Re: [PATCH -tip ] [BUGFIX] kprobes: Move hash_64() into.text.kprobe section

[Ananth N Mavinakayanahalli]

On Mon, Mar 11, 2013 at 11:22:33PM +0900, Masami Hiramatsu 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 <masami.hiramatsu.pt@xxxxxxxxxxx>
> Reported-by: Timo Juhani Lindfors <timo.lindfors@xxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Nadia Yvette Chambers <nyc@xxxxxxxxxxxxxx>
> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
> Cc: Jiri Kosina <jkosina@xxxxxxx>
> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>

Acked-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>

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