On Tue, Feb 09, 2021 at 12:36:20PM +1000, Nicholas Piggin wrote: > What if you did this?
> +static inline struct task_struct *get_current(void) > +{ > + register struct task_struct *task asm ("r2"); > + > + return task; > +} Local register asm variables are *only* guaranteed to live in that register as operands to an asm. See https://gcc.gnu.org/onlinedocs/gcc/Local-Register-Variables.html#Local-Register-Variables ("The only supported use" etc.) You can do something like static inline struct task_struct *get_current(void) { register struct task_struct *task asm ("r2"); asm("" : "+r"(task)); return task; } which makes sure that "task" actually is in r2 at the point of that asm. Segher