summaryrefslogtreecommitdiff
path: root/arch/csky/kernel/probes/decode-insn.c
diff options
context:
space:
mode:
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/decode-insn.c
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/decode-insn.c')
-rw-r--r--arch/csky/kernel/probes/decode-insn.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/csky/kernel/probes/decode-insn.c b/arch/csky/kernel/probes/decode-insn.c
new file mode 100644
index 000000000000..bbc4edc25dc9
--- /dev/null
+++ b/arch/csky/kernel/probes/decode-insn.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <asm/sections.h>
+
+#include "decode-insn.h"
+#include "simulate-insn.h"
+
+/* Return:
+ * INSN_REJECTED If instruction is one not allowed to kprobe,
+ * INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
+ */
+enum probe_insn __kprobes
+csky_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *api)
+{
+ probe_opcode_t insn = le32_to_cpu(*addr);
+
+ CSKY_INSN_SET_SIMULATE(br16, insn);
+ CSKY_INSN_SET_SIMULATE(bt16, insn);
+ CSKY_INSN_SET_SIMULATE(bf16, insn);
+ CSKY_INSN_SET_SIMULATE(jmp16, insn);
+ CSKY_INSN_SET_SIMULATE(jsr16, insn);
+ CSKY_INSN_SET_SIMULATE(lrw16, insn);
+ CSKY_INSN_SET_SIMULATE(pop16, insn);
+
+ CSKY_INSN_SET_SIMULATE(br32, insn);
+ CSKY_INSN_SET_SIMULATE(bt32, insn);
+ CSKY_INSN_SET_SIMULATE(bf32, insn);
+ CSKY_INSN_SET_SIMULATE(jmp32, insn);
+ CSKY_INSN_SET_SIMULATE(jsr32, insn);
+ CSKY_INSN_SET_SIMULATE(lrw32, insn);
+ CSKY_INSN_SET_SIMULATE(pop32, insn);
+
+ CSKY_INSN_SET_SIMULATE(bez32, insn);
+ CSKY_INSN_SET_SIMULATE(bnez32, insn);
+ CSKY_INSN_SET_SIMULATE(bnezad32, insn);
+ CSKY_INSN_SET_SIMULATE(bhsz32, insn);
+ CSKY_INSN_SET_SIMULATE(bhz32, insn);
+ CSKY_INSN_SET_SIMULATE(blsz32, insn);
+ CSKY_INSN_SET_SIMULATE(blz32, insn);
+ CSKY_INSN_SET_SIMULATE(bsr32, insn);
+ CSKY_INSN_SET_SIMULATE(jmpi32, insn);
+ CSKY_INSN_SET_SIMULATE(jsri32, insn);
+
+ return INSN_GOOD;
+}