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

From: Stephen Rothwell <[email-masked]>
Date: Thu, 1 Feb 2024 13:57:47 +1100

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

Presumably caused by commit

  d869d3fb362c ("stackdepot: use variable size records for non-evictable entries")

from the mm-unstable branch of the mm tree.

I have reverted that commit and the following one for today.

-- 
Cheers,
Stephen Rothwell