All of lore.kernel.org
 help / color / mirror / Atom feed
From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peterz@infradead.org>,
	Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
	Anton Arapov <anton@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/7] uprobes: introduce MMF_HAS_UPROBES
Date: Mon, 13 Aug 2012 18:52:21 +0530	[thread overview]
Message-ID: <20120813132221.GJ31805@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120808173747.GA13272@redhat.com>

* Oleg Nesterov <oleg@redhat.com> [2012-08-08 19:37:47]:

> Add the new MMF_HAS_UPROBES flag. It is set by install_breakpoint()
> and it is copied by dup_mmap(), uprobe_pre_sstep_notifier() checks
> it to avoid the slow path if the task was never probed. Perhaps it
> makes sense to check it in valid_vma(is_register => false) as well.
> 
> This needs the new dup_mmap()->uprobe_dup_mmap() hook. We can't use
> uprobe_reset_state() or put MMF_HAS_UPROBES into MMF_INIT_MASK, we
> need oldmm->mmap_sem to avoid the race with uprobe_register() or
> mmap() from another thread.
> 
> Currently we never clear this bit, it can be false-positive after
> uprobe_unregister() or uprobe_munmap() or if dup_mmap() hits the
> probed VM_DONTCOPY vma. But this is fine correctness-wise and has
> no effect unless the task hits the non-uprobe breakpoint.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>


  parent reply	other threads:[~2012-08-13 13:23 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-08 17:36 [PATCH 0/7] uprobes: kill uprobes_state->count, add MMF_HAS_UPROBES Oleg Nesterov
2012-08-08 17:37 ` [PATCH 1/7] uprobes: kill uprobes_state->count Oleg Nesterov
2012-08-13 13:18   ` Srikar Dronamraju
2012-08-08 17:37 ` [PATCH 2/7] uprobes: kill dup_mmap()->uprobe_mmap(), simplify uprobe_mmap/munmap Oleg Nesterov
2012-08-13 13:20   ` Srikar Dronamraju
2012-08-08 17:37 ` [PATCH 3/7] uprobes: change uprobe_mmap() to ignore the errors but check fatal_signal_pending() Oleg Nesterov
2012-08-13 13:21   ` Srikar Dronamraju
2012-08-08 17:37 ` [PATCH 4/7] uprobes: do not use -EEXIST in install_breakpoint() paths Oleg Nesterov
2012-08-13 13:21   ` Srikar Dronamraju
2012-08-08 17:37 ` [PATCH 5/7] uprobes: introduce MMF_HAS_UPROBES Oleg Nesterov
2012-08-09 13:32   ` Srikar Dronamraju
2012-08-09 14:17     ` Oleg Nesterov
2012-08-13 13:22   ` Srikar Dronamraju [this message]
2012-08-08 17:37 ` [PATCH 6/7] uprobes: fold uprobe_reset_state() into uprobe_dup_mmap() Oleg Nesterov
2012-08-13 13:23   ` Srikar Dronamraju
2012-08-08 17:37 ` [PATCH 7/7] uprobes: remove "verify" argument from set_orig_insn() Oleg Nesterov
2012-08-09 13:33   ` Srikar Dronamraju

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20120813132221.GJ31805@linux.vnet.ibm.com \
    --to=srikar@linux.vnet.ibm.com \
    --cc=ananth@in.ibm.com \
    --cc=anton@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.