All of lore.kernel.org
 help / color / mirror / Atom feed
From: Michael Ellerman <mpe@ellerman.id.au>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v2 5/6] powerpc/32s: prepare prevent_user_access() for user_access_end()
Date: Thu, 23 Jan 2020 21:59:07 +1100	[thread overview]
Message-ID: <87pnfaiglg.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <824b69f5452d1d41d12c4dbd306d4b8f32d493fc.1579715466.git.christophe.leroy@c-s.fr>

Christophe Leroy <christophe.leroy@c-s.fr> writes:
> In preparation of implementing user_access_begin and friends
> on powerpc, the book3s/32 version of prevent_user_access() need
> to be prepared for user_access_end().
>
> user_access_end() doesn't provide the address and size which
> were passed to user_access_begin(), required by prevent_user_access()
> to know which segment to modify.
>
> The list of segments which where unprotected by allow_user_access()
> are available in current->kuap. But we don't want prevent_user_access()
> to read this all the time, especially everytime it is 0 (for instance
> because the access was not a write access).
>
> Implement a special direction case named KUAP_SELF. In this case only,
> the addr and end are retrieved from current->kuap.

Can we call it KUAP_CURRENT?

ie. "use the KUAP state in current"

cheers

WARNING: multiple messages have this Message-ID (diff)
From: Michael Ellerman <mpe@ellerman.id.au>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>
Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 5/6] powerpc/32s: prepare prevent_user_access() for user_access_end()
Date: Thu, 23 Jan 2020 21:59:07 +1100	[thread overview]
Message-ID: <87pnfaiglg.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <824b69f5452d1d41d12c4dbd306d4b8f32d493fc.1579715466.git.christophe.leroy@c-s.fr>

Christophe Leroy <christophe.leroy@c-s.fr> writes:
> In preparation of implementing user_access_begin and friends
> on powerpc, the book3s/32 version of prevent_user_access() need
> to be prepared for user_access_end().
>
> user_access_end() doesn't provide the address and size which
> were passed to user_access_begin(), required by prevent_user_access()
> to know which segment to modify.
>
> The list of segments which where unprotected by allow_user_access()
> are available in current->kuap. But we don't want prevent_user_access()
> to read this all the time, especially everytime it is 0 (for instance
> because the access was not a write access).
>
> Implement a special direction case named KUAP_SELF. In this case only,
> the addr and end are retrieved from current->kuap.

Can we call it KUAP_CURRENT?

ie. "use the KUAP state in current"

cheers

  reply	other threads:[~2020-01-23 10:59 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-22 17:52 [PATCH v2 1/6] fs/readdir: Fix filldir() and filldir64() use of user_access_begin() Christophe Leroy
2020-01-22 17:52 ` Christophe Leroy
2020-01-22 17:52 ` [PATCH v2 2/6] powerpc/32s: Fix bad_kuap_fault() Christophe Leroy
2020-01-22 17:52   ` Christophe Leroy
2020-01-22 17:52 ` [PATCH v2 3/6] powerpc/kuap: Fix set direction in allow/prevent_user_access() Christophe Leroy
2020-01-22 17:52   ` Christophe Leroy
2020-01-22 17:52 ` [PATCH v2 4/6] powerpc/32s: Drop NULL addr verification Christophe Leroy
2020-01-22 17:52   ` Christophe Leroy
2020-01-22 17:52 ` [PATCH v2 5/6] powerpc/32s: prepare prevent_user_access() for user_access_end() Christophe Leroy
2020-01-22 17:52   ` Christophe Leroy
2020-01-23 10:59   ` Michael Ellerman [this message]
2020-01-23 10:59     ` Michael Ellerman
2020-01-22 17:52 ` [PATCH v2 6/6] powerpc: Implement user_access_begin and friends Christophe Leroy
2020-01-22 17:52   ` Christophe Leroy
2020-01-23 12:05   ` Michael Ellerman
2020-01-23 12:05     ` Michael Ellerman
2020-01-23 12:31     ` Michael Ellerman
2020-01-23 12:31       ` Michael Ellerman
2020-01-24 11:40       ` Christophe Leroy
2020-01-24 11:40         ` Christophe Leroy
2020-01-22 18:24 ` [PATCH v2 1/6] fs/readdir: Fix filldir() and filldir64() use of user_access_begin() Linus Torvalds
2020-01-22 18:24   ` Linus Torvalds
2020-01-22 20:00   ` Linus Torvalds
2020-01-22 20:00     ` Linus Torvalds
2020-01-22 20:00     ` Linus Torvalds
2020-01-22 20:15     ` Linus Torvalds
2020-01-22 20:15       ` Linus Torvalds
2020-01-22 20:15       ` Linus Torvalds
2020-01-22 20:37     ` Linus Torvalds
2020-01-22 20:37       ` Linus Torvalds
2020-01-22 20:37       ` Linus Torvalds
2020-01-23  6:27       ` Christophe Leroy
2020-01-23  6:27         ` Christophe Leroy
2020-01-23 11:56 ` Michael Ellerman
2020-01-23 11:56   ` Michael Ellerman
2020-01-23 12:00   ` Michael Ellerman
2020-01-23 12:00     ` Michael Ellerman
2020-01-23 12:43     ` Christophe Leroy
2020-01-23 12:43       ` Christophe Leroy
2020-01-23 18:38     ` Linus Torvalds
2020-01-23 18:38       ` Linus Torvalds
2020-01-23 18:38       ` Linus Torvalds
2020-01-24 10:42       ` Michael Ellerman
2020-01-24 10:42         ` Michael Ellerman

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=87pnfaiglg.fsf@mpe.ellerman.id.au \
    --to=mpe@ellerman.id.au \
    --cc=benh@kernel.crashing.org \
    --cc=christophe.leroy@c-s.fr \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=paulus@samba.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.