From: Dan Streetman <ddstreet@ieee•org>
To: Rusty Russell <rusty@rustcorp•com.au>
Cc: Stephen Rothwell <sfr@canb•auug.org.au>,
linux-next@vger•kernel.org, linux-kernel@vger•kernel.org,
Dan Streetman <ddstreet@ieee•org>
Subject: [PATCH] modules: elide param_lock if !CONFIG_SYSFS
Date: Thu, 25 Jun 2015 09:04:08 -0400 [thread overview]
Message-ID: <1435237448-13684-1-git-send-email-ddstreet@ieee.org> (raw)
In-Reply-To: <CALZtONA4kOn2yciNYA2C9QdXuovdjFXBca4EU4CDs6XDiQtxJQ@mail.gmail.com>
Only include the built-in and per-module param_lock, and corresponding
lock/unlock functions, if sysfs is enabled. If there is no sysfs there
is no need for locking kernel params.
This fixes a build break when CONFIG_SYSFS is not enabled, introduced
by commit b51d23e.
Reported-by: Stephen Rothwell <sfr@canb•auug.org.au>
Signed-off-by: Dan Streetman <ddstreet@ieee•org>
---
include/linux/module.h | 2 ++
kernel/params.c | 21 ++++++++++++++++-----
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index 6ba0e87..46efa1c 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -240,7 +240,9 @@ struct module {
unsigned int num_syms;
/* Kernel parameters. */
+#ifdef CONFIG_SYSFS
struct mutex param_lock;
+#endif
struct kernel_param *kp;
unsigned int num_kp;
diff --git a/kernel/params.c b/kernel/params.c
index 9c955cd..d2c6a2a 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -25,6 +25,7 @@
#include <linux/slab.h>
#include <linux/ctype.h>
+#ifdef CONFIG_SYSFS
/* Protects all built-in parameters, modules use their own param_lock */
static DEFINE_MUTEX(param_lock);
@@ -38,6 +39,17 @@ static inline struct mutex *__param_lock(struct module *mod)
#endif
}
+static inline void __check_param_lock(struct module *mod)
+{
+ BUG_ON(!mutex_is_locked(__param_lock(mod)));
+}
+#else /* !CONFIG_SYSFS */
+/* we don't need any param lock if there's no sysfs */
+static inline void __check_param_lock(struct module *mod)
+{
+}
+#endif
+
/* This just allows us to keep track of which parameters are kmalloced. */
struct kmalloced_param {
struct list_head list;
@@ -465,7 +477,7 @@ static int param_array(struct module *mod,
/* nul-terminate and parse */
save = val[len];
((char *)val)[len] = '\0';
- BUG_ON(!mutex_is_locked(__param_lock(mod)));
+ __check_param_lock(mod);
ret = set(val, &kp);
if (ret != 0)
@@ -502,7 +514,7 @@ static int param_array_get(char *buffer, const struct kernel_param *kp)
if (i)
buffer[off++] = ',';
p.arg = arr->elem + arr->elemsize * i;
- BUG_ON(!mutex_is_locked(__param_lock(p.mod)));
+ __check_param_lock(p.mod);
ret = arr->ops->get(buffer + off, &p);
if (ret < 0)
return ret;
@@ -622,18 +634,17 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
#define __modinit __init
#endif
+#ifdef CONFIG_SYSFS
void kernel_param_lock(struct module *mod)
{
mutex_lock(__param_lock(mod));
}
+EXPORT_SYMBOL(kernel_param_lock);
void kernel_param_unlock(struct module *mod)
{
mutex_unlock(__param_lock(mod));
}
-
-#ifdef CONFIG_SYSFS
-EXPORT_SYMBOL(kernel_param_lock);
EXPORT_SYMBOL(kernel_param_unlock);
/*
--
2.1.0
next prev parent reply other threads:[~2015-06-25 13:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-25 6:54 linux-next: build failure after merge of the modules tree Stephen Rothwell
2015-06-25 9:51 ` Dan Streetman
2015-06-25 13:04 ` Dan Streetman [this message]
2015-06-25 21:18 ` [PATCH] modules: elide param_lock if !CONFIG_SYSFS Rusty Russell
2015-06-25 21:34 ` Dan Streetman
2015-06-27 0:21 ` Stephen Rothwell
2015-06-28 5:21 ` Rusty Russell
2015-06-25 22:39 ` Stephen Rothwell
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