From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:49354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730798AbeJICAh (ORCPT ); Mon, 8 Oct 2018 22:00:37 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eugeniy Paltsev , "Peter Zijlstra (Intel)" , Will Deacon , Vineet Gupta , Sasha Levin Subject: [PATCH 4.18 044/168] ARC: atomics: unbork atomic_fetch_##op() Date: Mon, 8 Oct 2018 20:30:24 +0200 Message-Id: <20181008175621.727112508@linuxfoundation.org> In-Reply-To: <20181008175620.043587728@linuxfoundation.org> References: <20181008175620.043587728@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon [ Upstream commit 3fcbb8260a87efb691d837e8cd24e81f65b3eb70 ] In 4.19-rc1, Eugeniy reported weird boot and IO errors on ARC HSDK | INFO: task syslogd:77 blocked for more than 10 seconds. | Not tainted 4.19.0-rc1-00007-gf213acea4e88 #40 | "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this | message. | syslogd D 0 77 76 0x00000000 | | Stack Trace: | __switch_to+0x0/0xac | __schedule+0x1b2/0x730 | io_schedule+0x5c/0xc0 | __lock_page+0x98/0xdc | find_lock_entry+0x38/0x100 | shmem_getpage_gfp.isra.3+0x82/0xbfc | shmem_fault+0x46/0x138 | handle_mm_fault+0x5bc/0x924 | do_page_fault+0x100/0x2b8 | ret_from_exception+0x0/0x8 He bisected to 84c6591103db ("locking/atomics, asm-generic/bitops/lock.h: Rewrite using atomic_fetch_*()") This commit however only unmasked the real issue introduced by commit 4aef66c8ae9 ("locking/atomic, arch/arc: Fix build") which missed the retry-if-scond-failed branch in atomic_fetch_##op() macros. The bisected commit started using atomic_fetch_##op() macros for building the rest of atomics. Fixes: 4aef66c8ae9 ("locking/atomic, arch/arc: Fix build") Reported-by: Eugeniy Paltsev Acked-by: Peter Zijlstra (Intel) Signed-off-by: Will Deacon Signed-off-by: Vineet Gupta [vgupta: wrote changelog] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/arc/include/asm/atomic.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -84,7 +84,7 @@ static inline int atomic_fetch_##op(int "1: llock %[orig], [%[ctr]] \n" \ " " #asm_op " %[val], %[orig], %[i] \n" \ " scond %[val], [%[ctr]] \n" \ - " \n" \ + " bnz 1b \n" \ : [val] "=&r" (val), \ [orig] "=&r" (orig) \ : [ctr] "r" (&v->counter), \