Messages in this thread | | | Date | Sat, 24 Sep 2022 17:54:11 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH v4] rethook: add riscv rethook implementation. |
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Hi Binglei,
On Thu, 22 Sep 2022 21:44:28 +0800 l3b2w1@gmail.com wrote:
> From: Binglei Wang <l3b2w1@gmail.com> > > Implement the kretprobes function on riscv arch by > using rethook machenism which abstracts general kretprobe info > into the struct rethook_node > to be embedded in the struct kretprobe_instance
Thanks for working on it.
BTW, you might work on older kernel. Could you check your kernel has commit 73f9b911faa7 ("kprobes: Use rethook for kretprobe if possible") ?
It replaces the kretprobe implementation in kernel/kprobes.c with rethook. This means your patch also must remove the arch dependent kretprobe implementation (arch_prepare_kretprobe(), __kretprobe_trampoline, trampoline_handler() and arch_kretprobe_fixup_return()), and you don't need to create kprobes_trampoline.h, but just rename kprobes_trampoline.S to rethook_trampoline.S.
Thank you,
> > Signed-off-by: Binglei Wang <l3b2w1@gmail.com> > --- > arch/riscv/Kconfig | 1 + > arch/riscv/kernel/probes/Makefile | 1 + > arch/riscv/kernel/probes/kprobes.c | 8 -- > arch/riscv/kernel/probes/kprobes_trampoline.S | 73 +---------------- > arch/riscv/kernel/probes/kprobes_trampoline.h | 79 +++++++++++++++++++ > arch/riscv/kernel/probes/rethook.c | 24 ++++++ > arch/riscv/kernel/probes/rethook_trampoline.S | 22 ++++++ > include/linux/kprobes.h | 6 ++ > 8 files changed, 134 insertions(+), 80 deletions(-) > create mode 100644 arch/riscv/kernel/probes/kprobes_trampoline.h > create mode 100644 arch/riscv/kernel/probes/rethook.c > create mode 100644 arch/riscv/kernel/probes/rethook_trampoline.S > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index ed66c31e4..c5cae0825 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/kernel/probes/Makefile b/arch/riscv/kernel/probes/Makefile > index 7f0840dcc..ee345e7e9 100644 > --- a/arch/riscv/kernel/probes/Makefile > +++ b/arch/riscv/kernel/probes/Makefile > @@ -3,4 +3,5 @@ obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o simulate-insn.o > obj-$(CONFIG_KPROBES) += kprobes_trampoline.o > obj-$(CONFIG_KPROBES_ON_FTRACE) += ftrace.o > obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o simulate-insn.o > +obj-$(CONFIG_RETHOOK) += rethook.o rethook_trampoline.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..04911cc42 100644 > --- a/arch/riscv/kernel/probes/kprobes.c > +++ b/arch/riscv/kernel/probes/kprobes.c > @@ -350,14 +350,6 @@ 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/kprobes_trampoline.S b/arch/riscv/kernel/probes/kprobes_trampoline.S > index 7bdb09ded..54937f342 100644 > --- a/arch/riscv/kernel/probes/kprobes_trampoline.S > +++ b/arch/riscv/kernel/probes/kprobes_trampoline.S > @@ -2,78 +2,7 @@ > /* > * Author: Patrick Stählin <me@packi.ch> > */ > -#include <linux/linkage.h> > - > -#include <asm/asm.h> > -#include <asm/asm-offsets.h> > - > - .text > - .altmacro > - > - .macro save_all_base_regs > - REG_S x1, PT_RA(sp) > - REG_S x3, PT_GP(sp) > - REG_S x4, PT_TP(sp) > - REG_S x5, PT_T0(sp) > - REG_S x6, PT_T1(sp) > - REG_S x7, PT_T2(sp) > - REG_S x8, PT_S0(sp) > - REG_S x9, PT_S1(sp) > - REG_S x10, PT_A0(sp) > - REG_S x11, PT_A1(sp) > - REG_S x12, PT_A2(sp) > - REG_S x13, PT_A3(sp) > - REG_S x14, PT_A4(sp) > - REG_S x15, PT_A5(sp) > - REG_S x16, PT_A6(sp) > - REG_S x17, PT_A7(sp) > - REG_S x18, PT_S2(sp) > - REG_S x19, PT_S3(sp) > - REG_S x20, PT_S4(sp) > - REG_S x21, PT_S5(sp) > - REG_S x22, PT_S6(sp) > - REG_S x23, PT_S7(sp) > - REG_S x24, PT_S8(sp) > - REG_S x25, PT_S9(sp) > - REG_S x26, PT_S10(sp) > - REG_S x27, PT_S11(sp) > - REG_S x28, PT_T3(sp) > - REG_S x29, PT_T4(sp) > - REG_S x30, PT_T5(sp) > - REG_S x31, PT_T6(sp) > - .endm > - > - .macro restore_all_base_regs > - REG_L x3, PT_GP(sp) > - REG_L x4, PT_TP(sp) > - REG_L x5, PT_T0(sp) > - REG_L x6, PT_T1(sp) > - REG_L x7, PT_T2(sp) > - REG_L x8, PT_S0(sp) > - REG_L x9, PT_S1(sp) > - REG_L x10, PT_A0(sp) > - REG_L x11, PT_A1(sp) > - REG_L x12, PT_A2(sp) > - REG_L x13, PT_A3(sp) > - REG_L x14, PT_A4(sp) > - REG_L x15, PT_A5(sp) > - REG_L x16, PT_A6(sp) > - REG_L x17, PT_A7(sp) > - REG_L x18, PT_S2(sp) > - REG_L x19, PT_S3(sp) > - REG_L x20, PT_S4(sp) > - REG_L x21, PT_S5(sp) > - REG_L x22, PT_S6(sp) > - REG_L x23, PT_S7(sp) > - REG_L x24, PT_S8(sp) > - REG_L x25, PT_S9(sp) > - REG_L x26, PT_S10(sp) > - REG_L x27, PT_S11(sp) > - REG_L x28, PT_T3(sp) > - REG_L x29, PT_T4(sp) > - REG_L x30, PT_T5(sp) > - REG_L x31, PT_T6(sp) > - .endm > +#include "kprobes_trampoline.h" > > ENTRY(__kretprobe_trampoline) > addi sp, sp, -(PT_SIZE_ON_STACK) > diff --git a/arch/riscv/kernel/probes/kprobes_trampoline.h b/arch/riscv/kernel/probes/kprobes_trampoline.h > new file mode 100644 > index 000000000..48895a5e3 > --- /dev/null > +++ b/arch/riscv/kernel/probes/kprobes_trampoline.h > @@ -0,0 +1,79 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > +#ifndef _KPROBES_TRAMPOLINE_H > +#define _KPROBES_TRAMPOLINE_H > +/* > + * Author: Patrick Stählin <me@packi.ch> > + */ > +#include <linux/linkage.h> > + > +#include <asm/asm.h> > +#include <asm/asm-offsets.h> > + > + .text > + .altmacro > + > + .macro save_all_base_regs > + REG_S x1, PT_RA(sp) > + REG_S x3, PT_GP(sp) > + REG_S x4, PT_TP(sp) > + REG_S x5, PT_T0(sp) > + REG_S x6, PT_T1(sp) > + REG_S x7, PT_T2(sp) > + REG_S x8, PT_S0(sp) > + REG_S x9, PT_S1(sp) > + REG_S x10, PT_A0(sp) > + REG_S x11, PT_A1(sp) > + REG_S x12, PT_A2(sp) > + REG_S x13, PT_A3(sp) > + REG_S x14, PT_A4(sp) > + REG_S x15, PT_A5(sp) > + REG_S x16, PT_A6(sp) > + REG_S x17, PT_A7(sp) > + REG_S x18, PT_S2(sp) > + REG_S x19, PT_S3(sp) > + REG_S x20, PT_S4(sp) > + REG_S x21, PT_S5(sp) > + REG_S x22, PT_S6(sp) > + REG_S x23, PT_S7(sp) > + REG_S