* Dave Martin: > On Tue, Aug 25, 2020 at 04:34:27PM -0700, Yu, Yu-cheng wrote: >> On 8/25/2020 4:20 PM, Dave Hansen wrote: >> >On 8/25/20 2:04 PM, Yu, Yu-cheng wrote: >> >>>>I think this is more arch-specific. Even if it becomes a new syscall, >> >>>>we still need to pass the same parameters. >> >>> >> >>>Right, but without the copying in and out of memory. >> >>> >> >>Linux-api is already on the Cc list. Do we need to add more people to >> >>get some agreements for the syscall? >> >What kind of agreement are you looking for? I'd suggest just coding it >> >up and posting the patches. Adding syscalls really is really pretty >> >straightforward and isn't much code at all. >> > >> >> Sure, I will do that. > > Alternatively, would a regular prctl() work here? Is this something appliation code has to call, or just the dynamic loader? prctl in glibc is a variadic function, so if there's a mismatch between the kernel/userspace syscall convention and the userspace calling convention (for variadic functions) for specific types, it can't be made to work in a generic way. The loader can use inline assembly for system calls and does not have this issue, but applications would be implcated by it. Thanks, Florian
