[Patch]Documentation/vm/slabinfo.c: clean up this code

[Patch]Documentation/vm/slabinfo.c: clean up this code

[WANG Cong]

This patch does the following cleanups for Documentation/vm/slabinfo.c:

	- Fix two memory leaks;
	- Constify some char pointers;
	- Use snprintf instead of sprintf in case of buffer overflow;
	- Fix some indentations;
	- Other little improvements.

And it is against 2.6.23-rc9.

CC: Christoph Lameter <clameter@sgi.com>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>

---
 Documentation/vm/slabinfo.c |   27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

Index: linux-2.6.23-rc9/Documentation/vm/slabinfo.c
===================================================================
--- linux-2.6.23-rc9.orig/Documentation/vm/slabinfo.c
+++ linux-2.6.23-rc9/Documentation/vm/slabinfo.c
@@ -11,6 +11,7 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #include <dirent.h>
+#include <strings.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdarg.h>
@@ -84,7 +85,7 @@ void fatal(const char *x, ...)
 	va_start(ap, x);
 	vfprintf(stderr, x, ap);
 	va_end(ap);
-	exit(1);
+	exit(EXIT_FAILURE);
 }
 
 void usage(void)
@@ -119,14 +120,14 @@ void usage(void)
 	);
 }
 
-unsigned long read_obj(char *name)
+unsigned long read_obj(const char *name)
 {
 	FILE *f = fopen(name, "r");
 
 	if (!f)
 		buffer[0] = 0;
 	else {
-		if (!fgets(buffer,sizeof(buffer), f))
+		if (!fgets(buffer, sizeof(buffer), f))
 			buffer[0] = 0;
 		fclose(f);
 		if (buffer[strlen(buffer)] == '\n')
@@ -139,7 +140,7 @@ unsigned long read_obj(char *name)
 /*
  * Get the contents of an attribute
  */
-unsigned long get_obj(char *name)
+unsigned long get_obj(const char *name)
 {
 	if (!read_obj(name))
 		return 0;
@@ -147,7 +148,7 @@ unsigned long get_obj(char *name)
 	return atol(buffer);
 }
 
-unsigned long get_obj_and_str(char *name, char **x)
+unsigned long get_obj_and_str(const char *name, char **x)
 {
 	unsigned long result = 0;
 	char *p;
@@ -166,12 +167,12 @@ unsigned long get_obj_and_str(char *name
 	return result;
 }
 
-void set_obj(struct slabinfo *s, char *name, int n)
+void set_obj(struct slabinfo *s, const char *name, int n)
 {
 	char x[100];
 	FILE *f;
 
-	sprintf(x, "%s/%s", s->name, name);
+	snprintf(x, 100, "%s/%s", s->name, name);
 	f = fopen(x, "w");
 	if (!f)
 		fatal("Cannot write to %s\n", x);
@@ -180,13 +181,13 @@ void set_obj(struct slabinfo *s, char *n
 	fclose(f);
 }
 
-unsigned long read_slab_obj(struct slabinfo *s, char *name)
+unsigned long read_slab_obj(struct slabinfo *s, const char *name)
 {
 	char x[100];
 	FILE *f;
-	int l;
+	size_t l;
 
-	sprintf(x, "%s/%s", s->name, name);
+	snprintf(x, 100, "%s/%s", s->name, name);
 	f = fopen(x, "r");
 	if (!f) {
 		buffer[0] = 0;
@@ -453,7 +454,7 @@ void slabcache(struct slabinfo *s)
 		return;
 
 	store_size(size_str, slab_size(s));
-	sprintf(dist_str,"%lu/%lu/%d", s->slabs, s->partial, s->cpu_slabs);
+	snprintf(dist_str, 40, "%lu/%lu/%d", s->slabs, s->partial, s->cpu_slabs);
 
 	if (!line++)
 		first_line();
@@ -1062,6 +1063,7 @@ void read_slab_dir(void)
 			slab->partial = get_obj("partial");
 			slab->partial = get_obj_and_str("partial", &t);
 			decode_numa_list(slab->numa_partial, t);
+			free(t);
 			slab->poison = get_obj("poison");
 			slab->reclaim_account = get_obj("reclaim_account");
 			slab->red_zone = get_obj("red_zone");
@@ -1069,6 +1071,7 @@ void read_slab_dir(void)
 			slab->slab_size = get_obj("slab_size");
 			slab->slabs = get_obj_and_str("slabs", &t);
 			decode_numa_list(slab->numa, t);
+			free(t);
 			slab->store_user = get_obj("store_user");
 			slab->trace = get_obj("trace");
 			chdir("..");
@@ -1148,7 +1151,7 @@ int main(int argc, char *argv[])
 
 	while ((c = getopt_long(argc, argv, "ad::efhil1noprstvzTS",
 						opts, NULL)) != -1)
-	switch(c) {
+		switch (c) {
 		case '1':
 			show_single_ref = 1;
 			break;

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Re: [Patch]Documentation/vm/slabinfo.c: clean up this code

[Christoph Lameter]

On Fri, 5 Oct 2007, WANG Cong wrote:

> 
> This patch does the following cleanups for Documentation/vm/slabinfo.c:
> 
> 	- Fix two memory leaks;

For user space code? Memory will be released as soon as the program 
terminates.

> 	- Constify some char pointers;
> 	- Use snprintf instead of sprintf in case of buffer overflow;
> 	- Fix some indentations;
> 	- Other little improvements.

Acked-by: Christoph Lameter <clameter@sgi.com>

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Re: [Patch]Documentation/vm/slabinfo.c: clean up this code

[WANG Cong]

On Fri, Oct 05, 2007 at 12:17:41PM -0700, Christoph Lameter wrote:
>On Fri, 5 Oct 2007, WANG Cong wrote:
>
>> 
>> This patch does the following cleanups for Documentation/vm/slabinfo.c:
>> 
>> 	- Fix two memory leaks;
>
>For user space code? Memory will be released as soon as the program 
>terminates.

Yes, it's of course in user space. But there really exists memory leaks,
since strdup(3) uses malloc(3) to allocate memory for new string, we
should use free(3) to free the memory, or this memory will be lost.

Regards. ;)


WANG Cong

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