Re: [PATCH v4] rethook: add riscv rethook implementation.

From: Conor Dooley
Date: Fri Sep 23 2022 - 13:26:51 EST

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In reply to: l3b2w1: "[PATCH v4] rethook: add riscv rethook implementation."
Next in thread: Wangbinglei: "Re: [PATCH] rethook: add riscv rethook implementation."
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Hey Binglei Wang,

I don't know anything about rethooks, so just more minor comments from
me. Don't respin until someone more knowledgable comes back with a
review of the patch itself.

Please send new versions of the patch as a new mail thread & not as
a reply to the existing one.

On Thu, Sep 22, 2022 at 09:44:28PM +0800, l3b2w1@xxxxxxxxx wrote:
> From: Binglei Wang <l3b2w1@xxxxxxxxx>
>
> Implement the kretprobes function on riscv arch by
> using rethook machenism which abstracts general kretprobe info
^mechanism
> into the struct rethook_node
> to be embedded in the struct kretprobe_instance

Whenever you resend, please fix the line wrapping here too.

> Signed-off-by: Binglei Wang <l3b2w1@xxxxxxxxx>

Again, your first version of the patch used your work email as the
commit author/signer. The sending email does not need to match your
authorship/signature email so is there a reason not to have your h3c
email here?
Thanks,
Conor.

> ---
> 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@xxxxxxxx>
> */
> -#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@xxxxxxxx>
> + */
> +#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@xxxxxxxx>
> + */
> +#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
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Next message: Jason Gunthorpe: "Re: some likely bugs in IOMMUv2 (in tlb_finish_mmu() nested flush and mremap())"
Previous message: Krzysztof Kozlowski: "Re: [PATCH v8 7/7] remoteproc: qcom: Add support for memory sandbox"
In reply to: l3b2w1: "[PATCH v4] rethook: add riscv rethook implementation."
Next in thread: Wangbinglei: "Re: [PATCH] rethook: add riscv rethook implementation."
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