regmap: debugfs: Ensure we don't underflow when printing access masks
If a read is attempted which is smaller than the line length then we may
underflow the subtraction we're doing with the unsigned size_t type so
move some of the calculation to be additions on the right hand side
instead in order to avoid this.
Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index f42f2ba..1f32789 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -432,7 +432,7 @@
/* If we're in the region the user is trying to read */
if (p >= *ppos) {
/* ...but not beyond it */
- if (buf_pos >= count - 1 - tot_len)
+ if (buf_pos + tot_len + 1 >= count)
break;
/* Format the register */