Messages in this thread Patch in this message | | | Date | Thu, 13 Nov 2008 16:27:39 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 4/7] kprobes: Support probing module __exit function |
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On Tue, 11 Nov 2008 15:56:58 -0500 Masami Hiramatsu <mhiramat@redhat.com> wrote:
> @@ -69,9 +69,6 @@ struct kprobe { > /* list of kprobes for multi-handler support */ > struct list_head list; > > - /* Indicates that the corresponding module has been ref counted */ > - unsigned int mod_refcounted; > - > /*count the number of times this probe was temporarily disarmed */ > unsigned long nmissed; > > @@ -103,8 +100,19 @@ struct kprobe { > > /* copy of the original instruction */ > struct arch_specific_insn ainsn; > + > + /* Indicates various status flags */ > + u32 flags; > }; > > +/* Kprobe status flags */ > +#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ > + > +static inline int kprobe_gone(struct kprobe *p) > +{ > + return p->flags & KPROBE_FLAG_GONE; > +}
If we're not going to use atomic bitops on kprobe.flags then modifications to that member will require that the caller hold a lock. The comment above that member should describe its locking protocol. It seems that it is kprobe_mutex, so...
--- a/include/linux/kprobes.h~kprobes-support-probing-module-__exit-function-fix +++ a/include/linux/kprobes.h @@ -101,7 +101,7 @@ struct kprobe { /* copy of the original instruction */ struct arch_specific_insn ainsn; - /* Indicates various status flags */ + /* Indicates various status flags. Protected by kprobe_mutex. */ u32 flags; }; _
yes?
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