treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index dc062b1..a3fdb4f 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -1603,8 +1603,8 @@ static int btrfsic_read_block(struct btrfsic_state *state,
 
 	num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
 		    PAGE_SHIFT;
-	block_ctx->mem_to_free = kzalloc((sizeof(*block_ctx->datav) +
-					  sizeof(*block_ctx->pagev)) *
+	block_ctx->mem_to_free = kcalloc(sizeof(*block_ctx->datav) +
+						sizeof(*block_ctx->pagev),
 					 num_pages, GFP_NOFS);
 	if (!block_ctx->mem_to_free)
 		return -ENOMEM;
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 5aca336..42329b2 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2077,7 +2077,7 @@ struct cifs_writedata *
 cifs_writedata_alloc(unsigned int nr_pages, work_func_t complete)
 {
 	struct page **pages =
-		kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
+		kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
 	if (pages)
 		return cifs_writedata_direct_alloc(pages, complete);
 
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 87eece6..8d41ca7 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2900,7 +2900,7 @@ static struct cifs_readdata *
 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
 {
 	struct page **pages =
-		kzalloc(sizeof(struct page *) * nr_pages, GFP_KERNEL);
+		kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
 	struct cifs_readdata *ret = NULL;
 
 	if (pages) {
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index c969275..0057fe3 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -577,7 +577,7 @@ int ext4_ext_precache(struct inode *inode)
 	down_read(&ei->i_data_sem);
 	depth = ext_depth(inode);
 
-	path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
+	path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
 		       GFP_NOFS);
 	if (path == NULL) {
 		up_read(&ei->i_data_sem);
@@ -879,7 +879,7 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
 	}
 	if (!path) {
 		/* account possible depth increase */
-		path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
+		path = kcalloc(depth + 2, sizeof(struct ext4_ext_path),
 				GFP_NOFS);
 		if (unlikely(!path))
 			return ERR_PTR(-ENOMEM);
@@ -1063,7 +1063,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	 * We need this to handle errors and free blocks
 	 * upon them.
 	 */
-	ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
+	ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), GFP_NOFS);
 	if (!ablocks)
 		return -ENOMEM;
 
@@ -2921,7 +2921,7 @@ int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
 			path[k].p_block =
 				le16_to_cpu(path[k].p_hdr->eh_entries)+1;
 	} else {
-		path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
+		path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
 			       GFP_NOFS);
 		if (path == NULL) {
 			ext4_journal_stop(handle);
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index c75ad98..956f278 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -461,7 +461,7 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 		fh_count = be32_to_cpup(p);
 
 		fls->mirror_array[i]->fh_versions =
-			kzalloc(fh_count * sizeof(struct nfs_fh),
+			kcalloc(fh_count, sizeof(struct nfs_fh),
 				gfp_flags);
 		if (fls->mirror_array[i]->fh_versions == NULL) {
 			rc = -ENOMEM;
diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
index d62279d..59aa049 100644
--- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c
+++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
@@ -99,7 +99,8 @@ nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 	version_count = be32_to_cpup(p);
 	dprintk("%s: version count %d\n", __func__, version_count);
 
-	ds_versions = kzalloc(version_count * sizeof(struct nfs4_ff_ds_version),
+	ds_versions = kcalloc(version_count,
+			      sizeof(struct nfs4_ff_ds_version),
 			      gfp_flags);
 	if (!ds_versions)
 		goto out_scratch;
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 8ceb25a..a1143f7 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -404,8 +404,9 @@ fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
 	if (fsloc->locations_count == 0)
 		return 0;
 
-	fsloc->locations = kzalloc(fsloc->locations_count
-			* sizeof(struct nfsd4_fs_location), GFP_KERNEL);
+	fsloc->locations = kcalloc(fsloc->locations_count,
+				   sizeof(struct nfsd4_fs_location),
+				   GFP_KERNEL);
 	if (!fsloc->locations)
 		return -ENOMEM;
 	for (i=0; i < fsloc->locations_count; i++) {
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index e5dcea6..bd34756 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -1383,7 +1383,7 @@ static int __ocfs2_recovery_thread(void *arg)
 		goto bail;
 	}
 
