Re: [PATCH v3] riscv: entry: set a0 = -ENOSYS only when syscall != -1

From: Björn Töpel
Date: Wed Jul 19 2023 - 12:28:57 EST


Andreas Schwab <schwab@xxxxxxx> writes:

> On Jul 19 2023, Celeste Liu wrote:
>
>> @@ -308,7 +312,7 @@ asmlinkage __visible __trap_section void do_trap_ecall_u(struct pt_regs *regs)
>>
>> if (syscall < NR_syscalls)
>> syscall_handler(regs, syscall);
>> - else
>> + else if ((long)syscall != -1L)
>
> You can also use syscall != -1UL or even syscall != -1.

The former is indeed better for the eyes! :-) The latter will get a
-Wsign-compare warning, no?


Björn