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From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
	"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
	Steven Rostedt <rostedt@goodmis.org>
Cc: "x86@kernel.org" <x86@kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: [PATCH 4/4] arm64: implement KPROBES_ON_FTRACE
Date: Mon, 19 Aug 2019 11:38:10 +0000	[thread overview]
Message-ID: <20190819192706.46ce2c1d@xhacker.debian> (raw)
In-Reply-To: <20190819192422.5ed79702@xhacker.debian>

This patch implements KPROBES_ON_FTRACE for arm64.

~ # mount -t debugfs debugfs /sys/kernel/debug/
~ # cd /sys/kernel/debug/
/sys/kernel/debug # echo 'p _do_fork' > tracing/kprobe_events

before the patch:

/sys/kernel/debug # cat kprobes/list
ffffff801009ff7c  k  _do_fork+0x4    [DISABLED]

after the patch:

/sys/kernel/debug # cat kprobes/list
ffffff801009ff7c  k  _do_fork+0x4    [DISABLED][FTRACE]

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
---
 arch/arm64/Kconfig                |  1 +
 arch/arm64/kernel/probes/Makefile |  1 +
 arch/arm64/kernel/probes/ftrace.c | 16 ++++++++++++++++
 3 files changed, 18 insertions(+)
 create mode 100644 arch/arm64/kernel/probes/ftrace.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 663392d1eae2..928700f15e23 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -167,6 +167,7 @@ config ARM64
 	select HAVE_STACKPROTECTOR
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_KPROBES
+	select HAVE_KPROBES_ON_FTRACE
 	select HAVE_KRETPROBES
 	select HAVE_GENERIC_VDSO
 	select IOMMU_DMA if IOMMU_SUPPORT
diff --git a/arch/arm64/kernel/probes/Makefile b/arch/arm64/kernel/probes/Makefile
index 8e4be92e25b1..4020cfc66564 100644
--- a/arch/arm64/kernel/probes/Makefile
+++ b/arch/arm64/kernel/probes/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_KPROBES)		+= kprobes.o decode-insn.o	\
 				   simulate-insn.o
 obj-$(CONFIG_UPROBES)		+= uprobes.o decode-insn.o	\
 				   simulate-insn.o
+obj-$(CONFIG_KPROBES_ON_FTRACE)	+= ftrace.o
diff --git a/arch/arm64/kernel/probes/ftrace.c b/arch/arm64/kernel/probes/ftrace.c
new file mode 100644
index 000000000000..1fe8f105e02e
--- /dev/null
+++ b/arch/arm64/kernel/probes/ftrace.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Dynamic Ftrace based Kprobes Optimization
+ *
+ * Copyright (C) 2019 Synaptics Incorporated
+ *
+ * Author: Jisheng Zhang <jszhang@kernel.org>
+ */
+
+#include <linux/kprobes.h>
+
+int arch_prepare_kprobe_ftrace(struct kprobe *p)
+{
+	p->ainsn.api.insn = NULL;
+	return 0;
+}
-- 
2.23.0.rc1


  parent reply	other threads:[~2019-08-19 11:38 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-19 11:35 [PATCH 0/4] arm64: KPROBES_ON_FTRACE Jisheng Zhang
2019-08-19 11:36 ` [PATCH 1/4] kprobes: adjust kprobe addr for KPROBES_ON_FTRACE Jisheng Zhang
2019-08-19 16:43   ` Naveen N. Rao
2019-08-20  1:51     ` Jisheng Zhang
2019-08-20  0:01   ` Masami Hiramatsu
2019-08-20  2:05     ` Jisheng Zhang
2019-08-19 11:36 ` [PATCH 2/4] kprobes/x86: use instruction_pointer and instruction_pointer_set Jisheng Zhang
2019-08-20  0:09   ` Masami Hiramatsu
2019-08-19 11:37 ` [PATCH 3/4] kprobes: move kprobe_ftrace_handler() from x86 and make it weak Jisheng Zhang
2019-08-20  0:07   ` Masami Hiramatsu
2019-08-20  1:56     ` Jisheng Zhang
2019-08-19 11:38 ` Jisheng Zhang [this message]
2019-08-19 16:52   ` [PATCH 4/4] arm64: implement KPROBES_ON_FTRACE Naveen N. Rao
2019-08-20  2:16     ` Jisheng Zhang
2019-08-19 12:53 ` [PATCH 0/4] arm64: KPROBES_ON_FTRACE Mark Rutland
2019-08-19 13:10 ` Masami Hiramatsu

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