Hi Rusty,
After merging the modules tree, today's linux-next build (powerpc
allnoconfig) failed like this:
kernel/params.c:628:6: error: redefinition of 'kernel_param_lock'
void kernel_param_lock(struct module *mod)
^
In file included from include/linux/module.h:18:0,
from kernel/params.c:21:
include/linux/moduleparam.h:246:20: note: previous definition of 'kernel_param_lock' was here
static inline void kernel_param_lock(struct module *mod)
^
kernel/params.c:633:6: error: redefinition of 'kernel_param_unlock'
void kernel_param_unlock(struct module *mod)
^
In file included from include/linux/module.h:18:0,
from kernel/params.c:21:
include/linux/moduleparam.h:249:20: note: previous definition of 'kernel_param_unlock' was here
static inline void kernel_param_unlock(struct module *mod)
^
Caused by commit b51d23e4e9fe ("module: add per-module param_lock").
This had not been tested with CONFIG_SYSFS not set.
I have added the following patch for today (which may not be complete,
but builds).
From: Stephen Rothwell <[email protected]>
Date: Thu, 25 Jun 2015 16:38:51 +1000
Subject: [PATCH] modules: clean up add per-module param_lock
Signed-off-by: Stephen Rothwell <[email protected]>
---
include/linux/moduleparam.h | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index c12f2147c350..428d7c25c383 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -239,17 +239,8 @@ __check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
return 0;
}
-#ifdef CONFIG_SYSFS
extern void kernel_param_lock(struct module *mod);
extern void kernel_param_unlock(struct module *mod);
-#else
-static inline void kernel_param_lock(struct module *mod)
-{
-}
-static inline void kernel_param_unlock(struct module *mod)
-{
-}
-#endif
#ifndef MODULE
/**
--
2.1.4
--
Cheers,
Stephen Rothwell [email protected]
On Thu, Jun 25, 2015 at 2:54 AM, Stephen Rothwell <[email protected]> wrote:
> Hi Rusty,
>
> After merging the modules tree, today's linux-next build (powerpc
> allnoconfig) failed like this:
I promise I'll build with all[no|mod|yes]config next time! ;-)
Thanks for catching this one too.
>
> kernel/params.c:628:6: error: redefinition of 'kernel_param_lock'
> void kernel_param_lock(struct module *mod)
> ^
> In file included from include/linux/module.h:18:0,
> from kernel/params.c:21:
> include/linux/moduleparam.h:246:20: note: previous definition of 'kernel_param_lock' was here
> static inline void kernel_param_lock(struct module *mod)
> ^
> kernel/params.c:633:6: error: redefinition of 'kernel_param_unlock'
> void kernel_param_unlock(struct module *mod)
> ^
> In file included from include/linux/module.h:18:0,
> from kernel/params.c:21:
> include/linux/moduleparam.h:249:20: note: previous definition of 'kernel_param_unlock' was here
> static inline void kernel_param_unlock(struct module *mod)
> ^
>
> Caused by commit b51d23e4e9fe ("module: add per-module param_lock").
> This had not been tested with CONFIG_SYSFS not set.
>
> I have added the following patch for today (which may not be complete,
> but builds).
this is one way to handle it, but it will cause all modules to use the
built-in param_lock,
which (I don't think) is needed if there's no sysfs; another way would
be to elide the
param_lock entirely if !CONFIG_SYSFS. I'll send a patch for that.
Rusty, is param locking needed if there is no sysfs?
>
> From: Stephen Rothwell <[email protected]>
> Date: Thu, 25 Jun 2015 16:38:51 +1000
> Subject: [PATCH] modules: clean up add per-module param_lock
>
> Signed-off-by: Stephen Rothwell <[email protected]>
> ---
> include/linux/moduleparam.h | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
> index c12f2147c350..428d7c25c383 100644
> --- a/include/linux/moduleparam.h
> +++ b/include/linux/moduleparam.h
> @@ -239,17 +239,8 @@ __check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
> return 0;
> }
>
> -#ifdef CONFIG_SYSFS
> extern void kernel_param_lock(struct module *mod);
> extern void kernel_param_unlock(struct module *mod);
> -#else
> -static inline void kernel_param_lock(struct module *mod)
> -{
> -}
> -static inline void kernel_param_unlock(struct module *mod)
> -{
> -}
> -#endif
>
> #ifndef MODULE
> /**
> --
> 2.1.4
>
> --
> Cheers,
> Stephen Rothwell [email protected]
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 <[email protected]>
Signed-off-by: Dan Streetman <[email protected]>
---
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
Dan Streetman <[email protected]> writes:
> 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.
This doesn't even come close to applying to my tree?
I've fixed it like so, and tested it compiles both with and without
SYSFS.
Subject: param: fix module param locks when !CONFIG_SYSFS.
As Dan Streetman points out, the entire point of locking for is to
stop sysfs accesses, so they're elided entirely in the !SYSFS case.
