Re: [PATCH v2 7/9] trace_uprobe/sdt: Fix multiple update of same reference counter

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Ravi,

On 04/10, Ravi Bangoria wrote:
>
> > and what if __mmu_notifier_register() fails simply because signal_pending() == T?
> > see mm_take_all_locks().
> >
> > at first glance this all look suspicious and sub-optimal,
>
> Yes. I should have added checks for failure cases.
> Will fix them in v3.

And what can you do if it fails? Nothing except report the problem. But
signal_pending() is not the unlikely or error condition, it should not
cause the tracing errors.

Plus mm_take_all_locks() is very heavy... BTW, uprobe_mmap_callback() is
called unconditionally. Whatever it does, can we at least move it after
the no_uprobe_events() check? Can't we also check MMF_HAS_UPROBES?

Either way, I do not feel that mmu_notifier is the right tool... Did you
consider the uprobe_clear_state() hook we already have?

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux