All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Frederic Barrat <fbarrat@linux.ibm.com>,
	Andrew Donnellan <ajd@linux.ibm.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Jessica Yu <jeyu@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
	Petr Mladek <pmladek@suse.com>,
	Joe Lawrence <joe.lawrence@redhat.com>,
	Michal Marek <michal.lkml@markovi.net>,
	linux-kbuild@vger.kernel.org,
	Masahiro Yamada <masahiroy@kernel.org>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	live-patching@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 04/13] module: use RCU to synchronize find_module
Date: Fri, 29 Jan 2021 18:29:43 -0300	[thread overview]
Message-ID: <871re31lfc.fsf@manicouagan.localdomain> (raw)
In-Reply-To: <20210129051012.GA2053@lst.de>


Christoph Hellwig <hch@lst.de> writes:

> On Thu, Jan 28, 2021 at 05:50:56PM -0300, Thiago Jung Bauermann wrote:
>> >  struct module *find_module(const char *name)
>> >  {
>> > -	module_assert_mutex();
>> 
>> Does it make sense to replace the assert above with the warn below (untested)?
>> 
>>      RCU_LOCKDEP_WARN(rcu_read_lock_sched_held());
>
> One caller actually holds module_mutex still.  And find_module_all,
> which implements the actual logic already asserts that either
> module_mutex is held or rcu_read_lock, so I don't tink we need an
> extra one here.

Ok, thanks for the clarification.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

WARNING: multiple messages have this Message-ID (diff)
From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Petr Mladek <pmladek@suse.com>, Jiri Kosina <jikos@kernel.org>,
	Andrew Donnellan <ajd@linux.ibm.com>,
	linux-kbuild@vger.kernel.org, David Airlie <airlied@linux.ie>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	linux-kernel@vger.kernel.org, Maxime Ripard <mripard@kernel.org>,
	live-patching@vger.kernel.org,
	Michal Marek <michal.lkml@markovi.net>,
	Joe Lawrence <joe.lawrence@redhat.com>,
	dri-devel@lists.freedesktop.org,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Jessica Yu <jeyu@kernel.org>,
	Frederic Barrat <fbarrat@linux.ibm.com>,
	Daniel Vetter <daniel@ffwll.ch>, Miroslav Benes <mbenes@suse.cz>,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 04/13] module: use RCU to synchronize find_module
Date: Fri, 29 Jan 2021 18:29:43 -0300	[thread overview]
Message-ID: <871re31lfc.fsf@manicouagan.localdomain> (raw)
In-Reply-To: <20210129051012.GA2053@lst.de>


Christoph Hellwig <hch@lst.de> writes:

> On Thu, Jan 28, 2021 at 05:50:56PM -0300, Thiago Jung Bauermann wrote:
>> >  struct module *find_module(const char *name)
>> >  {
>> > -	module_assert_mutex();
>> 
>> Does it make sense to replace the assert above with the warn below (untested)?
>> 
>>      RCU_LOCKDEP_WARN(rcu_read_lock_sched_held());
>
> One caller actually holds module_mutex still.  And find_module_all,
> which implements the actual logic already asserts that either
> module_mutex is held or rcu_read_lock, so I don't tink we need an
> extra one here.

Ok, thanks for the clarification.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

