[PATCH] create a kstrdup library function

This patch creates a new kstrdup library function and changes the "local"
implementations in several places to use this function.

Most of the changes come from the sound and net subsystems. The sound part
had already been acknowledged by Takashi Iwai and the net part by David S.
Miller.

I left UML alone for now because I would need more time to read the code
carefully before making changes there.

Signed-off-by: Paulo Marques <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/md/dm-ioctl.c

···
 /*-----------------------------------------------------------------
  * Inserting, removing and renaming a device.
  *---------------------------------------------------------------*/
-static inline char *kstrdup(const char *str)
-{
-	char *r = kmalloc(strlen(str) + 1, GFP_KERNEL);
-	if (r)
-		strcpy(r, str);
-	return r;
-}
-
 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
 				    struct mapped_device *md)
 {
···
 	if (!hc)
 		return NULL;
 
-	hc->name = kstrdup(name);
+	hc->name = kstrdup(name, GFP_KERNEL);
 	if (!hc->name) {
 		kfree(hc);
 		return NULL;
···
 		hc->uuid = NULL;
 
 	else {
-		hc->uuid = kstrdup(uuid);
+		hc->uuid = kstrdup(uuid, GFP_KERNEL);
 		if (!hc->uuid) {
 			kfree(hc->name);
 			kfree(hc);
···
 	/*
 	 * duplicate new.
 	 */
-	new_name = kstrdup(new);
+	new_name = kstrdup(new, GFP_KERNEL);
 	if (!new_name)
 		return -ENOMEM;
 

drivers/parport/probe.c

···
 	printk("\n");
 }
 
-static char *strdup(char *str)
-{
-	int n = strlen(str)+1;
-	char *s = kmalloc(n, GFP_KERNEL);
-	if (!s) return NULL;
-	return strcpy(s, str);
-}
-
 static void parse_data(struct parport *port, int device, char *str)
 {
 	char *txt = kmalloc(strlen(str)+1, GFP_KERNEL);
···
 			if (!strcmp(p, "MFG") || !strcmp(p, "MANUFACTURER")) {
 				if (info->mfr)
 					kfree (info->mfr);
-				info->mfr = strdup(sep);
+				info->mfr = kstrdup(sep, GFP_KERNEL);
 			} else if (!strcmp(p, "MDL") || !strcmp(p, "MODEL")) {
 				if (info->model)
 					kfree (info->model);
-				info->model = strdup(sep);
+				info->model = kstrdup(sep, GFP_KERNEL);
 			} else if (!strcmp(p, "CLS") || !strcmp(p, "CLASS")) {
 				int i;
 				if (info->class_name)
 					kfree (info->class_name);
-				info->class_name = strdup(sep);
+				info->class_name = kstrdup(sep, GFP_KERNEL);
 				for (u = sep; *u; u++)
 					*u = toupper(*u);
 				for (i = 0; classes[i].token; i++) {
···
 				   !strcmp(p, "COMMAND SET")) {
 				if (info->cmdset)
 					kfree (info->cmdset);
-				info->cmdset = strdup(sep);
+				info->cmdset = kstrdup(sep, GFP_KERNEL);
 				/* if it speaks printer language, it's
 				   probably a printer */
 				if (strstr(sep, "PJL") || strstr(sep, "PCL"))
···
 			} else if (!strcmp(p, "DES") || !strcmp(p, "DESCRIPTION")) {
 				if (info->description)
 					kfree (info->description);
-				info->description = strdup(sep);
+				info->description = kstrdup(sep, GFP_KERNEL);
 			}
 		}
 	rock_on:

include/linux/netdevice.h

···
 extern void		net_enable_timestamp(void);
 extern void		net_disable_timestamp(void);
 
-#ifdef CONFIG_SYSCTL
-extern char *net_sysctl_strdup(const char *s);
-#endif
-
 #endif /* __KERNEL__ */
 
