From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x241.google.com (mail-pf0-x241.google.com [IPv6:2607:f8b0:400e:c00::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zqLXR1WQYzF1Pb for ; Mon, 26 Feb 2018 10:20:06 +1100 (AEDT) Received: by mail-pf0-x241.google.com with SMTP id m5so5770388pff.7 for ; Sun, 25 Feb 2018 15:20:06 -0800 (PST) Date: Mon, 26 Feb 2018 10:19:51 +1100 From: Balbir Singh To: Ram Pai Cc: shuahkh@osg.samsung.com, linux-kselftest@vger.kernel.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, akpm@linux-foundation.org, dave.hansen@intel.com, benh@kernel.crashing.org, paulus@samba.org, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, hbabu@us.ibm.com, mhocko@kernel.org, bauerman@linux.vnet.ibm.com, ebiederm@xmission.com, arnd@arndb.de Subject: Re: [PATCH v12 22/22] selftests/vm: Fix deadlock in protection_keys.c Message-ID: <20180226101951.0136f963@balbir.ozlabs.ibm.com> In-Reply-To: <1519264541-7621-23-git-send-email-linuxram@us.ibm.com> References: <1519264541-7621-1-git-send-email-linuxram@us.ibm.com> <1519264541-7621-23-git-send-email-linuxram@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 21 Feb 2018 17:55:41 -0800 Ram Pai wrote: > From: Thiago Jung Bauermann > > The sig_chld() handler calls dprintf2() taking care of setting > dprint_in_signal so that sigsafe_printf() won't call printf(). > Unfortunately, this precaution is is negated by dprintf_level(), which > has a call to fflush(). > fflush() is not the signal-safe function list, so this makes sense. I wonder if fflush() is needed in sigsafe_printf()? How about? diff --git a/tools/testing/selftests/x86/pkey-helpers.h b/tools/testing/selftests/x86/pkey-helpers.h index b3cb7670e026..2c3b39851f10 100644 --- a/tools/testing/selftests/x86/pkey-helpers.h +++ b/tools/testing/selftests/x86/pkey-helpers.h @@ -29,6 +29,7 @@ static inline void sigsafe_printf(const char *format, ...) va_start(ap, format); if (!dprint_in_signal) { vprintf(format, ap); + fflush(NULL); \ } else { int ret; int len = vsnprintf(dprint_in_signal_buffer, @@ -49,7 +50,6 @@ static inline void sigsafe_printf(const char *format, ...) #define dprintf_level(level, args...) do { \ if (level <= DEBUG_LEVEL) \ sigsafe_printf(args); \ - fflush(NULL); \ } while (0) #define dprintf0(args...) dprintf_level(0, args) #define dprintf1(args...) dprintf_level(1, args) But both are equivalent I guess, so Acked-by: Balbir Singh