6 files changed, 28 insertions, 9 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 65c62e1bfd6f..eb97f2897e2b 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -169,7 +169,7 @@ static inline char *task_state(struct task_struct *p, char *buffer)
         ppid = pid_alive(p) ?
                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
         tpid = pid_alive(p) && p->ptrace ?
-                task_ppid_nr_ns(rcu_dereference(p->parent), ns) : 0;
+                task_pid_nr_ns(rcu_dereference(p->parent), ns) : 0;
         buffer += sprintf(buffer,
                 "State:\t%s\n"
                 "Tgid:\t%d\n"
@@ -464,8 +464,8 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
                 }
 
                 sid = task_session_nr_ns(task, ns);
+                ppid = task_tgid_nr_ns(task->real_parent, ns);
                 pgid = task_pgrp_nr_ns(task, ns);
-                ppid = task_ppid_nr_ns(task, ns);
 
                 unlock_task_sighand(task, &flags);
         }
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 02a63ac04178..7411bfb0b7cc 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -202,6 +202,26 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
          (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
          security_ptrace(current,task) == 0))
 
+struct mm_struct *mm_for_maps(struct task_struct *task)
+{
+        struct mm_struct *mm = get_task_mm(task);
+        if (!mm)
+                return NULL;
+        down_read(&mm->mmap_sem);
+        task_lock(task);
+        if (task->mm != mm)
+                goto out;
+        if (task->mm != current->mm && __ptrace_may_attach(task) < 0)
+                goto out;
+        task_unlock(task);
+        return mm;
+out:
+        task_unlock(task);
+        up_read(&mm->mmap_sem);
+        mmput(mm);
+        return NULL;
+}
+
 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
 {
         int res = 0;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 1820eb2ef762..05b3e9006262 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -27,6 +27,8 @@ struct vmalloc_info {
         unsigned long   largest_chunk;
 };
 
+extern struct mm_struct *mm_for_maps(struct task_struct *);
+
 #ifdef CONFIG_MMU
 #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
 extern void get_vmalloc_info(struct vmalloc_info *vmi);
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index e0d064e9764e..3462bfde89f6 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -410,7 +410,7 @@ static const struct file_operations proc_modules_operations = {
 };
 #endif
 
-#ifdef CONFIG_SLAB
+#ifdef CONFIG_SLABINFO
 static int slabinfo_open(struct inode *inode, struct file *file)
 {
         return seq_open(file, &slabinfo_op);
@@ -728,7 +728,7 @@ void __init proc_misc_init(void)
 #endif
         create_seq_entry("stat", 0, &proc_stat_operations);
         create_seq_entry("interrupts", 0, &proc_interrupts_operations);
-#ifdef CONFIG_SLAB
+#ifdef CONFIG_SLABINFO
         create_seq_entry("slabinfo",S_IWUSR|S_IRUGO,&proc_slabinfo_operations);
 #ifdef CONFIG_DEBUG_SLAB_LEAK
         create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations);
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c24d81a5a040..8043a3eab52c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -397,12 +397,11 @@ static void *m_start(struct seq_file *m, loff_t *pos)
         if (!priv->task)
                 return NULL;
 
-        mm = get_task_mm(priv->task);
+        mm = mm_for_maps(priv->task);
         if (!mm)
                 return NULL;
 
         priv->tail_vma = tail_vma = get_gate_vma(priv->task);
-        down_read(&mm->mmap_sem);
 
         /* Start with last addr hint */
         if (last_addr && (vma = find_vma(mm, last_addr))) {
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index d8b8c7183c24..1932c2ca3457 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -165,15 +165,13 @@ static void *m_start(struct seq_file *m, loff_t *pos)
         if (!priv->task)
                 return NULL;
 
-        mm = get_task_mm(priv->task);
+        mm = mm_for_maps(priv->task);
         if (!mm) {
                 put_task_struct(priv->task);
                 priv->task = NULL;
                 return NULL;
         }
 
-        down_read(&mm->mmap_sem);
-
         /* start from the Nth VMA */
         for (vml = mm->context.vmlist; vml; vml = vml->next)
                 if (n-- == 0)