-	rm_quota = kzalloc(osb->max_slots * sizeof(int), GFP_NOFS);
+	rm_quota = kcalloc(osb->max_slots, sizeof(int), GFP_NOFS);
 	if (!rm_quota) {
 		status = -ENOMEM;
 		goto bail;
diff --git a/fs/ocfs2/sysfile.c b/fs/ocfs2/sysfile.c
index af155c1..5965f38 100644
--- a/fs/ocfs2/sysfile.c
+++ b/fs/ocfs2/sysfile.c
@@ -69,10 +69,11 @@ static struct inode **get_local_system_inode(struct ocfs2_super *osb,
 	spin_unlock(&osb->osb_lock);
 
 	if (unlikely(!local_system_inodes)) {
-		local_system_inodes = kzalloc(sizeof(struct inode *) *
-					      NUM_LOCAL_SYSTEM_INODES *
-					      osb->max_slots,
-					      GFP_NOFS);
+		local_system_inodes =
+			kzalloc(array3_size(sizeof(struct inode *),
+					    NUM_LOCAL_SYSTEM_INODES,
+					    osb->max_slots),
+				GFP_NOFS);
 		if (!local_system_inodes) {
 			mlog_errno(-ENOMEM);
 			/*
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 08801b4..c993dd8 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -612,7 +612,7 @@ static int ovl_get_index_name_fh(struct ovl_fh *fh, struct qstr *name)
 {
 	char *n, *s;
 
-	n = kzalloc(fh->len * 2, GFP_KERNEL);
+	n = kcalloc(fh->len, 2, GFP_KERNEL);
 	if (!n)
 		return -ENOMEM;
 
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 4d765e5..89921a0 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1426,7 +1426,7 @@ static int register_leaf_sysctl_tables(const char *path, char *pos,
 	/* If there are mixed files and directories we need a new table */
 	if (nr_dirs && nr_files) {
 		struct ctl_table *new;
-		files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1),
+		files = kcalloc(nr_files + 1, sizeof(struct ctl_table),
 				GFP_KERNEL);
 		if (!files)
 			goto out;
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index b13fc02..132ec44 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -1044,7 +1044,8 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
 			if (blocks_needed == 1) {
 				un = &unf_single;
 			} else {
-				un = kzalloc(min(blocks_needed, max_to_insert) * UNFM_P_SIZE, GFP_NOFS);
+				un = kcalloc(min(blocks_needed, max_to_insert),
+					     UNFM_P_SIZE, GFP_NOFS);
 				if (!un) {
 					un = &unf_single;
 					blocks_needed = 1;
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 0d27d41..fc77ea7 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1585,7 +1585,7 @@ static struct udf_vds_record *handle_partition_descriptor(
 		struct udf_vds_record *new_loc;
 		unsigned int new_size = ALIGN(partnum, PART_DESC_ALLOC_STEP);
 
-		new_loc = kzalloc(sizeof(*new_loc) * new_size, GFP_KERNEL);
+		new_loc = kcalloc(new_size, sizeof(*new_loc), GFP_KERNEL);
 		if (!new_loc)
 			return ERR_PTR(-ENOMEM);
 		memcpy(new_loc, data->part_descs_loc,
@@ -1644,8 +1644,9 @@ static noinline int udf_process_sequence(
 
 	memset(data.vds, 0, sizeof(struct udf_vds_record) * VDS_POS_LENGTH);
 	data.size_part_descs = PART_DESC_ALLOC_STEP;
-	data.part_descs_loc = kzalloc(sizeof(*data.part_descs_loc) *
-					data.size_part_descs, GFP_KERNEL);
+	data.part_descs_loc = kcalloc(data.size_part_descs,
+				      sizeof(*data.part_descs_loc),
+				      GFP_KERNEL);
 	if (!data.part_descs_loc)
 		return -ENOMEM;