On Thu, Jun 9, 2022 at 3:25 PM Andrew Morton akpm@linux-foundation.org wrote:
On Thu, 9 Jun 2022 22:16:19 +0000 Bill Wendling morbo@google.com wrote:
This patch set fixes some clang warnings when -Wformat is enabled.
tldr:
printk(msg);
printk("%s", msg);the only reason to make this change is where `msg' could contain a `%'. Generally, it came from userspace.
It helps kernel developers not accidentally to insert an unescaped '%' in their messages, potentially exposing their code to an attack vector.
Otherwise these changes are a useless consumer of runtime resources.
Calling a "printf" style function is already insanely expensive. :-) I understand that it's not okay blithely to increase runtime resources simply because it's already slow, but in this case it's worthwhile.
I think it would be better to quieten clang in some fashion.
The "printk" and similar functions all have the "__printf" attribute. I don't know of a modification to that attribute which can turn off this type of check.
-bw