4 Commits

Author SHA1 Message Date
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
Guo Ren
bfe47f358a csky: Implement ptrace regs and stack API
Needed for kprobes support. Copied and adapted from Patrick's patch,
but it has been modified for csky's pt_regs.

ref:
https://lore.kernel.org/linux-riscv/1572919114-3886-2-git-send-email-vincent.chen@sifive.com/raw

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Patrick Staehlin <me@packi.ch>
2020-03-08 20:55:14 +08:00
Guo Ren
f4625ee0e4 csky: Use in_syscall & forget_syscall instead of r11_sig
We could use regs->sr 16-24 bits to detect syscall: VEC_TRAP0 and
r11_sig is no necessary for current implementation.

In this patch, we implement the in_syscall and forget_syscall which are
inspired from arm & nds32, but csky pt_regs has no syscall_num element
and we just set zero to regs->sr's vector-bits-field instead.

For ret_from_fork, current task was forked from parent which is in syscall
progress and its regs->sr has been already setted with VEC_TRAP0. See:
arch/csky/kernel/process.c: copy_thread()

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
2019-04-22 13:44:57 +08:00
Guo Ren
f335b10f3b csky: Add non-uapi asm/ptrace.h namespace
Move #ifdef __KERNEL__ code in the uapi namespace to non-uapi
include/asm/ptrace.h namespace and remove #ifdef __KERNEL__ in
include/asm/ptrace.h. Seperate ptrace.h in uapi and non-uapi is more
common and clear.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Dmitry V. Levin <ldv@altlinux.org>
2019-04-22 13:44:57 +08:00