procfs: fix some wrong error code usage

[root@wei 1]# cat /proc/1/mem
cat: /proc/1/mem: No such process

error code -ESRCH is wrong in this situation.  Return -EPERM instead.

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index c3af15e9c070..daba13653256 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -775,7 +775,8 @@ static ssize_t mem_read(struct file * file, char __user * buf,
         if (!task)
                 goto out_no_task;
 
-        if (check_mem_permission(task))
+        ret = check_mem_permission(task);
+        if (ret)
                 goto out;
 
         ret = -ENOMEM;
@@ -845,7 +846,8 @@ static ssize_t mem_write(struct file * file, const char __user *buf,
         if (!task)
                 goto out_no_task;
 
-        if (check_mem_permission(task))
+        copied = check_mem_permission(task);
+        if (copied)
                 goto out;
 
         copied = -ENOMEM;
@@ -917,6 +919,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
         if (!task)
                 goto out_no_task;
 
+        ret = -EPERM;
         if (!ptrace_may_access(task, PTRACE_MODE_READ))
                 goto out;