All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
To: Masami Hiramatsu <mhiramat@kernel.org>, Ingo Molnar <mingo@kernel.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
	"David S . Miller" <davem@davemloft.net>,
	linux-kernel@vger.kernel.org,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH -tip v2] kprobes: Prohibit probing on BUG() and WARN() address
Date: Wed, 04 Sep 2019 14:43:26 +0530	[thread overview]
Message-ID: <1567588343.zi51gn8p0w.naveen@linux.ibm.com> (raw)
In-Reply-To: <156750890133.19112.3393666300746167111.stgit@devnote2>

Masami Hiramatsu wrote:
> Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to
> get the address where the BUG() has occurred, kprobes can not
> do single-step out-of-line that instruction. So prohibit
> probing on such address.
> 
> Without this fix, if someone put a kprobe on WARN(), the
> kernel will crash with invalid opcode error instead of
> outputing warning message, because kernel can not find
> correct bug address.
> 
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
>   Changes in v2:
>    - Add find_bug() stub function for !CONFIG_GENERIC_BUG
>    - Cast the p->addr to unsigned long.
> ---
>  include/linux/bug.h |    5 +++++
>  kernel/kprobes.c    |    3 ++-
>  2 files changed, 7 insertions(+), 1 deletion(-)

Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

- Naveen


  reply	other threads:[~2019-09-04  9:13 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-03 11:08 Masami Hiramatsu
2019-09-04  9:13 ` Naveen N. Rao [this message]
2019-09-04 12:29 ` Steven Rostedt

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=1567588343.zi51gn8p0w.naveen@linux.ibm.com \
    --to=naveen.n.rao@linux.ibm.com \
    --cc=anil.s.keshavamurthy@intel.com \
    --cc=davem@davemloft.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mhiramat@kernel.org \
    --cc=mingo@kernel.org \
    --cc=rostedt@goodmis.org \
    --subject='Re: [PATCH -tip v2] kprobes: Prohibit probing on BUG() and WARN() address' \
    /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

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.