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=-5.4 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 223D1C3567B for ; Mon, 24 Feb 2020 09:22:01 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E717220714 for ; Mon, 24 Feb 2020 09:22:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="vBCVXUj4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E717220714 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 49DBE6E2D5; Mon, 24 Feb 2020 09:22:00 +0000 (UTC) Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by gabe.freedesktop.org (Postfix) with ESMTPS id C0B166E053 for ; Mon, 24 Feb 2020 03:29:02 +0000 (UTC) Received: by mail-pj1-x1041.google.com with SMTP id m7so3557184pjs.0 for ; Sun, 23 Feb 2020 19:29:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=K0JW2EfFhuCbUtNkMo3m3FY0j1WPwSQhES6P2P+ACdw=; b=vBCVXUj4Pgidp3lXYVnC7n+3XRqhCoUXuj+3Uiqouorh0riEdjxWV17kshwmp8fkOR zUOBgK7+2al1nxKWGr4NHPQlfaAdITZLKAAfi0koYPp/EPCuIYkDU8yKcFEf5HL5vvpu kmiyamt0Dfu3IstcTTZM+hVR0ZjKvyzuNTCZdYJGC1M6zR9t55Oph2TjJGfdxY2x92HF KrDXeaNKYYQdA5GbeLSYido7K555QXO5V2WPYQ3KkT2m36xS1GQ0ORbJPjeQztYyzwzx tPyDC5EHAvLh+aVsmthNgYTlNIu20vxW96GzHAzY30ysA6RuETjmF+XaX0ASmBXjiSYW B12Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=K0JW2EfFhuCbUtNkMo3m3FY0j1WPwSQhES6P2P+ACdw=; b=duKNQeBdglHA5IKyjwWaIxzM7Xr3jJN+f5aiRj/du5CckUIwEf/qhCGihe9LPzdt/G 6u0YJ+pcOuHaMQYAllDOD2mfjydmxUbRR+lq+5McCNMSkWNHPWc5YdUfxcEJ13OOYkqG hHFpVNZDqjlrR+koCK7TcRJeOgUBl9ZwlRU7zTv+3rpWL8O6na7H+q7KF/jfFWobXKRv iXKbC8GdrWXXpjAgXBtQdMwdHB1lXulowXson91b5fnpBz1tnb3NrTvaWdOgf3BabfqJ M/BM/lM3VZVu4Rr/pWzES9BkZGjOKBbgn2Kpx/U0daTnxeeJ3WQ+frfVlKjQuqNs5qRz SvWA== X-Gm-Message-State: APjAAAXi0vZpQfO1688hp8HwWtB6WbOrVTBcM9+yurZohmULXCg/Msw4 kHkhz/SjfVAezUgqRR3Csarrug== X-Google-Smtp-Source: APXvYqztxRjiovsa78Cv3oB8wD+gtm1MQM6nFAf7AeO8HF1kElzb/LH7H2rVLKYsJDh9HXcKRSrv5A== X-Received: by 2002:a17:902:103:: with SMTP id 3mr48206826plb.34.1582514941893; Sun, 23 Feb 2020 19:29:01 -0800 (PST) Received: from google.com ([2401:fa00:fc:1:28b:9f23:d296:c845]) by smtp.gmail.com with ESMTPSA id r7sm10870261pfg.34.2020.02.23.19.28.