From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 5 Feb 2014 00:08:21 +0000 (-0500)
Subject: read_code(): go through vfs_read() instead of calling the method directly
X-Git-Tag: firefly_0821_release~176^2~4070^2~29
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=ec69557982563c97b3a7d68dd271be5105b83869;p=firefly-linux-kernel-4.4.55.git

read_code(): go through vfs_read() instead of calling the method directly

... and don't skip on sanity checks.  It's *not* a hot path, TYVM
(a couple of calls per a.out execve(), for pity sake) and headers of
random a.out binary are not to be trusted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/exec.c b/fs/exec.c
index 3d78fccdd723..4cc94534ed5b 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -810,7 +810,7 @@ EXPORT_SYMBOL(kernel_read);
 
 ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
 {
-	ssize_t res = file->f_op->read(file, (void __user *)addr, len, &pos);
+	ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
 	if (res > 0)
 		flush_icache_range(addr, addr + len);
 	return res;