Messages in this thread | | | Date | Wed, 9 Jun 2021 23:42:39 +0900 | From | Masami Hiramatsu <> | Subject | Re: [RFC PATCH 3/5] kprobe: Simplify prepare_kprobe() by dropping redundant version |
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On Wed, 9 Jun 2021 19:50:17 +0900 Punit Agrawal <punitagrawal@gmail.com> wrote:
> The function prepare_kprobe() is called during kprobe registration and > is responsible for ensuring any architecture related preparation for > the kprobe is done before returning. > > One of two versions of prepare_kprobe() is chosen depending on the > availability of KPROBE_ON_FTRACE in the kernel configuration. > > Simplify the code by dropping the version when KPROBE_ON_FTRACE is not > selected - instead relying on kprobe_ftrace() to return false when > KPROBE_ON_FTRACE is not set. >
OK, since kprobe_ftrace() just checks a flag is set or not, it is always usable in kprobes.c. Looks good to me :)
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Thank you!
> No functional change. > > Signed-off-by: Punit Agrawal <punitagrawal@gmail.com> > --- > include/linux/kprobes.h | 5 +++++ > kernel/kprobes.c | 23 +++++++++-------------- > 2 files changed, 14 insertions(+), 14 deletions(-) > > diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h > index 1883a4a9f16a..771013bab18a 100644 > --- a/include/linux/kprobes.h > +++ b/include/linux/kprobes.h > @@ -362,6 +362,11 @@ static inline void wait_for_kprobe_optimizer(void) { } > extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, > struct ftrace_ops *ops, struct ftrace_regs *fregs); > extern int arch_prepare_kprobe_ftrace(struct kprobe *p); > +#else > +static inline int arch_prepare_kprobe_ftrace(struct kprobe *p) > +{ > + return -EINVAL; > +} > #endif > > int arch_check_ftrace_location(struct kprobe *p); > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 1a11d3c411bf..54d37d4ab897 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1022,15 +1022,6 @@ static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = { > static int kprobe_ipmodify_enabled; > static int kprobe_ftrace_enabled; > > -/* Must ensure p->addr is really on ftrace */ > -static int prepare_kprobe(struct kprobe *p) > -{ > - if (!kprobe_ftrace(p)) > - return arch_prepare_kprobe(p); > - > - return arch_prepare_kprobe_ftrace(p); > -} > - > /* Caller must lock kprobe_mutex */ > static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > int *cnt) > @@ -1102,11 +1093,6 @@ static int disarm_kprobe_ftrace(struct kprobe *p) > ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled); > } > #else /* !CONFIG_KPROBES_ON_FTRACE */ > -static inline int prepare_kprobe(struct kprobe *p) > -{ > - return arch_prepare_kprobe(p); > -} > - > static inline int arm_kprobe_ftrace(struct kprobe *p) > { > return -ENODEV; > @@ -1118,6 +1104,15 @@ static inline int disarm_kprobe_ftrace(struct kprobe *p) > } > #endif > > +static int prepare_kprobe(struct kprobe *p) > +{ > + /* Must ensure p->addr is really on ftrace */ > + if (kprobe_ftrace(p)) > + return arch_prepare_kprobe_ftrace(p); > + > + return arch_prepare_kprobe(p); > +} > + > /* Arm a kprobe with text_mutex */ > static int arm_kprobe(struct kprobe *kp) > { > -- > 2.30.2 >
-- Masami Hiramatsu <mhiramat@kernel.org>
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