Messages in this thread | | | Date | Sun, 2 Oct 2022 18:10:35 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH v8] rethook: add riscv rethook implementation |
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On Fri, 30 Sep 2022 16:13:57 +0800 Binglei Wang <l3b2w1@gmail.com> wrote:
> From: Binglei Wang <l3b2w1@gmail.com> > > Implement the kretprobes on riscv arch by using rethook machenism > which abstracts general kretprobe info into a struct rethook_node > to be embedded in the struct kretprobe_instance. > > Signed-off-by: Binglei Wang <l3b2w1@gmail.com>
This looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Thank you,
> --- > > Notes: > v8: Add the omitted rethook.h > v7: Add the changelog. > v6: Remove the kretprobes trampoline. > v5: Trt to fix robot compiling error and warnings. > v4: Add patch version number. > v3: Trt to fix robot compiling error and warnings. > v2: Add comit log to explain reasons behind changes. > Use my personal email instead of work email > to avoid the attachments of company informaton. > Make the kprobes_trampoline.S code to be shared. > v1: Add riscv rethook implementation. > > arch/riscv/Kconfig | 1 + > arch/riscv/include/asm/kprobes.h | 2 -- > arch/riscv/kernel/probes/Makefile | 2 +- > arch/riscv/kernel/probes/kprobes.c | 13 --------- > arch/riscv/kernel/probes/rethook.c | 27 +++++++++++++++++++ > arch/riscv/kernel/probes/rethook.h | 8 ++++++ > ...obes_trampoline.S => rethook_trampoline.S} | 6 ++--- > 7 files changed, 40 insertions(+), 19 deletions(-) > create mode 100644 arch/riscv/kernel/probes/rethook.c > create mode 100644 arch/riscv/kernel/probes/rethook.h > rename arch/riscv/kernel/probes/{kprobes_trampoline.S => rethook_trampoline.S} (94%) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 59d18881f..bfb66cdc5 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -97,6 +97,7 @@ config RISCV > select HAVE_KPROBES if !XIP_KERNEL > select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL > select HAVE_KRETPROBES if !XIP_KERNEL > + select HAVE_RETHOOK if !XIP_KERNEL > select HAVE_MOVE_PMD > select HAVE_MOVE_PUD > select HAVE_PCI > diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h > index 217ef89f2..e7882ccb0 100644 > --- a/arch/riscv/include/asm/kprobes.h > +++ b/arch/riscv/include/asm/kprobes.h > @@ -40,8 +40,6 @@ void arch_remove_kprobe(struct kprobe *p); > int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr); > bool kprobe_breakpoint_handler(struct pt_regs *regs); > bool kprobe_single_step_handler(struct pt_regs *regs); > -void __kretprobe_trampoline(void); > -void __kprobes *trampoline_probe_handler(struct pt_regs *regs); > > #endif /* CONFIG_KPROBES */ > #endif /* _ASM_RISCV_KPROBES_H */ > diff --git a/arch/riscv/kernel/probes/Makefile b/arch/riscv/kernel/probes/Makefile > index 7f0840dcc..c40139e9c 100644 > --- a/arch/riscv/kernel/probes/Makefile > +++ b/arch/riscv/kernel/probes/Makefile > @@ -1,6 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o simulate-insn.o > -obj-$(CONFIG_KPROBES) += kprobes_trampoline.o > +obj-$(CONFIG_RETHOOK) += rethook.o rethook_trampoline.o > obj-$(CONFIG_KPROBES_ON_FTRACE) += ftrace.o > obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o simulate-insn.o > CFLAGS_REMOVE_simulate-insn.o = $(CC_FLAGS_FTRACE) > diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c > index e6e950b7c..f21592d20 100644 > --- a/arch/riscv/kernel/probes/kprobes.c > +++ b/arch/riscv/kernel/probes/kprobes.c > @@ -345,19 +345,6 @@ int __init arch_populate_kprobe_blacklist(void) > return ret; > } > > -void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) > -{ > - return (void *)kretprobe_trampoline_handler(regs, NULL); > -} > - > -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, > - struct pt_regs *regs) > -{ > - ri->ret_addr = (kprobe_opcode_t *)regs->ra; > - ri->fp = NULL; > - regs->ra = (unsigned long) &__kretprobe_trampoline; > -} > - > int __kprobes arch_trampoline_kprobe(struct kprobe *p) > { > return 0; > diff --git a/arch/riscv/kernel/probes/rethook.c b/arch/riscv/kernel/probes/rethook.c > new file mode 100644 > index 000000000..cbd0da059 > --- /dev/null > +++ b/arch/riscv/kernel/probes/rethook.c > @@ -0,0 +1,27 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Generic return hook for riscv. > + */ > + > +#include <linux/kprobes.h> > +#include <linux/rethook.h> > +#include "rethook.h" > + > +/* This is called from arch_rethook_trampoline() */ > +unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs) > +{ > + return rethook_trampoline_handler(regs, regs->s0); > +} > +NOKPROBE_SYMBOL(arch_rethook_trampoline_callback); > + > + > +void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount) > +{ > + rhn->ret_addr = regs->ra; > + rhn->frame = regs->s0; > + > + /* replace return addr with trampoline */ > + regs->ra = (unsigned long)arch_rethook_trampoline; > +} > +NOKPROBE_SYMBOL(arch_rethook_prepare); > + > diff --git a/arch/riscv/kernel/probes/rethook.h b/arch/riscv/kernel/probes/rethook.h > new file mode 100644 > index 000000000..cc573d701 > --- /dev/null > +++ b/arch/riscv/kernel/probes/rethook.h > @@ -0,0 +1,8 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +#ifndef __RISCV_RETHOOK_H > +#define __RISCV_RETHOOK_H > + > +unsigned long arch_rethook_trampoline_callback(struct pt_regs *regs); > +void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount); > + > +#endif > diff --git a/arch/riscv/kernel/probes/kprobes_trampoline.S b/arch/riscv/kernel/probes/rethook_trampoline.S > similarity index 94% > rename from arch/riscv/kernel/probes/kprobes_trampoline.S > rename to arch/riscv/kernel/probes/rethook_trampoline.S > index 7bdb09ded..21bac92a1 100644 > --- a/arch/riscv/kernel/probes/kprobes_trampoline.S > +++ b/arch/riscv/kernel/probes/rethook_trampoline.S > @@ -75,13 +75,13 @@ > REG_L x31, PT_T6(sp) > .endm > > -ENTRY(__kretprobe_trampoline) > +ENTRY(arch_rethook_trampoline) > addi sp, sp, -(PT_SIZE_ON_STACK) > save_all_base_regs > > move a0, sp /* pt_regs */ > > - call trampoline_probe_handler > + call arch_rethook_trampoline_callback > > /* use the result as the return-address */ > move ra, a0 > @@ -90,4 +90,4 @@ ENTRY(__kretprobe_trampoline) > addi sp, sp, PT_SIZE_ON_STACK > > ret > -ENDPROC(__kretprobe_trampoline) > +ENDPROC(arch_rethook_trampoline) > -- > 2.27.0 >
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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