report errors in /proc/*/*map* sanely
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index df73573..c282811 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -225,15 +225,17 @@
struct mm_struct *mm_for_maps(struct task_struct *task)
{
struct mm_struct *mm;
+ int err;
- if (mutex_lock_killable(&task->signal->cred_guard_mutex))
- return NULL;
+ err = mutex_lock_killable(&task->signal->cred_guard_mutex);
+ if (err)
+ return ERR_PTR(err);
mm = get_task_mm(task);
if (mm && mm != current->mm &&
!ptrace_may_access(task, PTRACE_MODE_READ)) {
mmput(mm);
- mm = NULL;
+ mm = ERR_PTR(-EACCES);
}
mutex_unlock(&task->signal->cred_guard_mutex);
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c966413..8fed0f8 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -119,11 +119,11 @@
priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
if (!priv->task)
- return NULL;
+ return ERR_PTR(-ESRCH);
mm = mm_for_maps(priv->task);
- if (!mm)
- return NULL;
+ if (!mm || IS_ERR(mm))
+ return mm;
down_read(&mm->mmap_sem);
tail_vma = get_gate_vma(priv->task);
@@ -728,9 +728,9 @@
if (!task)
goto out;
- ret = -EACCES;
mm = mm_for_maps(task);
- if (!mm)
+ ret = PTR_ERR(mm);
+ if (!mm || IS_ERR(mm))
goto out_task;
ret = -EINVAL;
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index b535d3e..980de54 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -199,13 +199,13 @@
/* pin the task and mm whilst we play with them */
priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
if (!priv->task)
- return NULL;
+ return ERR_PTR(-ESRCH);
mm = mm_for_maps(priv->task);
- if (!mm) {
+ if (!mm || IS_ERR(mm)) {
put_task_struct(priv->task);
priv->task = NULL;
- return NULL;
+ return mm;
}
down_read(&mm->mmap_sem);