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
next prev parent 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 [PATCH -tip v2] kprobes: Prohibit probing on BUG() and WARN() address Masami Hiramatsu
2019-09-04 9:13 ` Naveen N. Rao [this message]
2019-09-04 12:29 ` Steven Rostedt
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