From 9d2a789c1db75d0f55b14fa57bec548d94332ad8 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Tue, 12 Jun 2018 14:28:35 -0700
Subject: [PATCH] treewide: Use array_size in f2fs_kvzalloc()

The f2fs_kvzalloc() function has no 2-factor argument form, so
multiplication factors need to be wrapped in array_size(). This patch
replaces cases of:

        f2fs_kvzalloc(handle, a * b, gfp)

with:
        f2fs_kvzalloc(handle, array_size(a, b), gfp)

as well as handling cases of:

        f2fs_kvzalloc(handle, a * b * c, gfp)

with:

        f2fs_kvzalloc(handle, array3_size(a, b, c), gfp)

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

        f2fs_kvzalloc(handle, 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().
@@
expression HANDLE;
type TYPE;
expression THING, E;
@@

(
  f2fs_kvzalloc(HANDLE,
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

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

(
  f2fs_kvzalloc(HANDLE,
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

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

(
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * COUNT_ID
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * COUNT_ID
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
)

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

  f2fs_kvzalloc(HANDLE,
-	SIZE * COUNT
+	array_size(COUNT, SIZE)
  , ...)

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

(
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

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

(
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

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

(
  f2fs_kvzalloc(HANDLE,
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  f2fs_kvzalloc(HANDLE,
-	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 HANDLE;
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  f2fs_kvzalloc(HANDLE, C1 * C2 * C3, ...)
|
  f2fs_kvzalloc(HANDLE,
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression HANDLE;
expression E1, E2;
constant C1, C2;
@@

(
  f2fs_kvzalloc(HANDLE, C1 * C2, ...)
|
  f2fs_kvzalloc(HANDLE,
-	E1 * E2
+	array_size(E1, E2)
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 fs/f2fs/file.c    |  6 ++++--
 fs/f2fs/node.c    |  6 ++++--
 fs/f2fs/segment.c | 12 ++++++++----
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 13f2f6845e87..cadb425c02d7 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1122,12 +1122,14 @@ static int __exchange_data_block(struct inode *src_inode,
 		olen = min((pgoff_t)4 * ADDRS_PER_BLOCK, len);
 
 		src_blkaddr = f2fs_kvzalloc(F2FS_I_SB(src_inode),
-					sizeof(block_t) * olen, GFP_KERNEL);
+					array_size(olen, sizeof(block_t)),
+					GFP_KERNEL);
 		if (!src_blkaddr)
 			return -ENOMEM;
 
 		do_replace = f2fs_kvzalloc(F2FS_I_SB(src_inode),
-					sizeof(int) * olen, GFP_KERNEL);
+					array_size(olen, sizeof(int)),
+					GFP_KERNEL);
 		if (!do_replace) {
 			kvfree(src_blkaddr);
 			return -ENOMEM;
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 53e5bc6f9efb..10643b11bd59 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -2772,8 +2772,10 @@ static int init_free_nid_cache(struct f2fs_sb_info *sbi)
 	if (!nm_i->nat_block_bitmap)
 		return -ENOMEM;
 
-	nm_i->free_nid_count = f2fs_kvzalloc(sbi, nm_i->nat_blocks *
-					sizeof(unsigned short), GFP_KERNEL);
+	nm_i->free_nid_count =
+		f2fs_kvzalloc(sbi, array_size(sizeof(unsigned short),
+					      nm_i->nat_blocks),
+			      GFP_KERNEL);
 	if (!nm_i->free_nid_count)
 		return -ENOMEM;
 	return 0;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 50a10f512051..9efce174c51a 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3517,8 +3517,10 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 
 	SM_I(sbi)->sit_info = sit_i;
 
-	sit_i->sentries = f2fs_kvzalloc(sbi, MAIN_SEGS(sbi) *
-					sizeof(struct seg_entry), GFP_KERNEL);
+	sit_i->sentries =
+		f2fs_kvzalloc(sbi, array_size(sizeof(struct seg_entry),
+					      MAIN_SEGS(sbi)),
+			      GFP_KERNEL);
 	if (!sit_i->sentries)
 		return -ENOMEM;
 
@@ -3558,8 +3560,10 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 		return -ENOMEM;
 
 	if (sbi->segs_per_sec > 1) {
-		sit_i->sec_entries = f2fs_kvzalloc(sbi, MAIN_SECS(sbi) *
-					sizeof(struct sec_entry), GFP_KERNEL);
+		sit_i->sec_entries =
+			f2fs_kvzalloc(sbi, array_size(sizeof(struct sec_entry),
+						      MAIN_SECS(sbi)),
+				      GFP_KERNEL);
 		if (!sit_i->sec_entries)
 			return -ENOMEM;
 	}
-- 
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