From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuZj02+Ro03ad1bQzULFmrXfOT6kKfcn+2ANsfXSsZBSbMNEdgLdYxi/mqBa37qhkj9uGtF ARC-Seal: i=1; a=rsa-sha256; t=1520954970; cv=none; d=google.com; s=arc-20160816; b=gdGRbZe+eOSc9+PNrKHMRDj3nbBppnv5pO6CqTUSeI2jHjfEjklUkGTtkA6zpevTGU owStXMPkg/3NQcdKzsvQPUbcDBHrTYbPkVz7b3ZFoGWMwfs6aGBg2sWBi0N2rQKwSXoR KeIl/hbAboDxSR7qXk6Puf9XasgG+7WYY/PVzKLUZao7u0mTgknpFn/mWj5VnjOz6dc2 F9rMAgCEPfyVhBgyAUVkr8HGp4/uPXCd5b0WbXk9mMRBgdwQKnEUX704HZnGCXRCH+Eb HGLQZdmPb4lekVa428y9VPmB1XIs0MtH7Ui+Qs+rBBlfz3iw2rCdHdcZWuqDuysQdbEO gCoA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=9WxqrN3uqxfaSl6bdEUWPkaJqaZf1mPFMucLrYroSwk=; b=rlr1ZAAVTM3t4dVDm0oQV2UlipTGofIAJGR/W1tgcp2F25WnHhbUZG9ANDXy3fiUnn kuDMFsOO4AGrMos6JxBNoUUxyLqL4K/gBDEf5hpAzosLgOWrperArqPDOs9rP/Vy0ve9 4Im2vyjVS0S1Wp2H5Jo5wZDpUQa8Y7x7/yoNe8QVofZzO9UgjCxv99cDvp5fxVv0fERu ZBtGKWbiNchuO2Dl65SMdmju6eAfBxBuerZ5ybbMiHec3TjFRE/5jQ11+bmPoLTDBsun RRWhTo3W/1JGmqemSH3NvBLsjUe020tBqmTHZJaurUeiky+D5PTutnKn+TXZpk0f+S/I VB1w== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Natanael Copa , Damien Le Moal , Bart Van Assche , Alexandre Oliva , Pavel Tikhomirov , Hannes Reinecke , Johannes Thumshirn , "Martin K. Petersen" Subject: [PATCH 4.15 017/146] scsi: core: Avoid that ATA error handling can trigger a kernel hang or oops Date: Tue, 13 Mar 2018 16:23:04 +0100 Message-Id: <20180313152321.845919842@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180313152320.439085687@linuxfoundation.org> References: <20180313152320.439085687@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1594836878897044643?= X-GMAIL-MSGID: =?utf-8?q?1594836878897044643?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 3be8828fc507cdafe7040a3dcf361a2bcd8e305b upstream. Avoid that the recently introduced call_rcu() call in the SCSI core triggers a double call_rcu() call. Reported-by: Natanael Copa Reported-by: Damien Le Moal References: https://bugzilla.kernel.org/show_bug.cgi?id=198861 Fixes: 3bd6f43f5cb3 ("scsi: core: Ensure that the SCSI error handler gets woken up") Signed-off-by: Bart Van Assche Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Cc: Natanael Copa Cc: Damien Le Moal Cc: Alexandre Oliva Cc: Pavel Tikhomirov Cc: Hannes Reinecke Cc: Johannes Thumshirn Cc: Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/hosts.c | 3 --- drivers/scsi/scsi_error.c | 5 +++-- drivers/scsi/scsi_lib.c | 2 ++ include/scsi/scsi_cmnd.h | 3 +++ include/scsi/scsi_host.h | 2 -- 5 files changed, 8 insertions(+), 7 deletions(-) --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -328,8 +328,6 @@ static void scsi_host_dev_release(struct if (shost->work_q) destroy_workqueue(shost->work_q); - destroy_rcu_head(&shost->rcu); - if (shost->shost_state == SHOST_CREATED) { /* * Free the shost_dev device name here if scsi_host_alloc() @@ -404,7 +402,6 @@ struct Scsi_Host *scsi_host_alloc(struct INIT_LIST_HEAD(&shost->starved_list); init_waitqueue_head(&shost->host_wait); mutex_init(&shost->scan_mutex); - init_rcu_head(&shost->rcu); index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); if (index < 0) --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -222,7 +222,8 @@ static void scsi_eh_reset(struct scsi_cm static void scsi_eh_inc_host_failed(struct rcu_head *head) { - struct Scsi_Host *shost = container_of(head, typeof(*shost), rcu); + struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu); + struct Scsi_Host *shost = scmd->device->host; unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); @@ -258,7 +259,7 @@ void scsi_eh_scmd_add(struct scsi_cmnd * * Ensure that all tasks observe the host state change before the * host_failed change. */ - call_rcu(&shost->rcu, scsi_eh_inc_host_failed); + call_rcu(&scmd->rcu, scsi_eh_inc_host_failed); } /** --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -670,6 +670,7 @@ static bool scsi_end_request(struct requ if (!blk_rq_is_scsi(req)) { WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED)); cmd->flags &= ~SCMD_INITIALIZED; + destroy_rcu_head(&cmd->rcu); } if (req->mq_ctx) { @@ -1150,6 +1151,7 @@ void scsi_initialize_rq(struct request * struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); scsi_req_init(&cmd->req); + init_rcu_head(&cmd->rcu); cmd->jiffies_at_alloc = jiffies; cmd->retries = 0; } --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -69,6 +69,9 @@ struct scsi_cmnd { struct list_head list; /* scsi_cmnd participates in queue lists */ struct list_head eh_entry; /* entry for the host eh_cmd_q */ struct delayed_work abort_work; + + struct rcu_head rcu; + int eh_eflags; /* Used by error handlr */ /* --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -571,8 +571,6 @@ struct Scsi_Host { struct blk_mq_tag_set tag_set; }; - struct rcu_head rcu; - atomic_t host_busy; /* commands actually active on low-level */ atomic_t host_blocked;