Merge branch 'akpm' (Andrew's incoming - part two)

Says Andrew:

 "60 patches.  That's good enough for -rc1 I guess.  I have quite a lot
  of detritus to be rechecked, work through maintainers, etc.

 - most of the remains of MM
 - rtc
 - various misc
 - cgroups
 - memcg
 - cpusets
 - procfs
 - ipc
 - rapidio
 - sysctl
 - pps
 - w1
 - drivers/misc
 - aio"

* akpm: (60 commits)
  memcg: replace ss->id_lock with a rwlock
  aio: allocate kiocbs in batches
  drivers/misc/vmw_balloon.c: fix typo in code comment
  drivers/misc/vmw_balloon.c: determine page allocation flag can_sleep outside loop
  w1: disable irqs in critical section
  drivers/w1/w1_int.c: multiple masters used same init_name
  drivers/power/ds2780_battery.c: fix deadlock upon insertion and removal
  drivers/power/ds2780_battery.c: add a nolock function to w1 interface
  drivers/power/ds2780_battery.c: create central point for calling w1 interface
  w1: ds2760 and ds2780, use ida for id and ida_simple_get() to get it
  pps gpio client: add missing dependency
  pps: new client driver using GPIO
  pps: default echo function
  include/linux/dma-mapping.h: add dma_zalloc_coherent()
  sysctl: make CONFIG_SYSCTL_SYSCALL default to n
  sysctl: add support for poll()
  RapidIO: documentation update
  drivers/net/rionet.c: fix ethernet address macros for LE platforms
  RapidIO: fix potential null deref in rio_setup_device()
  RapidIO: add mport driver for Tsi721 bridge
  ...

1 files changed, 55 insertions, 1 deletions

diff --git a/ipc/sem.c b/ipc/sem.c
index c8e00f8b4be1..5215a81420df 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -90,6 +90,52 @@
 #include <asm/uaccess.h>
 #include "util.h"
 
+/* One semaphore structure for each semaphore in the system. */
+struct sem {
+        int     semval;         /* current value */
+        int     sempid;         /* pid of last operation */
+        struct list_head sem_pending; /* pending single-sop operations */
+};
+
+/* One queue for each sleeping process in the system. */
+struct sem_queue {
+        struct list_head        simple_list; /* queue of pending operations */
+        struct list_head        list;    /* queue of pending operations */
+        struct task_struct      *sleeper; /* this process */
+        struct sem_undo         *undo;   /* undo structure */
+        int                     pid;     /* process id of requesting process */
+        int                     status;  /* completion status of operation */
+        struct sembuf           *sops;   /* array of pending operations */
+        int                     nsops;   /* number of operations */
+        int                     alter;   /* does *sops alter the array? */
+};
+
+/* Each task has a list of undo requests. They are executed automatically
+ * when the process exits.
+ */
+struct sem_undo {
+        struct list_head        list_proc;      /* per-process list: *
+                                                 * all undos from one process
+                                                 * rcu protected */
+        struct rcu_head         rcu;            /* rcu struct for sem_undo */
+        struct sem_undo_list    *ulp;           /* back ptr to sem_undo_list */
+        struct list_head        list_id;        /* per semaphore array list:
+                                                 * all undos for one array */
+        int                     semid;          /* semaphore set identifier */
+        short                   *semadj;        /* array of adjustments */
+                                                /* one per semaphore */
+};
+
+/* sem_undo_list controls shared access to the list of sem_undo structures
+ * that may be shared among all a CLONE_SYSVSEM task group.
+ */
+struct sem_undo_list {
+        atomic_t                refcnt;
+        spinlock_t              lock;
+        struct list_head        list_proc;
+};
+
+
 #define sem_ids(ns)     ((ns)->ids[IPC_SEM_IDS])
 
 #define sem_unlock(sma)         ipc_unlock(&(sma)->sem_perm)
@@ -1426,6 +1472,8 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 
         queue.status = -EINTR;
         queue.sleeper = current;
+
+sleep_again:
         current->state = TASK_INTERRUPTIBLE;
         sem_unlock(sma);
 
@@ -1460,7 +1508,6 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
          * Array removed? If yes, leave without sem_unlock().
          */
         if (IS_ERR(sma)) {
-                error = -EIDRM;
                 goto out_free;
         }
 
@@ -1479,6 +1526,13 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
          */
         if (timeout && jiffies_left == 0)
                 error = -EAGAIN;
+
+        /*
+         * If the wakeup was spurious, just retry
+         */
+        if (error == -EINTR && !signal_pending(current))
+                goto sleep_again;
+
         unlink_queue(sma, &queue);
 
 out_unlock_free: