linux_dsm_epyc7002/arch/csky/kernel/probes/kprobes_trampoline.S
Guo Ren 33e53ae1ce 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>
2020-04-03 11:14:17 +08:00

20 lines
312 B
ArmAsm

/* 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)