Reported-by: Stephen Rothwell <[email protected]>
diff --git a/include/linux/module.h b/include/linux/module.h
index abaecf1a63df..237bce382e32 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/module.c b/kernel/module.c
index 1dcf09f214fa..c19b2c50b317 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1820,6 +1820,10 @@ static void mod_sysfs_fini(struct module *mod)
mod_kobject_put(mod);
}
+static void init_param_lock(struct module *mod)
+{
+ mutex_init(&mod->param_lock);
+}
#else /* !CONFIG_SYSFS */
static int mod_sysfs_setup(struct module *mod,
@@ -1842,6 +1846,9 @@ static void del_usage_links(struct module *mod)
{
}
+static void init_param_lock(struct module *mod)
+{
+}
#endif /* CONFIG_SYSFS */
static void mod_sysfs_teardown(struct module *mod)
@@ -3442,7 +3449,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
if (err)
goto unlink_mod;
- mutex_init(&mod->param_lock);
+ init_param_lock(mod);
/* Now we've got everything in the final locations, we can
* find optional sections. */
diff --git a/kernel/params.c b/kernel/params.c
index 8890d0b8dffc..faa461c16f12 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -25,12 +25,22 @@
#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);
/* Use the module's mutex, or if built-in use the built-in mutex */
#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock)
-#define KPARAM_IS_LOCKED(mod) mutex_is_locked(KPARAM_MUTEX(mod))
+
+static inline void check_kparam_locked(struct module *mod)
+{
+ BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod)));
+}
+#else
+static inline void check_kparam_locked(struct module *mod)
+{
+}
+#endif /* !CONFIG_SYSFS */
/* This just allows us to keep track of which parameters are kmalloced. */
struct kmalloced_param {
@@ -459,7 +469,7 @@ static int param_array(struct module *mod,
/* nul-terminate and parse */
save = val[len];
((char *)val)[len] = '\0';
- BUG_ON(!KPARAM_IS_LOCKED(mod));
+ check_kparam_locked(mod);
ret = set(val, &kp);
if (ret != 0)
@@ -496,7 +506,7 @@ 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(!KPARAM_IS_LOCKED(p.mod));
+ check_kparam_locked(p.mod);
ret = arr->ops->get(buffer + off, &p);
if (ret < 0)
return ret;
@@ -616,6 +626,7 @@ 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(KPARAM_MUTEX(mod));
@@ -626,7 +637,6 @@ void kernel_param_unlock(struct module *mod)
mutex_unlock(KPARAM_MUTEX(mod));
}
-#ifdef CONFIG_SYSFS
EXPORT_SYMBOL(kernel_param_lock);
EXPORT_SYMBOL(kernel_param_unlock);
On Thu, Jun 25, 2015 at 5:18 PM, Rusty Russell <[email protected]> wrote:
> Dan Streetman <[email protected]> writes:
>> 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.
>
> This doesn't even come close to applying to my tree?
sorry, I had the !CONFIG_MODULES patch in my tree also, so this was on
top of that one:
https://lkml.org/lkml/2015/6/24/550
I can resend that one, on top of this one, or you can fix it up.
Sorry for not getting it right the first time ;-)
>
> I've fixed it like so, and tested it compiles both with and without
> SYSFS.
>
> Subject: param: fix module param locks when !CONFIG_SYSFS.
>
> As Dan Streetman points out, the entire point of locking for is to
> stop sysfs accesses, so they're elided entirely in the !SYSFS case.
