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author | Rafael J. Wysocki <rjw@sisk.pl> | 2012-03-28 21:29:45 (GMT) |
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committer | Rafael J. Wysocki <rjw@sisk.pl> | 2012-03-28 21:29:45 (GMT) |
commit | fe2e39d8782d885755139304d8dba0b3e5bfa878 (patch) | |
tree | 200fb998fe94b9ccd93d07c59656b8f5ab62c5d7 /kernel | |
parent | 9a4768d849d28a79566aa37de19b9852d2da8ec4 (diff) | |
download | linux-fe2e39d8782d885755139304d8dba0b3e5bfa878.tar.xz |
firmware_class: Rework usermodehelper check
Instead of two functions, read_lock_usermodehelper() and
usermodehelper_is_disabled(), used in combination, introduce
usermodehelper_read_trylock() that will only return with umhelper_sem
held if usermodehelper_disabled is unset (and will return -EAGAIN
otherwise) and make _request_firmware() use it.
Rename read_unlock_usermodehelper() to
usermodehelper_read_unlock() to follow the naming convention of the
new function.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/kmod.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c index 957a7aa..4079ac1 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -339,17 +339,24 @@ static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq); */ #define RUNNING_HELPERS_TIMEOUT (5 * HZ) -void read_lock_usermodehelper(void) +int usermodehelper_read_trylock(void) { + int ret = 0; + down_read(&umhelper_sem); + if (usermodehelper_disabled) { + up_read(&umhelper_sem); + ret = -EAGAIN; + } + return ret; } -EXPORT_SYMBOL_GPL(read_lock_usermodehelper); +EXPORT_SYMBOL_GPL(usermodehelper_read_trylock); -void read_unlock_usermodehelper(void) +void usermodehelper_read_unlock(void) { up_read(&umhelper_sem); } -EXPORT_SYMBOL_GPL(read_unlock_usermodehelper); +EXPORT_SYMBOL_GPL(usermodehelper_read_unlock); /** * usermodehelper_disable - prevent new helpers from being started @@ -390,15 +397,6 @@ void usermodehelper_enable(void) up_write(&umhelper_sem); } -/** - * usermodehelper_is_disabled - check if new helpers are allowed to be started - */ -bool usermodehelper_is_disabled(void) -{ - return usermodehelper_disabled; -} -EXPORT_SYMBOL_GPL(usermodehelper_is_disabled); - static void helper_lock(void) { atomic_inc(&running_helpers); |