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 23 Feb 2020 19:29:01 -0800 (PST) Date: Mon, 24 Feb 2020 11:28:54 +0800 From: Martin Liu To: Sumit Semwal , minchan@kernel.org, surenb@google.com, wvw@google.com, hridya@google.com Subject: Re: [PATCH] dma-buf: use spinlock to protect set/get name operation Message-ID: <20200224032854.GA215090@google.com> References: <20200114150658.205302-1-liumartin@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Mailman-Approved-At: Mon, 24 Feb 2020 09:20:26 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, jenhaochen@google.com, liumartin@google.com, linux-media@vger.kernel.org Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" T24gVHVlLCBGZWIgMTgsIDIwMjAgYXQgMTI6MDU6NTNQTSArMDUzMCwgU3VtaXQgU2Vtd2FsIHdy b3RlOgo+IEhlbGxvIE1hcnRpbiwKPiAKPiBUaGFua3MgZm9yIHlvdXIgcGF0Y2hlcyAtIHRoZXkg bG9vayBkZWNlbnQuCj4gCj4gTWF5IEkgcGxlYXNlIHJlcXVlc3QgeW91IHRvIHJ1biBnZXRfbWFp bnRhaW5lcnMucGwgKHRoZSBwYXRjaGVzIG5lZWQKPiB0byBiZSBzZW50IHRvIGEgY291cGxlIG9m IG90aGVyIE1McyB0b28gZm9yIHdpZGVyIHJldmlldykuCj4gCj4gQmVzdCwKPiBTdW1pdC4KU29y cnkgZm9yIHRoZSBsYXRlIHJlcGx5LiBTdXJlLCBJIHdpbGwgaW5jbHVkZSBtb3JlIE1McyBmb3Ig d2lkZXIKcmV2aWV3LiBUaGFua3MgZm9yIHRoZSBzdWdnZXN0aW9uLgoKPiBPbiBUdWUsIDE0IEph biAyMDIwIGF0IDIwOjM3LCBNYXJ0aW4gTGl1IDxsaXVtYXJ0aW5AZ29vZ2xlLmNvbT4gd3JvdGU6 Cj4gPgo+ID4gV2UgaW50cm9kdWNlZCBzZXRuYW1lIGlvY3RsIGluIGNvbW1pdCBiYjJiYjkwMzA0 MjUgKCJkbWEtYnVmOgo+ID4gYWRkIERNQV9CVUZfU0VUX05BTUUgaW9jdGxzIikgdGhhdCBwcm92 aWRlcyB1c2VycHNhY2UKPiA+IHRvIGF0dGFjaCBhIGZyZWUtZm9ybSBuYW1lIGZvciB0cmFja2lu ZyBhbmQgY291bnRpbmcgc2hhcmVkCj4gPiBidWZmZXJzLiBIb3dldmVyIHRoZSBkX2RuYW1lIGNh bGxiYWNrIGNvdWxkIGJlIGNhbGxlZCBpbiBhdG9taWMKPiA+IGNvbnRleHQuIFRoaXMgY2FsbCBw YXRoIGNvbWVzIGZyb20gc2VsaW51eCB0aGF0IHZlcmlmaWVzIGFsbAo+ID4gaW5oZXJpdGVkIG9w ZW4gZmlsZXMgZnJvbSBleGVjIGNhbGwuIFRvIHZlcmlmeSBhbGwgaW5oZXJpdGVkCj4gPiBvcGVu IGZpbGVzLCBrZXJuZWwgd291bGQgaXRlcmF0ZSBhbGwgZmRzIHdoaWNoIG5lZWQgdG8gaG9sZAo+ ID4gc3Bpbl9sb2NrIHRvIGdldCBkZW50eSBuYW1lIGJ5IGNhbGxpbmcgZF9kbmFtZSBvcGVyYXRp b24uCj4gPiBJbiBkbWEtYnVmIGRfZG5hbWUgY2FsbGJhY2ssIHdlIHVzZSBtdXRleCBsb2NrIHRv IHByZXZlbnQgdGhlCj4gPiByYWNlIGZyb20gc2V0bmFtZSBjYXVzaW5nIHRoaXMgaXNzdWUuCj4g Pgo+ID4gVGhpcyBjb21taXQgYWRkcyBhIHNwaW5sb2NrIHRvIHByb3RlY3Qgc2V0L2dldCBuYW1l IG9wZXJhdGlvbgo+ID4gdG8gZml4IHRoaXMgaXNzdWUuCj4gPgo+ID4gWyAgMTY1LjYxNzA5MF0g Q2FsbCB0cmFjZToKPiA+IFsgIDE2NS42MjA1MDRdICBfX19taWdodF9zbGVlcCsweDExNC8weDEx OAo+ID4gWyAgMTY1LjYyNTM0NF0gIF9fbWlnaHRfc2xlZXArMHg1MC8weDg0Cj4gPiBbICAxNjUu NjI5OTI4XSAgX19tdXRleF9sb2NrX2NvbW1vbisweDVjLzB4MTBiMAo+ID4gWyAgMTY1LjYzNTIx NV0gIG11dGV4X2xvY2tfbmVzdGVkKzB4NDAvMHg1MAo+ID4gWyAgMTY1LjY0MDE1N10gIGRtYWJ1 ZmZzX2RuYW1lKzB4NDgvMHhkYwo+ID4gWyAgMTY1LjY0NDgyMV0gIGRfcGF0aCsweDc4LzB4MWU0 