After merging the kspp-gustavo tree, today's linux-next build (powerpc
pseries_le_defconfig) failed like this:

In file included from include/linux/perf_event.h:49,
                 from arch/powerpc/perf/callchain.c:9:
include/linux/ftrace.h:49:41: error: 'struct ftrace_regs' declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
   49 |           struct ftrace_ops *op, struct ftrace_regs *fregs);
      |                                         ^~~~~~~~~~~
cc1: all warnings being treated as errors

(many of these)

Caused by commit

  c45ede6c2781 ("ftrace: Fix -Wmissing-prototypes errors")

I have added the following fixup for today.

From: Stephen Rothwell <redacted>
Date: Mon, 18 Oct 2021 17:56:30 +1100
Subject: [PATCH] fixup for "ftrace: Fix -Wmissing-prototypes errors"

Signed-off-by: Stephen Rothwell <redacted>
---
 include/linux/ftrace.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 871b51bec170..ada656c6824d 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h

@@ -45,6 +45,7 @@ struct ftrace_ops;
 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
 #else
 # define FTRACE_FORCE_LIST_FUNC 0
+struct ftrace_regs;
 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
 			       struct ftrace_ops *op, struct ftrace_regs *fregs);
 #endif

-- 
2.33.0