From: Peter Zijlstra <peterz@infradead.org>
To: Jiri Kosina <jikos@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
"Woodhouse, David" <dwmw@amazon.co.uk>,
Oleg Nesterov <oleg@redhat.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH v3 2/3] x86/speculation: apply IBPB more strictly to avoid cross-process data leak
Date: Wed, 5 Sep 2018 11:40:12 +0200 [thread overview]
Message-ID: <20180905094012.GT24082@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <nycvar.YFH.7.76.1809051001360.15880@cbobk.fhfr.pm>
On Wed, Sep 05, 2018 at 10:02:41AM +0200, Jiri Kosina wrote:
> Yeah, I did more or less that earlier today; my series currently has
Excellent, maybe add a wee comment like so?
> +static bool ibpb_needed(struct task_struct *tsk, u64 last_ctx_id)
> +{
/*
* Check if the current (previous) task has access to the memory
* of the @tsk (next) task. If access is denied, make sure to
* issue a IBPB to stop user->user Spectre-v2 attacks.
*
* Note: __ptrace_may_access() returns 0 or -ERRNO.
*/
> + return (tsk && tsk->mm && tsk->mm->context.ctx_id != last_ctx_id &&
> + __ptrace_may_access(tsk, PTRACE_MODE_IBPB));
> +}
next prev parent reply other threads:[~2018-09-05 9:40 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-31 20:56 [PATCH] x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation Jiri Kosina
2018-09-03 8:51 ` Jiri Kosina
2018-09-03 12:45 ` [PATCH v2 0/3] Harden spectrev2 userspace-userspace protection Jiri Kosina
2018-09-04 14:23 ` [PATCH v3 " Jiri Kosina
2018-09-04 14:40 ` [PATCH v3 1/3] ptrace: Provide ___ptrace_may_access() that can be applied on arbitrary tasks Jiri Kosina
2018-09-04 16:13 ` Thomas Gleixner
2018-09-04 16:21 ` Thomas Gleixner
2018-09-04 17:26 ` Tim Chen
2018-09-04 17:35 ` Jiri Kosina
2018-09-04 18:10 ` Schaufler, Casey
2018-09-04 18:48 ` Jiri Kosina
2018-09-04 23:26 ` Tim Chen
2018-09-05 6:22 ` Jiri Kosina
2018-09-05 15:58 ` Andi Kleen
2018-09-05 18:04 ` Andrea Arcangeli
2018-09-05 18:29 ` Jiri Kosina
2018-09-05 18:40 ` Andrea Arcangeli
2018-09-05 18:42 ` Jiri Kosina
2018-09-05 19:03 ` Peter Zijlstra
2018-09-05 19:27 ` Schaufler, Casey
2018-09-05 20:02 ` Jiri Kosina
2018-09-05 18:26 ` Thomas Gleixner
2018-09-05 18:35 ` Jiri Kosina
2018-09-04 23:37 ` Andrea Arcangeli
2018-09-05 1:00 ` Schaufler, Casey
2018-09-05 2:38 ` Andrea Arcangeli
2018-09-05 8:00 ` Peter Zijlstra
2018-09-05 15:37 ` Schaufler, Casey
2018-09-05 7:51 ` Peter Zijlstra
2018-09-04 14:42 ` [PATCH v3 2/3] x86/speculation: apply IBPB more strictly to avoid cross-process data leak Jiri Kosina
2018-09-04 16:18 ` Thomas Gleixner
2018-09-05 7:59 ` Peter Zijlstra
2018-09-05 8:02 ` Jiri Kosina
2018-09-05 9:40 ` Peter Zijlstra [this message]
2018-09-05 7:52 ` Peter Zijlstra
2018-09-05 7:55 ` Jiri Kosina
2018-09-04 14:42 ` [PATCH v3 3/3] x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation Jiri Kosina
2018-09-04 14:24 [PATCH v3 2/3] x86/speculation: apply IBPB more strictly to avoid cross-process data leak Jiri Kosina
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