22 files changed, 522 insertions, 244 deletions

diff --git a/kernel/compat.c b/kernel/compat.c
index 1867290c37e3..8c9cd88b6785 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -23,7 +23,6 @@
 #include <linux/security.h>
 
 #include <asm/uaccess.h>
-#include <asm/bug.h>
 
 int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
 {
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index fe2f71f92ae0..ba42b0a76961 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -641,7 +641,7 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
  * task has been modifying its cpuset.
  */
 
-void cpuset_update_task_memory_state()
+void cpuset_update_task_memory_state(void)
 {
         int my_cpusets_mem_gen;
         struct task_struct *tsk = current;
diff --git a/kernel/fork.c b/kernel/fork.c
index 4ae8cfc1c89c..8e88b374cee9 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -446,6 +446,55 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
         }
 }
 
+/*
+ * Allocate a new mm structure and copy contents from the
+ * mm structure of the passed in task structure.
+ */
+static struct mm_struct *dup_mm(struct task_struct *tsk)
+{
+        struct mm_struct *mm, *oldmm = current->mm;
+        int err;
+
+        if (!oldmm)
+                return NULL;
+
+        mm = allocate_mm();
+        if (!mm)
+                goto fail_nomem;
+
+        memcpy(mm, oldmm, sizeof(*mm));
+
+        if (!mm_init(mm))
+                goto fail_nomem;
+
+        if (init_new_context(tsk, mm))
+                goto fail_nocontext;
+
+        err = dup_mmap(mm, oldmm);
+        if (err)
+                goto free_pt;
+
+        mm->hiwater_rss = get_mm_rss(mm);
+        mm->hiwater_vm = mm->total_vm;
+
+        return mm;
+
+free_pt:
+        mmput(mm);
+
+fail_nomem:
+        return NULL;
+
+fail_nocontext:
+        /*
+         * If init_new_context() failed, we cannot use mmput() to free the mm
+         * because it calls destroy_context()
+         */
+        mm_free_pgd(mm);
+        free_mm(mm);
+        return NULL;
+}
+
 static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
 {
         struct mm_struct * mm, *oldmm;
@@ -473,43 +522,17 @@ static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
         }
 
         retval = -ENOMEM;
-        mm = allocate_mm();
+        mm = dup_mm(tsk);
         if (!mm)
                 goto fail_nomem;
 
-        /* Copy the current MM stuff.. */
-        memcpy(mm, oldmm, sizeof(*mm));
-        if (!mm_init(mm))
-                goto fail_nomem;
-
-        if (init_new_context(tsk,mm))
-                goto fail_nocontext;
-
-        retval = dup_mmap(mm, oldmm);
-        if (retval)
-                goto free_pt;
-
-        mm->hiwater_rss = get_mm_rss(mm);
-        mm->hiwater_vm = mm->total_vm;
-
 good_mm:
         tsk->mm = mm;
         tsk->active_mm = mm;
         return 0;
 
-free_pt:
-        mmput(mm);
 fail_nomem:
         return retval;
-
-fail_nocontext:
-        /*
-         * If init_new_context() failed, we cannot use mmput() to free the mm
-         * because it calls destroy_context()
-         */
-        mm_free_pgd(mm);
-        free_mm(mm);
-        return retval;
 }
 
 static inline struct fs_struct *__copy_fs_struct(struct fs_struct *old)
@@ -597,32 +620,17 @@ out:
         return newf;
 }
 
-static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
+/*
+ * Allocate a new files structure and copy contents from the
+ * passed in files structure.
+ */
+static struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
 {
-        struct files_struct *oldf, *newf;
+        struct files_struct *newf;
         struct file **old_fds, **new_fds;
-        int open_files, size, i, error = 0, expand;
+        int open_files, size, i, expand;
         struct fdtable *old_fdt, *new_fdt;
 
-        /*
-         * A background process may not have any files ...
-         */
-        oldf = current->files;
-        if (!oldf)
-                goto out;
-
-        if (clone_flags & CLONE_FILES) {
-                atomic_inc(&oldf->count);
-                goto out;
-        }
-
-        /*
-         * Note: we may be using current for both targets (See exec.c)
-         * This works because we cache current->files (old) as oldf. Don't
-         * break this.
-         */
-        tsk->files = NULL;
-        error = -ENOMEM;
         newf = alloc_files();
         if (!newf)
                 goto out;
@@ -651,9 +659,9 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
         if (expand) {
                 spin_unlock(&oldf->file_lock);
                 spin_lock(&newf->file_lock);
-                error = expand_files(newf, open_files-1);
+                *errorp = expand_files(newf, open_files-1);
                 spin_unlock(&newf->file_lock);
-                if (error < 0)
+                if (*errorp < 0)
                         goto out_release;
                 new_fdt = files_fdtable(newf);
                 /*
@@ -702,10 +710,8 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
                 memset(&new_fdt->close_on_exec->fds_bits[start], 0, left);
         }
 
-        tsk->files = newf;
-        error = 0;
 out:
-        return error;
+        return newf;
 
 out_release:
         free_fdset (new_fdt->close_on_exec, new_fdt->max_fdset);
@@ -715,6 +721,40 @@ out_release:
         goto out;
 }
 
+static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
+{
+        struct files_struct *oldf, *newf;
+        int error = 0;
+
+        /*
+         * A background process may not have any files ...
+         */
+        oldf = current->files;
+        if (!oldf)
+                goto out;
+
+        if (clone_flags & CLONE_FILES) {
+                atomic_inc(&oldf->count);
+                goto out;
+        }
+
+        /*
+         * Note: we may be using current for both targets (See exec.c)
+         * This works because we cache current->files (old) as oldf. Don't
+         * break this.
+         */
+        tsk->files = NULL;
+        error = -ENOMEM;
+        newf = dup_fd(oldf, &error);
+        if (!newf)
+                goto out;
+
+        tsk->files = newf;
+        error = 0;
+out:
+        return error;
+}
+
 /*
  *      Helper to unshare the files of the current task.
  *      We don't want to expose copy_files internals to
@@ -802,7 +842,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
         init_sigpending(&sig->shared_pending);
         INIT_LIST_HEAD(&sig->posix_timers);
 
