Subject: Re: linux-next: build failure after merge of the mm tree

From: Marco Elver <[email-masked]>
Date: Thu, 1 Feb 2024 09:35:40 +0100

On Thu, 1 Feb 2024 at 03:57, Stephen Rothwell <[email-masked]> wrote:
>
> Hi all,
>
> After merging the mm tree, today's linux-next build (i386 defconfig)
> failed like this:
>
> In file included from arch/x86/include/asm/string.h:3,
>                  from include/linux/string.h:61,
>                  from arch/x86/include/asm/page_32.h:18,
>                  from arch/x86/include/asm/page.h:14,
>                  from arch/x86/include/asm/thread_info.h:12,
>                  from include/linux/thread_info.h:60,
>                  from include/linux/spinlock.h:60,
>                  from include/linux/wait.h:9,
>                  from include/linux/wait_bit.h:8,
>                  from include/linux/fs.h:6,
>                  from include/linux/debugfs.h:15,
>                  from lib/stackdepot.c:17:
> In function 'depot_alloc_stack',
>     inlined from 'stack_depot_save_flags' at lib/stackdepot.c:688:4:
> arch/x86/include/asm/string_32.h:150:25: error: '__builtin_memcpy' specified bound 4294967295 exceeds maximum object size 2147483647 [-Werror=stringop-overflow=]
>   150 | #define memcpy(t, f, n) __builtin_memcpy(t, f, n)
>       |                         ^~~~~~~~~~~~~~~~~~~~~~~~~
> lib/stackdepot.c:459:9: note: in expansion of macro 'memcpy'
>   459 |         memcpy(stack->entries, entries, flex_array_size(stack, entries, nr_entries));
>       |         ^~~~~~
> cc1: all warnings being treated as errors

This is a false positives due to -next enabling some new warnings by
default: https://lore.kernel.org/all/[email-masked]/T/#u