From mboxrd@z Thu Jan 1 00:00:00 1970 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 D0D9DC43463 for ; Sat, 19 Sep 2020 03:26:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A02921534 for ; Sat, 19 Sep 2020 03:26:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726306AbgISD0B (ORCPT ); Fri, 18 Sep 2020 23:26:01 -0400 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:33247 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726104AbgISD0A (ORCPT ); Fri, 18 Sep 2020 23:26:00 -0400 X-Greylist: delayed 347 seconds by postgrey-1.27 at vger.kernel.org; Fri, 18 Sep 2020 23:26:00 EDT Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 5FDD8C85; Fri, 18 Sep 2020 23:20:12 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute3.internal (MEProxy); Fri, 18 Sep 2020 23:20:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sholland.org; h= from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; s=fm3; bh=+klDHT4tIeJVl4fgQHq2RfH08C mREckooi3m30a5UCo=; b=jQ0RJFmNOpIwpCANwC4OJdLY4yyTqiSWbNqzQrBvIU yUeMnR2j/ohd+NhiZcavWACRKnql+z+0GbYFw05W9/D3QPD9/Ji10/a3GV5uex7B RA9AC4vD34GqfrnVvKhK35PCedstAEtmQZUJXSL9PgRdlm03iMQMQhRcsnL5aFHj pDuuhujCAKdbdN+/slMynwW4YQkQxpZ9iHotjVU4MmqdfJw9iJjzF3EtW8sniRgX KNKj8HBOG3nkvJW+0hUg1ekim0blgLkwH3rtQ2uQBPTAMqe8XSmcRuO9UmWP80Nf Biz43slSF8iNI2jptUPzkcy53D+C3JgdWuEEZqMgtL5w== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :message-id:mime-version:subject:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=+klDHT4tIeJVl4fgQ Hq2RfH08CmREckooi3m30a5UCo=; b=Qhr5ijpX6iqjimQMjwfFdGgNVENqOM+TQ vTFRwZNrZNl0MXZ9bf6cdak9eTv+gVUpHzMZuE0KM1JJzG2NjENp77liHWBXXcgT drTz/1D6hbMyl9meC/3IpkHZYVkUuVk8AxhCbczFgqXJ5qSqlSyovI6wCVq2qsOM pkFVZcShuZ3paZj0dK+8dUAGcMVpQNYIbyHqHHztWYCG0YG9+yEpDmg9wNY1GTG5 H8JUL+J3BUyzNuf2EyivN9dmgxj9Hlgv5JzTBGR3wZ+UlxiSPzUkxZ7rsMCJagQ4 dggJK7dnKeKkQviLT0XY5+5tdXTzP0T6SoWl0cicHqDhg0pesn6HA== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedrtdejgdeikecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofgggfestdekredtredttdenucfhrhhomhepufgrmhhuvghlucfj ohhllhgrnhguuceoshgrmhhuvghlsehshhholhhlrghnugdrohhrgheqnecuggftrfgrth htvghrnhepieetkefhheduudfgledtudefjeejfeegveehkeeufffhhfejkeehiefftdev tdevnecukfhppeejtddrudefhedrudegkedrudehudenucevlhhushhtvghrufhiiigvpe dtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehsrghmuhgvlhesshhhohhllhgrnhgurdho rhhg X-ME-Proxy: Received: from titanium.stl.sholland.net (70-135-148-151.lightspeed.stlsmo.sbcglobal.net [70.135.148.151]) by mail.messagingengine.com (Postfix) with ESMTPA id 5C4D2306467E; Fri, 18 Sep 2020 23:20:10 -0400 (EDT) From: Samuel Holland To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, Samuel Holland Subject: [PATCH] powerpc: Select HAVE_FUTEX_CMPXCHG Date: Fri, 18 Sep 2020 22:20:09 -0500 Message-Id: <20200919032009.8346-1-samuel@sholland.org> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On powerpc, access_ok() succeeds for the NULL pointer. This breaks the dynamic check in futex_detect_cmpxchg(), which expects -EFAULT. As a result, robust futex operations are not functional on powerpc. Since the architecture's futex_atomic_cmpxchg_inatomic() implementation requires no runtime feature detection, we can select HAVE_FUTEX_CMPXCHG to skip futex_detect_cmpxchg() and enable the use of robust futexes. Signed-off-by: Samuel Holland --- arch/powerpc/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index ad620637cbd1..5ad1deb0c669 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -196,6 +196,7 @@ config PPC select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER + select HAVE_FUTEX_CMPXCHG select HAVE_GCC_PLUGINS if GCC_VERSION >= 50200 # plugin support on gcc <= 5.1 is buggy on PPC select HAVE_HW_BREAKPOINT if PERF_EVENTS && (PPC_BOOK3S || PPC_8xx) select HAVE_IDE -- 2.26.2