Cj4gPiBbICAxNjUuNjQ4ODcwXSAgYXVkaXRfbG9nX2RfcGF0aCsweDY4LzB4MTM0Cj4gPiBbICAx NjUuNjUzODA3XSAgY29tbW9uX2xzbV9hdWRpdCsweDMzYy8weDZmNAo+ID4gWyAgMTY1LjY1ODgz Ml0gIHNsb3dfYXZjX2F1ZGl0KzB4YjQvMHhmMAo+ID4gWyAgMTY1LjY2MzUwM10gIGF2Y19oYXNf cGVybSsweGRjLzB4MWE0Cj4gPiBbICAxNjUuNjY4MDgxXSAgZmlsZV9oYXNfcGVybSsweDcwLzB4 MTU0Cj4gPiBbICAxNjUuNjcyNzUwXSAgbWF0Y2hfZmlsZSsweDU0LzB4NmMKPiA+IFsgIDE2NS42 NzcwNjRdICBpdGVyYXRlX2ZkKzB4NzQvMHhhYwo+ID4gWyAgMTY1LjY4MTM2OV0gIHNlbGludXhf YnBybV9jb21taXR0aW5nX2NyZWRzKzB4ZmMvMHgyMTAKPiA+IFsgIDE2NS42ODc0NTldICBzZWN1 cml0eV9icHJtX2NvbW1pdHRpbmdfY3JlZHMrMHgyYy8weDQwCj4gPiBbICAxNjUuNjkzNTQ2XSAg aW5zdGFsbF9leGVjX2NyZWRzKzB4MWMvMHg2OAo+ID4gWyAgMTY1LjY5ODU2OV0gIGxvYWRfZWxm X2JpbmFyeSsweDNhMC8weDEzYzgKPiA+IFsgIDE2NS43MDM1OTBdICBzZWFyY2hfYmluYXJ5X2hh bmRsZXIrMHhiOC8weDFlNAo+ID4gWyAgMTY1LjcwODk2NF0gIF9fZG9fZXhlY3ZlX2ZpbGUrMHg2 ZTQvMHg5YzgKPiA+IFsgIDE2NS43MTM5ODRdICBfX2FybTY0X3N5c19leGVjdmUrMHg0NC8weDU0 Cj4gPiBbICAxNjUuNzE5MDA4XSAgZWwwX3N2Y19jb21tb24rMHhhOC8weDE2OAo+ID4gWyAgMTY1 LjcyMzc2NV0gIGVsMF9zdmNfaGFuZGxlcisweDc4LzB4OTQKPiA+IFsgIDE2NS43Mjg1MjJdICBl bDBfc3ZjKzB4OC8weGMKPiA+Cj4gPiBTaWduZWQtb2ZmLWJ5OiBNYXJ0aW4gTGl1IDxsaXVtYXJ0 aW5AZ29vZ2xlLmNvbT4KPiA+IC0tLQo+ID4gIGRyaXZlcnMvZG1hLWJ1Zi9kbWEtYnVmLmMgfCAx MSArKysrKysrLS0tLQo+ID4gIGluY2x1ZGUvbGludXgvZG1hLWJ1Zi5oICAgfCAgMiArKwo+ID4g IDIgZmlsZXMgY2hhbmdlZCwgOSBpbnNlcnRpb25zKCspLCA0IGRlbGV0aW9ucygtKQo+ID4KPiA+ IGRpZmYgLS1naXQgYS9kcml2ZXJzL2RtYS1idWYvZG1hLWJ1Zi5jIGIvZHJpdmVycy9kbWEtYnVm L2RtYS1idWYuYwo+ID4gaW5kZXggY2U0MWNkOWI3NThhLi43Y2JjYjIyYWQwZTQgMTAwNjQ0Cj4g PiAtLS0gYS9kcml2ZXJzL2RtYS1idWYvZG1hLWJ1Zi5jCj4gPiArKysgYi9kcml2ZXJzL2RtYS1i dWYvZG1hLWJ1Zi5jCj4gPiBAQCAtNDUsMTAgKzQ1LDEwIEBAIHN0YXRpYyBjaGFyICpkbWFidWZm c19kbmFtZShzdHJ1Y3QgZGVudHJ5ICpkZW50cnksIGNoYXIgKmJ1ZmZlciwgaW50IGJ1ZmxlbikK PiA+ICAgICAgICAgc2l6ZV90IHJldCA9IDA7Cj4gPgo+ID4gICAgICAgICBkbWFidWYgPSBkZW50 cnktPmRfZnNkYXRhOwo+ID4gLSAgICAgICBkbWFfcmVzdl9sb2NrKGRtYWJ1Zi0+cmVzdiwgTlVM TCk7Cj4gPiArICAgICAgIHNwaW5fbG9jaygmZG1hYnVmLT5uYW1lX2xvY2spOwo+ID4gICAgICAg ICBpZiAoZG1hYnVmLT5uYW1lKQo+ID4gICAgICAgICAgICAgICAgIHJldCA9IHN0cmxjcHkobmFt ZSwgZG1hYnVmLT5uYW1lLCBETUFfQlVGX05BTUVfTEVOKTsKPiA+IC0gICAgICAgZG1hX3Jlc3Zf dW5sb2NrKGRtYWJ1Zi0+cmVzdik7Cj4gPiArICAgICAgIHNwaW5fdW5sb2NrKCZkbWFidWYtPm5h bWVfbG9jayk7Cj4gPgo+ID4gICAgICAgICByZXR1cm4gZHluYW1pY19kbmFtZShkZW50cnksIGJ1 ZmZlciwgYnVmbGVuLCAiLyVzOiVzIiwKPiA+ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg ZGVudHJ5LT5kX25hbWUubmFtZSwgcmV0ID4gMCA/IG5hbWUgOiAiIik7Cj4gPiBAQCAtMzM1LDYg KzMzNSw3IEBAIHN0YXRpYyBsb25nIGRtYV9idWZfc2V0X25hbWUoc3RydWN0IGRtYV9idWYgKmRt YWJ1ZiwgY29uc3QgY2hhciBfX3VzZXIgKmJ1ZikKPiA+ICAgICAgICAgICAgICAgICByZXR1cm4g UFRSX0VSUihuYW1lKTsKPiA+Cj4gPiAgICAgICAgIGRtYV9yZXN2X2xvY2soZG1hYnVmLT5yZXN2 LCBOVUxMKTsKPiA+ICsgICAgICAgc3Bpbl9sb2NrKCZkbWFidWYtPm5hbWVfbG9jayk7Cj4gPiAg ICAgICAgIGlmICghbGlzdF9lbXB0eSgmZG1hYnVmLT5hdHRhY2htZW50cykpIHsKPiA+ICAgICAg ICAgICAgICAgICByZXQgPSAtRUJVU1k7Cj4gPiAgICAgICAgICAgICAgICAga2ZyZWUobmFtZSk7 Cj4gPiBAQCAtMzQ0LDYgKzM0NSw3IEBAIHN0YXRpYyBsb25nIGRtYV9idWZfc2V0X25hbWUoc3Ry dWN0IGRtYV9idWYgKmRtYWJ1ZiwgY29uc3QgY2hhciBfX3VzZXIgKmJ1ZikKPiA+ICAgICAgICAg ZG1hYnVmLT5uYW1lID0gbmFtZTsKPiA+Cj4gPiAgb3V0X3VubG9jazoKPiA+ICsgICAgICAgc3Bp bl91bmxvY2soJmRtYWJ1Zi0+bmFtZV9sb2NrKTsKPiA+ICAgICAgICAgZG1hX3Jlc3ZfdW5sb2Nr KGRtYWJ1Zi0+cmVzdik7Cj4gPiAgICAgICAgIHJldHVybiByZXQ7Cj4gPiAgfQo+ID4gQEAgLTQw MywxMCArNDA1LDEwIEBAIHN0YXRpYyB2b2lkIGRtYV9idWZfc2hvd19mZGluZm8oc3RydWN0IHNl cV9maWxlICptLCBzdHJ1Y3QgZmlsZSAqZmlsZSkKPiA+ICAgICAgICAgLyogRG9uJ3QgY291bnQg dGhlIHRlbXBvcmFyeSByZWZlcmVuY2UgdGFrZW4gaW5zaWRlIHByb2NmcyBzZXFfc2hvdyAqLwo+ ID4gICAgICAgICBzZXFfcHJpbnRmKG0sICJjb3VudDpcdCVsZFxuIiwgZmlsZV9jb3VudChkbWFi dWYtPmZpbGUpIC0gMSk7Cj4gPiAgICAgICAgIHNlcV9wcmludGYobSwgImV4cF9uYW1lOlx0JXNc biIsIGRtYWJ1Zi0+ZXhwX25hbWUpOwo+ID4gLSAgICAgICBkbWFfcmVzdl9sb2NrKGRtYWJ1Zi0+ cmVzdiwgTlVMTCk7Cj4gPiArICAgICAgIHNwaW5fbG9jaygmZG1hYnVmLT5uYW1lX2xvY2spOwo+ ID4gICAgICAgICBpZiAoZG1hYnVmLT5uYW1lKQo+ID4gICAgICAgICAgICAgICAgIHNlcV9wcmlu dGYobSwgIm5hbWU6XHQlc1xuIiwgZG1hYnVmLT5uYW1lKTsKPiA+IC0gICAgICAgZG1hX3Jlc3Zf dW5sb2NrKGRtYWJ1Zi0+cmVzdik7Cj4gPiArICAgICAgIHNwaW5fdW5sb2NrKCZkbWFidWYtPm5h bWVfbG9jayk7Cj4gPiAgfQo+ID4KPiA+ICBzdGF0aWMgY29uc3Qgc3RydWN0IGZpbGVfb3BlcmF0 aW9ucyBkbWFfYnVmX2ZvcHMgPSB7Cj4gPiBAQCAtNTYxLDYgKzU2Myw3IEBAIHN0cnVjdCBkbWFf YnVmICpkbWFfYnVmX2V4cG9ydChjb25zdCBzdHJ1Y3QgZG1hX2J1Zl9leHBvcnRfaW5mbyAqZXhw X2luZm8pCj4gPiAgICAgICAgIGRtYWJ1Zi0+ZmlsZSA9IGZpbGU7Cj4gPgo+ID4gICAgICAgICBt dXRleF9pbml0KCZkbWFidWYtPmxvY2spOwo+ID4gKyAgICAgICBzcGluX2xvY2tfaW5pdCgmZG1h YnVmLT5uYW1lX2xvY2spOwo+ID4gICAgICAgICBJTklUX0xJU1RfSEVBRCgmZG1hYnVmLT5hdHRh Y2htZW50cyk7Cj4gPgo+ID4gICAgICAgICBtdXRleF9sb2NrKCZkYl9saXN0LmxvY2spOwo+ID4g ZGlmZiAtLWdpdCBhL2luY2x1ZGUvbGludXgvZG1hLWJ1Zi5oIGIvaW5jbHVkZS9saW51eC9kbWEt