[MTD] slram driver cleanup
Add error checks to read/write functions and add an eraseblock size.
Makes slram a suitable device for JFFS2.
Signed-off-by: Josh Boyer <jdub@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/mtd/devices/slram.c b/drivers/mtd/devices/slram.c
index 5ab15e6..84fa913 100644
--- a/drivers/mtd/devices/slram.c
+++ b/drivers/mtd/devices/slram.c
@@ -1,6 +1,6 @@
/*======================================================================
- $Id: slram.c,v 1.33 2005/01/05 18:05:13 dwmw2 Exp $
+ $Id: slram.c,v 1.34 2005/01/06 21:16:42 jwboyer Exp $
This driver provides a method to access memory not used by the kernel
itself (i.e. if the kernel commandline mem=xxx is used). To actually
@@ -50,6 +50,7 @@
#include <linux/mtd/mtd.h>
#define SLRAM_MAX_DEVICES_PARAMS 6 /* 3 parameters / device */
+#define SLRAM_BLK_SZ 0x4000
#define T(fmt, args...) printk(KERN_DEBUG fmt, ## args)
#define E(fmt, args...) printk(KERN_NOTICE fmt, ## args)
@@ -108,6 +109,9 @@
{
slram_priv_t *priv = mtd->priv;
+ if (from + len > mtd->size)
+ return -EINVAL;
+
*mtdbuf = priv->start + from;
*retlen = len;
return(0);
@@ -121,7 +125,13 @@
size_t *retlen, u_char *buf)
{
slram_priv_t *priv = mtd->priv;
-
+
+ if (from > mtd->size)
+ return -EINVAL;
+
+ if (from + len > mtd->size)
+ len = mtd->size - from;
+
memcpy(buf, priv->start + from, len);
*retlen = len;
@@ -133,6 +143,9 @@
{
slram_priv_t *priv = mtd->priv;
+ if (to + len > mtd->size)
+ return -EINVAL;
+
memcpy(priv->start + to, buf, len);
*retlen = len;
@@ -188,7 +201,7 @@
(*curmtd)->mtdinfo->name = name;
(*curmtd)->mtdinfo->size = length;
(*curmtd)->mtdinfo->flags = MTD_CLEAR_BITS | MTD_SET_BITS |
- MTD_WRITEB_WRITEABLE | MTD_VOLATILE;
+ MTD_WRITEB_WRITEABLE | MTD_VOLATILE | MTD_CAP_RAM;
(*curmtd)->mtdinfo->erase = slram_erase;
(*curmtd)->mtdinfo->point = slram_point;
(*curmtd)->mtdinfo->unpoint = slram_unpoint;
@@ -196,7 +209,7 @@
(*curmtd)->mtdinfo->write = slram_write;
(*curmtd)->mtdinfo->owner = THIS_MODULE;
(*curmtd)->mtdinfo->type = MTD_RAM;
- (*curmtd)->mtdinfo->erasesize = 0x0;
+ (*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;
if (add_mtd_device((*curmtd)->mtdinfo)) {
E("slram: Failed to register new device\n");
@@ -261,7 +274,7 @@
}
T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n",
devname, devstart, devlength);
- if ((devstart < 0) || (devlength < 0)) {
+ if ((devstart < 0) || (devlength < 0) || (devlength % SLRAM_BLK_SZ != 0)) {
E("slram: Illegal start / length parameter.\n");
return(-EINVAL);
}