On 11/23/21 7:19 AM, Arnd Bergmann wrote:

On Tue, Nov 23, 2021 at 12:38 PM Naresh Kamboju
[off-list ref] wrote:

quoted

While building Linux next 20211123 tag for sh with gcc-11
following warnings / errors noticed.

Nothing in here looks like a recent regression from either the kernel
or gcc-11.

quoted

make --silent --keep-going --jobs=8
O=/home/tuxbuild/.cache/tuxmake/builds/current ARCH=sh
CROSS_COMPILE=sh4-linux-gnu- 'CC=sccache sh4-linux-gnu-gcc'
'HOSTCC=sccache gcc'
  Generating include/generated/machtypes.h
<stdin>:1517:2: warning: #warning syscall clone3 not implemented [-Wcpp]
<stdin>:1559:2: warning: #warning syscall futex_waitv not implemented [-Wcpp]

These happen with any compiler version, someone needs to write the correct
entry code for clone3 and hook up futex_waitv().

I did a naieve "add them both to the .tbl" patch and the result booted to a
shell prompt, but that doesn't mean much. What arch-specific entry code does
clone3 need here? The SYSCALL_DEFINE2(clone3) in kernel/fork.c seems reasonably
straightforward? (Unlike the #ifdef stack around the previous clone...)

quoted

include/linux/sh_intc.h:100:63: warning: division 'sizeof (void *) / sizeof (void)' does not compute the number of array elements

These are old bugs, they show up in any kernel version with gcc-8 or higher.

I looked at trying to fix that but it seems to be a compiler bug. Gcc is warning
about an ? : else case that's dead code eliminated. It's already GOT a test
protecting it from being evaluated...

quoted

fs/mpage.c:336:1: warning: the frame size of 1092 bytes is larger than

I see these going back to gcc-6, it looks like this is caused by
CONFIG_PAGE_SIZE_64KB.

In which case the stack size is going to be 64k as well?

     Arnd

Rob