Re: [PATCH] mtd: fix memory leaks in phram_setup

From: David Woodhouse
Date: Sun May 14 2006 - 07:04:10 EST


On Sun, 2006-05-14 at 08:37 +0200, JÃrn Engel wrote:
> The only question is: does it make the code better? The code has
> seven printk/return combinations. Each of them would chew up 2 more
> lines without the macro. So phram_setup would grow from 44 to 58
> lines, not nice either.

How about this then...

diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
index e09e416..fd2d43f 100644
--- a/drivers/mtd/devices/phram.c
+++ b/drivers/mtd/devices/phram.c
@@ -187,36 +187,41 @@ static int ustrtoul(const char *cp, char
return result;
}

-static int parse_num32(uint32_t *num32, const char *token)
+static int parse_num32(uint32_t *num32, const char *token, char *name)
{
char *endp;
unsigned long n;

n = ustrtoul(token, &endp, 0);
- if (*endp)
+ if (*endp) {
+ ERROR("Illegal %s\n", name);
return -EINVAL;
+ }

*num32 = n;
return 0;
}

-static int parse_name(char **pname, const char *token)
+static char *parse_name(const char *token)
{
size_t len;
char *name;

len = strlen(token) + 1;
- if (len > 64)
- return -ENOSPC;
+ if (len > 64) {
+ ERROR("name too long");
+ return ERR_PTR(-ENOSPC);
+ }

name = kmalloc(len, GFP_KERNEL);
- if (!name)
- return -ENOMEM;
+ if (!name) {
+ ERROR("out of memory");
+ return ERR_PTR(-ENOMEM);
+ }

strcpy(name, token);

- *pname = name;
- return 0;
+ return name;
}


@@ -228,11 +233,6 @@ static inline void kill_final_newline(ch
}


-#define parse_err(fmt, args...) do { \
- ERROR(fmt , ## args); \
- return 0; \
-} while (0)
-
static int phram_setup(const char *val, struct kernel_param *kp)
{
char buf[64+12+12], *str = buf;
@@ -242,8 +242,10 @@ static int phram_setup(const char *val,
uint32_t len;
int i, ret;

- if (strnlen(val, sizeof(buf)) >= sizeof(buf))
- parse_err("parameter too long\n");
+ if (strnlen(val, sizeof(buf)) >= sizeof(buf)) {
+ ERROR("parameter too long\n");
+ return -EINVAL;
+ }

strcpy(str, val);
kill_final_newline(str);
@@ -251,30 +253,24 @@ static int phram_setup(const char *val,
for (i=0; i<3; i++)
token[i] = strsep(&str, ",");

- if (str)
- parse_err("too many arguments\n");
-
- if (!token[2])
- parse_err("not enough arguments\n");
-
- ret = parse_name(&name, token[0]);
- if (ret == -ENOMEM)
- parse_err("out of memory\n");
- if (ret == -ENOSPC)
- parse_err("name too long\n");
- if (ret)
- return 0;
+ if (str) {
+ ERROR("too many arguments\n");
+ return -EINVAL;
+ }

- ret = parse_num32(&start, token[1]);
- if (ret) {
- kfree(name);
- parse_err("illegal start address\n");
+ if (!token[2]) {
+ ERROR("not enough arguments\n");
+ return -EINVAL;
}

- ret = parse_num32(&len, token[2]);
- if (ret) {
+ name = prase_name(token[0]);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ if ((ret = parse_num32(&start, token[1], "start address")) ||
+ (ret = parse_num32(&len, token[2], "device length"))) {
kfree(name);
- parse_err("illegal device length\n");
+ return ret;
}

register_device(name, start, len);

--
dwmw2

-
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