Re: [PATCH v8] rethook: add riscv rethook implementation

[Conor Dooley]

On Mon, Oct 17, 2022 at 10:31:28PM +0800, binglei wang wrote:
> Hi Conor,
> could you please help me to push forward merging process of this patch
> into the 6.1 ?  Thank you!

Hey Binglei,
Unfortunately it is too late for v6.1 (the merge window closed on
Sunday, Palmer sent his second PR on Friday) but I don't see why this
should not be picked for v6.2. I tried last week & again just now to
check the status of this patch on patchwork but I cannot find it there.
Similarly, the patch does not appear on lore:
https://lore.kernel.org/linux-riscv/CAJ3C4KzyAR7dKYFBKHzFEXr-dzr-JMGRFVx+dybMhRPy0uHUgA@xxxxxxxxxxxxxx/T/#t
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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     [not found] <20220930081357.651914-1-l3b2w1@xxxxxxxxx>
2022-10-02  9:10 ` [PATCH v8] rethook: add riscv rethook implementation Masami Hiramatsu
2022-10-02 16:39 ` Conor Dooley
2022-10-17 14:31   ` binglei wang

I'm not really sure what's happened there.. I can only see your v1 and
your v4 on lore/patchwork. Maybe take a look if you changed anything
between versions & try resending as v9?

HTH,
Conor.

> 
> Binglei Wang
> Best wishes.
> 
> 
> On 2022-10-03 00:39, Conor Dooley wrote:
> > Hey Binglei,
> > I am not qualified to give you an actual R-b on this patch, but I see
> > you did get one from Masami who very much is!
> >
> > That said, the patch looks a lot better (and much simpler!) now. Thanks
> > for sticking with it despite the initial issues with your email setup
> > and the submission process.
> >
> > Thanks,
> > Conor.
> >
> > On Fri, Sep 30, 2022 at 04:13:57PM +0800, Binglei Wang wrote:
> >> 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.
> >>
> >> Signed-off-by: Binglei Wang <l3b2w1@xxxxxxxxx>
> >> ---
> >>
> >> Notes:
> >>      v8: Add the omitted rethook.h
> >>      v7: Add the changelog.
> >>      v6: Remove the kretprobes trampoline.
> >>      v5: Trt to fix robot compiling error and warnings.
> >>      v4: Add patch version number.
> >>      v3: Trt to fix robot compiling error and warnings.
> >>      v2: Add comit log to explain reasons behind changes.
> >>          Use my personal email instead of work email
> >>              to avoid the attachments of company informaton.
> >>          Make the kprobes_trampoline.S code to be shared.
> >>      v1: Add riscv rethook implementation.
> >>
> >>   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 59d18881f..bfb66cdc5 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/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h
> >> index 217ef89f2..e7882ccb0 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 7f0840dcc..c40139e9c 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 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..cbd0da059
> >> --- /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 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 94%
> >> rename from arch/riscv/kernel/probes/kprobes_trampoline.S
> >> rename to arch/riscv/kernel/probes/rethook_trampoline.S
> >> index 7bdb09ded..21bac92a1 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)
> >> --
> >> 2.27.0
> >>
> 
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