treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>

7 files changed, 14 insertions, 14 deletions

diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index ad292c5a43a9..b5cdac9b0368 100644
--- a/fs/ubifs/commit.c
+++ b/fs/ubifs/commit.c
@@ -552,11 +552,11 @@ out:
  */
 int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
 {
-	int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
+	int lnum, offs, len, err = 0, last_level, child_cnt;
 	int first = 1, iip;
 	struct ubifs_debug_info *d = c->dbg;
-	union ubifs_key uninitialized_var(lower_key), upper_key, l_key, u_key;
-	unsigned long long uninitialized_var(last_sqnum);
+	union ubifs_key lower_key, upper_key, l_key, u_key;
+	unsigned long long last_sqnum;
 	struct ubifs_idx_node *idx;
 	struct list_head list;
 	struct idx_node *i;
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index ef85ec167a84..9d042942d8b2 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1260,7 +1260,7 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
 			.dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
 	struct timespec64 time;
-	unsigned int uninitialized_var(saved_nlink);
+	unsigned int saved_nlink;
 	struct fscrypt_name old_nm, new_nm;
 
 	/*
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 49fe062ce45e..b77d1637bbbc 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -222,7 +222,7 @@ static int write_begin_slow(struct address_space *mapping,
 	struct ubifs_info *c = inode->i_sb->s_fs_info;
 	pgoff_t index = pos >> PAGE_SHIFT;
 	struct ubifs_budget_req req = { .new_page = 1 };
-	int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
+	int err, appending = !!(pos + len > inode->i_size);
 	struct page *page;
 
 	dbg_gen("ino %lu, pos %llu, len %u, i_size %lld",
@@ -426,7 +426,7 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping,
 	struct ubifs_info *c = inode->i_sb->s_fs_info;
 	struct ubifs_inode *ui = ubifs_inode(inode);
 	pgoff_t index = pos >> PAGE_SHIFT;
-	int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
+	int err, appending = !!(pos + len > inode->i_size);
 	int skipped_read = 0;
 	struct page *page;
 
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index e5ec1afe1c66..2e6264318bd9 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -1222,7 +1222,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 	int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ;
 	int last_reference = !!(new_inode && new_inode->i_nlink == 0);
 	int move = (old_dir != new_dir);
-	struct ubifs_inode *uninitialized_var(new_ui);
+	struct ubifs_inode *new_ui;
 	u8 hash_old_dir[UBIFS_HASH_ARR_SZ];
 	u8 hash_new_dir[UBIFS_HASH_ARR_SZ];
 	u8 hash_new_inode[UBIFS_HASH_ARR_SZ];
@@ -1507,7 +1507,7 @@ int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
 	union ubifs_key key, to_key;
 	struct ubifs_ino_node *ino;
 	struct ubifs_trun_node *trun;
-	struct ubifs_data_node *uninitialized_var(dn);
+	struct ubifs_data_node *dn;
 	int err, dlen, len, lnum, offs, bit, sz, sync = IS_SYNC(inode);
 	struct ubifs_inode *ui = ubifs_inode(inode);
 	ino_t inum = inode->i_ino;
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index e21abf250951..6e0a153b7194 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -275,7 +275,7 @@ uint32_t ubifs_unpack_bits(const struct ubifs_info *c, uint8_t **addr, int *pos,
 	const int k = 32 - nrbits;
 	uint8_t *p = *addr;
 	int b = *pos;
-	uint32_t uninitialized_var(val);
+	uint32_t val;
 	const int bytes = (nrbits + b + 7) >> 3;
 
 	ubifs_assert(c, nrbits > 0);
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index e8e7b0e9532e..f609f6cdde70 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -892,7 +892,7 @@ static int fallible_resolve_collision(struct ubifs_info *c,
 				      int adding)
 {
 	struct ubifs_znode *o_znode = NULL, *znode = *zn;
-	int uninitialized_var(o_n), err, cmp, unsure = 0, nn = *n;
+	int o_n, err, cmp, unsure = 0, nn = *n;
 
 	cmp = fallible_matches_name(c, &znode->zbranch[nn], nm);
 	if (unlikely(cmp < 0))
@@ -1514,8 +1514,8 @@ out:
  */
 int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu)
 {
-	int n, err = 0, lnum = -1, uninitialized_var(offs);
-	int uninitialized_var(len);
+	int n, err = 0, lnum = -1, offs;
+	int len;
 	unsigned int block = key_block(c, &bu->key);
 	struct ubifs_znode *znode;
 
diff --git a/fs/ubifs/tnc_misc.c b/fs/ubifs/tnc_misc.c
index 49cb34c3f324..ccaf94ea5be3 100644
--- a/fs/ubifs/tnc_misc.c
+++ b/fs/ubifs/tnc_misc.c
@@ -126,8 +126,8 @@ int ubifs_search_zbranch(const struct ubifs_info *c,
 			 const struct ubifs_znode *znode,
 			 const union ubifs_key *key, int *n)
 {
-	int beg = 0, end = znode->child_cnt, uninitialized_var(mid);
-	int uninitialized_var(cmp);
+	int beg = 0, end = znode->child_cnt, mid;
+	int cmp;
 	const struct ubifs_zbranch *zbr = &znode->zbranch[0];
 
 	ubifs_assert(c, end > beg);