Re: [PATCH 2/4] riscv: uaccess: use input constraints for ptr of __put_user

Andreas Schwab
2024-06-26T13:35:56Z

On Jun 26 2024, Jisheng Zhang wrote:

> no output constraints either. It just uses "r" input constraints to tell
> gcc to read the store address into one proper GP reg.

Again, this is backwards. Being an input operand means the asm is using
this operand as an input to the instructions. The compiler needs to
arrange to put the value in the allocated operand location according to
the constraint.

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Andreas Schwab, SUSE Labs, schwab@suse.de
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