OpenCloudOS-Kernel/arch/riscv
Guo Ren c22b0bcb1d
riscv: Add kprobes supported
This patch enables "kprobe & kretprobe" to work with ftrace
interface. It utilized software breakpoint as single-step
mechanism.

Some instructions which can't be single-step executed must be
simulated in kernel execution slot, such as: branch, jal, auipc,
la ...

Some instructions should be rejected for probing and we use a
blacklist to filter, such as: ecall, ebreak, ...

We use ebreak & c.ebreak to replace origin instruction and the
kprobe handler prepares an executable memory slot for out-of-line
execution with a copy of the original instruction being probed.
In execution slot we add ebreak behind original instruction to
simulate a single-setp mechanism.

The patch is based on packi's work [1] and csky's work [2].
 - The kprobes_trampoline.S is all from packi's patch
 - The single-step mechanism is new designed for riscv without hw
   single-step trap
 - The simulation codes are from csky
 - Frankly, all codes refer to other archs' implementation

 [1] https://lore.kernel.org/linux-riscv/20181113195804.22825-1-me@packi.ch/
 [2] https://lore.kernel.org/linux-csky/20200403044150.20562-9-guoren@kernel.org/

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Patrick Stählin <me@packi.ch>
Signed-off-by: Patrick Stählin <me@packi.ch>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Patrick Stählin <me@packi.ch>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 15:09:06 -08:00
..
boot riscv: Fix Canaan Kendryte K210 device tree 2021-01-14 15:08:47 -08:00
configs riscv: Use vendor name for K210 SoC support 2021-01-14 15:08:46 -08:00
include riscv: Add kprobes supported 2021-01-14 15:09:06 -08:00
kernel riscv: Add kprobes supported 2021-01-14 15:09:06 -08:00
lib riscv: provide memmove implementation 2020-12-10 17:27:54 -08:00
mm riscv: Add kprobes supported 2021-01-14 15:09:06 -08:00
net treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
Kbuild riscv: Allow device trees to be built into the kernel 2020-05-18 11:38:05 -07:00
Kconfig riscv: Add kprobes supported 2021-01-14 15:09:06 -08:00
Kconfig.debug RISC-V: Remove EARLY_PRINTK support 2018-12-17 10:23:46 -08:00
Kconfig.socs riscv: Add Canaan Kendryte K210 reset controller 2021-01-14 15:08:53 -08:00
Makefile riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT 2021-01-14 15:09:05 -08:00