Messages in this thread | | | Date | Tue, 28 Feb 2017 01:11:40 +0900 | From | Masami Hiramatsu <> | Subject | Re: [lkp-robot] [x86/mm/ptdump] 243b72aae2: WARNING:at_arch/x86/mm/dump_pagetables.c:#note_page |
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On Mon, 27 Feb 2017 16:01:34 +0300 Andrey Ryabinin <aryabinin@virtuozzo.com> wrote:
> On 02/27/2017 04:03 AM, kernel test robot wrote: > > > > FYI, we noticed the following commit: > > > > commit: 243b72aae28ca1032284028323bb81c9235b15c9 ("x86/mm/ptdump: Optimize check for W+X mappings for CONFIG_KASAN=y") > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > ... > > > > caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): > > > > > > +-----------------------------------------------------+------------+------------+ > > | | 5b1ad68f9b | 243b72aae2 | > > +-----------------------------------------------------+------------+------------+ > > | boot_successes | 0 | 0 | > > | boot_failures | 8 | 6 | > > | BUG:KASAN:slab-out-of-bounds | 8 | 6 | > > | WARNING:at_arch/x86/mm/dump_pagetables.c:#note_page | 0 | 6 | > > +-----------------------------------------------------+------------+------------+ > > Ok, I reproduced this, but it's definitely caused *not* by 243b72aae28. > This WARN is also reproducible on the parent commit 5b1ad68f9b. > The only difference here is that on parent one needs dozens of seconds to reach this WARNING. > It seems that this time difference somehow confused the robot. > > As for the warning itself, it caused by kprobes. krpobe code use module_alloc() which > creates these RWX mappings. > I'm not sure how to fix this as AFAIK kprobes actually need RWX mapping.
Thanks! I also noticed this issue. I actually have a plan to make kprobes with R+X mappings (as ftrace does). I'll queue this on my TODO list.
-- Masami Hiramatsu <mhiramat@kernel.org>
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