YnVmLmgKPiA+IGluZGV4IGFmNzNmODM1YzUxYy4uMWIxMzg1ODBmNzQ2IDEwMDY0NAo+ID4gLS0t IGEvaW5jbHVkZS9saW51eC9kbWEtYnVmLmgKPiA+ICsrKyBiL2luY2x1ZGUvbGludXgvZG1hLWJ1 Zi5oCj4gPiBAQCAtMjkyLDYgKzI5Miw3IEBAIHN0cnVjdCBkbWFfYnVmX29wcyB7Cj4gPiAgICog QGV4cF9uYW1lOiBuYW1lIG9mIHRoZSBleHBvcnRlcjsgdXNlZnVsIGZvciBkZWJ1Z2dpbmcuCj4g PiAgICogQG5hbWU6IHVzZXJzcGFjZS1wcm92aWRlZCBuYW1lOyB1c2VmdWwgZm9yIGFjY291bnRp bmcgYW5kIGRlYnVnZ2luZywKPiA+ICAgKiAgICAgICAgcHJvdGVjdGVkIGJ5IEByZXN2Lgo+ID4g KyAqIEBuYW1lX2xvY2s6IGxvY2sgdG8gcHJvdGVjdCBuYW1lLgo+ID4gICAqIEBvd25lcjogcG9p bnRlciB0byBleHBvcnRlciBtb2R1bGU7IHVzZWQgZm9yIHJlZmNvdW50aW5nIHdoZW4gZXhwb3J0 ZXIgaXMgYQo+ID4gICAqICAgICAgICAga2VybmVsIG1vZHVsZS4KPiA+ICAgKiBAbGlzdF9ub2Rl OiBub2RlIGZvciBkbWFfYnVmIGFjY291bnRpbmcgYW5kIGRlYnVnZ2luZy4KPiA+IEBAIC0zMjAs NiArMzIxLDcgQEAgc3RydWN0IGRtYV9idWYgewo+ID4gICAgICAgICB2b2lkICp2bWFwX3B0cjsK PiA+ICAgICAgICAgY29uc3QgY2hhciAqZXhwX25hbWU7Cj4gPiAgICAgICAgIGNvbnN0IGNoYXIg Km5hbWU7Cj4gPiArICAgICAgIHNwaW5sb2NrX3QgbmFtZV9sb2NrOwo+ID4gICAgICAgICBzdHJ1 Y3QgbW9kdWxlICpvd25lcjsKPiA+ICAgICAgICAgc3RydWN0IGxpc3RfaGVhZCBsaXN0X25vZGU7 Cj4gPiAgICAgICAgIHZvaWQgKnByaXY7Cj4gPiAtLQo+ID4gMi4yNS4wLnJjMS4yODMuZzg4ZGZk YzQxOTMtZ29vZwo+ID4KPiAKPiAKPiAtLSAKPiBUaGFua3MgYW5kIHJlZ2FyZHMsCj4gCj4gU3Vt aXQgU2Vtd2FsCj4gTGluYXJvIENvbnN1bWVyIEdyb3VwIC0gS2VybmVsIFRlYW0gTGVhZAo+IExp bmFyby5vcmcg4pSCIE9wZW4gc291cmNlIHNvZnR3YXJlIGZvciBBUk0gU29DcwpfX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBs aXN0CmRyaS1kZXZlbEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVz a3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWwK 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=-14.1 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL 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 180D5C35641 for ; Mon, 24 Feb 2020 03:29:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DAB44206E0 for ; Mon, 24 Feb 2020 03:29:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vBCVXUj4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727210AbgBXD3H (ORCPT ); Sun, 23 Feb 2020 22:29:07 -0500 Received: from mail-pl1-f196.google.com ([209.85.214.196]:33233 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727158AbgBXD3E (ORCPT ); Sun, 23 Feb 2020 22:29:04 -0500 Received: by mail-pl1-f196.google.com with SMTP id ay11so3476816plb.0 for ; Sun, 23 Feb 2020 19:29:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=K0JW2EfFhuCbUtNkMo3m3FY0j1WPwSQhES6P2P+ACdw=; b=vBCVXUj4Pgidp3lXYVnC7n+3XRqhCoUXuj+3Uiqouorh0riEdjxWV17kshwmp8fkOR