powerpc: use non-racy method for proc entries creation

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 22 insertions, 47 deletions

diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 1ffacc698ff..1e656b43ad7 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -591,10 +591,8 @@ int __init lparcfg_init(void)
 			!firmware_has_feature(FW_FEATURE_ISERIES))
 		mode |= S_IWUSR;
 
-	ent = create_proc_entry("ppc64/lparcfg", mode, NULL);
-	if (ent) {
-		ent->proc_fops = &lparcfg_fops;
-	} else {
+	ent = proc_create("ppc64/lparcfg", mode, NULL, &lparcfg_fops);
+	if (!ent) {
 		printk(KERN_ERR "Failed to create ppc64/lparcfg\n");
 		return -EIO;
 	}
diff --git a/arch/powerpc/kernel/proc_ppc64.c b/arch/powerpc/kernel/proc_ppc64.c
index f78dfce1b77..c647ddef40d 100644
--- a/arch/powerpc/kernel/proc_ppc64.c
+++ b/arch/powerpc/kernel/proc_ppc64.c
@@ -68,12 +68,11 @@ static int __init proc_ppc64_init(void)
 {
 	struct proc_dir_entry *pde;
 
-	pde = create_proc_entry("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL);
+	pde = proc_create_data("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL,
+			       &page_map_fops, vdso_data);
 	if (!pde)
 		return 1;
-	pde->data = vdso_data;
 	pde->size = PAGE_SIZE;
-	pde->proc_fops = &page_map_fops;
 
 	return 0;
 }
diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c
index f2e3bc714d7..f9c6abc84a9 100644
--- a/arch/powerpc/kernel/rtas-proc.c
+++ b/arch/powerpc/kernel/rtas-proc.c
@@ -255,8 +255,6 @@ static void check_location(struct seq_file *m, const char *c);
 
 static int __init proc_rtas_init(void)
 {
-	struct proc_dir_entry *entry;
-
 	if (!machine_is(pseries))
 		return -ENODEV;
 
@@ -264,35 +262,20 @@ static int __init proc_rtas_init(void)
 	if (rtas_node == NULL)
 		return -ENODEV;
 
-	entry = create_proc_entry("ppc64/rtas/progress", S_IRUGO|S_IWUSR, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_progress_operations;
-
-	entry = create_proc_entry("ppc64/rtas/clock", S_IRUGO|S_IWUSR, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_clock_operations;
-
-	entry = create_proc_entry("ppc64/rtas/poweron", S_IWUSR|S_IRUGO, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_poweron_operations;
-
-	entry = create_proc_entry("ppc64/rtas/sensors", S_IRUGO, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_sensors_operations;
-
-	entry = create_proc_entry("ppc64/rtas/frequency", S_IWUSR|S_IRUGO,
-				  NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_tone_freq_operations;
-
-	entry = create_proc_entry("ppc64/rtas/volume", S_IWUSR|S_IRUGO, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_tone_volume_operations;
-
-	entry = create_proc_entry("ppc64/rtas/rmo_buffer", S_IRUSR, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_rmo_buf_ops;
-
+	proc_create("ppc64/rtas/progress", S_IRUGO|S_IWUSR, NULL,
+		    &ppc_rtas_progress_operations);
+	proc_create("ppc64/rtas/clock", S_IRUGO|S_IWUSR, NULL,
+		    &ppc_rtas_clock_operations);
+	proc_create("ppc64/rtas/poweron", S_IWUSR|S_IRUGO, NULL,
+		    &ppc_rtas_poweron_operations);
+	proc_create("ppc64/rtas/sensors", S_IRUGO, NULL,
+		    &ppc_rtas_sensors_operations);
+	proc_create("ppc64/rtas/frequency", S_IWUSR|S_IRUGO, NULL,
+		    &ppc_rtas_tone_freq_operations);
+	proc_create("ppc64/rtas/volume", S_IWUSR|S_IRUGO, NULL,
+		    &ppc_rtas_tone_volume_operations);
+	proc_create("ppc64/rtas/rmo_buffer", S_IRUSR, NULL,
+		    &ppc_rtas_rmo_buf_ops);
 	return 0;
 }
 
diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index 627f126d184..0a5e22b2272 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c
@@ -704,18 +704,11 @@ static int initialize_flash_pde_data(const char *rtas_call_name,
 static struct proc_dir_entry *create_flash_pde(const char *filename,
 					       const struct file_operations *fops)
 {
-	struct proc_dir_entry *ent = NULL;
-
-	ent = create_proc_entry(filename, S_IRUSR | S_IWUSR, NULL);
-	if (ent != NULL) {
-		ent->proc_fops = fops;
-		ent->owner = THIS_MODULE;
-	}
-
-	return ent;
+	return proc_create(filename, S_IRUSR | S_IWUSR, NULL, fops);
 }
 
 static const struct file_operations rtas_flash_operations = {
+	.owner		= THIS_MODULE,
 	.read		= rtas_flash_read,
 	.write		= rtas_flash_write,
 	.open		= rtas_excl_open,
@@ -723,6 +716,7 @@ static const struct file_operations rtas_flash_operations = {
 };
 
 static const struct file_operations manage_flash_operations = {
+	.owner		= THIS_MODULE,
 	.read		= manage_flash_read,
 	.write		= manage_flash_write,
 	.open		= rtas_excl_open,
@@ -730,6 +724,7 @@ static const struct file_operations manage_flash_operations = {
 };
 
 static const struct file_operations validate_flash_operations = {
+	.owner		= THIS_MODULE,
 	.read		= validate_flash_read,
 	.write		= validate_flash_write,
 	.open		= rtas_excl_open,