On Wed, 2021-03-24 at 22:27 +0100, Rasmus Villemoes wrote:
On 24/03/2021 20.24, Joe Perches wrote:
On Wed, 2021-03-24 at 18:33 +0100, Rasmus Villemoes wrote:
On 24/03/2021 18.20, Joe Perches wrote:
Maybe it's better to output non PTR_ERR %pe uses as decimal so this sort of code would work.
No, because that would leak the pointer value when somebody has accidentally passed a real kernel pointer to %pe.
I think it's not really an issue.
_All_ code that uses %p<foo> extensions need inspection anyway.
There are now a bunch of sanity checks in place that catch e.g. an ERR_PTR passed to an extension that would derefence the pointer; enforcing that only ERR_PTRs are passed to %pe (or falling back to %p) is another of those safeguards.
It's already possible to intentionally 'leak' the ptr value by using %pe, -ptr so I think that's not really an issue.
Huh, what? I assume -ptr is shorthand for (void*)-(unsigned long)ptr. How would that leak the value if ptr is an ordinary kernel pointer? That's not an ERR_PTR unless (unsigned long)ptr is < 4095 or so.
You are confusing ERR_PTR with IS_ERR
ERR_PTR is just
include/linux/err.h:static inline void * __must_check ERR_PTR(long error) include/linux/err.h-{ include/linux/err.h- return (void *) error; include/linux/err.h-}f
If you want to print the pointer value just do %px. No need for silly games.
There's no silly game here. %pe would either print a string or a value. It already does that in 2 cases.