zUOBgK7+2al1nxKWGr4NHPQlfaAdITZLKAAfi0koYPp/EPCuIYkDU8yKcFEf5HL5vvpu kmiyamt0Dfu3IstcTTZM+hVR0ZjKvyzuNTCZdYJGC1M6zR9t55Oph2TjJGfdxY2x92HF KrDXeaNKYYQdA5GbeLSYido7K555QXO5V2WPYQ3KkT2m36xS1GQ0ORbJPjeQztYyzwzx tPyDC5EHAvLh+aVsmthNgYTlNIu20vxW96GzHAzY30ysA6RuETjmF+XaX0ASmBXjiSYW B12Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=K0JW2EfFhuCbUtNkMo3m3FY0j1WPwSQhES6P2P+ACdw=; b=m6O5Up4fuipTj8gMss/RhrOQC6HRcOVo55iK8ZijTCZu3fpqcMXQazPPW/7SClKXdD /wR8GOqR0Z5Mm+gvzjDlR0nlZQcYtYlvrIxYfspdGFRCkJlkfK1V7C4YaiLVaGyyiBNn MdAsxsWRTyKofmuIwRRaHA9QCTmg3IacCCUUryeM5STMb477/tG+Mf9c0K++4K6m6/hm 32zKRS2xalZGiZ6XcHq+ez5JTx7KE2VNnAOmEN49sZM4F89v9vjJosOBnq2cjscyoKnp o/kiK+OmE8sw4RYjVsqMvqTjXpaVzjJD8Advf+t2nKu1O+XX2s95BwJ2SrPuB4y0MOId 24ZA== X-Gm-Message-State: APjAAAXme30uLGmRViNsEjLi+ajMaYjmTNxLSnt0belQLs73/iT2RvKV 7gb6eYmihDZFKJWDWmAeiIoY6g== X-Google-Smtp-Source: APXvYqztxRjiovsa78Cv3oB8wD+gtm1MQM6nFAf7AeO8HF1kElzb/LH7H2rVLKYsJDh9HXcKRSrv5A== X-Received: by 2002:a17:902:103:: with SMTP id 3mr48206826plb.34.1582514941893; Sun, 23 Feb 2020 19:29:01 -0800 (PST) Received: from google.com ([2401:fa00:fc:1:28b:9f23:d296:c845]) by smtp.gmail.com with ESMTPSA id r7sm10870261pfg.34.2020.02.23.19.28.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 23 Feb 2020 19:29:01 -0800 (PST) Date: Mon, 24 Feb 2020 11:28:54 +0800 From: Martin Liu To: Sumit Semwal , minchan@kernel.org, surenb@google.com, wvw@google.com, hridya@google.com Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, liumartin@google.com, jenhaochen@google.com Subject: Re: [PATCH] dma-buf: use spinlock to protect set/get name operation Message-ID: <20200224032854.GA215090@google.com> References: <20200114150658.205302-1-liumartin@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Tue, Feb 18, 2020 at 12:05:53PM +0530, Sumit Semwal wrote: > Hello Martin, > > Thanks for your patches - they look decent. > > May I please request you to run get_maintainers.pl (the patches need > to be sent to a couple of other MLs too for wider review). > > Best, > Sumit. Sorry for the late reply. Sure, I will include more MLs for wider review. Thanks for the suggestion. > On Tue, 14 Jan 2020 at 20:37, Martin Liu wrote: > > > > We introduced setname ioctl in commit bb2bb9030425 ("dma-buf: > > add DMA_BUF_SET_NAME ioctls") that provides userpsace > > to attach a free-form name for tracking and counting shared > > buffers. However the d_dname callback could be called in atomic > > context. This call path comes from selinux that verifies all > > inherited open files from exec call. To verify all inherited > > open files, kernel would iterate all fds which need to hold > > spin_lock to get denty name by calling d_dname operation. > > In dma-buf d_dname callback, we use mutex lock to prevent the > > race from setname causing this issue. > > > > This commit adds a spinlock to protect set/get name operation > > to fix this issue. > > > > [ 165.617090] Call trace: > > [ 165.620504] ___might_sleep+0x114/0x118 > > [ 165.625344] __might_sleep+0x50/0x84 > > [ 165.629928] __mutex_lock_common+0x5c/0x10b0 > > [ 165.635215] mutex_lock_nested+0x40/0x50 > > [ 165.640157] dmabuffs_dname+0x48/0xdc > > [ 165.644821] d_path+0x78/0x1e4 > > [ 165.648870] audit_log_d_path+0x68/0x134 > > [ 165.653807] common_lsm_audit+0x33c/0x6f4 > > [ 165.658832] slow_avc_audit+0xb4/0xf0 > > [ 165.663503] avc_has_perm+0xdc/0x1a4 > > [ 165.668081] file_has_perm+0x70/0x154 > > [ 165.672750] match_file+0x54/0x6c > > [ 165.677064] iterate_fd+0x74/0xac > > [ 165.681369] selinux_bprm_committing_creds+0xfc/0x210 > > [ 165.687459] security_bprm_committing_creds+0x2c/0x40 > > [ 165.693546] install_exec_creds+0x1c/0x68 > > [ 165.698569] load_elf_binary+0x3a0/0x13c8 > > [ 165.703590] search_binary_handler+0xb8/0x1e4 > > [ 165.708964] __do_execve_file+0x6e4/0x9c8 > > [ 165.713984] __arm64_sys_execve+0x44/0x54 > > [ 165.719008] el0_svc_common+0xa8/0x168 > > [ 165.723765] el0_svc_handler+0x78/0x94 > > [ 165.728522] el0_svc+0x8/0xc > > > > Signed-off-by: Martin Liu > > --- > > drivers/dma-buf/dma-buf.c | 11 +++++++---- > > include/linux/dma-buf.h | 2 ++ > > 2 files changed, 9 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > > index ce41cd9b758a..7cbcb22ad0e4 100644 > > --- a/drivers/dma-buf/dma-buf.c > > +++ b/drivers/dma-buf/dma-buf.c > > @@ -45,10 +45,10 @@ static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen) > > size_t ret = 0; > > > > dmabuf = dentry->d_fsdata; > > - dma_resv_lock(dmabuf->resv, NULL); > > + spin_lock(&dmabuf->name_lock); > > if (dmabuf->name) > > ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN); > > - dma_resv_unlock(dmabuf->resv); > > + spin_unlock(&dmabuf->name_lock); > > > > return