x24, PT_S8(sp) > + REG_S x25, PT_S9(sp) > + REG_S x26, PT_S10(sp) > + REG_S x27, PT_S11(sp) > + REG_S x28, PT_T3(sp) > + REG_S x29, PT_T4(sp) > + REG_S x30, PT_T5(sp) > + REG_S x31, PT_T6(sp) > + .endm > + > + .macro restore_all_base_regs > + REG_L x3, PT_GP(sp) > + REG_L x4, PT_TP(sp) > + REG_L x5, PT_T0(sp) > + REG_L x6, PT_T1(sp) > + REG_L x7, PT_T2(sp) > + REG_L x8, PT_S0(sp) > + REG_L x9, PT_S1(sp) > + REG_L x10, PT_A0(sp) > + REG_L x11, PT_A1(sp) > + REG_L x12, PT_A2(sp) > + REG_L x13, PT_A3(sp) > + REG_L x14, PT_A4(sp) > + REG_L x15, PT_A5(sp) > + REG_L x16, PT_A6(sp) > + REG_L x17, PT_A7(sp) > + REG_L x18, PT_S2(sp) > + REG_L x19, PT_S3(sp) > + REG_L x20, PT_S4(sp) > + REG_L x21, PT_S5(sp) > + REG_L x22, PT_S6(sp) > + REG_L x23, PT_S7(sp) > + REG_L x24, PT_S8(sp) > + REG_L x25, PT_S9(sp) > + REG_L x26, PT_S10(sp) > + REG_L x27, PT_S11(sp) > + REG_L x28, PT_T3(sp) > + REG_L x29, PT_T4(sp) > + REG_L x30, PT_T5(sp) > + REG_L x31, PT_T6(sp) > + .endm > +#endif > diff --git a/arch/riscv/kernel/probes/rethook.c b/arch/riscv/kernel/probes/rethook.c > new file mode 100644 > index 000000000..47853bc36 > --- /dev/null > +++ b/arch/riscv/kernel/probes/rethook.c > @@ -0,0 +1,24 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Generic return hook for riscv. > + */ > + > +#include <linux/kprobes.h> > +#include <linux/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 = (u64)arch_rethook_trampoline; > +} > +NOKPROBE_SYMBOL(arch_rethook_prepare); > diff --git a/arch/riscv/kernel/probes/rethook_trampoline.S b/arch/riscv/kernel/probes/rethook_trampoline.S > new file mode 100644 > index 000000000..e81c3d4e0 > --- /dev/null > +++ b/arch/riscv/kernel/probes/rethook_trampoline.S > @@ -0,0 +1,22 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > +/* > + * Author: Patrick Stählin <me@packi.ch> > + */ > +#include "kprobes_trampoline.h" > + > +ENTRY(arch_rethook_trampoline) > + addi sp, sp, -(PT_SIZE_ON_STACK) > + save_all_base_regs > + > + move a0, sp /* pt_regs */ > + > + call arch_rethook_trampoline_callback > + > + /* use the result as the return-address */ > + move ra, a0 > + > + restore_all_base_regs > + addi sp, sp, PT_SIZE_ON_STACK > + > + ret > +ENDPROC(arch_rethook_trampoline) > diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h > index 55041d2f8..a3805b5b2 100644 > --- a/include/linux/kprobes.h > +++ b/include/linux/kprobes.h > @@ -210,6 +210,12 @@ static nokprobe_inline unsigned long get_kretprobe_retaddr(struct kretprobe_inst > { > return ri->node.ret_addr; > } > +static nokprobe_inline > +unsigned long kretprobe_trampoline_handler(struct pt_regs *regs, > + void *frame_pointer) > +{ > + return 0; > +} > #else > extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, > struct pt_regs *regs); > > base-commit: f30480cdeafc79d1f017d41335a96d8e3b973c91 > -- > 2.25.1 >
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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