Merge branch 'akpm' (Andrew's patch-bomb)

Merge misc patches from Andrew Morton:

 - the "misc" tree - stuff from all over the map

 - checkpatch updates

 - fatfs

 - kmod changes

 - procfs

 - cpumask

 - UML

 - kexec

 - mqueue

 - rapidio

 - pidns

 - some checkpoint-restore feature work.  Reluctantly.  Most of it
   delayed a release.  I'm still rather worried that we don't have a
   clear roadmap to completion for this work.

* emailed from Andrew Morton <akpm@linux-foundation.org>: (78 patches)
  kconfig: update compression algorithm info
  c/r: prctl: add ability to set new mm_struct::exe_file
  c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
  c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
  syscalls, x86: add __NR_kcmp syscall
  fs, proc: introduce /proc/<pid>/task/<tid>/children entry
  sysctl: make kernel.ns_last_pid control dependent on CHECKPOINT_RESTORE
  aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
  eventfd: change int to __u64 in eventfd_signal()
  fs/nls: add Apple NLS
  pidns: make killed children autoreap
  pidns: use task_active_pid_ns in do_notify_parent
  rapidio/tsi721: add DMA engine support
  rapidio: add DMA engine support for RIO data transfers
  ipc/mqueue: add rbtree node caching support
  tools/selftests: add mq_perf_tests
  ipc/mqueue: strengthen checks on mqueue creation
  ipc/mqueue: correct mq_attr_ok test
  ipc/mqueue: improve performance of send/recv
  selftests: add mq_open_tests
  ...

8 files changed, 52 insertions, 46 deletions

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index b735521a4a54..2c7217d971db 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -109,7 +109,6 @@ static void percpu_timer_stop(void);
 int __cpu_disable(void)
 {
         unsigned int cpu = smp_processor_id();
-        struct task_struct *p;
         int ret;
 
         ret = platform_cpu_disable(cpu);
@@ -139,12 +138,7 @@ int __cpu_disable(void)
         flush_cache_all();
         local_flush_tlb_all();
 
-        read_lock(&tasklist_lock);
-        for_each_process(p) {
-                if (p->mm)
-                        cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
-        }
-        read_unlock(&tasklist_lock);
+        clear_tasks_mm_cpumask(cpu);
 
         return 0;
 }
diff --git a/arch/blackfin/kernel/trace.c b/arch/blackfin/kernel/trace.c
index 44bbf2f564cb..f7f7a18abca9 100644
--- a/arch/blackfin/kernel/trace.c
+++ b/arch/blackfin/kernel/trace.c
@@ -10,6 +10,8 @@
 #include <linux/hardirq.h>
 #include <linux/thread_info.h>
 #include <linux/mm.h>
+#include <linux/oom.h>
+#include <linux/sched.h>
 #include <linux/uaccess.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
@@ -27,8 +29,7 @@ void decode_address(char *buf, unsigned long address)
 {
         struct task_struct *p;
         struct mm_struct *mm;
-        unsigned long flags, offset;
-        unsigned char in_atomic = (bfin_read_IPEND() & 0x10) || in_atomic();
+        unsigned long offset;
         struct rb_node *n;
 
 #ifdef CONFIG_KALLSYMS
@@ -112,17 +113,17 @@ void decode_address(char *buf, unsigned long address)
          * mappings of all our processes and see if we can't be a whee
          * bit more specific
          */
-        write_lock_irqsave(&tasklist_lock, flags);
+        read_lock(&tasklist_lock);
         for_each_process(p) {
-                mm = (in_atomic ? p->mm : get_task_mm(p));
-                if (!mm)
-                        continue;
+                struct task_struct *t;
 
-                if (!down_read_trylock(&mm->mmap_sem)) {
-                        if (!in_atomic)
-                                mmput(mm);
+                t = find_lock_task_mm(p);
+                if (!t)
                         continue;
-                }
+
+                mm = t->mm;
+                if (!down_read_trylock(&mm->mmap_sem))
+                        goto __continue;
 
                 for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
                         struct vm_area_struct *vma;
@@ -131,7 +132,7 @@ void decode_address(char *buf, unsigned long address)
 
                         if (address >= vma->vm_start && address < vma->vm_end) {
                                 char _tmpbuf[256];
-                                char *name = p->comm;
+                                char *name = t->comm;
                                 struct file *file = vma->vm_file;
 
                                 if (file) {
@@ -164,8 +165,7 @@ void decode_address(char *buf, unsigned long address)
                                                 name, vma->vm_start, vma->vm_end);
 
                                 up_read(&mm->mmap_sem);
-                                if (!in_atomic)
-                                        mmput(mm);
+                                task_unlock(t);
 
                                 if (buf[0] == '\0')
                                         sprintf(buf, "[ %s ] dynamic memory", name);
@@ -175,8 +175,8 @@ void decode_address(char *buf, unsigned long address)
                 }
 
                 up_read(&mm->mmap_sem);
-                if (!in_atomic)
-                        mmput(mm);
+__continue:
+                task_unlock(t);
         }
 
         /*
@@ -186,7 +186,7 @@ void decode_address(char *buf, unsigned long address)
         sprintf(buf, "/* kernel dynamic memory */");
 
 done:
-        write_unlock_irqrestore(&tasklist_lock, flags);
+        read_unlock(&tasklist_lock);
 }
 
