3 files changed, 55 insertions, 61 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 8e4528c9909f..f5e9491ef7ac 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -917,6 +917,10 @@ static int check_version(Elf_Shdr *sechdrs,
         if (!crc)
                 return 1;
 
+        /* No versions at all?  modprobe --force does this. */
+        if (versindex == 0)
+                return try_to_force_load(mod, symname) == 0;
+
         versions = (void *) sechdrs[versindex].sh_addr;
         num_versions = sechdrs[versindex].sh_size
                 / sizeof(struct modversion_info);
@@ -932,8 +936,9 @@ static int check_version(Elf_Shdr *sechdrs,
                 goto bad_version;
         }
 
-        if (!try_to_force_load(mod, symname))
-                return 1;
+        printk(KERN_WARNING "%s: no symbol version for %s\n",
+               mod->name, symname);
+        return 0;
 
 bad_version:
         printk("%s: disagrees about version of symbol %s\n",
@@ -952,11 +957,14 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
         return check_version(sechdrs, versindex, "struct_module", mod, crc);
 }
 
-/* First part is kernel version, which we ignore. */
-static inline int same_magic(const char *amagic, const char *bmagic)
+/* First part is kernel version, which we ignore if module has crcs. */
+static inline int same_magic(const char *amagic, const char *bmagic,
+                             bool has_crcs)
 {
-        amagic += strcspn(amagic, " ");
-        bmagic += strcspn(bmagic, " ");
+        if (has_crcs) {
+                amagic += strcspn(amagic, " ");
+                bmagic += strcspn(bmagic, " ");
+        }
         return strcmp(amagic, bmagic) == 0;
 }
 #else
@@ -976,7 +984,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
         return 1;
 }
 
-static inline int same_magic(const char *amagic, const char *bmagic)
+static inline int same_magic(const char *amagic, const char *bmagic,
+                             bool has_crcs)
 {
         return strcmp(amagic, bmagic) == 0;
 }
@@ -1869,7 +1878,7 @@ static struct module *load_module(void __user *umod,
                 err = try_to_force_load(mod, "magic");
                 if (err)
                         goto free_hdr;
-        } else if (!same_magic(modmagic, vermagic)) {
+        } else if (!same_magic(modmagic, vermagic, versindex)) {
                 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
                        mod->name, modmagic, vermagic);
                 err = -ENOEXEC;
diff --git a/kernel/sched.c b/kernel/sched.c
index 58fb8af15776..c51b6565e07c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4567,8 +4567,6 @@ EXPORT_SYMBOL(schedule);
 asmlinkage void __sched preempt_schedule(void)
 {
         struct thread_info *ti = current_thread_info();
-        struct task_struct *task = current;
-        int saved_lock_depth;
 
         /*
          * If there is a non-zero preempt_count or interrupts are disabled,
@@ -4579,16 +4577,7 @@ asmlinkage void __sched preempt_schedule(void)
 
         do {
                 add_preempt_count(PREEMPT_ACTIVE);
-
-                /*
-                 * We keep the big kernel semaphore locked, but we
-                 * clear ->lock_depth so that schedule() doesnt
-                 * auto-release the semaphore:
-                 */
-                saved_lock_depth = task->lock_depth;
-                task->lock_depth = -1;
                 schedule();
-                task->lock_depth = saved_lock_depth;
                 sub_preempt_count(PREEMPT_ACTIVE);
 
                 /*
@@ -4609,26 +4598,15 @@ EXPORT_SYMBOL(preempt_schedule);
 asmlinkage void __sched preempt_schedule_irq(void)
 {
         struct thread_info *ti = current_thread_info();
-        struct task_struct *task = current;
-        int saved_lock_depth;
 
         /* Catch callers which need to be fixed */
         BUG_ON(ti->preempt_count || !irqs_disabled());
 
         do {
                 add_preempt_count(PREEMPT_ACTIVE);
-
-                /*
-                 * We keep the big kernel semaphore locked, but we
-                 * clear ->lock_depth so that schedule() doesnt
-                 * auto-release the semaphore:
-                 */
-                saved_lock_depth = task->lock_depth;
-                task->lock_depth = -1;
                 local_irq_enable();
                 schedule();
                 local_irq_disable();
-                task->lock_depth = saved_lock_depth;
                 sub_preempt_count(PREEMPT_ACTIVE);
 
                 /*
@@ -5853,8 +5831,11 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
         spin_unlock_irqrestore(&rq->lock, flags);
 
         /* Set the preempt count _outside_ the spinlocks! */
+#if defined(CONFIG_PREEMPT)
+        task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
+#else
         task_thread_info(idle)->preempt_count = 0;
-
+#endif
         /*
          * The idle tasks have their own, simple scheduling class:
          */
diff --git a/kernel/semaphore.c b/kernel/semaphore.c
index 5e41217239e8..5c2942e768cd 100644
--- a/kernel/semaphore.c
+++ b/kernel/semaphore.c
@@ -54,9 +54,10 @@ void down(struct semaphore *sem)
         unsigned long flags;
 
         spin_lock_irqsave(&sem->lock, flags);
-        if (unlikely(!sem->count))
+        if (likely(sem->count > 0))
+                sem->count--;
+        else
                 __down(sem);
-        sem->count--;
         spin_unlock_irqrestore(&sem->lock, flags);
 }
 EXPORT_SYMBOL(down);
@@ -76,10 +77,10 @@ int down_interruptible(struct semaphore *sem)
         int result = 0;
 
         spin_lock_irqsave(&sem->lock, flags);
-        if (unlikely(!sem->count))
-                result = __down_interruptible(sem);
-        if (!result)
+        if (likely(sem->count > 0))
                 sem->count--;
+        else
+                result = __down_interruptible(sem);
         spin_unlock_irqrestore(&sem->lock, flags);
 
         return result;
@@ -102,10 +103,10 @@ int down_killable(struct semaphore *sem)
         int result = 0;
 
         spin_lock_irqsave(&sem->lock, flags);
-        if (unlikely(!sem->count))
-                result = __down_killable(sem);
-        if (!result)
+        if (likely(sem->count > 0))
                 sem->count--;
+        else
+                result = __down_killable(sem);
         spin_unlock_irqrestore(&sem->lock, flags);
 
         return result;
@@ -156,10 +157,10 @@ int down_timeout(struct semaphore *sem, long jiffies)
         int result = 0;
 
         spin_lock_irqsave(&sem->lock, flags);
-        if (unlikely(!sem->count))
-                result = __down_timeout(sem, jiffies);
-        if (!result)
+        if (likely(sem->count > 0))
                 sem->count--;
+        else
+                result = __down_timeout(sem, jiffies);
         spin_unlock_irqrestore(&sem->lock, flags);
 
         return result;
@@ -178,8 +179,9 @@ void up(struct semaphore *sem)
         unsigned long flags;
 
         spin_lock_irqsave(&sem->lock, flags);
-        sem->count++;
-        if (unlikely(!list_empty(&sem->wait_list)))
+        if (likely(list_empty(&sem->wait_list)))
+                sem->count++;
+        else
                 __up(sem);
         spin_unlock_irqrestore(&sem->lock, flags);
 }
@@ -190,6 +192,7 @@ EXPORT_SYMBOL(up);
 struct semaphore_waiter {
         struct list_head list;
         struct task_struct *task;
+        int up;
 };
 
 /*
@@ -202,34 +205,33 @@ static inline int __sched __down_common(struct semaphore *sem, long state,
 {
         struct task_struct *task = current;
         struct semaphore_waiter waiter;
-        int ret = 0;
 
-        waiter.task = task;
         list_add_tail(&waiter.list, &sem->wait_list);
+        waiter.task = task;
+        waiter.up = 0;
 
         for (;;) {
-                if (state == TASK_INTERRUPTIBLE && signal_pending(task)) {
-                        ret = -EINTR;
-                        break;
-                }
-                if (state == TASK_KILLABLE && fatal_signal_pending(task)) {
-                        ret = -EINTR;
-                        break;
-                }
-                if (timeout <= 0) {
-                        ret = -ETIME;
-                        break;
-                }
+                if (state == TASK_INTERRUPTIBLE && signal_pending(task))
+                        goto interrupted;
+                if (state == TASK_KILLABLE && fatal_signal_pending(task))
+                        goto interrupted;
+                if (timeout <= 0)
+                        goto timed_out;
                 __set_task_state(task, state);
                 spin_unlock_irq(&sem->lock);
                 timeout = schedule_timeout(timeout);
                 spin_lock_irq(&sem->lock);
-                if (sem->count > 0)
-                        break;
+                if (waiter.up)
+                        return 0;
         }
 
+ timed_out:
+        list_del(&waiter.list);
+        return -ETIME;
+
+ interrupted:
         list_del(&waiter.list);
-        return ret;
+        return -EINTR;
 }
 
 static noinline void __sched __down(struct semaphore *sem)
@@ -256,5 +258,7 @@ static noinline void __sched __up(struct semaphore *sem)
 {
         struct semaphore_waiter *waiter = list_first_entry(&sem->wait_list,
                                                 struct semaphore_waiter, list);
+        list_del(&waiter->list);
+        waiter->up = 1;
         wake_up_process(waiter->task);
 }