Commit 8ef9724b authored by Guenter Roeck's avatar Guenter Roeck Committed by Mark Brown

regmap: regcache-rbtree: Clean new present bits on present bitmap resize

When inserting a new register into a block, the present bit map size is
increased using krealloc. krealloc does not clear the additionally
allocated memory, leaving it filled with random values. Result is that
some registers are considered cached even though this is not the case.

Fix the problem by clearing the additionally allocated memory. Also, if
the bitmap size does not increase, do not reallocate the bitmap at all
to reduce overhead.

Fixes: 3f4ff561 ("regmap: rbtree: Make cache_present bitmap per node")
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
parent d770e558
......@@ -296,11 +296,20 @@ static int regcache_rbtree_insert_to_block(struct regmap *map,
if (!blk)
return -ENOMEM;
present = krealloc(rbnode->cache_present,
BITS_TO_LONGS(blklen) * sizeof(*present), GFP_KERNEL);
if (!present) {
kfree(blk);
return -ENOMEM;
if (BITS_TO_LONGS(blklen) > BITS_TO_LONGS(rbnode->blklen)) {
present = krealloc(rbnode->cache_present,
BITS_TO_LONGS(blklen) * sizeof(*present),
GFP_KERNEL);
if (!present) {
kfree(blk);
return -ENOMEM;
}
memset(present + BITS_TO_LONGS(rbnode->blklen), 0,
(BITS_TO_LONGS(blklen) - BITS_TO_LONGS(rbnode->blklen))
* sizeof(*present));
} else {
present = rbnode->cache_present;
}
/* insert the register value in the correct place in the rbnode block */
......
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