 #define EXPAND_LEN ((1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN) * 256 - 1)
diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index 5b63bd3da4a9..e779642c25e5 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -333,9 +333,7 @@ static int __cpuinit mmu_context_cpu_notify(struct notifier_block *self,
                                             unsigned long action, void *hcpu)
 {
         unsigned int cpu = (unsigned int)(long)hcpu;
-#ifdef CONFIG_HOTPLUG_CPU
-        struct task_struct *p;
-#endif
+
         /* We don't touch CPU 0 map, it's allocated at aboot and kept
          * around forever
          */
@@ -358,12 +356,7 @@ static int __cpuinit mmu_context_cpu_notify(struct notifier_block *self,
                 stale_map[cpu] = NULL;
 
                 /* We also clear the cpu_vm_mask bits of CPUs going away */
-                read_lock(&tasklist_lock);
-                for_each_process(p) {
-                        if (p->mm)
-                                cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
-                }
-                read_unlock(&tasklist_lock);
+                clear_tasks_mm_cpumask(cpu);
         break;
 #endif /* CONFIG_HOTPLUG_CPU */
         }
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
index b86e9ca79455..2062aa88af41 100644
--- a/arch/sh/kernel/smp.c
+++ b/arch/sh/kernel/smp.c
@@ -123,7 +123,6 @@ void native_play_dead(void)
 int __cpu_disable(void)
 {
         unsigned int cpu = smp_processor_id();
-        struct task_struct *p;
         int ret;
 
         ret = mp_ops->cpu_disable(cpu);
@@ -153,11 +152,7 @@ int __cpu_disable(void)
         flush_cache_all();
         local_flush_tlb_all();
 
-        read_lock(&tasklist_lock);
-        for_each_process(p)
-                if (p->mm)
-                        cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
-        read_unlock(&tasklist_lock);
+        clear_tasks_mm_cpumask(cpu);
 
         return 0;
 }
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 4d93dff6b371..3d15243ce692 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -4,7 +4,9 @@
  */
 
 #include "linux/sched.h"
+#include "linux/spinlock.h"
 #include "linux/slab.h"
+#include "linux/oom.h"
 #include "kern_util.h"
 #include "os.h"
 #include "skas.h"
@@ -22,13 +24,18 @@ static void kill_off_processes(void)
                 struct task_struct *p;
                 int pid;
 
+                read_lock(&tasklist_lock);
                 for_each_process(p) {
-                        if (p->mm == NULL)
-                                continue;
+                        struct task_struct *t;
 
-                        pid = p->mm->context.id.u.pid;
+                        t = find_lock_task_mm(p);
+                        if (!t)
+                                continue;
+                        pid = t->mm->context.id.u.pid;
+                        task_unlock(t);
                         os_kill_ptraced_process(pid, 1);
                 }
+                read_unlock(&tasklist_lock);
         }
 }
 
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index dafc94715950..3be60765c0e2 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -30,6 +30,8 @@ int handle_page_fault(unsigned long address, unsigned long ip,
         pmd_t *pmd;
         pte_t *pte;
         int err = -EFAULT;
+        unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
+                                 (is_write ? FAULT_FLAG_WRITE : 0);
 
         *code_out = SEGV_MAPERR;
 
@@ -40,6 +42,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
         if (in_atomic())
                 goto out_nosemaphore;
 
+retry:
         down_read(&mm->mmap_sem);
         vma = find_vma(mm, address);
         if (!vma)
@@ -65,7 +68,11 @@ good_area:
         do {
                 int fault;
 
-                fault = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : 0);
+                fault = handle_mm_fault(mm, vma, address, flags);
+
+                if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+                        goto out_nosemaphore;
+
                 if (unlikely(fault & VM_FAULT_ERROR)) {
                         if (fault & VM_FAULT_OOM) {
                                 goto out_of_memory;
@@ -75,10 +82,17 @@ good_area:
                         }
                         BUG();
                 }
-                if (fault & VM_FAULT_MAJOR)
-                        current->maj_flt++;
-                else
-                        current->min_flt++;
+                if (flags & FAULT_FLAG_ALLOW_RETRY) {
+                        if (fault & VM_FAULT_MAJOR)
+                                current->maj_flt++;
+                        else
+                                current->min_flt++;
+                        if (fault & VM_FAULT_RETRY) {
+                                flags &= ~FAULT_FLAG_ALLOW_RETRY;
+
+                                goto retry;
+                        }
+                }
 
                 pgd = pgd_offset(mm, address);
                 pud = pud_offset(pgd, address);
diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl
index 29f9f0554f7d..7a35a6e71d44 100644
--- a/arch/x86/syscalls/syscall_32.tbl
+++ b/arch/x86/syscalls/syscall_32.tbl
@@ -355,3 +355,4 @@
 346     i386    setns                   sys_setns
 347     i386    process_vm_readv        sys_process_vm_readv            compat_sys_process_vm_readv
 348     i386    process_vm_writev       sys_process_vm_writev           compat_sys_process_vm_writev
+349     i386    kcmp                    sys_kcmp
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index dd29a9ea27c5..51171aeff0dc 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -318,6 +318,8 @@
 309     common  getcpu                  sys_getcpu
 310     64      process_vm_readv        sys_process_vm_readv
 311     64      process_vm_writev       sys_process_vm_writev
+312     64      kcmp                    sys_kcmp
+
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
 # for native 64-bit operation.