-        hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC);
+        hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_REL);
         sig->it_real_incr.tv64 = 0;
         sig->real_timer.function = it_real_fn;
         sig->real_timer.data = tsk;
@@ -1323,3 +1363,249 @@ void __init proc_caches_init(void)
                         sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
 }
+
+
+/*
+ * Check constraints on flags passed to the unshare system call and
+ * force unsharing of additional process context as appropriate.
+ */
+static inline void check_unshare_flags(unsigned long *flags_ptr)
+{
+        /*
+         * If unsharing a thread from a thread group, must also
+         * unshare vm.
+         */
+        if (*flags_ptr & CLONE_THREAD)
+                *flags_ptr |= CLONE_VM;
+
+        /*
+         * If unsharing vm, must also unshare signal handlers.
+         */
+        if (*flags_ptr & CLONE_VM)
+                *flags_ptr |= CLONE_SIGHAND;
+
+        /*
+         * If unsharing signal handlers and the task was created
+         * using CLONE_THREAD, then must unshare the thread
+         */
+        if ((*flags_ptr & CLONE_SIGHAND) &&
+            (atomic_read(&current->signal->count) > 1))
+                *flags_ptr |= CLONE_THREAD;
+
+        /*
+         * If unsharing namespace, must also unshare filesystem information.
+         */
+        if (*flags_ptr & CLONE_NEWNS)
+                *flags_ptr |= CLONE_FS;
+}
+
+/*
+ * Unsharing of tasks created with CLONE_THREAD is not supported yet
+ */
+static int unshare_thread(unsigned long unshare_flags)
+{
+        if (unshare_flags & CLONE_THREAD)
+                return -EINVAL;
+
+        return 0;
+}
+
+/*
+ * Unshare the filesystem structure if it is being shared
+ */
+static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
+{
+        struct fs_struct *fs = current->fs;
+
+        if ((unshare_flags & CLONE_FS) &&
+            (fs && atomic_read(&fs->count) > 1)) {
+                *new_fsp = __copy_fs_struct(current->fs);
+                if (!*new_fsp)
+                        return -ENOMEM;
+        }
+
+        return 0;
+}
+
+/*
+ * Unshare the namespace structure if it is being shared
+ */
+static int unshare_namespace(unsigned long unshare_flags, struct namespace **new_nsp, struct fs_struct *new_fs)
+{
+        struct namespace *ns = current->namespace;
+
+        if ((unshare_flags & CLONE_NEWNS) &&
+            (ns && atomic_read(&ns->count) > 1)) {
+                if (!capable(CAP_SYS_ADMIN))
+                        return -EPERM;
+
+                *new_nsp = dup_namespace(current, new_fs ? new_fs : current->fs);
+                if (!*new_nsp)
+                        return -ENOMEM;
+        }
+
+        return 0;
+}
+
+/*
+ * Unsharing of sighand for tasks created with CLONE_SIGHAND is not
+ * supported yet
+ */
+static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
+{
+        struct sighand_struct *sigh = current->sighand;
+
+        if ((unshare_flags & CLONE_SIGHAND) &&
+            (sigh && atomic_read(&sigh->count) > 1))
+                return -EINVAL;
+        else
+                return 0;
+}
+
+/*
+ * Unshare vm if it is being shared
+ */
+static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp)
+{
+        struct mm_struct *mm = current->mm;
+
+        if ((unshare_flags & CLONE_VM) &&
+            (mm && atomic_read(&mm->mm_users) > 1)) {
+                *new_mmp = dup_mm(current);
+                if (!*new_mmp)
+                        return -ENOMEM;
+        }
+
+        return 0;
+}
+
+/*
+ * Unshare file descriptor table if it is being shared
+ */
+static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp)
+{
+        struct files_struct *fd = current->files;
+        int error = 0;
+
+        if ((unshare_flags & CLONE_FILES) &&
+            (fd && atomic_read(&fd->count) > 1)) {
+                *new_fdp = dup_fd(fd, &error);
+                if (!*new_fdp)
+                        return error;
+        }
+
+        return 0;
+}
+
+/*
+ * Unsharing of semundo for tasks created with CLONE_SYSVSEM is not
+ * supported yet
+ */
+static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **new_ulistp)
+{
+        if (unshare_flags & CLONE_SYSVSEM)
+                return -EINVAL;
+
+        return 0;
+}
+
+/*
+ * unshare allows a process to 'unshare' part of the process
+ * context which was originally shared using clone.  copy_*
+ * functions used by do_fork() cannot be used here directly
+ * because they modify an inactive task_struct that is being
+ * constructed. Here we are modifying the current, active,
+ * task_struct.
+ */
+asmlinkage long sys_unshare(unsigned long unshare_flags)
+{
+        int err = 0;
+        struct fs_struct *fs, *new_fs = NULL;
+        struct namespace *ns, *new_ns = NULL;
+        struct sighand_struct *sigh, *new_sigh = NULL;
+        struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
+        struct files_struct *fd, *new_fd = NULL;
+        struct sem_undo_list *new_ulist = NULL;
+
+        check_unshare_flags(&unshare_flags);
+
+        if ((err = unshare_thread(unshare_flags)))
+                goto bad_unshare_out;
+        if ((err = unshare_fs(unshare_flags, &new_fs)))
+                goto bad_unshare_cleanup_thread;
+        if ((err = unshare_namespace(unshare_flags, &new_ns, new_fs)))
+                goto bad_unshare_cleanup_fs;
+        if ((err = unshare_sighand(unshare_flags, &new_sigh)))
+                goto bad_unshare_cleanup_ns;
+        if ((err = unshare_vm(unshare_flags, &new_mm)))
+                goto bad_unshare_cleanup_sigh;
+        if ((err = unshare_fd(unshare_flags, &new_fd)))
+                goto bad_unshare_cleanup_vm;
+        if ((err = unshare_semundo(unshare_flags, &new_ulist)))
+                goto bad_unshare_cleanup_fd;
+
+        if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist) {
+
+                task_lock(current);
+
+                if (new_fs) {
+                        fs = current->fs;
+                        current->fs = new_fs;
+                        new_fs = fs;
+                }
+
+                if (new_ns) {
+                        ns = current->namespace;
+                        current->namespace = new_ns;
+                        new_ns = ns;
+                }
+
+                if (new_sigh) {
+                        sigh = current->sighand;
+                        current->sighand = new_sigh;
+                        new_sigh = sigh;
+                }
+
+                if (new_mm) {
+                        mm = current->mm;
+                        active_mm = current->active_mm;
+                        current->mm = new_mm;
+                        current->active_mm = new_mm;
+                        activate_mm(active_mm, new_mm);
+                        new_mm = mm;
+                }
+
+                if (new_fd) {
+                        fd = current->files;
+                        current->files = new_fd;
+                        new_fd = fd;
+                }
+
+                task_unlock(current);
+        }
+
+bad_unshare_cleanup_fd:
+        if (new_fd)
+                put_files_struct(new_fd);
+
+bad_unshare_cleanup_vm:
+        if (new_mm)
+                mmput(new_mm);
+
+bad_unshare_cleanup_sigh:
+        if (new_sigh)
+                if (atomic_dec_and_test(&new_sigh->count))
+                        kmem_cache_free(sighand_cachep, new_sigh);
+
+bad_unshare_cleanup_ns:
+        if (new_ns)
+                put_namespace(new_ns);
+
+bad_unshare_cleanup_fs:
+        if (new_fs)
+                put_fs_struct(new_fs);
+
+bad_unshare_cleanup_thread:
+bad_unshare_out:
+        return err;
+}
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f1c4155b49ac..2b6e1757aedd 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -21,6 +21,12 @@
  *  Credits:
  *      based on kernel/timer.c
  *
+ *      Help, testing, suggestions, bugfixes, improvements were
+ *      provided by:
+ *
+ *      George Anzinger, Andrew Morton, Steven Rostedt, Roman Zippel
+ *      et. al.
+ *
  *  For licencing details see kernel-base/COPYING
  */
 