dynamic_dname(dentry, buffer, buflen, "/%s:%s", > > dentry->d_name.name, ret > 0 ? name : ""); > > @@ -335,6 +335,7 @@ static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) > > return PTR_ERR(name); > > > > dma_resv_lock(dmabuf->resv, NULL); > > + spin_lock(&dmabuf->name_lock); > > if (!list_empty(&dmabuf->attachments)) { > > ret = -EBUSY; > > kfree(name); > > @@ -344,6 +345,7 @@ static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) > > dmabuf->name = name; > > > > out_unlock: > > + spin_unlock(&dmabuf->name_lock); > > dma_resv_unlock(dmabuf->resv); > > return ret; > > } > > @@ -403,10 +405,10 @@ static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file) > > /* Don't count the temporary reference taken inside procfs seq_show */ > > seq_printf(m, "count:\t%ld\n", file_count(dmabuf->file) - 1); > > seq_printf(m, "exp_name:\t%s\n", dmabuf->exp_name); > > - dma_resv_lock(dmabuf->resv, NULL); > > + spin_lock(&dmabuf->name_lock); > > if (dmabuf->name) > > seq_printf(m, "name:\t%s\n", dmabuf->name); > > - dma_resv_unlock(dmabuf->resv); > > + spin_unlock(&dmabuf->name_lock); > > } > > > > static const struct file_operations dma_buf_fops = { > > @@ -561,6 +563,7 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) > > dmabuf->file = file; > > > > mutex_init(&dmabuf->lock); > > + spin_lock_init(&dmabuf->name_lock); > > INIT_LIST_HEAD(&dmabuf->attachments); > > > > mutex_lock(&db_list.lock); > > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > > index af73f835c51c..1b138580f746 100644 > > --- a/include/linux/dma-buf.h > > +++ b/include/linux/dma-buf.h > > @@ -292,6 +292,7 @@ struct dma_buf_ops { > > * @exp_name: name of the exporter; useful for debugging. > > * @name: userspace-provided name; useful for accounting and debugging, > > * protected by @resv. > > + * @name_lock: lock to protect name. > > * @owner: pointer to exporter module; used for refcounting when exporter is a > > * kernel module. > > * @list_node: node for dma_buf accounting and debugging. > > @@ -320,6 +321,7 @@ struct dma_buf { > > void *vmap_ptr; > > const char *exp_name; > > const char *name; > > + spinlock_t name_lock; > > struct module *owner; > > struct list_head list_node; > > void *priv; > > -- > > 2.25.0.rc1.283.g88dfdc4193-goog > > > > > -- > Thanks and regards, > > Sumit Semwal > Linaro Consumer Group - Kernel Team Lead > Linaro.org │ Open source software for ARM SoCs