All of lore.kernel.org
 help / color / mirror / Atom feed
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 2/2] arm64: enable context tracking
Date: Wed, 7 May 2014 11:17:09 +0100	[thread overview]
Message-ID: <20140507101709.GE18456@arm.com> (raw)
In-Reply-To: <1399419149-26685-3-git-send-email-larry.bassel@linaro.org>

On Wed, May 07, 2014 at 12:32:29AM +0100, Larry Bassel wrote:
> Make calls to ct_user_enter when the kernel is exited
> and ct_user_exit when the kernel is entered (in el0_da,
> el0_ia, el0_svc, el0_irq).

Why only these entry points? I can reschedule after any exception from EL0,
so I'd expect all exceptions from userspace to need annotating, no?

> These macros expand to function calls which will only work
> properly if el0_sync and related code has been rearranged
> (in a previous patch of this series).
> 
> In order to avoid saving registers, the slow syscall path
> is forced (as x86 does).

... and if you decide to handle undef exceptions, I think you'll need
the register saving too, in case the kernel needs to perform emulation.

Will

WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: Larry Bassel <larry.bassel@linaro.org>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linaro-kernel@lists.linaro.org" <linaro-kernel@lists.linaro.org>,
	"khilman@linaro.org" <khilman@linaro.org>
Subject: Re: [PATCH v2 2/2] arm64: enable context tracking
Date: Wed, 7 May 2014 11:17:09 +0100	[thread overview]
Message-ID: <20140507101709.GE18456@arm.com> (raw)
In-Reply-To: <1399419149-26685-3-git-send-email-larry.bassel@linaro.org>

On Wed, May 07, 2014 at 12:32:29AM +0100, Larry Bassel wrote:
> Make calls to ct_user_enter when the kernel is exited
> and ct_user_exit when the kernel is entered (in el0_da,
> el0_ia, el0_svc, el0_irq).

Why only these entry points? I can reschedule after any exception from EL0,
so I'd expect all exceptions from userspace to need annotating, no?

> These macros expand to function calls which will only work
> properly if el0_sync and related code has been rearranged
> (in a previous patch of this series).
> 
> In order to avoid saving registers, the slow syscall path
> is forced (as x86 does).

... and if you decide to handle undef exceptions, I think you'll need
the register saving too, in case the kernel needs to perform emulation.

Will

  reply	other threads:[~2014-05-07 10:17 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-06 23:32 [PATCH v2 0/2] context tracker support for arm64 Larry Bassel
2014-05-06 23:32 ` Larry Bassel
2014-05-06 23:32 ` [PATCH v2 1/2] arm64: adjust el0_sync so that a function can be called Larry Bassel
2014-05-06 23:32   ` Larry Bassel
2014-05-06 23:32 ` [PATCH v2 2/2] arm64: enable context tracking Larry Bassel
2014-05-06 23:32   ` Larry Bassel
2014-05-07 10:17   ` Will Deacon [this message]
2014-05-07 10:17     ` Will Deacon
2014-05-07 21:35     ` Larry Bassel
2014-05-07 21:35       ` Larry Bassel
2014-05-07 23:49     ` Kevin Hilman
2014-05-08 10:25       ` Will Deacon
2014-05-08 10:25         ` Will Deacon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140507101709.GE18456@arm.com \
    --to=will.deacon@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.