Add a new errno: EMACS - Editor too big.

emacs.patch

From d8f85b3eeff44c31d21e987a4494ee1f8299322d Mon Sep 17 00:00:00 2001
From: Olli Vanhoja <olli.vanhoja@gmail.com>
Date: Tue, 1 Apr 2014 18:03:56 +0300
Subject: [PATCH] Add a new errno: EMACS - Editor too big.

Make a best-effort to detect that Emacs is about to executed and return the error.
---
 fs/exec.c                        |   13 ++++++++++++-
 include/uapi/asm-generic/errno.h |    2 ++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/fs/exec.c b/fs/exec.c
index 3d78fcc..36c5a4b 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -19,7 +19,7 @@
  * current->executable is only used by the procfs.  This allows a dispatch
  * table to check for several different types  of binary formats.  We keep
  * trying until we recognize the file or we run out of supported binary
- * formats. 
+ * formats.
  */
 
 #include <linux/slab.h>
@@ -758,6 +758,17 @@ static struct file *do_open_exec(struct filename *name)
 		.intent = LOOKUP_OPEN,
 		.lookup_flags = LOOKUP_FOLLOW,
 	};
+	char *e;
+
+	if (name->name != NULL) {
+		e = (char *)name->name + strlen(name->name);
+		while (e > name->name && *e != '/')
+			e--;
+		if (strcasecmp(e, "/emacs") == 0) {
+			err = -EMACS;
+			goto exit;
+		}
+	}
 
 	file = do_filp_open(AT_FDCWD, name, &open_exec_flags);
 	if (IS_ERR(file))
diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/errno.h
index 1e1ea6e..2e8067c 100644
--- a/include/uapi/asm-generic/errno.h
+++ b/include/uapi/asm-generic/errno.h
@@ -110,4 +110,6 @@
 
 #define EHWPOISON	133	/* Memory page has hardware error */
 
+#define EMACS		134	/* Editor too big */
+
 #endif
-- 
1.7.9.5

Related to this:
http://lists.freebsd.org/pipermail/svn-src-head/2014-April/057249.html