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>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index c3af15e..daba136 100644 (file)
--- 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;