On Thu, Mar 14, 2013 at 08:52:43PM +0900, Masami Hiramatsu wrote: > Currently kprobes check whether the copied instruction modifies > IF (interrupt flag) on each probe hit. This means not only > introducing overhead but also involving inat_get_opcode_attribute > into kprobes hot path, and it can cause an infinit recursive > call (and kernel panic in the end). > > Actually, since the copied instruction itself never be modified > on the buffer, it is needless to analyze the instruction every > probe hit. > > To fix this issue, we checks it only once when registering probe > and store the result on ainsn->if_modifier. > > Signed-off-by: Masami Hiramatsu <[email protected]> > Reported-by: Timo Juhani Lindfors <[email protected]> > Cc: "David S. Miller" <[email protected]> > Cc: Ananth N Mavinakayanahalli <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: "H. Peter Anvin" <[email protected]> > Cc: Steven Rostedt <[email protected]> > Cc: Linus Torvalds <[email protected]>
Acked-by: Ananth N Mavinakayanahalli <[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/
