This check warns when the max argument of ida_alloc_range is not of the
the form "2^x-1".
It is fine to not warn when min argument is 1 and max argument is a
power of 2.
Before this patch:
drivers/net/ethernet/mellanox/mlx5/core/lib/macsec_fs.c:587 macsec_fs_tx_setup_fte() error: Calling ida_alloc_range() with a 'max' argument which is a power of 2. -1 missing?
After this patch:
Smatch will not warn as the min argument is one.
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
---
check_ida_alloc.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/check_ida_alloc.c b/check_ida_alloc.c
index 7f1f7463..e29b8ff1 100644
--- a/check_ida_alloc.c
+++ b/check_ida_alloc.c
@@ -58,7 +58,7 @@ static bool is_power_of_two(struct expression *expr)
return false;
}
-static void match_ida_alloc(const char *fn, struct expression *expr, void *_arg_nr)
+static void match_ida_alloc_max(const char *fn, struct expression *expr, void *_arg_nr)
{
int arg_nr = PTR_INT(_arg_nr);
struct expression *arg_expr;
@@ -71,6 +71,28 @@ static void match_ida_alloc(const char *fn, struct expression *expr, void *_arg_
fn);
}
+static void match_ida_alloc_range(const char *fn, struct expression *expr, void *info)
+{
+ struct expression *arg_expr1, *arg_expr2;
+
+ sval_t sval;
+
+ arg_expr1 = get_argument_from_call_expr(expr->args, 1);
+ arg_expr1 = strip_expr(arg_expr1);
+ arg_expr2 = get_argument_from_call_expr(expr->args, 2);
+ arg_expr2 = strip_expr(arg_expr2);
+
+ if (!get_implied_value(arg_expr1, &sval))
+ return;
+
+ if (sval.uvalue == 1)
+ return;
+
+ if (is_power_of_two(arg_expr2))
+ sm_error("Calling %s() with a 'max' argument which is a power of 2. -1 missing?",
+ fn);
+}
+
void check_ida_alloc(int id)
{
if (option_project != PROJ_KERNEL)
@@ -78,6 +100,6 @@ void check_ida_alloc(int id)
my_id = id;
- add_function_hook("ida_alloc_max", &match_ida_alloc, INT_PTR(1));
- add_function_hook("ida_alloc_range", &match_ida_alloc, INT_PTR(2));
+ add_function_hook("ida_alloc_max", &match_ida_alloc_max, INT_PTR(1));
+ add_function_hook("ida_alloc_range", &match_ida_alloc_range, NULL);
}
--
2.39.3
