diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2015-06-25 17:14:38 -0400 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2015-06-28 01:16:14 -0400 |
| commit | cf2fde7b39e9446e2af015215d7fb695781af0c1 (patch) | |
| tree | 646bec4e1717bf8370a3d4153c59a06a4a78f73f /kernel/params.c | |
| parent | 38183b9c31cf21d8996d6eee2e3a14508b20c418 (diff) | |
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 @@ | |||
| 25 | #include <linux/slab.h> | 25 | #include <linux/slab.h> |
| 26 | #include <linux/ctype.h> | 26 | #include <linux/ctype.h> |
| 27 | 27 | ||
| 28 | #ifdef CONFIG_SYSFS | ||
| 28 | /* Protects all built-in parameters, modules use their own param_lock */ | 29 | /* Protects all built-in parameters, modules use their own param_lock */ |
| 29 | static DEFINE_MUTEX(param_lock); | 30 | static DEFINE_MUTEX(param_lock); |
| 30 | 31 | ||
| 31 | /* Use the module's mutex, or if built-in use the built-in mutex */ | 32 | /* Use the module's mutex, or if built-in use the built-in mutex */ |
| 32 | #define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock) | 33 | #define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock) |
| 33 | #define KPARAM_IS_LOCKED(mod) mutex_is_locked(KPARAM_MUTEX(mod)) | 34 | |
| 35 | static inline void check_kparam_locked(struct module *mod) | ||
| 36 | { | ||
| 37 | BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod))); | ||
| 38 | } | ||
| 39 | #else | ||
| 40 | static inline void check_kparam_locked(struct module *mod) | ||
| 41 | { | ||
| 42 | } | ||
| 43 | #endif /* !CONFIG_SYSFS */ | ||
| 34 | 44 | ||
| 35 | /* This just allows us to keep track of which parameters are kmalloced. */ | 45 | /* This just allows us to keep track of which parameters are kmalloced. */ |
| 36 | struct kmalloced_param { | 46 | struct kmalloced_param { |
| @@ -459,7 +469,7 @@ static int param_array(struct module *mod, | |||
| 459 | /* nul-terminate and parse */ | 469 | /* nul-terminate and parse */ |
| 460 | save = val[len]; | 470 | save = val[len]; |
| 461 | ((char *)val)[len] = '\0'; | 471 | ((char *)val)[len] = '\0'; |
| 462 | BUG_ON(!KPARAM_IS_LOCKED(mod)); | 472 | check_kparam_locked(mod); |
| 463 | ret = set(val, &kp); | 473 | ret = set(val, &kp); |
| 464 | 474 | ||
| 465 | if (ret != 0) | 475 | if (ret != 0) |
| @@ -496,7 +506,7 @@ static int param_array_get(char *buffer, const struct kernel_param *kp) | |||
| 496 | if (i) | 506 | if (i) |
| 497 | buffer[off++] = ','; | 507 | buffer[off++] = ','; |
| 498 | p.arg = arr->elem + arr->elemsize * i; | 508 | p.arg = arr->elem + arr->elemsize * i; |
| 499 | BUG_ON(!KPARAM_IS_LOCKED(p.mod)); | 509 | check_kparam_locked(p.mod); |
| 500 | ret = arr->ops->get(buffer + off, &p); | 510 | ret = arr->ops->get(buffer + off, &p); |
| 501 | if (ret < 0) | 511 | if (ret < 0) |
| 502 | return ret; | 512 | return ret; |
| @@ -616,6 +626,7 @@ static ssize_t param_attr_store(struct module_attribute *mattr, | |||
| 616 | #define __modinit __init | 626 | #define __modinit __init |
| 617 | #endif | 627 | #endif |
| 618 | 628 | ||
| 629 | #ifdef CONFIG_SYSFS | ||
| 619 | void kernel_param_lock(struct module *mod) | 630 | void kernel_param_lock(struct module *mod) |
| 620 | { | 631 | { |
| 621 | mutex_lock(KPARAM_MUTEX(mod)); | 632 | mutex_lock(KPARAM_MUTEX(mod)); |
| @@ -626,7 +637,6 @@ void kernel_param_unlock(struct module *mod) | |||
| 626 | mutex_unlock(KPARAM_MUTEX(mod)); | 637 | mutex_unlock(KPARAM_MUTEX(mod)); |
| 627 | } | 638 | } |
| 628 | 639 | ||
| 629 | #ifdef CONFIG_SYSFS | ||
| 630 | EXPORT_SYMBOL(kernel_param_lock); | 640 | EXPORT_SYMBOL(kernel_param_lock); |
| 631 | EXPORT_SYMBOL(kernel_param_unlock); | 641 | EXPORT_SYMBOL(kernel_param_unlock); |
| 632 | 642 | ||