@@ -66,6 +72,12 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
 
 /*
  * The timer bases:
+ *
+ * Note: If we want to add new timer bases, we have to skip the two
+ * clock ids captured by the cpu-timers. We do this by holding empty
+ * entries rather than doing math adjustment of the clock ids.
+ * This ensures that we capture erroneous accesses to these clock ids
+ * rather than moving them into the range of valid clock id's.
  */
 
 #define MAX_HRTIMER_BASES 2
@@ -483,29 +495,25 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
 }
 
 /**
- * hrtimer_rebase - rebase an initialized hrtimer to a different base
+ * hrtimer_init - initialize a timer to the given clock
  *
- * @timer:      the timer to be rebased
+ * @timer:      the timer to be initialized
  * @clock_id:   the clock to be used
+ * @mode:       timer mode abs/rel
  */
-void hrtimer_rebase(struct hrtimer *timer, const clockid_t clock_id)
+void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
+                  enum hrtimer_mode mode)
 {
         struct hrtimer_base *bases;
 
+        memset(timer, 0, sizeof(struct hrtimer));
+
         bases = per_cpu(hrtimer_bases, raw_smp_processor_id());
-        timer->base = &bases[clock_id];
-}
 
-/**
- * hrtimer_init - initialize a timer to the given clock
- *
- * @timer:      the timer to be initialized
- * @clock_id:   the clock to be used
- */
-void hrtimer_init(struct hrtimer *timer, const clockid_t clock_id)
-{
-        memset(timer, 0, sizeof(struct hrtimer));
-        hrtimer_rebase(timer, clock_id);
+        if (clock_id == CLOCK_REALTIME && mode != HRTIMER_ABS)
+                clock_id = CLOCK_MONOTONIC;
+
+        timer->base = &bases[clock_id];
 }
 
 /**
@@ -550,6 +558,7 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base)
                 fn = timer->function;
                 data = timer->data;
                 set_curr_timer(base, timer);
+                timer->state = HRTIMER_RUNNING;
                 __remove_hrtimer(timer, base);
                 spin_unlock_irq(&base->lock);
 
@@ -565,6 +574,10 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base)
 
                 spin_lock_irq(&base->lock);
 
+                /* Another CPU has added back the timer */
+                if (timer->state != HRTIMER_RUNNING)
+                        continue;
+
                 if (restart == HRTIMER_RESTART)
                         enqueue_hrtimer(timer, base);
                 else
@@ -638,8 +651,7 @@ schedule_hrtimer_interruptible(struct hrtimer *timer,
         return schedule_hrtimer(timer, mode);
 }
 
-static long __sched
-nanosleep_restart(struct restart_block *restart, clockid_t clockid)
+static long __sched nanosleep_restart(struct restart_block *restart)
 {
         struct timespec __user *rmtp;
         struct timespec tu;
@@ -649,7 +661,7 @@ nanosleep_restart(struct restart_block *restart, clockid_t clockid)
 
         restart->fn = do_no_restart_syscall;
 
-        hrtimer_init(&timer, clockid);
+        hrtimer_init(&timer, (clockid_t) restart->arg3, HRTIMER_ABS);
 
         timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0;
 
@@ -669,16 +681,6 @@ nanosleep_restart(struct restart_block *restart, clockid_t clockid)
         return -ERESTART_RESTARTBLOCK;
 }
 
-static long __sched nanosleep_restart_mono(struct restart_block *restart)
-{
-        return nanosleep_restart(restart, CLOCK_MONOTONIC);
-}
-
-static long __sched nanosleep_restart_real(struct restart_block *restart)
-{
-        return nanosleep_restart(restart, CLOCK_REALTIME);
-}
-
 long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
                        const enum hrtimer_mode mode, const clockid_t clockid)
 {
@@ -687,7 +689,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
         struct timespec tu;
         ktime_t rem;
 
