From: Christoph Hellwig <hch@lst.de>
To: 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>
Cc: Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
dri-devel@lists.freedesktop.org, live-patching@vger.kernel.org,
linux-kbuild@vger.kernel.org
Subject: [PATCH 02/13] module: add a module_loaded helper
Date: Thu, 21 Jan 2021 08:49:48 +0100 [thread overview]
Message-ID: <20210121074959.313333-3-hch@lst.de> (raw)
In-Reply-To: <20210121074959.313333-1-hch@lst.de>
Add a helper that takes modules_mutex and uses find_module to check if a
given module is loaded. This provides a better abstraction for the two
callers, and allows to unexport modules_mutex and find_module.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/gpu/drm/drm_fb_helper.c | 7 +------
include/linux/module.h | 3 +++
kernel/module.c | 14 ++++++++++++--
kernel/trace/trace_kprobe.c | 4 +---
4 files changed, 17 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 4b81195106875d..ce6d63ca75c32a 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2508,13 +2508,8 @@ int __init drm_fb_helper_modinit(void)
{
#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
const char name[] = "fbcon";
- struct module *fbcon;
- mutex_lock(&module_mutex);
- fbcon = find_module(name);
- mutex_unlock(&module_mutex);
-
- if (!fbcon)
+ if (!module_loaded(name))
request_module_nowait(name);
#endif
return 0;
diff --git a/include/linux/module.h b/include/linux/module.h
index 7a0bcb5b1ffccd..b4654f8a408134 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -589,6 +589,9 @@ static inline bool within_module(unsigned long addr, const struct module *mod)
/* Search for module by name: must hold module_mutex. */
struct module *find_module(const char *name);
+/* Check if a module is loaded. */
+bool module_loaded(const char *name);
+
struct symsearch {
const struct kernel_symbol *start, *stop;
const s32 *crcs;
diff --git a/kernel/module.c b/kernel/module.c
index 4bf30e4b3eaaa1..619ea682e64cd1 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -88,7 +88,6 @@
* (delete and add uses RCU list operations).
*/
DEFINE_MUTEX(module_mutex);
-EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
/* Work queue for freeing init sections in success case */
@@ -672,7 +671,18 @@ struct module *find_module(const char *name)
module_assert_mutex();
return find_module_all(name, strlen(name), false);
}
-EXPORT_SYMBOL_GPL(find_module);
+
+bool module_loaded(const char *name)
+{
+ bool ret;
+
+ mutex_lock(&module_mutex);
+ ret = !!find_module(name);
+ mutex_unlock(&module_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(module_loaded);
#ifdef CONFIG_SMP
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index e6fba1798771b4..c2e453f88bce70 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -124,9 +124,7 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
if (!p)
return true;
*p = '\0';
- mutex_lock(&module_mutex);
- ret = !!find_module(tk->symbol);
- mutex_unlock(&module_mutex);
+ ret = module_loaded(tk->symbol);
*p = ':';
return ret;
--
2.29.2
next prev parent reply other threads:[~2021-01-21 20:22 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 7:49 module loader dead code removal and cleanusp Christoph Hellwig
2021-01-21 7:49 ` [PATCH 01/13] powerpc/powernv: remove get_cxl_module Christoph Hellwig
2021-01-21 9:09 ` Andrew Donnellan
2021-01-21 7:49 ` Christoph Hellwig [this message]
2021-01-21 10:00 ` [PATCH 02/13] module: add a module_loaded helper Christophe Leroy
2021-01-21 17:11 ` Christoph Hellwig
2021-01-21 17:44 ` David Laight
2021-01-21 7:49 ` [PATCH 03/13] livepatch: refactor klp_init_object Christoph Hellwig
2021-01-27 12:58 ` Petr Mladek
2021-01-28 16:22 ` Christoph Hellwig
2021-01-28 16:24 ` Christoph Hellwig
2021-01-21 7:49 ` [PATCH 04/13] livepatch: move klp_find_object_module to module.c Christoph Hellwig
2021-01-21 21:45 ` Josh Poimboeuf
2021-01-26 14:25 ` Jessica Yu
2021-01-27 11:55 ` Petr Mladek
2021-01-21 7:49 ` [PATCH 05/13] kallsyms: refactor {,module_}kallsyms_on_each_symbol Christoph Hellwig
2021-01-21 7:49 ` [PATCH 06/13] kallsyms: only build {,module_}kallsyms_on_each_symbol when required Christoph Hellwig
2021-01-21 7:49 ` [PATCH 07/13] module: mark module_mutex static Christoph Hellwig
2021-01-21 7:49 ` [PATCH 08/13] drm: remove drm_fb_helper_modinit Christoph Hellwig
2021-01-21 8:25 ` Daniel Vetter
2021-01-21 8:28 ` Christoph Hellwig
2021-01-21 8:39 ` Daniel Vetter
2021-01-21 7:49 ` [PATCH 09/13] module: remove each_symbol_in_section Christoph Hellwig
2021-01-21 7:49 ` [PATCH 10/13] module: merge each_symbol_section into find_symbol Christoph Hellwig
2021-01-21 7:49 ` [PATCH 11/13] module: pass struct find_symbol_args to find_symbol Christoph Hellwig
2021-01-21 7:49 ` [PATCH 12/13] module: remove EXPORT_SYMBOL_GPL_FUTURE Christoph Hellwig
2021-01-21 7:49 ` [PATCH 13/13] module: remove EXPORY_UNUSED_SYMBOL* Christoph Hellwig
2021-01-27 13:49 ` Jessica Yu
2021-01-28 16:09 ` 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=20210121074959.313333-3-hch@lst.de \
--to=hch@lst.de \
--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=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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).