From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1092440-1521804457-2-7448455865584460674 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES roen, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1521804456; b=Wy1DJNB41bv7SL1SQQ+Gv09JmnE8+87WN3WfIcF+2lp3uAI I6bTl16204k4KGqJ5Z9CJXl9oFe4sgadJ1cO4luD498sx7QJQ17zIV4LvglrH/Nm NQg/YcEkJryDXOujgpHsHAfI5B5rLmbzRrDKDqGHOvZNiOdhe0WQOg7JDbFrxhrx o5L9TMAT8h5uOpuLAiWm+n3UP7BsEtWPnl9MZYXYMqGNPfJrHgXQrvLpQwPWzgRi oKZ0sSB36FPcjds12xJornuMvZq71Kh97qy/wedGMhmnm+g4gA9/zANK/GGJO3jz 8QtYQS9FegCOv3Vu+6PNwlQCdywM4qu8KwvB7xw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1521804456; bh=8/tfImPPqnb7k5Pwsu3h0oiT1W EkejlHWo7zpN3lkPg=; b=o3TmV7sk64AVE67DyT5js+iUE6JThs8JKELu2dMDCK dJLHj9mlMXeOkokTRiTxVDflBdltAawUfMgLc4Cgzt2BSz2xgw9JrlhxQWTyn0xC 8jXp6Os00dCJdIKIGGp5Ru+zC/RVtJgXr6ErS9JdH2tNs1uLRtTsPxFl0zGSnvs9 5pl+Iaq3UWInmor2muQs6KrMO13NXFPxnTy5VaPIyEz4uvbu9DQxlDWw9D6bL9wn DGPj2zYGr1lBqgMshNMkTFRYDeTVu4rI6r1zbxVeSEIrykCjuJzzG8RUUkZEYvSi bmFer64u1AEe/1o2mSvKhiPe0Y/lkH15Q46h9raYVQPw== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932326AbeCWKHE (ORCPT ); Fri, 23 Mar 2018 06:07:04 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41068 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932312AbeCWKHA (ORCPT ); Fri, 23 Mar 2018 06:07:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Finn Thain , Michael Schmitz , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.9 067/177] scsi: mac_esp: Replace bogus memory barrier with spinlock Date: Fri, 23 Mar 2018 10:53:15 +0100 Message-Id: <20180323094208.286238281@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180323094205.090519271@linuxfoundation.org> References: <20180323094205.090519271@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Finn Thain [ Upstream commit 4da2b1eb230ba4ad19b58984dc52e05b1073df5f ] Commit da244654c66e ("[SCSI] mac_esp: fix for quadras with two esp chips") added mac_scsi_esp_intr() to handle the IRQ lines from a pair of on-board ESP chips (a normal shared IRQ did not work). Proper mutual exclusion was missing from that patch. This patch fixes race conditions between comparison and assignment of esp_chips[] pointers. Signed-off-by: Finn Thain Reviewed-by: Michael Schmitz Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/mac_esp.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) --- a/drivers/scsi/mac_esp.c +++ b/drivers/scsi/mac_esp.c @@ -55,6 +55,7 @@ struct mac_esp_priv { int error; }; static struct esp *esp_chips[2]; +static DEFINE_SPINLOCK(esp_chips_lock); #define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \ platform_get_drvdata((struct platform_device *) \ @@ -562,15 +563,18 @@ static int esp_mac_probe(struct platform } host->irq = IRQ_MAC_SCSI; - esp_chips[dev->id] = esp; - mb(); - if (esp_chips[!dev->id] == NULL) { - err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL); - if (err < 0) { - esp_chips[dev->id] = NULL; - goto fail_free_priv; - } + + /* The request_irq() call is intended to succeed for the first device + * and fail for the second device. + */ + err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL); + spin_lock(&esp_chips_lock); + if (err < 0 && esp_chips[!dev->id] == NULL) { + spin_unlock(&esp_chips_lock); + goto fail_free_priv; } + esp_chips[dev->id] = esp; + spin_unlock(&esp_chips_lock); err = scsi_esp_register(esp, &dev->dev); if (err) @@ -579,8 +583,13 @@ static int esp_mac_probe(struct platform return 0; fail_free_irq: - if (esp_chips[!dev->id] == NULL) + spin_lock(&esp_chips_lock); + esp_chips[dev->id] = NULL; + if (esp_chips[!dev->id] == NULL) { + spin_unlock(&esp_chips_lock); free_irq(host->irq, esp); + } else + spin_unlock(&esp_chips_lock); fail_free_priv: kfree(mep); fail_free_command_block: @@ -599,9 +608,13 @@ static int esp_mac_remove(struct platfor scsi_esp_unregister(esp); + spin_lock(&esp_chips_lock); esp_chips[dev->id] = NULL; - if (!(esp_chips[0] || esp_chips[1])) + if (esp_chips[!dev->id] == NULL) { + spin_unlock(&esp_chips_lock); free_irq(irq, NULL); + } else + spin_unlock(&esp_chips_lock); kfree(mep);