linux-kernel - [tip: core/kprobes] x86/ftrace: Mark ftrace_modify_code_direct() _

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Date:   Tue, 19 Nov 2019 09:55:09 -0000
From:   "tip-bot2 for Borislav Petkov" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Borislav Petkov <bp@...e.de>,
        "Steven Rostedt (VMware)" <rostedt@...dmis.org>,
        Alexei Starovoitov <ast@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...nel.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Borislav Petkov <bp@...en8.de>, linux-kernel@...r.kernel.org
Subject: [tip: core/kprobes] x86/ftrace: Mark ftrace_modify_code_direct() __ref

The following commit has been merged into the core/kprobes branch of tip:

Commit-ID:     994795481ddb8efbeda9e5924aca7d0c275efcd9
Gitweb:        https://git.kernel.org/tip/994795481ddb8efbeda9e5924aca7d0c275efcd9
Author:        Borislav Petkov <bp@...e.de>
AuthorDate:    Mon, 18 Nov 2019 18:20:12 +01:00
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Tue, 19 Nov 2019 10:50:12 +01:00

x86/ftrace: Mark ftrace_modify_code_direct() __ref

... because it calls the .init.text function text_poke_early(). That is
ok because it does call that function early, during boot.

Fixes: 9706f7c3531f ("x86/ftrace: Use text_poke()")
Suggested-by: Peter Zijlstra <peterz@...radead.org>
Signed-off-by: Borislav Petkov <bp@...e.de>
Acked-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
Cc: Alexei Starovoitov <ast@...nel.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Daniel Bristot de Oliveira <bristot@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Link: https://lkml.kernel.org/r/20191116204607.GC23231@zn.tnic
---
 arch/x86/kernel/ftrace.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 2a179fb..108ee96 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -99,7 +99,12 @@ static int ftrace_verify_code(unsigned long ip, const char *old_code)
 	return 0;
 }
 
-static int
+/*
+ * Marked __ref because it calls text_poke_early() which is .init.text. That is
+ * ok because that call will happen early, during boot, when .init sections are
+ * still present.
+ */
+static int __ref
 ftrace_modify_code_direct(unsigned long ip, const char *old_code,
 			  const char *new_code)
 {