>
> Reported-by: Stephen Rothwell <[email protected]>
>
> diff --git a/include/linux/module.h b/include/linux/module.h
> index abaecf1a63df..237bce382e32 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/module.c b/kernel/module.c
> index 1dcf09f214fa..c19b2c50b317 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -1820,6 +1820,10 @@ static void mod_sysfs_fini(struct module *mod)
> mod_kobject_put(mod);
> }
>
> +static void init_param_lock(struct module *mod)
> +{
> + mutex_init(&mod->param_lock);
> +}
> #else /* !CONFIG_SYSFS */
>
> static int mod_sysfs_setup(struct module *mod,
> @@ -1842,6 +1846,9 @@ static void del_usage_links(struct module *mod)
> {
> }
>
> +static void init_param_lock(struct module *mod)
> +{
> +}
> #endif /* CONFIG_SYSFS */
>
> static void mod_sysfs_teardown(struct module *mod)
> @@ -3442,7 +3449,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
> if (err)
> goto unlink_mod;
>
> - mutex_init(&mod->param_lock);
> + init_param_lock(mod);
oops, i missed fixing this up, when I tested with allnoconfig this
wasn't built due to CONFIG_MODULES=n. I should have built only with
syfs=n :(
>
> /* Now we've got everything in the final locations, we can
> * find optional sections. */
> diff --git a/kernel/params.c b/kernel/params.c
> index 8890d0b8dffc..faa461c16f12 100644
> --- a/kernel/params.c
> +++ b/kernel/params.c
> @@ -25,12 +25,22 @@
> #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);
>
> /* Use the module's mutex, or if built-in use the built-in mutex */
> #define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock)
> -#define KPARAM_IS_LOCKED(mod) mutex_is_locked(KPARAM_MUTEX(mod))
> +
> +static inline void check_kparam_locked(struct module *mod)
> +{
> + BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod)));
> +}
> +#else
> +static inline void check_kparam_locked(struct module *mod)
> +{
> +}
> +#endif /* !CONFIG_SYSFS */
>
> /* This just allows us to keep track of which parameters are kmalloced. */
> struct kmalloced_param {
> @@ -459,7 +469,7 @@ static int param_array(struct module *mod,
> /* nul-terminate and parse */
> save = val[len];
> ((char *)val)[len] = '\0';
> - BUG_ON(!KPARAM_IS_LOCKED(mod));
> + check_kparam_locked(mod);
> ret = set(val, &kp);
>
> if (ret != 0)
> @@ -496,7 +506,7 @@ 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(!KPARAM_IS_LOCKED(p.mod));
> + check_kparam_locked(p.mod);
> ret = arr->ops->get(buffer + off, &p);
> if (ret < 0)
> return ret;
> @@ -616,6 +626,7 @@ 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(KPARAM_MUTEX(mod));
> @@ -626,7 +637,6 @@ void kernel_param_unlock(struct module *mod)
> mutex_unlock(KPARAM_MUTEX(mod));
> }
>
> -#ifdef CONFIG_SYSFS
> EXPORT_SYMBOL(kernel_param_lock);
> EXPORT_SYMBOL(kernel_param_unlock);
>
Hi Rusty,
On Fri, 26 Jun 2015 06:48:37 +0930 Rusty Russell <[email protected]> wrote:
>
> Dan Streetman <[email protected]> writes:
> > 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.
>
> This doesn't even come close to applying to my tree?
That's because (as Dan noted) there was another fix patch in the tree
he was fixing ...
> I've fixed it like so, and tested it compiles both with and without
> SYSFS.
>
> Subject: param: fix module param locks when !CONFIG_SYSFS.
>
> As Dan Streetman points out, the entire point of locking for is to
> stop sysfs accesses, so they're elided entirely in the !SYSFS case.
>
> Reported-by: Stephen Rothwell <[email protected]>
Except the commit you added to the modules tree has no signed off by or
commentary :-(
--
Cheers,
Stephen Rothwell [email protected]
Hi Rusty,
On Thu, 25 Jun 2015 17:34:31 -0400 Dan Streetman <[email protected]> wrote:
>
> On Thu, Jun 25, 2015 at 5:18 PM, Rusty Russell <[email protected]> wrote:
> > Dan Streetman <[email protected]> writes:
> >> 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.
> >
> > This doesn't even come close to applying to my tree?
>
> sorry, I had the !CONFIG_MODULES patch in my tree also, so this was on
> top of that one:
> https://lkml.org/lkml/2015/6/24/550
>
> I can resend that one, on top of this one, or you can fix it up.
>
> Sorry for not getting it right the first time ;-)
This is what I ended up applying to yesterday's linux-next:
From: Stephen Rothwell <[email protected]>
Date: Fri, 26 Jun 2015 13:19:19 +1000
Subject: [PATCH] modules: only use mod->param_lock if CONFIG_MODULES
Signed-off-by: Stephen Rothwell <[email protected]>
---
kernel/params.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/params.c b/kernel/params.c
index faa461c16f12..adc0bbc06cc5 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -30,7 +30,11 @@
static DEFINE_MUTEX(param_lock);
/* Use the module's mutex, or if built-in use the built-in mutex */
+#ifdef CONFIG_MODULES
#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock)
+#else
+#define KPARAM_MUTEX(mod) (¶m_lock)
+#endif
static inline void check_kparam_locked(struct module *mod)
{
--
2.1.4
--
Cheers,
Stephen Rothwell [email protected]
Stephen Rothwell <[email protected]> writes:
> Hi Rusty,
>
> On Thu, 25 Jun 2015 17:34:31 -0400 Dan Streetman <[email protected]> wrote:
>>
>> On Thu, Jun 25, 2015 at 5:18 PM, Rusty Russell <[email protected]> wrote:
>> > Dan Streetman <[email protected]> writes:
>> >> 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.
>> >
>> > This doesn't even come close to applying to my tree?
>>
>> sorry, I had the !CONFIG_MODULES patch in my tree also, so this was on
>> top of that one:
>> https://lkml.org/lkml/2015/6/24/550
>>
>> I can resend that one, on top of this one, or you can fix it up.
>>
>> Sorry for not getting it right the first time ;-)
>
> This is what I ended up applying to yesterday's linux-next:
Thanks, added correct description to previous patch and applied this
on top.
Sorry for the hassle,
Rusty.