From: Alan Cox <alan@linux.intel.com>
Date: Sat, 27 Dec 2014 13:59:03 +0000 (+0000)
Subject: execve: handle null files
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=bf4d70f439c82d5e88fed3c08822166df87aff47;p=FUZIX.git

execve: handle null files

When given an empty file execve was doing a bmap and trying to load block
-1 from the disk. Catch the empty file case earlier and error it.
---

diff --git a/Kernel/syscall_exec.c b/Kernel/syscall_exec.c
index a9257903..15a1cc2e 100644
--- a/Kernel/syscall_exec.c
+++ b/Kernel/syscall_exec.c
@@ -55,6 +55,11 @@ int16_t _execve(void)
 
 	setftime(ino, A_TIME);
 
+	if (ino->c_node.i_size == 0) {
+		udata.u_error = ENOEXEC;
+		goto nogood2;
+	}
+
 	/* Read in the first block of the new program */
 	buf = bread(ino->c_dev, bmap(ino, 0, 1), 0);
 
@@ -149,7 +154,7 @@ int16_t _execve(void)
 	brelse(buf);
 
 	c = ugetc((uint8_t *)PROGLOAD);
-	if (c != 0xC3)
+	if (c != EMAGIC)
 		kprintf("Botched uput\n");
 
 	/* At this point, we are committed to reading in and