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

From: Stephen Rothwell <[email-masked]>
Date: Tue, 2 Jun 2020 19:57:41 +1000

Hi all,

After merging the akpm tree, today's linux-next build (powerpc
ppc64_defconfig) failed like this:

ERROR: modpost: ".probe_user_write" [arch/powerpc/kvm/kvm-hv.ko] undefined!

Caused by patch

  "maccess: unexport probe_kernel_write and probe_user_write"

"These two functions are not used by any modular code." turns out to
not be true :-(

I have added this patch:

From: Stephen Rothwell <[email-masked]>
Date: Tue, 2 Jun 2020 19:54:05 +1000
Subject: [PATCH] turns out that probe_user_write is used in modular code

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 mm/maccess.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/maccess.c b/mm/maccess.c
index ddfda8e6f4a5..88845eda5047 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -246,6 +246,7 @@ long probe_user_write(void __user *dst, const void *src, size_t size)
 		return -EFAULT;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(probe_user_write);
 
 /**
  * strncpy_from_user_nofault: - Copy a NUL terminated string from unsafe user
-- 
2.26.2

-- 
Cheers,
Stephen Rothwell