[OpenBIOS] [commit] r764 - trunk/openbios-devel/libc

[repository service]

Author: mcayland
Date: Sat May  1 11:48:57 2010
New Revision: 764
URL: http://tracker.coreboot.org/trac/openbios/changeset/764

Log:
Add checks to the read_io, seek_io and close_io routines to ensure that they do not perform any actions if an invalid 
file handle (-1) is passed. This resolves the issue with extra arguments being left on the Forth stack when an invalid device 
access is attempted.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at siriusit.co.uk>

Modified:
   trunk/openbios-devel/libc/diskio.c

Modified: trunk/openbios-devel/libc/diskio.c
==============================================================================
--- trunk/openbios-devel/libc/diskio.c	Fri Apr 30 23:56:29 2010	(r763)
+++ trunk/openbios-devel/libc/diskio.c	Sat May  1 11:48:57 2010	(r764)
@@ -164,27 +164,40 @@
 int
 read_io( int fd, void *buf, size_t cnt )
 {
-	priv_fd_t *fdp = file_descriptors[fd];
+	priv_fd_t *fdp;
 	ucell ret;
 
-	PUSH( (ucell)buf );
-	PUSH( cnt );
-	call_package( fdp->read_xt, fdp->ih );
-	ret = POP();
+	if (fd != -1) {
+		fdp = file_descriptors[fd];
 
-	if( !ret && cnt )
+		PUSH( (ucell)buf );
+		PUSH( cnt );
+		call_package( fdp->read_xt, fdp->ih );
+		ret = POP();
+
+		if( !ret && cnt )
+			ret = -1;
+	} else {
 		ret = -1;
+	}
+
 	return ret;
 }
 
 int
 seek_io( int fd, llong offs )
 {
-	priv_fd_t *fdp = file_descriptors[fd];
+	priv_fd_t *fdp;
 
-	DPUSH( offs );
-	call_package( fdp->seek_xt, fdp->ih );
-	return ((((cell)POP()) >= 0)? 0 : -1);
+	if (fd != -1) {
+		fdp = file_descriptors[fd];
+		
+		DPUSH( offs );
+		call_package( fdp->seek_xt, fdp->ih );
+		return ((((cell)POP()) >= 0)? 0 : -1);
+	} else {
+		return -1;
+	}
 }
 
 llong
@@ -203,13 +216,17 @@
 int
 close_io( int fd )
 {
-	priv_fd_t *fdp = file_descriptors[fd];
+	priv_fd_t *fdp;
+
+	if (fd != -1) {
+		fdp = file_descriptors[fd];
 
-	if( fdp->do_close )
-		close_dev( fdp->ih );
-	free( fdp );
+		if( fdp->do_close )
+			close_dev( fdp->ih );
+		free( fdp );
 
-	file_descriptors[fd]=NULL;
+		file_descriptors[fd]=NULL;
+	}
 
 	return 0;
 }