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Diffstat (limited to 'kernel')
-rw-r--r--kernel/kmod.c44
-rw-r--r--kernel/sched.c7
-rw-r--r--kernel/timer.c4
3 files changed, 38 insertions, 17 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 3a7379aa31c..796276141e5 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -217,7 +217,10 @@ static int wait_for_helper(void *data)
sub_info->retval = ret;
}
- complete(sub_info->complete);
+ if (sub_info->wait < 0)
+ kfree(sub_info);
+ else
+ complete(sub_info->complete);
return 0;
}
@@ -239,6 +242,9 @@ static void __call_usermodehelper(struct work_struct *work)
pid = kernel_thread(____call_usermodehelper, sub_info,
CLONE_VFORK | SIGCHLD);
+ if (wait < 0)
+ return;
+
if (pid < 0) {
sub_info->retval = pid;
complete(sub_info->complete);
@@ -253,6 +259,9 @@ static void __call_usermodehelper(struct work_struct *work)
* @envp: null-terminated environment list
* @session_keyring: session keyring for process (NULL for an empty keyring)
* @wait: wait for the application to finish and return status.
+ * when -1 don't wait at all, but you get no useful error back when
+ * the program couldn't be exec'ed. This makes it safe to call
+ * from interrupt context.
*
* Runs a user-space application. The application is started
* asynchronously if wait is not set, and runs as a child of keventd.
@@ -265,17 +274,8 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
struct key *session_keyring, int wait)
{
DECLARE_COMPLETION_ONSTACK(done);
- struct subprocess_info sub_info = {
- .work = __WORK_INITIALIZER(sub_info.work,
- __call_usermodehelper),
- .complete = &done,
- .path = path,
- .argv = argv,
- .envp = envp,
- .ring = session_keyring,
- .wait = wait,
- .retval = 0,
- };
+ struct subprocess_info *sub_info;
+ int retval;
if (!khelper_wq)
return -EBUSY;
@@ -283,9 +283,25 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
if (path[0] == '\0')
return 0;
- queue_work(khelper_wq, &sub_info.work);
+ sub_info = kzalloc(sizeof(struct subprocess_info), GFP_ATOMIC);
+ if (!sub_info)
+ return -ENOMEM;
+
+ INIT_WORK(&sub_info->work, __call_usermodehelper);
+ sub_info->complete = &done;
+ sub_info->path = path;
+ sub_info->argv = argv;
+ sub_info->envp = envp;
+ sub_info->ring = session_keyring;
+ sub_info->wait = wait;
+
+ queue_work(khelper_wq, &sub_info->work);
+ if (wait < 0) /* task has freed sub_info */
+ return 0;
wait_for_completion(&done);
- return sub_info.retval;
+ retval = sub_info->retval;
+ kfree(sub_info);
+ return retval;
}
EXPORT_SYMBOL(call_usermodehelper_keys);
diff --git a/kernel/sched.c b/kernel/sched.c
index 08f86178aa3..0dc757246d8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1853,6 +1853,13 @@ context_switch(struct rq *rq, struct task_struct *prev,
struct mm_struct *mm = next->mm;
struct mm_struct *oldmm = prev->active_mm;
+ /*
+ * For paravirt, this is coupled with an exit in switch_to to
+ * combine the page table reload and the switch backend into
+ * one hypercall.
+ */
+ arch_enter_lazy_cpu_mode();
+
if (!mm) {
next->active_mm = oldmm;
atomic_inc(&oldmm->mm_count);
diff --git a/kernel/timer.c b/kernel/timer.c
index 8533c379608..4902181e10e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1162,11 +1162,9 @@ static inline void calc_load(unsigned long ticks)
* This read-write spinlock protects us from races in SMP while
* playing with xtime and avenrun.
*/
-#ifndef ARCH_HAVE_XTIME_LOCK
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
+__attribute__((weak)) __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
EXPORT_SYMBOL(xtime_lock);
-#endif
/*
* This function runs timers and the timer-tq in bottom half context.