(2015/02/04 1:21), Petr Mladek wrote: > __recover_probed_insn() should always be called from an address where > an instructions starts. The check for ftrace_location() might help to > discover a potential inconsistency. Something goes terribly wrong when > an address inside the ftrace location is checked. Let's BUG() in this case.
Looks good to me :) Acked-by: Masami Hiramatsu <[email protected]> Thank you, > > Suggested-by: Masami Hiramatsu <[email protected]> > Signed-off-by: Petr Mladek <[email protected]> > --- > arch/x86/kernel/kprobes/core.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > > This is follow up for the patch ("[PATCH v2] kprobes/x86: Use 5-byte NOP > when the code might be modified by ftrace") based on the Masami's > suggestion, see https://lkml.org/lkml/2015/2/3/207 > > Let me know if I should merge this with the first patch and send v3. > > > diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c > index 2f464b56766a..124577dcf768 100644 > --- a/arch/x86/kernel/kprobes/core.c > +++ b/arch/x86/kernel/kprobes/core.c > @@ -228,6 +228,12 @@ __recover_probed_insn(kprobe_opcode_t *buf, unsigned > long addr) > kp = get_kprobe((void *)addr); > faddr = ftrace_location(addr); > /* > + * Addresses inside the ftrace location are refused by > + * arch_check_ftrace_location(). Something went terribly wrong > + * if such an address is checked here. > + */ > + BUG_ON(faddr && faddr != addr); > + /* > * Use the current code if it is not modified by Kprobe > * and it cannot be modified by ftrace. > */ > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research 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/
