Re: [PATCH RESEND v9] riscv: add riscv rethook implementation
From: binglei wang
Date: Tue Nov 01 2022 - 09:40:47 EST
Hi Conor,
Thanks for your resending.
What to do next is just to wait patently, right ?
Binglei Wang
Best wishes.
Conor Dooley <conor@xxxxxxxxxx> 于2022年10月25日周二 23:19写道：
>
> From: Binglei Wang <l3b2w1@xxxxxxxxx>
>
> 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.
>
> Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
> Signed-off-by: Binglei Wang <l3b2w1@xxxxxxxxx>
> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> ---
> Binglei's patches do not seem to make it to the linux-riscv list, so
> blindly resending on their behalf, with Masami's ack from v8 added.
>
> 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 6b48a3ae9843..413aeca71ca0 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -99,6 +99,7 @@ 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 217ef89f22b9..e7882ccb0fd4 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 7f0840dcc31b..c40139e9ca47 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 e6e950b7cf32..f21592d20306 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 000000000000..5c27c1f50989
> --- /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 000000000000..4758f7e3ce88
> --- /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 7bdb09ded39b..21bac92a170a 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)
> --
> 2.38.0
>