-        hrtimer_init(&timer, clockid);
+        hrtimer_init(&timer, clockid, mode);
 
         timer.expires = timespec_to_ktime(*rqtp);
 
@@ -695,7 +697,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
         if (rem.tv64 <= 0)
                 return 0;
 
-        /* Absolute timers do not update the rmtp value: */
+        /* Absolute timers do not update the rmtp value and restart: */
         if (mode == HRTIMER_ABS)
                 return -ERESTARTNOHAND;
 
@@ -705,11 +707,11 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
                 return -EFAULT;
 
         restart = &current_thread_info()->restart_block;
-        restart->fn = (clockid == CLOCK_MONOTONIC) ?
-                nanosleep_restart_mono : nanosleep_restart_real;
+        restart->fn = nanosleep_restart;
         restart->arg0 = timer.expires.tv64 & 0xFFFFFFFF;
         restart->arg1 = timer.expires.tv64 >> 32;
         restart->arg2 = (unsigned long) rmtp;
+        restart->arg3 = (unsigned long) timer.base->index;
 
         return -ERESTART_RESTARTBLOCK;
 }
@@ -736,10 +738,8 @@ static void __devinit init_hrtimers_cpu(int cpu)
         struct hrtimer_base *base = per_cpu(hrtimer_bases, cpu);
         int i;
 
-        for (i = 0; i < MAX_HRTIMER_BASES; i++) {
+        for (i = 0; i < MAX_HRTIMER_BASES; i++, base++)
                 spin_lock_init(&base->lock);
-                base++;
-        }
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
diff --git a/kernel/intermodule.c b/kernel/intermodule.c
index 0cbe633420fb..55b1e5b85db9 100644
--- a/kernel/intermodule.c
+++ b/kernel/intermodule.c
@@ -179,3 +179,6 @@ EXPORT_SYMBOL(inter_module_register);
 EXPORT_SYMBOL(inter_module_unregister);
 EXPORT_SYMBOL(inter_module_get_request);
 EXPORT_SYMBOL(inter_module_put);
+
+MODULE_LICENSE("GPL");
+
diff --git a/kernel/itimer.c b/kernel/itimer.c
index c2c05c4ff28d..379be2f8c84c 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -49,9 +49,11 @@ int do_getitimer(int which, struct itimerval *value)
 
         switch (which) {
         case ITIMER_REAL:
+                spin_lock_irq(&tsk->sighand->siglock);
                 value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
                 value->it_interval =
                         ktime_to_timeval(tsk->signal->it_real_incr);
+                spin_unlock_irq(&tsk->sighand->siglock);
                 break;
         case ITIMER_VIRTUAL:
                 read_lock(&tasklist_lock);
@@ -150,18 +152,25 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 
         switch (which) {
         case ITIMER_REAL:
+again:
+                spin_lock_irq(&tsk->sighand->siglock);
                 timer = &tsk->signal->real_timer;
-                hrtimer_cancel(timer);
                 if (ovalue) {
                         ovalue->it_value = itimer_get_remtime(timer);
                         ovalue->it_interval
                                 = ktime_to_timeval(tsk->signal->it_real_incr);
                 }
+                /* We are sharing ->siglock with it_real_fn() */
+                if (hrtimer_try_to_cancel(timer) < 0) {
+                        spin_unlock_irq(&tsk->sighand->siglock);
+                        goto again;
+                }
                 tsk->signal->it_real_incr =
                         timeval_to_ktime(value->it_interval);
                 expires = timeval_to_ktime(value->it_value);
                 if (expires.tv64 != 0)
                         hrtimer_start(timer, expires, HRTIMER_REL);
+                spin_unlock_irq(&tsk->sighand->siglock);
                 break;
         case ITIMER_VIRTUAL:
                 nval = timeval_to_cputime(&value->it_value);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3ea6325228da..fef1af8a73ce 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -344,23 +344,6 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
         spin_unlock_irqrestore(&kretprobe_lock, flags);
 }
 
-/*
- * This kprobe pre_handler is registered with every kretprobe. When probe
- * hits it will set up the return probe.
- */
-static int __kprobes pre_handler_kretprobe(struct kprobe *p,
-                                           struct pt_regs *regs)
-{
-        struct kretprobe *rp = container_of(p, struct kretprobe, kp);
-        unsigned long flags = 0;
-
-        /*TODO: consider to only swap the RA after the last pre_handler fired */
-        spin_lock_irqsave(&kretprobe_lock, flags);
-        arch_prepare_kretprobe(rp, regs);
-        spin_unlock_irqrestore(&kretprobe_lock, flags);
-        return 0;
-}
-
 static inline void free_rp_inst(struct kretprobe *rp)
 {
         struct kretprobe_instance *ri;
@@ -578,6 +561,23 @@ void __kprobes unregister_jprobe(struct jprobe *jp)
 
 #ifdef ARCH_SUPPORTS_KRETPROBES
 
+/*
+ * This kprobe pre_handler is registered with every kretprobe. When probe
+ * hits it will set up the return probe.
+ */
+static int __kprobes pre_handler_kretprobe(struct kprobe *p,
+                                           struct pt_regs *regs)
+{
+        struct kretprobe *rp = container_of(p, struct kretprobe, kp);
+        unsigned long flags = 0;
+
+        /*TODO: consider to only swap the RA after the last pre_handler fired */
+        spin_lock_irqsave(&kretprobe_lock, flags);
+        arch_prepare_kretprobe(rp, regs);
+        spin_unlock_irqrestore(&kretprobe_lock, flags);
+        return 0;
+}
+
 int __kprobes register_kretprobe(struct kretprobe *rp)
 {
         int ret = 0;
@@ -631,12 +631,12 @@ void __kprobes unregister_kretprobe(struct kretprobe *rp)
         unregister_kprobe(&rp->kp);
         /* No race here */
         spin_lock_irqsave(&kretprobe_lock, flags);
-        free_rp_inst(rp);
         while ((ri = get_used_rp_inst(rp)) != NULL) {
                 ri->rp = NULL;
                 hlist_del(&ri->uflist);
         }
         spin_unlock_irqrestore(&kretprobe_lock, flags);
+        free_rp_inst(rp);
 }
 
 static int __init init_kprobes(void)
diff --git a/kernel/module.c b/kernel/module.c
index 618ed6e23ecc..5aad477ddc79 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1670,6 +1670,9 @@ static struct module *load_module(void __user *umod,
                 goto free_mod;
         }
 
+        /* Userspace could have altered the string after the strlen_user() */
+        args[arglen - 1] = '\0';
+
         if (find_module(mod->name)) {
                 err = -EEXIST;
                 goto free_mod;
@@ -2092,7 +2095,8 @@ static unsigned long mod_find_symname(struct module *mod, const char *name)
         unsigned int i;
 
         for (i = 0; i < mod->num_symtab; i++)
-                if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0)
+                if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
+                    mod->symtab[i].st_info != 'U')
                         return mod->symtab[i].st_value;
         return 0;
 }
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 197208b3aa2a..216f574b5ffb 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -194,9 +194,7 @@ static inline int common_clock_set(const clockid_t which_clock,
 
 static int common_timer_create(struct k_itimer *new_timer)
 {
-        hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock);
-        new_timer->it.real.timer.data = new_timer;
-        new_timer->it.real.timer.function = posix_timer_fn;
+        hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
         return 0;
 }
 
@@ -290,7 +288,8 @@ void do_schedule_next_timer(struct siginfo *info)
                 info->si_overrun = timr->it_overrun_last;
         }
 
-        unlock_timer(timr, flags);
+        if (timr)
+                unlock_timer(timr, flags);
 }
 
 int posix_timer_event(struct k_itimer *timr,int si_private)
@@ -692,6 +691,7 @@ common_timer_set(struct k_itimer *timr, int flags,
                  struct itimerspec *new_setting, struct itimerspec *old_setting)
 {
         struct hrtimer *timer = &timr->it.real.timer;
+        enum hrtimer_mode mode;
 
         if (old_setting)
                 common_timer_get(timr, old_setting);
@@ -713,14 +713,10 @@ common_timer_set(struct k_itimer *timr, int flags,
         if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
                 return 0;
 
-        /* Posix madness. Only absolute CLOCK_REALTIME timers
-         * are affected by clock sets. So we must reiniatilize
-         * the timer.
-         */
-        if (timr->it_clock == CLOCK_REALTIME && (flags & TIMER_ABSTIME))
-                hrtimer_rebase(timer, CLOCK_REALTIME);
-        else
-                hrtimer_rebase(timer, CLOCK_MONOTONIC);
+        mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL;
+        hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
+        timr->it.real.timer.data = timr;
+        timr->it.real.timer.function = posix_timer_fn;
 
         timer->expires = timespec_to_ktime(new_setting->it_value);
 
@@ -728,11 +724,15 @@ common_timer_set(struct k_itimer *timr, int flags,
         timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
 
         /* SIGEV_NONE timers are not queued ! See common_timer_get */
-        if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
+        if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
+                /* Setup correct expiry time for relative timers */
+                if (mode == HRTIMER_REL)
+                        timer->expires = ktime_add(timer->expires,
+                                                   timer->base->get_time());
                 return 0;
+        }
 
-        hrtimer_start(timer, timer->expires, (flags & TIMER_ABSTIME) ?
-                      HRTIMER_ABS : HRTIMER_REL);
+        hrtimer_start(timer, timer->expires, mode);
         return 0;
 }
 
@@ -875,12 +875,6 @@ int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp)
 }
 EXPORT_SYMBOL_GPL(do_posix_clock_nosettime);
 
-int do_posix_clock_notimer_create(struct k_itimer *timer)
-{
-        return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(do_posix_clock_notimer_create);
-
 int do_posix_clock_nonanosleep(const clockid_t clock, int flags,
                                struct timespec *t, struct timespec __user *r)
 {
@@ -947,21 +941,8 @@ sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp)
 static int common_nsleep(const clockid_t which_clock, int flags,
                          struct timespec *tsave, struct timespec __user *rmtp)
 {
-        int mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL;
-        int clockid = which_clock;
-
-        switch (which_clock) {
-        case CLOCK_REALTIME:
-                /* Posix madness. Only absolute timers on clock realtime
-                   are affected by clock set. */
-                if (mode != HRTIMER_ABS)
-                        clockid = CLOCK_MONOTONIC;
-        case CLOCK_MONOTONIC:
-                break;
-        default:
-                return -EINVAL;
-        }
-        return hrtimer_nanosleep(tsave, rmtp, mode, clockid);
+        return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
+                                 HRTIMER_ABS : HRTIMER_REL, which_clock);
 }
 
 asmlinkage long
diff --git a/kernel/power/console.c b/kernel/power/console.c
index 7ff375e7c95f..623786d44159 100644
--- a/kernel/power/console.c
+++ b/kernel/power/console.c
@@ -9,18 +9,13 @@
 #include <linux/console.h>
 #include "power.h"
 