 #endif	/* _LINUX_DEV_H */

include/linux/string.h

···
 extern void * memchr(const void *,int,__kernel_size_t);
 #endif
 
+extern char *kstrdup(const char *s, int gfp);
+
 #ifdef __cplusplus
 }
 #endif

include/sound/core.h

···
 void snd_hidden_kfree(const void *obj);
 void *snd_hidden_vmalloc(unsigned long size);
 void snd_hidden_vfree(void *obj);
+char *snd_hidden_kstrdup(const char *s, int flags);
 #define kmalloc(size, flags) snd_hidden_kmalloc(size, flags)
 #define kcalloc(n, size, flags) snd_hidden_kcalloc(n, size, flags)
 #define kfree(obj) snd_hidden_kfree(obj)
···
 #define vmalloc_nocheck(size) snd_wrapper_vmalloc(size)
 #define kfree_nocheck(obj) snd_wrapper_kfree(obj)
 #define vfree_nocheck(obj) snd_wrapper_vfree(obj)
+#define kstrdup(s, flags)  snd_hidden_kstrdup(s, flags)
 #else
 #define snd_memory_init() /*NOP*/
 #define snd_memory_done() /*NOP*/
···
 #define kfree_nocheck(obj) kfree(obj)
 #define vfree_nocheck(obj) vfree(obj)
 #endif
-char *snd_kmalloc_strdup(const char *string, int flags);
 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count);
 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count);
 

mm/slab.c

···
 #include	<linux/sysctl.h>
 #include	<linux/module.h>
 #include	<linux/rcupdate.h>
+#include	<linux/string.h>
 
 #include	<asm/uaccess.h>
 #include	<asm/cacheflush.h>
···
 
 	return size;
 }
+
+
+/*
+ * kstrdup - allocate space for and copy an existing string
+ *
+ * @s: the string to duplicate
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ */
+char *kstrdup(const char *s, int gfp)
+{
+	size_t len;
+	char *buf;
+
+	if (!s)
+		return NULL;
+
+	len = strlen(s) + 1;
+	buf = kmalloc(len, gfp);
+	if (buf)
+		memcpy(buf, s, len);
+	return buf;
+}
+EXPORT_SYMBOL(kstrdup);

net/core/neighbour.c

···
 #include <net/sock.h>
 #include <linux/rtnetlink.h>
 #include <linux/random.h>
+#include <linux/string.h>
 
 #define NEIGH_DEBUG 1
 
···
 		t->neigh_vars[17].extra1 = dev;
 	}
 
-	dev_name = net_sysctl_strdup(dev_name_source);
+	dev_name = kstrdup(dev_name_source, GFP_KERNEL);
 	if (!dev_name) {
 		err = -ENOBUFS;
 		goto free;

net/core/sysctl_net_core.c

···
 extern char sysctl_divert_version[];
 #endif /* CONFIG_NET_DIVERT */
 
-/*
- * This strdup() is used for creating copies of network 
- * device names to be handed over to sysctl.
- */
- 
-char *net_sysctl_strdup(const char *s)
-{
-	char *rv = kmalloc(strlen(s)+1, GFP_KERNEL);
-	if (rv)
-		strcpy(rv, s);
-	return rv;
-}
-
 ctl_table core_table[] = {
 #ifdef CONFIG_NET
 	{
···
 	},
 	{ .ctl_name = 0 }
 };
-
-EXPORT_SYMBOL(net_sysctl_strdup);
 
 #endif

net/ipv4/devinet.c

···
 	 * by sysctl and we wouldn't want anyone to change it under our feet
 	 * (see SIOCSIFNAME).
 	 */	
-	dev_name = net_sysctl_strdup(dev_name);
+	dev_name = kstrdup(dev_name, GFP_KERNEL);
 	if (!dev_name)
 	    goto free;
 

net/ipv6/addrconf.c

···
 #endif
 #include <linux/delay.h>
 #include <linux/notifier.h>
+#include <linux/string.h>
 
