On Tue, 30 Mar 2021 13:31:45 PDT (-0700), macro@orcam.me.uk wrote:

On Mon, 29 Mar 2021, Palmer Dabbelt wrote:

quoted

quoted

--- /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.

Thanks, I didn't realize this was part of the user BI.  In that case we 
really can't chage it, so we'll have to sort out some other way do fix 
whatever is going on.

I've dropped this from fixes.