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[patch] mtd: pmcmsp-flash: Allocating too much in init_msp_flash()

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  [patch] mtd: pmcmsp-flash: Allocating too much in init_msp_flash() Dan Carpenter <dan.carpenter@oracle.com> - 2016-07-14 12:50 +0200
    Re: [patch] mtd: pmcmsp-flash: Allocating too much in  init_msp_flash() Brian Norris <computersforpeace@gmail.com> - 2016-07-16 07:50 +0200

#1443353 — [patch] mtd: pmcmsp-flash: Allocating too much in init_msp_flash()

There is a cut and paste issue here.  The bug is that we are allocating
more memory than necessary for msp_maps.  We should be allocating enough
space for a map_info struct (144 bytes) but we instead allocate enough
for an mtd_info struct (1840 bytes).  It's a small waste.

The other part of this is not harmful but when we allocated msp_flash
then we allocated enough space fro a map_info pointer instead of an
mtd_info pointer.  But since pointers are the same size it works out
fine.

Anyway, I decided to clean up all three allocations a bit to make them
a bit more consistent and clear.

Fixes: 68aa0fa87f6d ('[MTD] PMC MSP71xx flash/rootfs mappings')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Not tested!!

diff --git a/drivers/mtd/maps/pmcmsp-flash.c b/drivers/mtd/maps/pmcmsp-flash.c
index 744ca5c..f9fa3fa 100644
--- a/drivers/mtd/maps/pmcmsp-flash.c
+++ b/drivers/mtd/maps/pmcmsp-flash.c
@@ -75,15 +75,15 @@ static int __init init_msp_flash(void)
 
 	printk(KERN_NOTICE "Found %d PMC flash devices\n", fcnt);
 
-	msp_flash = kmalloc(fcnt * sizeof(struct map_info *), GFP_KERNEL);
+	msp_flash = kcalloc(fcnt, sizeof(*msp_flash), GFP_KERNEL);
 	if (!msp_flash)
 		return -ENOMEM;
 
-	msp_parts = kmalloc(fcnt * sizeof(struct mtd_partition *), GFP_KERNEL);
+	msp_parts = kcalloc(fcnt, sizeof(*msp_parts), GFP_KERNEL);
 	if (!msp_parts)
 		goto free_msp_flash;
 
-	msp_maps = kcalloc(fcnt, sizeof(struct mtd_info), GFP_KERNEL);
+	msp_maps = kcalloc(fcnt, sizeof(*msp_maps), GFP_KERNEL);
 	if (!msp_maps)
 		goto free_msp_parts;
 

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#1444747 — Re: [patch] mtd: pmcmsp-flash: Allocating too much in init_msp_flash()

On Thu, Jul 14, 2016 at 01:44:56PM +0300, Dan Carpenter wrote:
> There is a cut and paste issue here.  The bug is that we are allocating
> more memory than necessary for msp_maps.  We should be allocating enough
> space for a map_info struct (144 bytes) but we instead allocate enough
> for an mtd_info struct (1840 bytes).  It's a small waste.
> 
> The other part of this is not harmful but when we allocated msp_flash
> then we allocated enough space fro a map_info pointer instead of an
> mtd_info pointer.  But since pointers are the same size it works out
> fine.
> 
> Anyway, I decided to clean up all three allocations a bit to make them
> a bit more consistent and clear.
> 
> Fixes: 68aa0fa87f6d ('[MTD] PMC MSP71xx flash/rootfs mappings')
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Applied to l2-mtd.git.

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