* Re: [PATCH v6] rethook: add riscv rethook implementation.
[not found] <20220926084136.629638-1-l3b2w1@gmail.com>
@ 2022-09-26 10:17 ` Conor Dooley
0 siblings, 0 replies; only message in thread
From: Conor Dooley @ 2022-09-26 10:17 UTC (permalink / raw)
To: Binglei Wang
Cc: paul.walmsley, palmer, aou, naveen.n.rao, anil.s.keshavamurthy,
davem, mhiramat, linux-riscv, linux-kernel
On Mon, Sep 26, 2022 at 04:41:36PM +0800, Binglei Wang wrote:
> From: Binglei Wang <l3b2w1@gmail.com>
>
> Implement the kretprobes on riscv arch by using rethook mechanism
> which abstracts general kretprobe info into a struct rethook_node
> to be embedded in the struct kretprobe_instance.
>
> 1. remove arch dependent kretprobe implementation
> 2. replace __kretprobe_trampoline with arch_hook_trampoline
>
> Signed-off-by: Binglei Wang <l3b2w1@gmail.com>
> ---
What changed since v5? You need to put a changelog under the --- for
what changed in each revision.
Thanks,
Conor.
> arch/riscv/Kconfig | 1 +
> arch/riscv/kernel/probes/Makefile | 2 +-
> arch/riscv/kernel/probes/kprobes.c | 13 ----------
> arch/riscv/kernel/probes/rethook.c | 26 +++++++++++++++++++
> arch/riscv/kernel/probes/rethook.h | 8 ++++++
> ...obes_trampoline.S => rethook_trampoline.S} | 0
> 6 files changed, 36 insertions(+), 14 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} (100%)
>
> 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..9a96a7038 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-$(CONFIG_KPROBES_ON_FTRACE) += ftrace.o
> obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o simulate-insn.o
> +obj-$(CONFIG_KPROBES) += 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..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..edfeaa256
> --- /dev/null
> +++ b/arch/riscv/kernel/probes/rethook.c
> @@ -0,0 +1,26 @@
> +// 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 = (u64)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 100%
> rename from arch/riscv/kernel/probes/kprobes_trampoline.S
> rename to arch/riscv/kernel/probes/rethook_trampoline.S
> --
> 2.27.0
>
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