[PATCH v4 5/6] add listmount(2) syscall

[Guenter Roeck]

On 1/10/24 16:32, Linus Torvalds wrote:
> On Wed, 10 Jan 2024 at 14:23, Guenter Roeck <linux at roeck-us.net> wrote:
>>
>> with this patch in the tree, all sh4 builds fail with ICE.
>>
>> during RTL pass: final
>> In file included from fs/namespace.c:11:
>> fs/namespace.c: In function '__se_sys_listmount':
>> include/linux/syscalls.h:258:9: internal compiler error: in change_address_1, at emit-rtl.c:2275
> 
> We do have those very ugly SYSCALL_DEFINEx() macros, but I'm not
> seeing _anything_ that would be odd about the listmount case.
> 
> And the "__se_sys" thing in particular is just a fairly trivial wrapper.
> 
> It does use that asmlinkage_protect() thing, and it is unquestionably
> horrendously ugly (staring too long at <linux/syscalls.h> has been
> known to cause madness and despair), but we do that for *every* single
> system call and I don't see why the new listmount entry would be
> different.
> 

I don't have much of a clue either, but here is a hint: The problem is
only seen if CONFIG_MMU=n. I tested with all configurations in
arch/sh/configs.

Guenter