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

From: Stephen Rothwell <[email-masked]>
Date: Fri, 15 May 2020 16:00:11 +1000

Hi all,

After merging the tip tree, today's linux-next build (x86_64 allmodconfig)
failed like this:

arch/x86/kernel/ftrace.c: In function 'set_ftrace_ops_ro':
arch/x86/kernel/ftrace.c:444:32: error: 'ftrace_epilogue' undeclared (first use in this function)
  444 |    end_offset = (unsigned long)ftrace_epilogue;
      |                                ^~~~~~~~~~~~~~~

Caused by commit

  0298739b7983 ("x86,ftrace: Fix ftrace_regs_caller() unwind")

from the tip tree ineracting with commit

  59566b0b622e ("x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up")

from Linus' tree.

I applied the following merge fix patch (I don't know if this is
correct, but it seemed reasonable):

From: Stephen Rothwell <[email-masked]>
Date: Fri, 15 May 2020 15:51:17 +1000
Subject: [PATCH] fixup for "x86/ftrace: Have ftrace trampolines turn read-only
 at the end of system boot up"

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 arch/x86/kernel/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index f8917a6f25b7..c84d28e90a58 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -441,7 +441,7 @@ void set_ftrace_ops_ro(void)
 			end_offset = (unsigned long)ftrace_regs_caller_end;
 		} else {
 			start_offset = (unsigned long)ftrace_caller;
-			end_offset = (unsigned long)ftrace_epilogue;
+			end_offset = (unsigned long)ftrace_caller_end;
 		}
 		size = end_offset - start_offset;
 		size = size + RET_SIZE + sizeof(void *);
-- 
2.26.2

-- 
Cheers,
Stephen Rothwell