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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46E61C6FD1A for ; Tue, 7 Mar 2023 17:49:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231859AbjCGRtJ (ORCPT ); Tue, 7 Mar 2023 12:49:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232102AbjCGRsW (ORCPT ); Tue, 7 Mar 2023 12:48:22 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C398088896 for ; Tue, 7 Mar 2023 09:43:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B7D1EB818F6 for ; Tue, 7 Mar 2023 17:42:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35A8AC433D2; Tue, 7 Mar 2023 17:42:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678210974; bh=IBCkHIpZeDJTFn+mUBCsEZmhHXCuKQdybjKciyxdnaA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JlaPr4AcfnnXhsp0wVa15+oLH7E52Ed2iVOe58tT0tTLQ1NWnZOnu8Mug2NfB/wwb 7hnBJeAl6BmzxUwxDJuydlUjIVYV1oao0riisWjp31PZ4ucoF3ZSeNlWAFud7/eca8 UYL6Pgf/8IjGcFrMsgMckKI5hixG9x2gqYL28jO8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, farah kassabri , Oded Gabbay , Sasha Levin Subject: [PATCH 6.2 0714/1001] habanalabs: fix bug in timestamps registration code Date: Tue, 7 Mar 2023 17:58:06 +0100 Message-Id: <20230307170052.629973856@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: farah kassabri [ Upstream commit ac5af9900f82b7034de7c9eb1d70d030ba325607 ] Protect re-using the same timestamp buffer record before actually adding it to the to interrupt wait list. Mark ts buff offset as in use in the spinlock protection area of the interrupt wait list to avoid getting in the re-use section in ts_buff_get_kernel_ts_record before adding the node to the list. this scenario might happen when multiple threads are racing on same offset and one thread could set data in the ts buff in ts_buff_get_kernel_ts_record then the other thread takes over and get to ts_buff_get_kernel_ts_record and we will try to re-use the same ts buff offset then we will try to delete a non existing node from the list. Signed-off-by: farah kassabri Reviewed-by: Oded Gabbay Signed-off-by: Oded Gabbay Signed-off-by: Sasha Levin --- .../habanalabs/common/command_submission.c | 33 ++++++++++++------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c index ea0e5101c10ed..6367cbea4ca2a 100644 --- a/drivers/misc/habanalabs/common/command_submission.c +++ b/drivers/misc/habanalabs/common/command_submission.c @@ -3119,19 +3119,18 @@ static int ts_buff_get_kernel_ts_record(struct hl_mmap_mem_buf *buf, goto start_over; } } else { + /* Fill up the new registration node info */ + requested_offset_record->ts_reg_info.buf = buf; + requested_offset_record->ts_reg_info.cq_cb = cq_cb; + requested_offset_record->ts_reg_info.timestamp_kernel_addr = + (u64 *) ts_buff->user_buff_address + ts_offset; + requested_offset_record->cq_kernel_addr = + (u64 *) cq_cb->kernel_address + cq_offset; + requested_offset_record->cq_target_value = target_value; + spin_unlock_irqrestore(wait_list_lock, flags); } - /* Fill up the new registration node info */ - requested_offset_record->ts_reg_info.in_use = 1; - requested_offset_record->ts_reg_info.buf = buf; - requested_offset_record->ts_reg_info.cq_cb = cq_cb; - requested_offset_record->ts_reg_info.timestamp_kernel_addr = - (u64 *) ts_buff->user_buff_address + ts_offset; - requested_offset_record->cq_kernel_addr = - (u64 *) cq_cb->kernel_address + cq_offset; - requested_offset_record->cq_target_value = target_value; - *pend = requested_offset_record; dev_dbg(buf->mmg->dev, "Found available node in TS kernel CB %p\n", @@ -3179,7 +3178,7 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, goto put_cq_cb; } - /* Find first available record */ + /* get ts buffer record */ rc = ts_buff_get_kernel_ts_record(buf, cq_cb, ts_offset, cq_counters_offset, target_value, &interrupt->wait_list_lock, &pend); @@ -3227,7 +3226,19 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, * Note that we cannot have sorted list by target value, * in order to shorten the list pass loop, since * same list could have nodes for different cq counter handle. + * Note: + * Mark ts buff offset as in use here in the spinlock protection area + * to avoid getting in the re-use section in ts_buff_get_kernel_ts_record + * before adding the node to the list. this scenario might happen when + * multiple threads are racing on same offset and one thread could + * set the ts buff in ts_buff_get_kernel_ts_record then the other thread + * takes over and get to ts_buff_get_kernel_ts_record and then we will try + * to re-use the same ts buff offset, and will try to delete a non existing + * node from the list. */ + if (register_ts_record) + pend->ts_reg_info.in_use = 1; + list_add_tail(&pend->wait_list_node, &interrupt->wait_list_head); spin_unlock_irqrestore(&interrupt->wait_list_lock, flags); -- 2.39.2