From: Peter Zijlstra <peterz@infradead.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: mark.rutland@arm.com, catalin.marinas@arm.com, will@kernel.org,
james.morse@arm.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] arm64: implement support for static call trampolines
Date: Thu, 29 Oct 2020 11:28:55 +0100 [thread overview]
Message-ID: <20201029102855.GJ2628@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20201028184114.6834-1-ardb@kernel.org>
On Wed, Oct 28, 2020 at 07:41:14PM +0100, Ard Biesheuvel wrote:
> This turned nasty really quickly when I realized that any sleeping task
> could have been interrupted right in the middle of the ADRP/ADD pair
> that we emit for static call targets that are out of immediate branching
> range.
Ha! Yes, that's a 'problem' allright. On x86 we normally only patch a
single instruction because of this, however we have some kprobe code
that has this issue and there we use tasks_rcu when PREEMPT=y.
Now, let me try and read this patch properly..
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next prev parent reply other threads:[~2020-10-29 10:30 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-28 18:41 [PATCH v2] arm64: implement support for static call trampolines Ard Biesheuvel
2020-10-29 10:28 ` Peter Zijlstra [this message]
2020-10-29 10:40 ` Peter Zijlstra
2020-10-29 10:58 ` Ard Biesheuvel
2020-10-29 11:46 ` Peter Zijlstra
2020-10-29 11:49 ` Ard Biesheuvel
2020-10-29 11:54 ` Peter Zijlstra
2020-10-29 12:14 ` Ard Biesheuvel
2020-10-29 11:27 ` Quentin Perret
2020-10-29 11:32 ` Ard Biesheuvel
2020-10-29 11:44 ` Peter Zijlstra
2020-10-29 14:10 ` Steven Rostedt
2020-10-29 11:54 ` Quentin Perret
2020-10-29 13:22 ` Ard Biesheuvel
2020-11-16 10:18 ` Quentin Perret
2020-11-16 10:31 ` Ard Biesheuvel
2020-11-16 12:05 ` Quentin Perret
2020-10-29 11:50 ` Mark Rutland
2020-10-29 11:58 ` Peter Zijlstra
2020-10-29 13:30 ` Mark Rutland
2020-10-29 11:59 ` Ard Biesheuvel
2020-10-29 13:21 ` Mark Rutland
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