linux-kernel - Re: [PATCH v3 26/57] perf: Simplify event

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]

Date:   Mon, 12 Jun 2023 16:58:05 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Dan Carpenter <dan.carpenter@...aro.org>
Cc:     torvalds@...ux-foundation.org, keescook@...omium.org,
        gregkh@...uxfoundation.org, pbonzini@...hat.com,
        masahiroy@...nel.org, nathan@...nel.org, ndesaulniers@...gle.com,
        nicolas@...sle.eu, catalin.marinas@....com, will@...nel.org,
        vkoul@...nel.org, trix@...hat.com, ojeda@...nel.org,
        mingo@...hat.com, longman@...hat.com, boqun.feng@...il.com,
        dennis@...nel.org, tj@...nel.org, cl@...ux.com, acme@...nel.org,
        mark.rutland@....com, alexander.shishkin@...ux.intel.com,
        jolsa@...nel.org, namhyung@...nel.org, irogers@...gle.com,
        adrian.hunter@...el.com, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, vschneid@...hat.com, paulmck@...nel.org,
        frederic@...nel.org, quic_neeraju@...cinc.com,
        joel@...lfernandes.org, josh@...htriplett.org,
        mathieu.desnoyers@...icios.com, jiangshanlai@...il.com,
        rientjes@...gle.com, vbabka@...e.cz, roman.gushchin@...ux.dev,
        42.hyeyoo@...il.com, apw@...onical.com, joe@...ches.com,
        dwaipayanray1@...il.com, lukas.bulwahn@...il.com,
        john.johansen@...onical.com, paul@...l-moore.com,
        jmorris@...ei.org, serge@...lyn.com, linux-kbuild@...r.kernel.org,
        linux-kernel@...r.kernel.org, dmaengine@...r.kernel.org,
        llvm@...ts.linux.dev, linux-perf-users@...r.kernel.org,
        rcu@...r.kernel.org, linux-security-module@...r.kernel.org,
        tglx@...utronix.de, ravi.bangoria@....com, error27@...il.com,
        luc.vanoostenryck@...il.com
Subject: Re: [PATCH v3 26/57] perf: Simplify event_function*()

On Mon, Jun 12, 2023 at 05:46:47PM +0300, Dan Carpenter wrote:
> On Mon, Jun 12, 2023 at 11:07:39AM +0200, Peter Zijlstra wrote:
> > @@ -224,17 +243,15 @@ static int event_function(void *info)
> >  	int ret = 0;
> >  
> >  	lockdep_assert_irqs_disabled();
> > +	guard(perf_ctx_lock)(cpuctx, task_ctx);
> >  
> > -	perf_ctx_lock(cpuctx, task_ctx);
> >  	/*
> >  	 * Since we do the IPI call without holding ctx->lock things can have
> >  	 * changed, double check we hit the task we set out to hit.
> >  	 */
> >  	if (ctx->task) {
> > -		if (ctx->task != current) {
> > -			ret = -ESRCH;
> > -			goto unlock;
> > -		}
> > +		if (ctx->task != current)
> > +			return -ESRCH;
> >  
> >  		/*
> >  		 * We only use event_function_call() on established contexts,
> > @@ -254,8 +271,6 @@ static int event_function(void *info)
> >  	}
> >  
> >  	efs->func(event, cpuctx, ctx, efs->data);
> > -unlock:
> > -	perf_ctx_unlock(cpuctx, task_ctx);
> >  
> >  	return ret;
> 
> 
> We can change this to a return 0; and get rid of the "ret" variable.

This and the previous one, done!