 #include <net/sock.h>
 #include <net/snmp.h>
···
 	 * by sysctl and we wouldn't want anyone to change it under our feet
 	 * (see SIOCSIFNAME).
 	 */	
-	dev_name = net_sysctl_strdup(dev_name);
+	dev_name = kstrdup(dev_name, GFP_KERNEL);
 	if (!dev_name)
 	    goto free;
 

net/sunrpc/svcauth_unix.c

···
 #include <linux/err.h>
 #include <linux/seq_file.h>
 #include <linux/hash.h>
+#include <linux/string.h>
 
 #define RPCDBG_FACILITY	RPCDBG_AUTH
 
···
  * AUTHNULL as for AUTHUNIX, and that is done here.
  */
 
-
-static char *strdup(char *s)
-{
-	char *rv = kmalloc(strlen(s)+1, GFP_KERNEL);
-	if (rv)
-		strcpy(rv, s);
-	return rv;
-}
 
 struct unix_domain {
 	struct auth_domain	h;
···
 	if (new == NULL)
 		return NULL;
 	cache_init(&new->h.h);
-	new->h.name = strdup(name);
+	new->h.name = kstrdup(name, GFP_KERNEL);
 	new->h.flavour = RPC_AUTH_UNIX;
 	new->addr_changes = 0;
 	new->h.h.expiry_time = NEVER;

sound/core/info.c

···
 #include <linux/vmalloc.h>
 #include <linux/time.h>
 #include <linux/smp_lock.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <sound/minors.h>
 #include <sound/info.h>
···
 	entry = kcalloc(1, sizeof(*entry), GFP_KERNEL);
 	if (entry == NULL)
 		return NULL;
-	entry->name = snd_kmalloc_strdup(name, GFP_KERNEL);
+	entry->name = kstrdup(name, GFP_KERNEL);
 	if (entry->name == NULL) {
 		kfree(entry);
 		return NULL;

sound/core/info_oss.c

···
 #include <sound/driver.h>
 #include <linux/slab.h>
 #include <linux/time.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <sound/minors.h>
 #include <sound/info.h>
···
 			x = NULL;
 		}
 	} else {
-		x = snd_kmalloc_strdup(string, GFP_KERNEL);
+		x = kstrdup(string, GFP_KERNEL);
 		if (x == NULL) {
 			up(&strings);
 			return -ENOMEM;

sound/core/memory.c

···
 	snd_wrapper_vfree(obj);
 }
 
+char *snd_hidden_kstrdup(const char *s, int flags)
+{
+	int len;
+	char *buf;
+
+	if (!s) return NULL;
+
+	len = strlen(s) + 1;
+	buf = _snd_kmalloc(len, flags);
+	if (buf)
+		memcpy(buf, s, len);
+	return buf;
+}
+
 static void snd_memory_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 {
 	snd_iprintf(buffer, "kmalloc: %li bytes\n", snd_alloc_kmalloc);
···
 	return 0;
 }
 
-#else
-
-#define _snd_kmalloc kmalloc
-
 #endif /* CONFIG_SND_DEBUG_MEMORY */
-
-/**
- * snd_kmalloc_strdup - copy the string
- * @string: the original string
- * @flags: allocation conditions, GFP_XXX
- *
- * Allocates a memory chunk via kmalloc() and copies the string to it.
- *
- * Returns the pointer, or NULL if no enoguh memory.
- */
-char *snd_kmalloc_strdup(const char *string, int flags)
-{
-	size_t len;
-	char *ptr;
-
-	if (!string)
-		return NULL;
-	len = strlen(string) + 1;
-	ptr = _snd_kmalloc(len, flags);
-	if (ptr)
-		memcpy(ptr, string, len);
-	return ptr;
-}
 
