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authorGuo Ren <guoren@linux.alibaba.com>2020-04-01 09:17:02 +0800
committerGuo Ren <guoren@linux.alibaba.com>2020-04-03 11:14:17 +0800
commit33e53ae1ce413a081254e686d9b27cc1b3585e2f (patch)
treedd6ddbf5a1707f1d0351143cedc00147a465abf4 /arch/csky/kernel/probes/kprobes_trampoline.S
parent000591f1ca3312d9a29e15a9e3fe5c4171f75586 (diff)
downloadlinux-sh-33e53ae1ce413a081254e686d9b27cc1b3585e2f.tar.gz
csky: Add kprobes supported
This patch enable kprobes, kretprobes, ftrace interface. It utilized software breakpoint and single step debug exceptions, instructions simulation on csky. We use USR_BKPT replace origin instruction, and the kprobe handler prepares an excutable memory slot for out-of-line execution with a copy of the original instruction being probed. Most of instructions could be executed by single-step, but some instructions need origin pc value to execute and we need software simulate these instructions. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/csky/kernel/probes/kprobes_trampoline.S')
-rw-r--r--arch/csky/kernel/probes/kprobes_trampoline.S19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/csky/kernel/probes/kprobes_trampoline.S b/arch/csky/kernel/probes/kprobes_trampoline.S
new file mode 100644
index 000000000000..b1fe3af24f03
--- /dev/null
+++ b/arch/csky/kernel/probes/kprobes_trampoline.S
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <linux/linkage.h>
+
+#include <abi/entry.h>
+
+ENTRY(kretprobe_trampoline)
+ SAVE_REGS_FTRACE
+
+ mov a0, sp /* pt_regs */
+
+ jbsr trampoline_probe_handler
+
+ /* use the result as the return-address */
+ mov lr, a0
+
+ RESTORE_REGS_FTRACE
+ rts
+ENDPROC(kretprobe_trampoline)