[PATCH RESEND v9] riscv: add riscv rethook implementation
Conor Dooley
conor at kernel.org
Tue Nov 1 10:07:56 PDT 2022
On Tue, Nov 01, 2022 at 09:40:23PM +0800, binglei wang wrote:
> Hi Conor,
>
> Thanks for your resending.
> What to do next is just to wait patently, right ?
Yup.. You'll get at least one email when it gets applied.
It's in patchwork [0] so it should not get forgotten about.
0 - https://patchwork.kernel.org/project/linux-riscv/patch/20221025151831.1097417-1-conor@kernel.org/
>
> Binglei Wang
> Best wishes.
>
>
> Conor Dooley <conor at kernel.org> 于2022年10月25日周二 23:19写道：
> >
> > From: Binglei Wang <l3b2w1 at 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.
> >
> > Acked-by: Masami Hiramatsu (Google) <mhiramat at kernel.org>
> > Signed-off-by: Binglei Wang <l3b2w1 at gmail.com>
> > Signed-off-by: Conor Dooley <conor.dooley at microchip.com>
> > ---
> > 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
> >
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