 /**
  * copy_to_user_fromio - copy data from mmio-space to user-space

sound/core/oss/mixer_oss.c

···
 #include <linux/smp_lock.h>
 #include <linux/slab.h>
 #include <linux/time.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <sound/minors.h>
 #include <sound/control.h>
···
 			goto __unlock;
 		}
 		tbl->oss_id = ch;
-		tbl->name = snd_kmalloc_strdup(str, GFP_KERNEL);
+		tbl->name = kstrdup(str, GFP_KERNEL);
 		if (! tbl->name) {
 			kfree(tbl);
 			goto __unlock;

sound/core/oss/pcm_oss.c

···
 #include <linux/time.h>
 #include <linux/vmalloc.h>
 #include <linux/moduleparam.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <sound/minors.h>
 #include <sound/pcm.h>
···
 					for (setup1 = pstr->oss.setup_list; setup1->next; setup1 = setup1->next);
 					setup1->next = setup;
 				}
-				template.task_name = snd_kmalloc_strdup(task_name, GFP_KERNEL);
+				template.task_name = kstrdup(task_name, GFP_KERNEL);
 			} else {
 				buffer->error = -ENOMEM;
 			}

sound/core/sound.c

···
 EXPORT_SYMBOL(snd_hidden_kfree);
 EXPORT_SYMBOL(snd_hidden_vmalloc);
 EXPORT_SYMBOL(snd_hidden_vfree);
+EXPORT_SYMBOL(snd_hidden_kstrdup);
 #endif
-EXPORT_SYMBOL(snd_kmalloc_strdup);
 EXPORT_SYMBOL(copy_to_user_fromio);
 EXPORT_SYMBOL(copy_from_user_toio);
   /* init.c */

sound/core/timer.c

···
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <linux/moduleparam.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <sound/timer.h>
 #include <sound/control.h>
···
 	timeri = kcalloc(1, sizeof(*timeri), GFP_KERNEL);
 	if (timeri == NULL)
 		return NULL;
-	timeri->owner = snd_kmalloc_strdup(owner, GFP_KERNEL);
+	timeri->owner = kstrdup(owner, GFP_KERNEL);
 	if (! timeri->owner) {
 		kfree(timeri);
 		return NULL;

sound/isa/gus/gus_mem.c

···
 
 #include <sound/driver.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <sound/gus.h>
 #include <sound/info.h>
···
 	if (share_id != NULL)
 		memcpy(&block.share_id, share_id, sizeof(block.share_id));
 	block.owner = owner;
-	block.name = snd_kmalloc_strdup(name, GFP_KERNEL);
+	block.name = kstrdup(name, GFP_KERNEL);
 	nblock = snd_gf1_mem_xalloc(alloc, &block);
 	snd_gf1_mem_lock(alloc, 1);
 	return nblock;
···
 	if (gus->gf1.enh_mode) {
 		block.ptr = 0;
 		block.size = 1024;
-		block.name = snd_kmalloc_strdup("InterWave LFOs", GFP_KERNEL);
+		block.name = kstrdup("InterWave LFOs", GFP_KERNEL);
 		if (snd_gf1_mem_xalloc(alloc, &block) == NULL)
 			return -ENOMEM;
 	}
 	block.ptr = gus->gf1.default_voice_address;
 	block.size = 4;
-	block.name = snd_kmalloc_strdup("Voice default (NULL's)", GFP_KERNEL);
+	block.name = kstrdup("Voice default (NULL's)", GFP_KERNEL);
 	if (snd_gf1_mem_xalloc(alloc, &block) == NULL)
 		return -ENOMEM;
 #ifdef CONFIG_SND_DEBUG

sound/pci/hda/patch_realtek.c

···
 
 	knew = &spec->kctl_alloc[spec->num_kctl_used];
 	*knew = alc880_control_templates[type];
-	knew->name = snd_kmalloc_strdup(name, GFP_KERNEL);
+	knew->name = kstrdup(name, GFP_KERNEL);
 	if (! knew->name)
 		return -ENOMEM;
 	knew->private_value = val;

sound/synth/emux/emux.c

···
 #include <linux/wait.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <sound/emux_synth.h>
 #include <linux/init.h>
···
 	snd_assert(name != NULL, return -EINVAL);
 
 	emu->card = card;
-	emu->name = snd_kmalloc_strdup(name, GFP_KERNEL);
+	emu->name = kstrdup(name, GFP_KERNEL);
 	emu->voices = kcalloc(emu->max_voices, sizeof(snd_emux_voice_t), GFP_KERNEL);
 	if (emu->voices == NULL)
 		return -ENOMEM;