From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mark Rutland <mark.rutland@arm.com>
Cc: "linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Torsten Duwe <duwe@suse.de>
Subject: [PATCH 1/3] ftrace: introdue ftrace_call_init
Date: Mon, 19 Aug 2019 11:27:28 +0000 [thread overview]
Message-ID: <20190819191622.57050fdf@xhacker.debian> (raw)
In-Reply-To: <20190819191530.0f47b9b1@xhacker.debian>
On some arch, the FTRACE_WITH_REGS is implemented with gcc's
-fpatchable-function-entry (=2), gcc adds 2 NOPs at the beginning
of each function, so this makes the MCOUNT_ADDR useless. In ftrace
common framework, MCOUNT_ADDR is mostly used to "init" the nop, so
let's introcude ftrace_call_init().
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
---
include/linux/ftrace.h | 1 +
kernel/trace/ftrace.c | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 8a8cb3c401b2..8175ffb671f0 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -458,6 +458,7 @@ extern void ftrace_regs_caller(void);
extern void ftrace_call(void);
extern void ftrace_regs_call(void);
extern void mcount_call(void);
+extern int ftrace_call_init(struct module *mod, struct dyn_ftrace *rec);
void ftrace_modify_all_code(int command);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eca34503f178..9df5a66a6811 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2500,7 +2500,11 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
if (unlikely(ftrace_disabled))
return 0;
+#ifdef MCOUNT_ADDR
ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
+#else
+ ret = ftrace_call_init(mod, rec);
+#endif
if (ret) {
ftrace_bug_type = FTRACE_BUG_INIT;
ftrace_bug(ret, rec);
--
2.23.0.rc1
next prev parent reply other threads:[~2019-08-19 11:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-19 11:26 [PATCH 0/3] arm64: ftrace with regs Jisheng Zhang
2019-08-19 11:27 ` Jisheng Zhang [this message]
2019-08-19 11:30 ` [PATCH 1/3] ftrace: introdue ftrace_call_init Jisheng Zhang
2019-08-20 9:27 ` Miroslav Benes
2019-08-21 2:12 ` Jisheng Zhang
2019-08-26 10:14 ` Jisheng Zhang
2019-08-19 11:28 ` [PATCH 2/3] arm64: implement ftrace with regs Jisheng Zhang
2019-08-19 11:29 ` [PATCH 3/3] arm64: use -fpatchable-function-entry if available Jisheng Zhang
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