2012-11-01 06:34:38

by Huang Shijie

[permalink] [raw]
Subject: [PATCH] mtd: cmdlinepart: fix the overflow of big mtd partitions

When the kernel parses the following cmdline

#mtdparts=gpmi-nand:16m(boot),16m(kernel),1g(home),4g(test),-(usr)

for a big nand chip Micron MT29F64G08AFAAAWP(8GB), we got the following wrong
result:

.............................................
"mtd: partition size too small (0)"
.............................................

We can not get any partition.

The "4g(test)" partition triggers a overflow of the "size". The memparse()
returns 4g to the "size", but the size is "unsigned long" type, so a overflow
occurs, the "size" becomes zero in the end.

This patch changes the "size"/"offset" to "unsigned long long" type,
and replaces the UINT_MAX with ULLONG_MAX for macros SIZE_REMAINING and
OFFSET_CONTINUOUS.

Signed-off-by: Huang Shijie <[email protected]>
---
drivers/mtd/cmdlinepart.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index 4baab3b..1cfd741 100644
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -56,8 +56,8 @@


/* special size referring to all the remaining space in a partition */
-#define SIZE_REMAINING UINT_MAX
-#define OFFSET_CONTINUOUS UINT_MAX
+#define SIZE_REMAINING ULLONG_MAX
+#define OFFSET_CONTINUOUS ULLONG_MAX

struct cmdline_mtd_partition {
struct cmdline_mtd_partition *next;
@@ -89,7 +89,7 @@ static struct mtd_partition * newpart(char *s,
int extra_mem_size)
{
struct mtd_partition *parts;
- unsigned long size, offset = OFFSET_CONTINUOUS;
+ unsigned long long size, offset = OFFSET_CONTINUOUS;
char *name;
int name_len;
unsigned char *extra_mem;
@@ -104,7 +104,7 @@ static struct mtd_partition * newpart(char *s,
} else {
size = memparse(s, &s);
if (size < PAGE_SIZE) {
- printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
+ printk(KERN_ERR ERRP "partition size too small (%llx)\n", size);
return ERR_PTR(-EINVAL);
}
}
@@ -296,7 +296,7 @@ static int parse_cmdline_partitions(struct mtd_info *master,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
- unsigned long offset;
+ unsigned long long offset;
int i, err;
struct cmdline_mtd_partition *part;
const char *mtd_id = master->name;
--
1.7.0.4


2012-11-15 13:44:27

by Artem Bityutskiy

[permalink] [raw]
Subject: Re: [PATCH] mtd: cmdlinepart: fix the overflow of big mtd partitions

On Thu, 2012-11-01 at 13:58 +0800, Huang Shijie wrote:
> When the kernel parses the following cmdline
>
> #mtdparts=gpmi-nand:16m(boot),16m(kernel),1g(home),4g(test),-(usr)
>
> for a big nand chip Micron MT29F64G08AFAAAWP(8GB), we got the following wrong
> result:
>
> .............................................
> "mtd: partition size too small (0)"
> .............................................
>
> We can not get any partition.
>
> The "4g(test)" partition triggers a overflow of the "size". The memparse()
> returns 4g to the "size", but the size is "unsigned long" type, so a overflow
> occurs, the "size" becomes zero in the end.
>
> This patch changes the "size"/"offset" to "unsigned long long" type,
> and replaces the UINT_MAX with ULLONG_MAX for macros SIZE_REMAINING and
> OFFSET_CONTINUOUS.
>
> Signed-off-by: Huang Shijie <[email protected]>

Pushed to l2-mtd.git, thanks!

--
Best Regards,
Artem Bityutskiy


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