linux-kernel - [patch] mtd: pmcmsp-flash: Allocating too much in init_msp

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Date:	Thu, 14 Jul 2016 13:44:56 +0300
From:	Dan Carpenter <dan.carpenter@...cle.com>
To:	David Woodhouse <dwmw2@...radead.org>,
	Marc St-Jean <stjeanma@...-sierra.com>
Cc:	Brian Norris <computersforpeace@...il.com>,
	linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org,
	kernel-janitors@...r.kernel.org
Subject: [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@...cle.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;