  reply	other threads:[~2021-01-29 21:31 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-28 18:14 module loader dead code removal and cleanups v2 Christoph Hellwig
2021-01-28 18:14 ` Christoph Hellwig
2021-01-28 18:14 ` [PATCH 01/13] powerpc/powernv: remove get_cxl_module Christoph Hellwig
2021-01-28 18:14   ` Christoph Hellwig
2021-01-28 18:14 ` [PATCH 02/13] drm: remove drm_fb_helper_modinit Christoph Hellwig
2021-02-03 10:34   ` Daniel Vetter
2021-02-03 10:34     ` Daniel Vetter
2021-02-03 10:34     ` Daniel Vetter
2021-02-03 10:49     ` Christoph Hellwig
2021-01-28 18:14 ` [PATCH 03/13] module: unexport find_module and module_mutex Christoph Hellwig
2021-01-28 18:14   ` Christoph Hellwig
2021-01-29 15:16   ` Miroslav Benes
2021-01-28 18:14 ` [PATCH 04/13] module: use RCU to synchronize find_module Christoph Hellwig
2021-01-28 18:14   ` Christoph Hellwig
2021-01-28 20:50   ` Thiago Jung Bauermann
2021-01-28 20:50     ` Thiago Jung Bauermann
2021-01-28 20:50     ` Thiago Jung Bauermann
2021-01-29  5:10     ` Christoph Hellwig
2021-01-29  5:10       ` Christoph Hellwig
2021-01-29 21:29       ` Thiago Jung Bauermann [this message]
2021-01-29 21:29         ` Thiago Jung Bauermann
2021-01-29 10:04   ` Petr Mladek
2021-01-29 10:04     ` Petr Mladek
2021-01-29 15:29   ` Miroslav Benes
2021-02-01 11:46     ` Christoph Hellwig
2021-02-01 11:46       ` Christoph Hellwig
2021-02-01 12:10     ` Jessica Yu
2021-02-01 12:10       ` Jessica Yu
2021-02-01 12:10       ` Jessica Yu
2021-02-01 13:16       ` Miroslav Benes
2021-02-01 13:16         ` Miroslav Benes
2021-02-01 13:16         ` Miroslav Benes
2021-01-28 18:14 ` [PATCH 05/13] kallsyms: refactor {,module_}kallsyms_on_each_symbol Christoph Hellwig
2021-01-29  9:43   ` Petr Mladek
2021-02-01 11:47     ` Christoph Hellwig
2021-02-01 11:47       ` Christoph Hellwig
2021-02-01 13:37       ` Miroslav Benes
2021-02-01 13:37         ` Miroslav Benes
2021-02-01 13:37         ` Miroslav Benes
2021-02-01 16:28         ` Christoph Hellwig
2021-02-01 16:28           ` Christoph Hellwig
2021-02-02 10:45           ` Miroslav Benes
2021-02-02 10:45             ` Miroslav Benes
2021-02-02 10:45             ` Miroslav Benes
2021-02-01 14:02   ` Miroslav Benes
2021-02-01 14:02     ` Miroslav Benes
2021-02-01 14:02     ` Miroslav Benes
2021-01-28 18:14 ` [PATCH 06/13] kallsyms: only build {, module_}kallsyms_on_each_symbol when required Christoph Hellwig
2021-01-28 18:14 ` [PATCH 07/13] module: mark module_mutex static Christoph Hellwig
2021-01-28 18:14   ` Christoph Hellwig
2021-01-28 18:14 ` [PATCH 08/13] module: remove each_symbol_in_section Christoph Hellwig
2021-01-28 18:14 ` [PATCH 09/13] module: merge each_symbol_section into find_symbol Christoph Hellwig
2021-01-28 18:14 ` [PATCH 10/13] module: pass struct find_symbol_args to find_symbol Christoph Hellwig
2021-01-28 18:14   ` Christoph Hellwig
2021-01-28 18:14 ` [PATCH 11/13] module: move struct symsearch to module.c Christoph Hellwig
2021-01-28 18:14   ` Christoph Hellwig
2021-01-28 18:14 ` [PATCH 12/13] module: remove EXPORT_SYMBOL_GPL_FUTURE Christoph Hellwig
2021-01-28 18:14   ` Christoph Hellwig
2021-01-28 18:14 ` [PATCH 13/13] module: remove EXPORT_UNUSED_SYMBOL* Christoph Hellwig
2021-02-02 12:13 module loader dead code removal and cleanups v3 Christoph Hellwig
2021-02-02 12:13 ` [PATCH 04/13] module: use RCU to synchronize find_module Christoph Hellwig
2021-02-02 12:13   ` Christoph Hellwig

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=871re31lfc.fsf@manicouagan.localdomain \
    --to=bauerman@linux.ibm.com \
    --cc=airlied@linux.ie \
    --cc=ajd@linux.ibm.com \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=fbarrat@linux.ibm.com \
    --cc=hch@lst.de \
    --cc=jeyu@kernel.org \
    --cc=jikos@kernel.org \
    --cc=joe.lawrence@redhat.com \
    --cc=jpoimboe@redhat.com \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=live-patching@vger.kernel.org \
    --cc=maarten.lankhorst@linux.intel.com \
    --cc=masahiroy@kernel.org \
    --cc=mbenes@suse.cz \
    --cc=michal.lkml@markovi.net \
    --cc=mripard@kernel.org \
    --cc=pmladek@suse.com \
    --cc=tzimmermann@suse.de \
    /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.