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Date: Tue, 26 Mar 2024 17:38:18 +0000
From: Mark Rutland <mark.rutland@arm.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
Cc: linux-kernel@vger.kernel.org, agordeev@linux.ibm.com,
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Subject: Re: [PATCH 4/4] kprobes: Remove core dependency on modules
Message-ID: <ZgMICo-dZJgVklc4@FVFF77S0Q05N.cambridge.arm.com>
References: <20240326163624.3253157-1-mark.rutland@arm.com>
 <20240326163624.3253157-5-mark.rutland@arm.com>
 <D03UMKC71414.2D6NN1BIWD5TZ@kernel.org>
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On Tue, Mar 26, 2024 at 07:13:51PM +0200, Jarkko Sakkinen wrote:
> On Tue Mar 26, 2024 at 6:36 PM EET, Mark Rutland wrote:

> > +#ifdef CONFIG_MODULES
> >  	/* Check if 'p' is probing a module. */
> >  	*probed_mod = __module_text_address((unsigned long) p->addr);
> >  	if (*probed_mod) {
> > @@ -1605,6 +1606,8 @@ static int check_kprobe_address_safe(struct kprobe *p,
> >  			ret = -ENOENT;
> >  		}
> >  	}
> > +#endif
> 
> This can be scoped a bit more (see v7 of my patch set).

> > +#ifdef CONFIG_MODULES
> >  static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
> >  {
> >  	char *p;
> > @@ -129,6 +130,9 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
> >  
> >  	return ret;
> >  }
> > +#else
> > +#define trace_kprobe_module_exist(tk) false /* aka a module never exists */
> > +#endif /* CONFIG_MODULES */
> >  
> >  static bool trace_kprobe_is_busy(struct dyn_event *ev)
> >  {
> > @@ -670,6 +674,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
> >  	return ret;
> >  }
> >  
> > +#ifdef CONFIG_MODULES
> >  /* Module notifier call back, checking event on the module */
> >  static int trace_kprobe_module_callback(struct notifier_block *nb,
> >  				       unsigned long val, void *data)
> > @@ -699,6 +704,9 @@ static int trace_kprobe_module_callback(struct notifier_block *nb,
> >  
> >  	return NOTIFY_DONE;
> >  }
> > +#else
> > +#define trace_kprobe_module_callback (NULL)
> > +#endif /* CONFIG_MODULES */
> 
> The last two CONFIG_MODULES sections could be combined. This was also in
> v7.

> Other than lgtm.

Great! I've folded your v7 changes in, and pushed that out to:

  https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=kprobes/without-modules

I'll hold off sending that out to the list until other folk have had a chance
to comment.

Mark.