Re: [PATCH] riscv: Bump COMMAND_LINE_SIZE value to 1024

[Maciej W. Rozycki]

On Mon, 29 Mar 2021, Palmer Dabbelt wrote:

> > --- /dev/null
> > +++ b/arch/riscv/include/uapi/asm/setup.h
> > @@ -0,0 +1,8 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
> > +
> > +#ifndef _UAPI_ASM_RISCV_SETUP_H
> > +#define _UAPI_ASM_RISCV_SETUP_H
> > +
> > +#define COMMAND_LINE_SIZE	1024
> > +
> > +#endif /* _UAPI_ASM_RISCV_SETUP_H */
> 
> I put this on fixes, but it seemes like this should really be a Kconfig
> enttry.  Either way, ours was quite a bit smaller than most architectures and
> it's great that syzbot has started to find bugs, so I'd rather get this in
> sooner.

 This macro is exported as a part of the user API so it must not depend on 
Kconfig.  Also changing it (rather than say adding COMMAND_LINE_SIZE_V2 or 
switching to an entirely new data object that has its dimension set in a 
different way) requires careful evaluation as external binaries have and 
will have the value it expands to compiled in, so it's a part of the ABI 
too.

  Maciej