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 04/13] livepatch: move klp_find_object_module to module.c
Date: Thu, 21 Jan 2021 08:49:50 +0100 [thread overview]
Message-ID: <20210121074959.313333-5-hch@lst.de> (raw)
In-Reply-To: <20210121074959.313333-1-hch@lst.de>
To uncouple the livepatch code from module loader internals move a
slightly refactored version of klp_find_object_module to module.c
This allows to mark find_module static and removes one of the last
users of module_mutex outside of module.c.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/module.h | 3 +--
kernel/livepatch/core.c | 39 +++++++++++++--------------------------
kernel/module.c | 17 ++++++++++++++++-
3 files changed, 30 insertions(+), 29 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index b4654f8a408134..8588482bde4116 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -586,8 +586,7 @@ static inline bool within_module(unsigned long addr, const struct module *mod)
return within_module_init(addr, mod) || within_module_core(addr, mod);
}
-/* Search for module by name: must hold module_mutex. */
-struct module *find_module(const char *name);
+struct module *find_klp_module(const char *name);
/* Check if a module is loaded. */
bool module_loaded(const char *name);
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index a7f625dc24add3..878759baadd81c 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -49,30 +49,6 @@ static bool klp_is_module(struct klp_object *obj)
return obj->name;
}
-/* sets obj->mod if object is not vmlinux and module is found */
-static void klp_find_object_module(struct klp_object *obj)
-{
- struct module *mod;
-
- mutex_lock(&module_mutex);
- /*
- * We do not want to block removal of patched modules and therefore
- * we do not take a reference here. The patches are removed by
- * klp_module_going() instead.
- */
- mod = find_module(obj->name);
- /*
- * Do not mess work of klp_module_coming() and klp_module_going().
- * Note that the patch might still be needed before klp_module_going()
- * is called. Module functions can be called even in the GOING state
- * until mod->exit() finishes. This is especially important for
- * patches that modify semantic of the functions.
- */
- if (mod && mod->klp_alive)
- obj->mod = mod;
- mutex_unlock(&module_mutex);
-}
-
static bool klp_initialized(void)
{
return !!klp_root_kobj;
@@ -820,14 +796,25 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
const char *name;
obj->patched = false;
- obj->mod = NULL;
if (klp_is_module(obj)) {
if (strlen(obj->name) >= MODULE_NAME_LEN)
return -EINVAL;
name = obj->name;
- klp_find_object_module(obj);
+ /*
+ * We do not want to block removal of patched modules and
+ * therefore we do not take a reference here. The patches are
+ * removed by klp_module_going() instead.
+ *
+ * Do not mess work of klp_module_coming() and
+ * klp_module_going(). Note that the patch might still be
+ * needed before klp_module_going() is called. Module functions
+ * can be called even in the GOING state until mod->exit()
+ * finishes. This is especially important for patches that
+ * modify semantic of the functions.
+ */
+ obj->mod = find_klp_module(obj->name);
} else {
name = "vmlinux";
}
diff --git a/kernel/module.c b/kernel/module.c
index 619ea682e64cd1..299cbac0775cf2 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -666,7 +666,7 @@ static struct module *find_module_all(const char *name, size_t len,
return NULL;
}
-struct module *find_module(const char *name)
+static struct module *find_module(const char *name)
{
module_assert_mutex();
return find_module_all(name, strlen(name), false);
@@ -684,6 +684,21 @@ bool module_loaded(const char *name)
}
EXPORT_SYMBOL_GPL(module_loaded);
+#ifdef CONFIG_LIVEPATCH
+struct module *find_klp_module(const char *name)
+{
+ struct module *mod;
+
+ mutex_lock(&module_mutex);
+ mod = find_module(name);
+ if (mod && !mod->klp_alive)
+ mod = NULL;
+ mutex_unlock(&module_mutex);
+
+ return mod;
+}
+#endif /* CONFIG_LIVEPATCH */
+
#ifdef CONFIG_SMP
static inline void __percpu *mod_percpu(struct module *mod)
--
2.29.2
next prev parent reply other threads:[~2021-01-21 20:12 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 ` [PATCH 02/13] module: add a module_loaded helper Christoph Hellwig
2021-01-21 10:00 ` 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 ` Christoph Hellwig [this message]
2021-01-21 21:45 ` [PATCH 04/13] livepatch: move klp_find_object_module to module.c 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
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