-static int new_loglevel = 10;
-static int orig_loglevel;
-#ifdef SUSPEND_CONSOLE
+#if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
+#define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1)
+
 static int orig_fgconsole, orig_kmsg;
-#endif
 
 int pm_prepare_console(void)
 {
-        orig_loglevel = console_loglevel;
-        console_loglevel = new_loglevel;
-
-#ifdef SUSPEND_CONSOLE
         acquire_console_sem();
 
         orig_fgconsole = fg_console;
@@ -41,18 +36,15 @@ int pm_prepare_console(void)
         }
         orig_kmsg = kmsg_redirect;
         kmsg_redirect = SUSPEND_CONSOLE;
-#endif
         return 0;
 }
 
 void pm_restore_console(void)
 {
-        console_loglevel = orig_loglevel;
-#ifdef SUSPEND_CONSOLE
         acquire_console_sem();
         set_console(orig_fgconsole);
         release_console_sem();
         kmsg_redirect = orig_kmsg;
-#endif
         return;
 }
+#endif
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index e24446f8d8cd..0b43847dc980 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -53,7 +53,7 @@ static void power_down(suspend_disk_method_t mode)
 
         switch(mode) {
         case PM_DISK_PLATFORM:
-                kernel_power_off_prepare();
+                kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
                 error = pm_ops->enter(PM_SUSPEND_DISK);
                 break;
         case PM_DISK_SHUTDOWN:
@@ -95,13 +95,6 @@ static int prepare_processes(void)
                 goto thaw;
         }
 
-        if (pm_disk_mode == PM_DISK_PLATFORM) {
-                if (pm_ops && pm_ops->prepare) {
-                        if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
-                                goto thaw;
-                }
-        }
-
         /* Free memory before shutting down devices. */
         if (!(error = swsusp_shrink_memory()))
                 return 0;
@@ -367,14 +360,14 @@ power_attr(resume);
 
 static ssize_t image_size_show(struct subsystem * subsys, char *buf)
 {
-        return sprintf(buf, "%u\n", image_size);
+        return sprintf(buf, "%lu\n", image_size);
 }
 
 static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
 {
-        unsigned int size;
+        unsigned long size;
 
-        if (sscanf(buf, "%u", &size) == 1) {
+        if (sscanf(buf, "%lu", &size) == 1) {
                 image_size = size;
                 return n;
         }
diff --git a/kernel/power/main.c b/kernel/power/main.c
index d253f3ae2fa5..9cb235cba4a9 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -133,10 +133,10 @@ static int suspend_enter(suspend_state_t state)
 static void suspend_finish(suspend_state_t state)
 {
         device_resume();
-        if (pm_ops && pm_ops->finish)
-                pm_ops->finish(state);
         thaw_processes();
         enable_nonboot_cpus();
+        if (pm_ops && pm_ops->finish)
+                pm_ops->finish(state);
         pm_restore_console();
 }
 
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 7e8492fd1423..388dba680841 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -1,14 +1,6 @@
 #include <linux/suspend.h>
 #include <linux/utsname.h>
 
-/* With SUSPEND_CONSOLE defined suspend looks *really* cool, but
-   we probably do not take enough locks for switching consoles, etc,
-   so bad things might happen.
-*/
-#if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
-#define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1)
-#endif
-
 struct swsusp_info {
         struct new_utsname      uts;
         u32                     version_code;
@@ -42,17 +34,14 @@ static struct subsys_attribute _name##_attr = {	\
 
 extern struct subsystem power_subsys;
 
-extern int pm_prepare_console(void);
-extern void pm_restore_console(void);
-
 /* References to section boundaries */
 extern const void __nosave_begin, __nosave_end;
 
 extern unsigned int nr_copy_pages;
 extern struct pbe *pagedir_nosave;
 
-/* Preferred image size in MB (default 500) */
-extern unsigned int image_size;
+/* Preferred image size in bytes (default 500 MB) */
+extern unsigned long image_size;
 
 extern asmlinkage int swsusp_arch_suspend(void);
 extern asmlinkage int swsusp_arch_resume(void);
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 55a18d26abed..4e90905f0e87 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -70,12 +70,12 @@
 #include "power.h"
 
 /*
- * Preferred image size in MB (tunable via /sys/power/image_size).
+ * Preferred image size in bytes (tunable via /sys/power/image_size).
  * When it is set to N, swsusp will do its best to ensure the image
- * size will not exceed N MB, but if that is impossible, it will
+ * size will not exceed N bytes, but if that is impossible, it will
  * try to create the smallest image possible.
  */
-unsigned int image_size = 500;
+unsigned long image_size = 500 * 1024 * 1024;
 
 #ifdef CONFIG_HIGHMEM
 unsigned int count_highmem_pages(void);
@@ -590,7 +590,7 @@ int swsusp_shrink_memory(void)
                         if (!tmp)
                                 return -ENOMEM;
                         pages += tmp;
-                } else if (size > (image_size * 1024 * 1024) / PAGE_SIZE) {
+                } else if (size > image_size / PAGE_SIZE) {
                         tmp = shrink_all_memory(SHRINK_BITE);
                         pages += tmp;
                 }
@@ -743,7 +743,6 @@ static int submit(int rw, pgoff_t page_off, void *page)
         if (!bio)
                 return -ENOMEM;
         bio->bi_sector = page_off * (PAGE_SIZE >> 9);
-        bio_get(bio);
         bio->bi_bdev = resume_bdev;
         bio->bi_end_io = end_io;
 
@@ -753,14 +752,13 @@ static int submit(int rw, pgoff_t page_off, void *page)
                 goto Done;
         }
 
-        if (rw == WRITE)
-                bio_set_pages_dirty(bio);
 
         atomic_set(&io_done, 1);
         submit_bio(rw | (1 << BIO_RW_SYNC), bio);
         while (atomic_read(&io_done))
                 yield();
-
+        if (rw == READ)
+                bio_set_pages_dirty(bio);
  Done:
         bio_put(bio);
         return error;
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 773219907dd8..7712912dbc84 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -114,16 +114,16 @@ rcu_torture_alloc(void)
 {
         struct list_head *p;
 
-        spin_lock(&rcu_torture_lock);
+        spin_lock_bh(&rcu_torture_lock);
         if (list_empty(&rcu_torture_freelist)) {
                 atomic_inc(&n_rcu_torture_alloc_fail);
-                spin_unlock(&rcu_torture_lock);
+                spin_unlock_bh(&rcu_torture_lock);
                 return NULL;
         }
         atomic_inc(&n_rcu_torture_alloc);
         p = rcu_torture_freelist.next;
         list_del_init(p);
-        spin_unlock(&rcu_torture_lock);
+        spin_unlock_bh(&rcu_torture_lock);
         return container_of(p, struct rcu_torture, rtort_free);
 }
 
