[PATCH v4 4/6] lib/cmdline: Fix get_option() for strings starting with hyphen

Andy Shevchenko
2020-11-12T18:07:43Z

When string doesn't have an integer and starts from hyphen get_option()
may return interesting results. Fix it to return 0.

The simple_strtoull() is used due to absence of simple_strtoul()
in a boot code on some architectures.

Note, the Fixes tag below is rather for anthropological curiosity.

Fixes: f68565831e72 ("Import 2.4.0-test2pre3")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v4: new patch
lib/cmdline.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/cmdline.c b/lib/cmdline.c
index fbb9981a04a4..ca89846ee0bb 100644
--- a/lib/cmdline.c
+++ b/lib/cmdline.c
@@ -45,6 +45,9 @@ static int get_range(char **str, int *pint, int n)
* 1 - int found, no subsequent comma
* 2 - int found including a subsequent comma
* 3 - hyphen found to denote a range
+ *
+ * Leading hyphen without integer is no integer case, but we consume it
+ * for the sake of simplification.
*/

int get_option(char **str, int *pint)
@@ -53,7 +56,10 @@ int get_option(char **str, int *pint)

if (!cur || !(*cur))
return 0;
- *pint = simple_strtol(cur, str, 0);
+ if (*cur == '-')
+ *pint = -simple_strtoull(++cur, str, 0);
+ else
+ *pint = simple_strtoull(cur, str, 0);
if (cur == *str)
return 0;
if (**str == ',') {
--
2.28.0