From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 525 invoked by alias); 20 Nov 2013 04:32:12 -0000 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org Received: (qmail 495 invoked by uid 89); 20 Nov 2013 04:32:11 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=0.5 required=5.0 tests=AWL,BAYES_50,RDNS_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no version=3.3.2 X-HELO: mailxx.hitachi.co.jp Received: from Unknown (HELO mailxx.hitachi.co.jp) (133.145.228.50) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 20 Nov 2013 04:30:12 +0000 Received: from mail7.hitachi.co.jp by mailxx.hitachi.co.jp (8.9.3p3/3.7W-mailx) id NAA14105; Wed, 20 Nov 2013 13:22:41 +0900 Received: from mlsv3.hitachi.co.jp (unknown [133.144.234.166]) by mail7.hitachi.co.jp (Postfix) with ESMTP id EB89337AC9; Wed, 20 Nov 2013 13:22:40 +0900 (JST) Received: from mfilter06.hitachi.co.jp by mlsv3.hitachi.co.jp (8.13.1/8.13.1) id rAK4Me6V011509; Wed, 20 Nov 2013 13:22:40 +0900 Received: from vshuts04.hitachi.co.jp (vshuts04.hitachi.co.jp [10.201.6.86]) by mfilter06.hitachi.co.jp (Switch-3.3.4/Switch-3.3.4) with ESMTP id rAK4MbQB005852; Wed, 20 Nov 2013 13:22:40 +0900 Received: from gmml27.itg.hitachi.co.jp (unknown [158.213.165.130]) by vshuts04.hitachi.co.jp (Postfix) with ESMTP id A278514004F; Wed, 20 Nov 2013 13:22:39 +0900 (JST) Received: from kbuild-fedora.novalocal by gmml27.itg.hitachi.co.jp (AIX5.2/8.11.6p2/8.11.0) id rAK4Mdu5419066; Wed, 20 Nov 2013 13:22:39 +0900 Subject: [PATCH -tip v3 19/23] [BUGFIX] kprobes/x86: Prohibit probing on debug_stack_* To: Ingo Molnar From: Masami Hiramatsu Cc: linux-arch@vger.kernel.org, Fenghua Yu , Seiji Aguchi , Ananth N Mavinakayanahalli , Sandeepa Prabhu , x86@kernel.org, lkml , "Steven Rostedt (Red Hat)" , virtualization@lists.linux-foundation.org, Ingo Molnar , systemtap@sourceware.org, "H. Peter Anvin" , Thomas Gleixner , Borislav Petkov , "David S. Miller" Date: Wed, 20 Nov 2013 04:32:00 -0000 Message-ID: <20131120042236.15296.74140.stgit@kbuild-fedora.novalocal> In-Reply-To: <20131120042148.15296.88360.stgit@kbuild-fedora.novalocal> References: <20131120042148.15296.88360.stgit@kbuild-fedora.novalocal> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2013-q4/txt/msg00248.txt.bz2 Prohibit probing on debug_stack_reset and debug_stack_set_zero. Since the both functions are called from TRACE_IRQS_ON/OFF_DEBUG macros which run in int3 ist entry, probing it may cause a soft lockup. This happens when the kernel built with CONFIG_DYNAMIC_FTRACE=y and CONFIG_TRACE_IRQFLAGS=y. Signed-off-by: Masami Hiramatsu Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Borislav Petkov Cc: Fenghua Yu Cc: Seiji Aguchi --- arch/x86/kernel/cpu/common.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 1789b06..d0a802a 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -1163,6 +1164,7 @@ int is_debug_stack(unsigned long addr) (addr <= __get_cpu_var(debug_stack_addr) && addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ)); } +NOKPROBE_SYMBOL(is_debug_stack); DEFINE_PER_CPU(u32, debug_idt_ctr); @@ -1171,6 +1173,7 @@ void debug_stack_set_zero(void) this_cpu_inc(debug_idt_ctr); load_current_idt(); } +NOKPROBE_SYMBOL(debug_stack_set_zero); void debug_stack_reset(void) { @@ -1179,6 +1182,7 @@ void debug_stack_reset(void) if (this_cpu_dec_return(debug_idt_ctr) == 0) load_current_idt(); } +NOKPROBE_SYMBOL(debug_stack_reset); #else /* CONFIG_X86_64 */