleanup_after_idle();
>  
> +		instrumentation_begin();
> +		// instrumentation for the noinstr rcu_dynticks_curr_cpu_in_eqs()
> +		instrument_atomic_read(&rdp->dynticks, sizeof(rdp->dynticks));
> +		// instrumentation for the noinstr rcu_dynticks_eqs_exit()
> +		instrument_atomic_write(&rdp->dynticks, sizeof(rdp->dynticks));
> +
>  		incby = 1;
>  	} else if (!in_nmi()) {
>  		instrumentation_begin();
>  		rcu_irq_enter_check_tick();
> -		instrumentation_end();
>  	}
> -	instrumentation_begin();
>  	trace_rcu_dyntick(incby == 1 ? TPS("Endirq") : TPS("++="),
>  			  rdp->dynticks_nmi_nesting,
>  			  rdp->dynticks_nmi_nesting + incby, atomic_read(&rdp->dynticks));

Oh, that's lost a possible instrumentation_begin() :/ But weirdly
objtool didn't complain about that... Let me poke at that.