Re: [PATCH RFC v3 03/13] sysctl, mod_devicetable: add macro MODULE_SYSCTL_TABLE

["Uwe Kleine-König" <u.kleine-koenig@baylibre.com>]

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Hello,

On Mon, Aug 24, 2026 at 06:04:03PM -0300, Mauricio Faria de Oliveira wrote:
> On 2026-08-23 19:12, Uwe Kleine-König wrote:
> > On Sat, Aug 22, 2026 at 01:57:24PM -0300, Mauricio Faria de Oliveira wrote:
> >> On 2026-08-22 10:41, Uwe Kleine-König wrote:
> >> > On Wed, Aug 19, 2026 at 03:16:16PM -0300, Mauricio Faria de Oliveira wrote:
> >> >> The MODULE_SYSCTL_TABLE macro emits a struct module_sysctl_table variable
> >> >> with pointers to a sysctl table's path and entries, and table/entry sizes.
> >> > 
> >> > That new struct doesn't seem to contain any pointer?
> >> 
> >> The struct module_sysctl_table fields .path and .table are pointers,
> >> although with kernel_ulong_t type so that the same 32/64-bit size is
> >> used in file2alias.c based on KERNEL_ELFCLASS (and not on the host,
> >> which might differ with CROSS_COMPILE).
> > 
> > Cross compilation isn't an issue for the already existing device id
> > structures; many of them also contain pointers.
> > (While modpost doesn't use the pointers, the size of the structures must
> > be known to correctly interpret the arrays.)
> 
> Indeed. I missed some device_id structures with pointers, and that
> devicetable-offsets.c is cross-compiled to generate
> devicetable-offsets.h for file2alias.c to use offsets and sizes of the
> target architecture.
> 
> I'll change .path and .table to pointers in the next version.

I *think* the existing device-id structs use char[] for strings that are
relevant for modpost. I look forward to you finding out if there is
still a justification for that :-D

> > I would be great if your series didn't introduce a new obstacle for
> > [CHERI].
> 
> Absolutely. I'll be happy to adjust the series and testing for that.
> 
> Could you please confirm one should just follow [1], which uses [2] to
> build the LLVM toolchain, and use it to build the kernel [3]?
> 
> [1] https://github.com/cheri-linux#building-and-running
> [2] https://github.com/cheri-linux/buildroot
> [3] https://github.com/CHERI-Alliance/linux/tree/codasip-cheri-riscv-7.1

I used
https://github.com/CHERI-Alliance/meta-cheri/tree/codasip-scarthgap and
didn't care about toolchain and rootfs. It also has qemu integrated, so
you can actually test it.

Best regards
Uwe

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