(2013/03/12 17:16), Ingo Molnar wrote: > > * Masami Hiramatsu <[email protected]> wrote: > >> Beacuse hash_64() is called from the get_kprobe() inside >> int3 handler, kernel causes int3 recursion and crashes if >> kprobes user puts a probe on it. >> >> Usually hash_64() is inlined into caller function, but in >> some cases, it has instances by gcc's interprocedural >> constant propagation. >> >> This patch adds __kprobes tag on the hash_64() and moves >> all those instances into .text.kprobe section so that >> kprobes can refuse probing on the instances. >> >> I've ensured that all hash_64 instances moves to the >> address between __kprobes_text_start and __kprobes_text_end >> with this patch as below. >> >> ffffffff8138bea0 T __kprobes_text_start >> ffffffff8138bec0 t hash_64.constprop.8 >> ffffffff8138ef98 t hash_64.constprop.26 >> ffffffff8138efae t hash_64 >> ffffffff8138f066 t hash_64.constprop.43 >> ffffffff8138f649 t hash_64.constprop.25 >> ffffffff8139103a t hash_64.constprop.77 >> ffffffff81391050 t hash_64.constprop.24 >> ffffffff81391066 t hash_64.constprop.40 >> ffffffff8139107c t hash_64.constprop.15 >> ffffffff81391092 T __kprobes_text_end >> >> Signed-off-by: Masami Hiramatsu <[email protected]> >> Reported-by: Timo Juhani Lindfors <[email protected]> >> Cc: "David S. Miller" <[email protected]> >> Cc: Nadia Yvette Chambers <[email protected]> >> Cc: Pavel Emelyanov <[email protected]> >> Cc: Jiri Kosina <[email protected]> >> Cc: Ananth N Mavinakayanahalli <[email protected]> >> --- >> include/linux/hash.h | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/include/linux/hash.h b/include/linux/hash.h >> index 61c97ae..d83f62f 100644 >> --- a/include/linux/hash.h >> +++ b/include/linux/hash.h >> @@ -15,6 +15,7 @@ >> */ >> >> #include <asm/types.h> >> +#include <linux/kprobes.h> > > I have no objections to the fix itself, but this inclusion of kprobes.h in > hash.h is somewhat sad: kprobes.h is a 'fat' header that includes a lot of > header files - while hash.h is a really basic type header included in > close to a hundred .c files. > > I think one solution would be for the __kprobes definition to move to a > more basic header file - such as types.h or compiler.h (where the > 'notrace' attribute is placed too), to stop this header dependency creep.
Agreed, that sounds nice to me too! Thank you, -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: [email protected] -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
