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

From: Stephen Rothwell <[email-masked]>
Date: Fri, 12 Apr 2024 13:34:07 +1000

Hi all,

After merging the kvm tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

kernel/events/uprobes.c: In function '__replace_page':
kernel/events/uprobes.c:160:35: error: storage size of 'range' isn't known
  160 |         struct mmu_notifier_range range;
      |                                   ^~~~~
kernel/events/uprobes.c:162:9: error: implicit declaration of function 'mmu_notifier_range_init' [-Werror=implicit-function-declaration]
  162 |         mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, addr,
      |         ^~~~~~~~~~~~~~~~~~~~~~~
kernel/events/uprobes.c:162:41: error: 'MMU_NOTIFY_CLEAR' undeclared (first use in this function)
  162 |         mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, addr,
      |                                         ^~~~~~~~~~~~~~~~
kernel/events/uprobes.c:162:41: note: each undeclared identifier is reported only once for each function it appears in
kernel/events/uprobes.c:175:9: error: implicit declaration of function 'mmu_notifier_invalidate_range_start' [-Werror=implicit-function-declaration]
  175 |         mmu_notifier_invalidate_range_start(&range);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/events/uprobes.c:208:9: error: implicit declaration of function 'mmu_notifier_invalidate_range_end' [-Werror=implicit-function-declaration]
  208 |         mmu_notifier_invalidate_range_end(&range);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/events/uprobes.c:160:35: warning: unused variable 'range' [-Wunused-variable]
  160 |         struct mmu_notifier_range range;
      |                                   ^~~~~
cc1: some warnings being treated as errors

Caused by commit

  b06d4c260e93 ("mm: replace set_pte_at_notify() with just set_pte_at()")

I have applied the following patial revert for today.

-- 
Cheers,
Stephen Rothwell