From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SUBJ_OBFU_PUNCT_FEW autolearn=ham autolearn_force=no version=3.4.2 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by inbox.vuxu.org (OpenSMTPD) with SMTP id 1ef90daa for ; Thu, 23 Jan 2020 01:31:19 +0000 (UTC) Received: (qmail 19473 invoked by uid 550); 23 Jan 2020 01:31:17 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 18417 invoked from network); 23 Jan 2020 01:31:17 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=J2Zvav7w3yEsSEIK/Vs/mjL/2lLRLiu3IekQ9s8zWZE=; b=l1TwUk74kmBlp1ryT85ubwfRh4XwY1gNfU6iU7kL4ICW8ZEOdg18zsRvFyY9hp4Ntk tfxHN1q5mkC2oTZqcSS3d4pW8/zlQWm4Zn9opI/8N6Le26Tr+YXarQylXAY6A6QXgAa+ h5fCrS0v9vlt1wIyqLwHlsCJO4XOK+iDqrmPWT5BEk5gEfi7aw3OZNMOFnUrsRmzwJFy yzhY63BcpVxE8G1puXKLJQ3msWRjT/Ac20+XZ1+XR+a7dZLBllOtE7V1PlChJrPShmIU b8SCn9NI6pQEwnsUiifVxc1HXsuwR4G5jpG7zBLblJl9POCJI75rZIc4dI5UDiwD2bfu 47aQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=J2Zvav7w3yEsSEIK/Vs/mjL/2lLRLiu3IekQ9s8zWZE=; b=HNMMidr+SRpsNNOjczCaM8QExCDnObb15pDRo2JMPS8HjhSjfYlT01lixhpmhs1Y3e aZl5mwGM2ZSaxKbamiL1a6SDjZOXmfQG2GjWy4wKihb055eKzCvGrirPblu0Dcz2bpCU qKib4v03YJ2COcJfwBKQImQdcnoXtacwfM8mFOMiV2jT/itZmjcYciDn3Lpit/QL8+g3 cEBH/G3sirEeG/zfbzaurDESqdXN2MMD/8kfbwTX3PkCbYK5i4WoC2uX3P6NLcn6ZxRe 16ZaLoxR+U/enR14p/fyz257HuN2Tv7PlWPdKmW0sWbGK55Hr9MYLQ/eRmMqkAFOMT6v C4dw== X-Gm-Message-State: APjAAAXY0aDzrHiWohKTpzD4ru30j36KEnGugXK27e6UQeMFD4wzVpRa Jn53YKmcHOavk/R0DPuCh/PqJ29FBiiBDCnejCeNQSId X-Google-Smtp-Source: APXvYqz47OjvpuV4xHYhpnxGibebCwYxHU9o+Yy7qC5Z/1k7jEakzgBq3pGDf/giJTaIEGFk9xJDmhheftyqI09rGTg= X-Received: by 2002:a05:6102:a10:: with SMTP id t16mr4893190vsa.130.1579743065071; Wed, 22 Jan 2020 17:31:05 -0800 (PST) MIME-Version: 1.0 From: Andre McCurdy Date: Wed, 22 Jan 2020 17:30:53 -0800 Message-ID: To: musl@lists.openwall.com Content-Type: text/plain; charset="UTF-8" Subject: [musl] arm __a_barrier_v6 register value should be zero? The arm1176jzfs documentation describing the armv6 CP15 Data Memory Barrier operation seems to specify the register value written to the coprocessor as "SBZ" ie Should Be Zero. See page 216 of: http://infocenter.arm.com/help/topic/com.arm.doc.ddi0301h/DDI0301H_arm1176jzfs_r0p7_trm.pdf However the __a_barrier_v6() function which implements this in musl uses r0 as the register written to the coprocessor and doesn't initialise it. Should __a_barrier_v6() set r0 to 0 before issuing the mcr instruction? Or is it defined somewhere that this register value doesn't matter?