From patchwork Wed Jun 2 11:46:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 453985 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDD5BC47083 for ; Wed, 2 Jun 2021 11:48:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB33A61246 for ; Wed, 2 Jun 2021 11:48:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229843AbhFBLuG (ORCPT ); Wed, 2 Jun 2021 07:50:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:50594 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229604AbhFBLuG (ORCPT ); Wed, 2 Jun 2021 07:50:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B149B610A8; Wed, 2 Jun 2021 11:48:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622634503; bh=lRDvJLbCzhr8ZIh/1K6OOoSk/itsTtf5FuzdVPT/XeY=; h=From:To:Cc:Subject:Date:From; b=Y5uslJctsJVe9JF8nakoU11NPmeFlMbwtrrERbze2dYUBc7gimJ53t4QrPW2NAP+A DH/EA1WEDd+wr/+Xw0NfPE6sFFM/l1mJzpZ/DUB87+XZnbpysz3t1Pnrtw3dce/9Eb GEyZ+c+TqeTTHFvf6xD/k44nqlf+TgPmkO5d9u3pwOf8rn+aoIyvSn0XICn73r+BAO bYps8jGhM4NvT5X8Nh/IkD2tPen1DCbSBvD0F1U8NXJOfpcjrpK6BpMLBU9YYeParH jzgv8DyU7YObjGGUux1sZcsAd+ucHxKaLLUFGQz73gqyy/3Q6ZszmogOBo4N5Lkhc2 1jm/7D79T4c/w== From: Arnd Bergmann To: stable@vger.kernel.org Cc: Michael Weiser , Martin Vajnar , musl@lists.openwall.com, Will Deacon , Greg Kroah-Hartman , Arnd Bergmann Subject: [PATCH] [stable v4.4] arm64: Remove unimplemented syscall log message Date: Wed, 2 Jun 2021 13:46:51 +0200 Message-Id: <20210602114651.423605-1-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michael Weiser commit 1962682d2b2fbe6cfa995a85c53c069fadda473e upstream. Stop printing a (ratelimited) kernel message for each instance of an unimplemented syscall being called. Userland making an unimplemented syscall is not necessarily misbehaviour and to be expected with a current userland running on an older kernel. Also, the current message looks scary to users but does not actually indicate a real problem nor help them narrow down the cause. Just rely on sys_ni_syscall() to return -ENOSYS. Cc: Cc: Martin Vajnar Cc: musl@lists.openwall.com Acked-by: Will Deacon Signed-off-by: Michael Weiser Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman Signed-off-by: Arnd Bergmann --- This was backported to v4.14 and later, but is missing in v4.4 and before, apparently because of a trivial merge conflict. This is a manual backport I did after I saw a report about the issue by Martin Vajnar on the musl mailing list. --- arch/arm64/kernel/traps.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 02710f99c137..a8c0fd0574fa 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -381,14 +381,6 @@ asmlinkage long do_ni_syscall(struct pt_regs *regs) } #endif - if (show_unhandled_signals_ratelimited()) { - pr_info("%s[%d]: syscall %d\n", current->comm, - task_pid_nr(current), (int)regs->syscallno); - dump_instr("", regs); - if (user_mode(regs)) - __show_regs(regs); - } - return sys_ni_syscall(); }