@@ -134,9 +134,9 @@ static void
 rcu_torture_free(struct rcu_torture *p)
 {
         atomic_inc(&n_rcu_torture_free);
-        spin_lock(&rcu_torture_lock);
+        spin_lock_bh(&rcu_torture_lock);
         list_add_tail(&p->rtort_free, &rcu_torture_freelist);
-        spin_unlock(&rcu_torture_lock);
+        spin_unlock_bh(&rcu_torture_lock);
 }
 
 static void
diff --git a/kernel/sched.c b/kernel/sched.c
index 3ee2ae45125f..bc38804e40dd 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4031,7 +4031,7 @@ long sched_getaffinity(pid_t pid, cpumask_t *mask)
                 goto out_unlock;
 
         retval = 0;
-        cpus_and(*mask, p->cpus_allowed, cpu_possible_map);
+        cpus_and(*mask, p->cpus_allowed, cpu_online_map);
 
 out_unlock:
         read_unlock(&tasklist_lock);
@@ -5141,7 +5141,7 @@ static void init_sched_build_groups(struct sched_group groups[], cpumask_t span,
 #define SEARCH_SCOPE            2
 #define MIN_CACHE_SIZE          (64*1024U)
 #define DEFAULT_CACHE_SIZE      (5*1024*1024U)
-#define ITERATIONS              2
+#define ITERATIONS              1
 #define SIZE_THRESH             130
 #define COST_THRESH             130
 
@@ -5480,9 +5480,9 @@ static unsigned long long measure_migration_cost(int cpu1, int cpu2)
                                 break;
                         }
                 /*
-                 * Increase the cachesize in 5% steps:
+                 * Increase the cachesize in 10% steps:
                  */
-                size = size * 20 / 19;
+                size = size * 10 / 9;
         }
 
         if (migration_debug)
@@ -5551,13 +5551,15 @@ static void calibrate_migration_costs(const cpumask_t *cpu_map)
                         -1
 #endif
                 );
-        printk("migration_cost=");
-        for (distance = 0; distance <= max_distance; distance++) {
-                if (distance)
-                        printk(",");
-                printk("%ld", (long)migration_cost[distance] / 1000);
+        if (system_state == SYSTEM_BOOTING) {
+                printk("migration_cost=");
+                for (distance = 0; distance <= max_distance; distance++) {
+                        if (distance)
+                                printk(",");
+                        printk("%ld", (long)migration_cost[distance] / 1000);
+                }
+                printk("\n");
         }
-        printk("\n");
         j1 = jiffies;
         if (migration_debug)
                 printk("migration: %ld seconds\n", (j1-j0)/HZ);
@@ -6109,7 +6111,7 @@ void __init sched_init(void)
         runqueue_t *rq;
         int i, j, k;
 
-        for (i = 0; i < NR_CPUS; i++) {
+        for_each_cpu(i) {
                 prio_array_t *array;
 
                 rq = cpu_rq(i);
diff --git a/kernel/signal.c b/kernel/signal.c
index d3efafd8109a..b373fc2420da 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -283,7 +283,7 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
         return(q);
 }
 
-static inline void __sigqueue_free(struct sigqueue *q)
+static void __sigqueue_free(struct sigqueue *q)
 {
         if (q->flags & SIGQUEUE_PREALLOC)
                 return;
diff --git a/kernel/sys.c b/kernel/sys.c
index d09cac23fdfd..f91218a5463e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -428,7 +428,7 @@ void kernel_kexec(void)
 {
 #ifdef CONFIG_KEXEC
         struct kimage *image;
-        image = xchg(&kexec_image, 0);
+        image = xchg(&kexec_image, NULL);
         if (!image) {
                 return;
         }
@@ -440,23 +440,25 @@ void kernel_kexec(void)
 }
 EXPORT_SYMBOL_GPL(kernel_kexec);
 
+void kernel_shutdown_prepare(enum system_states state)
+{
+        notifier_call_chain(&reboot_notifier_list,
+                (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
+        system_state = state;
+        device_shutdown();
+}
 /**
  *      kernel_halt - halt the system
  *
  *      Shutdown everything and perform a clean system halt.
  */
-void kernel_halt_prepare(void)
-{
-        notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
-        system_state = SYSTEM_HALT;
-        device_shutdown();
-}
 void kernel_halt(void)
 {
-        kernel_halt_prepare();
+        kernel_shutdown_prepare(SYSTEM_HALT);
         printk(KERN_EMERG "System halted.\n");
         machine_halt();
 }
+
 EXPORT_SYMBOL_GPL(kernel_halt);
 
 /**
@@ -464,20 +466,13 @@ EXPORT_SYMBOL_GPL(kernel_halt);
  *
  *      Shutdown everything and perform a clean system power_off.
  */
-void kernel_power_off_prepare(void)
-{
-        notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
-        system_state = SYSTEM_POWER_OFF;
-        device_shutdown();
-}
 void kernel_power_off(void)
 {
-        kernel_power_off_prepare();
+        kernel_shutdown_prepare(SYSTEM_POWER_OFF);
         printk(KERN_EMERG "Power down.\n");
         machine_power_off();
 }
 EXPORT_SYMBOL_GPL(kernel_power_off);
-
 /*
  * Reboot system call: for obvious reasons only root may call it,
  * and even root needs to set up some magic numbers in the registers
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index cb99a42f8b37..71dd6f62efec 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -878,7 +878,17 @@ static ctl_table vm_table[] = {
                 .maxlen         = sizeof(zone_reclaim_mode),
                 .mode           = 0644,
                 .proc_handler   = &proc_dointvec,
-                .strategy       = &zero,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &zero,
+        },
+        {
+                .ctl_name       = VM_ZONE_RECLAIM_INTERVAL,
+                .procname       = "zone_reclaim_interval",
+                .data           = &zone_reclaim_interval,
+                .maxlen         = sizeof(zone_reclaim_interval),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_jiffies,
+                .strategy       = &sysctl_jiffies,
         },
 #endif
         { .ctl_name = 0 }
diff --git a/kernel/time.c b/kernel/time.c
index 7477b1d2079e..804539165d8b 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -155,7 +155,7 @@ int do_sys_settimeofday(struct timespec *tv, struct timezone *tz)
         static int firsttime = 1;
         int error = 0;
 
