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

From: Stephen Rothwell <[email-masked]>
Date: Wed, 22 Apr 2020 16:39:35 +1000

Hi all,

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

arch/powerpc/platforms/powernv/vas-fault.c: In function 'update_csb':
arch/powerpc/platforms/powernv/vas-fault.c:130:2: error: implicit declaration of function 'use_mm' [-Werror=implicit-function-declaration]
  130 |  use_mm(window->mm);
      |  ^~~~~~
arch/powerpc/platforms/powernv/vas-fault.c:142:2: error: implicit declaration of function 'unuse_mm' [-Werror=implicit-function-declaration]
  142 |  unuse_mm(window->mm);
      |  ^~~~~~~~

Caused by commit

  7fe021a3f1c9 ("kernel: better document the use_mm/unuse_mm API contract")

interacting with commit

  c96c4436aba4 ("powerpc/vas: Update CSB and notify process for fault CRBs")

from the powerpc tree.

I added the following patch for today:

From: Stephen Rothwell <[email-masked]>
Date: Wed, 22 Apr 2020 16:35:23 +1000
Subject: [PATCH] powerpc/vas: fix up for {un}use_mm() rename

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 arch/powerpc/platforms/powernv/vas-fault.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/vas-fault.c b/arch/powerpc/platforms/powernv/vas-fault.c
index 25db70be4c9c..266a6ca5e15e 100644
--- a/arch/powerpc/platforms/powernv/vas-fault.c
+++ b/arch/powerpc/platforms/powernv/vas-fault.c
@@ -127,7 +127,7 @@ static void update_csb(struct vas_window *window,
 		return;
 	}
 
-	use_mm(window->mm);
+	kthread_use_mm(window->mm);
 	rc = copy_to_user(csb_addr, &csb, sizeof(csb));
 	/*
 	 * User space polls on csb.flags (first byte). So add barrier
@@ -139,7 +139,7 @@ static void update_csb(struct vas_window *window,
 		smp_mb();
 		rc = copy_to_user(csb_addr, &csb, sizeof(u8));
 	}
-	unuse_mm(window->mm);
+	kthread_unuse_mm(window->mm);
 	put_task_struct(tsk);
 
 	/* Success */
-- 
2.25.1

-- 
Cheers,
Stephen Rothwell