diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2015-06-26 06:44:38 +0930 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2015-06-28 14:46:14 +0930 |
| commit | cf2fde7b39e9446e2af015215d7fb695781af0c1 (patch) | |
| tree | 646bec4e1717bf8370a3d4153c59a06a4a78f73f /kernel/params.c | |
| parent | 38183b9c31cf21d8996d6eee2e3a14508b20c418 (diff) | |
| download | linux-stable-cf2fde7b39e9446e2af015215d7fb695781af0c1.tar.gz linux-stable-cf2fde7b39e9446e2af015215d7fb695781af0c1.tar.bz2 linux-stable-cf2fde7b39e9446e2af015215d7fb695781af0c1.zip | |
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 <sfr@canb.auug.org.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'kernel/params.c')
| -rw-r--r-- | kernel/params.c | 18 |
1 files changed, 14 insertions, 4 deletions
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); |