-        if (!timespec_valid(tv))
+        if (tv && !timespec_valid(tv))
                 return -EINVAL;
 
         error = security_settime(tv, tz);
@@ -637,15 +637,16 @@ void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec)
  *
  * Returns the timespec representation of the nsec parameter.
  */
-inline struct timespec ns_to_timespec(const nsec_t nsec)
+struct timespec ns_to_timespec(const nsec_t nsec)
 {
         struct timespec ts;
 
-        if (nsec)
-                ts.tv_sec = div_long_long_rem_signed(nsec, NSEC_PER_SEC,
-                                                     &ts.tv_nsec);
-        else
-                ts.tv_sec = ts.tv_nsec = 0;
+        if (!nsec)
+                return (struct timespec) {0, 0};
+
+        ts.tv_sec = div_long_long_rem_signed(nsec, NSEC_PER_SEC, &ts.tv_nsec);
+        if (unlikely(nsec < 0))
+                set_normalized_timespec(&ts, ts.tv_sec, ts.tv_nsec);
 
         return ts;
 }
diff --git a/kernel/timer.c b/kernel/timer.c
index 4f1cb0ab5251..b9dad3994676 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -495,7 +495,7 @@ unsigned long next_timer_interrupt(void)
         base = &__get_cpu_var(tvec_bases);
         spin_lock(&base->t_base.lock);
         expires = base->timer_jiffies + (LONG_MAX >> 1);
-        list = 0;
+        list = NULL;
 
         /* Look for timer events in tv1. */
         j = base->timer_jiffies & TVR_MASK;
diff --git a/kernel/user.c b/kernel/user.c
index 89e562feb1b1..d9deae43a9ab 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -13,6 +13,7 @@
 #include <linux/slab.h>
 #include <linux/bitops.h>
 #include <linux/key.h>
+#include <linux/interrupt.h>
 
 /*
  * UID task count cache, to get fast user lookup in "alloc_uid"
@@ -27,6 +28,16 @@
 
 static kmem_cache_t *uid_cachep;
 static struct list_head uidhash_table[UIDHASH_SZ];
+
+/*
+ * The uidhash_lock is mostly taken from process context, but it is
+ * occasionally also taken from softirq/tasklet context, when
+ * task-structs get RCU-freed. Hence all locking must be softirq-safe.
+ * But free_uid() is also called with local interrupts disabled, and running
+ * local_bh_enable() with local interrupts disabled is an error - we'll run
+ * softirq callbacks, and they can unconditionally enable interrupts, and
+ * the caller of free_uid() didn't expect that..
+ */
 static DEFINE_SPINLOCK(uidhash_lock);
 
 struct user_struct root_user = {
@@ -82,15 +93,19 @@ static inline struct user_struct *uid_hash_find(uid_t uid, struct list_head *has
 struct user_struct *find_user(uid_t uid)
 {
         struct user_struct *ret;
+        unsigned long flags;
 
-        spin_lock(&uidhash_lock);
+        spin_lock_irqsave(&uidhash_lock, flags);
         ret = uid_hash_find(uid, uidhashentry(uid));
-        spin_unlock(&uidhash_lock);
+        spin_unlock_irqrestore(&uidhash_lock, flags);
         return ret;
 }
 
 void free_uid(struct user_struct *up)
 {
+        unsigned long flags;
+
+        local_irq_save(flags);
         if (up && atomic_dec_and_lock(&up->__count, &uidhash_lock)) {
                 uid_hash_remove(up);
                 key_put(up->uid_keyring);
@@ -98,6 +113,7 @@ void free_uid(struct user_struct *up)
                 kmem_cache_free(uid_cachep, up);
                 spin_unlock(&uidhash_lock);
         }
+        local_irq_restore(flags);
 }
 
 struct user_struct * alloc_uid(uid_t uid)
@@ -105,9 +121,9 @@ struct user_struct * alloc_uid(uid_t uid)
         struct list_head *hashent = uidhashentry(uid);
         struct user_struct *up;
 
-        spin_lock(&uidhash_lock);
+        spin_lock_irq(&uidhash_lock);
         up = uid_hash_find(uid, hashent);
-        spin_unlock(&uidhash_lock);
+        spin_unlock_irq(&uidhash_lock);
 
         if (!up) {
                 struct user_struct *new;
@@ -137,7 +153,7 @@ struct user_struct * alloc_uid(uid_t uid)
                  * Before adding this, check whether we raced
                  * on adding the same user already..
                  */
-                spin_lock(&uidhash_lock);
+                spin_lock_irq(&uidhash_lock);
                 up = uid_hash_find(uid, hashent);
                 if (up) {
                         key_put(new->uid_keyring);
@@ -147,7 +163,7 @@ struct user_struct * alloc_uid(uid_t uid)
                         uid_hash_insert(new, hashent);
                         up = new;
                 }
-                spin_unlock(&uidhash_lock);
+                spin_unlock_irq(&uidhash_lock);
 
         }
         return up;
@@ -183,9 +199,9 @@ static int __init uid_cache_init(void)
                 INIT_LIST_HEAD(uidhash_table + n);
 
         /* Insert the root user immediately (init already runs as root) */
-        spin_lock(&uidhash_lock);
+        spin_lock_irq(&uidhash_lock);
         uid_hash_insert(&root_user, uidhashentry(0));
-        spin_unlock(&uidhash_lock);
+        spin_unlock_irq(&uidhash_lock);
 
         return 0;
 }