[PATCH] x86/lib: Fix num_digits() signed overflow for INT_MIN

[David Desobry]

In num_digits(), the negation of the input value "val = -val"
causes undefined behavior when val is INT_MIN, as its absolute
value cannot be represented as a signed 32-bit integer.

This leads to incorrect results (returning 2 instead of 11).
By promoting the value to long long before negation, we ensure
the absolute value is correctly handled.

Signed-off-by: David Desobry <david.desobry@xxxxxxxxxxxxx>
---
 arch/x86/lib/misc.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/lib/misc.c b/arch/x86/lib/misc.c
index 40b81c338ae5..c975db6ccb9f 100644
--- a/arch/x86/lib/misc.c
+++ b/arch/x86/lib/misc.c
@@ -8,15 +8,16 @@
  */
 int num_digits(int val)
 {
+	long long v = val;
 	long long m = 10;
 	int d = 1;
 
-	if (val < 0) {
+	if (v < 0) {
 		d++;
-		val = -val;
+		v = -v;
 	}
 
-	while (val >= m) {
+	while (v >= m) {
 		m *= 10;
 		d++;
 	}
-- 
2.43.0