From 14f8351a313f364afbc565f1ddcd43f8cfdccf52 Mon Sep 17 00:00:00 2001 From: Josh Boyer Date: Thu, 6 Jan 2005 21:16:45 +0000 Subject: [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 Signed-off-by: Thomas Gleixner --- drivers/mtd/devices/slram.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) (limited to 'drivers/mtd/devices') diff --git a/drivers/mtd/devices/slram.c b/drivers/mtd/devices/slram.c index 5ab15e643be..84fa91392a8 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 #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 @@ static int slram_point(struct mtd_info *mtd, loff_t from, size_t len, { 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 @@ static int slram_read(struct mtd_info *mtd, loff_t from, size_t len, 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 @@ static int slram_write(struct mtd_info *mtd, loff_t to, size_t len, { 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 @@ static int register_device(char *name, unsigned long start, unsigned long length (*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 @@ static int register_device(char *name, unsigned long start, unsigned long length (*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 @@ static int parse_cmdline(char *devname, char *szstart, char *szlength) } 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); } -- cgit v1.2.3-70-g09d2