[RFC PATCH 00/14] kprobes: Unify kretprobe trampoline handlers

Masami Hiramatsu
2020-08-26T13:46:19Z

Hi Peter,

Here is the series of patches to unify the kretprobe trampoline handler
implementation across all architectures which are currently kprobes supported.
Also, this finally removes the in_nmi() check from pre_kretprobe_handler()
since we can avoid double-lock deadlock from NMI by kprobe_busy_begin/end().

The unified generic kretprobe trampoline handler is based on x86 code, which
already support frame-pointer checker. I've enabled it on the arm and
arm64 which I can test. For other architecutres, currently the frame-pointer
checker does not work. If someone wants to enable it, please set the correct
frame pointer to ri->fp and pass it to kretprobe_trampoline_handler() as the
3rd parameter, instead of NULL.

Peter's lockless patch is not included yet because there seems more isses
to be solved. It seems that the cleanup_rp_inst() will be the biggest piece
of this pazzle.

Thank you,

---

Masami Hiramatsu (14):
kprobes: Add generic kretprobe trampoline handler
x86/kprobes: Use generic kretprobe trampoline handler
arm: kprobes: Use generic kretprobe trampoline handler
arm64: kprobes: Use generic kretprobe trampoline handler
arc: kprobes: Use generic kretprobe trampoline handler
csky: kprobes: Use generic kretprobe trampoline handler
ia64: kprobes: Use generic kretprobe trampoline handler
mips: kprobes: Use generic kretprobe trampoline handler
parisc: kprobes: Use generic kretprobe trampoline handler
powerpc: kprobes: Use generic kretprobe trampoline handler
s390: kprobes: Use generic kretprobe trampoline handler
sh: kprobes: Use generic kretprobe trampoline handler
sparc: kprobes: Use generic kretprobe trampoline handler
kprobes: Remove NMI context check

arch/arc/kernel/kprobes.c | 55 +----------------
arch/arm/probes/kprobes/core.c | 79 +-----------------------
arch/arm64/kernel/probes/kprobes.c | 79 +-----------------------
arch/csky/kernel/probes/kprobes.c | 78 +-----------------------
arch/ia64/kernel/kprobes.c | 79 +-----------------------
arch/mips/kernel/kprobes.c | 55 +----------------
arch/parisc/kernel/kprobes.c | 78 ++----------------------
arch/powerpc/kernel/kprobes.c | 55 ++---------------
arch/s390/kernel/kprobes.c | 81 +------------------------
arch/sh/kernel/kprobes.c | 59 +-----------------
arch/sparc/kernel/kprobes.c | 52 +---------------
arch/x86/kernel/kprobes/core.c | 109 +---------------------------------
include/linux/kprobes.h | 32 +++++++++-
kernel/kprobes.c | 117 ++++++++++++++++++++++++++++++++----
14 files changed, 182 insertions(+), 826 deletions(-)

--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>