| Message ID | 164826160914.2455864.505359679001055158.stgit@devnote2 (mailing list archive) |
|---|---|
| Headers | show |
| Series | kprobes: rethook: x86: Replace kretprobe trampoline with rethook | expand |
Hello: This series was applied to bpf/bpf.git (master) by Alexei Starovoitov <ast@kernel.org>: On Sat, 26 Mar 2022 11:26:49 +0900 you wrote: > Hi, > > Here are the 3rd version for generic kretprobe and kretprobe on x86 for > replacing the kretprobe trampoline with rethook. The previous version > is here[1] > > [1] https://lore.kernel.org/all/164821817332.2373735.12048266953420821089.stgit@devnote2/T/#u > > [...] Here is the summary with links: - [bpf-next,v3,1/4] kprobes: Use rethook for kretprobe if possible https://git.kernel.org/bpf/bpf/c/73f9b911faa7 - [bpf-next,v3,2/4] x86,rethook,kprobes: Replace kretprobe with rethook on x86 https://git.kernel.org/bpf/bpf/c/f3a112c0c40d - [bpf-next,v3,3/4] x86,rethook: Fix arch_rethook_trampoline() to generate a complete pt_regs https://git.kernel.org/bpf/bpf/c/0ef6f5c09371 - [bpf-next,v3,4/4] x86,kprobes: Fix optprobe trampoline to generate complete pt_regs https://git.kernel.org/bpf/bpf/c/45c23bf4d1a4 You are awesome, thank you!
Hi, Here are the 3rd version for generic kretprobe and kretprobe on x86 for replacing the kretprobe trampoline with rethook. The previous version is here[1] [1] https://lore.kernel.org/all/164821817332.2373735.12048266953420821089.stgit@devnote2/T/#u This version fixed typo and build issues for bpf-next and CONFIG_RETHOOK=y error. I also add temporary mitigation lines for ANNOTATE_NOENDBR macro issue for bpf-next tree [2/4]. #ifndef ANNOTATE_NOENDBR #define ANNOTATE_NOENDBR #endif This will be removed after merging kernel IBT series. Background: This rethook came from Jiri's request of multiple kprobe for bpf[2]. He tried to solve an issue that starting bpf with multiple kprobe will take a long time because bpf-kprobe will wait for RCU grace period for sync rcu events. Jiri wanted to attach a single bpf handler to multiple kprobes and he tried to introduce multiple-probe interface to kprobe. So I asked him to use ftrace and kretprobe-like hook if it is only for the function entry and exit, instead of adding ad-hoc interface to kprobes. For this purpose, I introduced the fprobe (kprobe like interface for ftrace) with the rethook (this is a generic return hook feature for fprobe exit handler)[3]. [2] https://lore.kernel.org/all/20220104080943.113249-1-jolsa@kernel.org/T/#u [3] https://lore.kernel.org/all/164191321766.806991.7930388561276940676.stgit@devnote2/T/#u The rethook is basically same as the kretprobe trampoline. I just made it decoupled from kprobes. Eventually, the all arch dependent kretprobe trampolines will be replaced with the rethook trampoline instead of cloning and set HAVE_RETHOOK=y. When I port the rethook for all arch which supports kretprobe, the legacy kretprobe specific code (which is for CONFIG_KRETPROBE_ON_RETHOOK=n) will be removed eventually. Thank you, --- Masami Hiramatsu (3): kprobes: Use rethook for kretprobe if possible x86,rethook,kprobes: Replace kretprobe with rethook on x86 x86,kprobes: Fix optprobe trampoline to generate complete pt_regs Peter Zijlstra (1): x86,rethook: Fix arch_rethook_trampoline() to generate a complete pt_regs arch/Kconfig | 8 ++ arch/x86/Kconfig | 1 arch/x86/include/asm/unwind.h | 23 +++---- arch/x86/kernel/Makefile | 1 arch/x86/kernel/kprobes/common.h | 1 arch/x86/kernel/kprobes/core.c | 106 -------------------------------- arch/x86/kernel/kprobes/opt.c | 25 +++++-- arch/x86/kernel/rethook.c | 127 ++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/unwind_orc.c | 10 +-- include/linux/kprobes.h | 51 +++++++++++++++ kernel/Makefile | 1 kernel/kprobes.c | 124 +++++++++++++++++++++++++++++++------ kernel/trace/trace_kprobe.c | 4 + 13 files changed, 325 insertions(+), 157 deletions(-) create mode 100644 arch/x86/kernel/rethook.c -- Masami Hiramatsu (Linaro) <mhiramat@kernel.org>