From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16F903A8C5; Fri, 24 Nov 2023 18:19:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xK3JP9z+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97E38C433C7; Fri, 24 Nov 2023 18:19:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700849947; bh=7sW12M0f93ur9WkRiQoUD1d1R8qzcAQsYF5APDVe/00=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xK3JP9z+eAskICRPaS4uRjUFXQ+zeE2mJzmtRivkdbRC6HW7WQiHcJRC5cCiok29v G31z9UJGx/1jcoxdj31YX5HTsn4z0+mSb+ruZYOgQp+fILwmpjOy5NiHZGlsk8rftn LoU4Leb6uVzVnm5qgnXwbM2grJYLZvaSRTTIPrmc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jim Harris , Jonathan Cameron , Dan Carpenter , Dave Jiang , Dan Williams Subject: [PATCH 6.6 385/530] cxl/region: Do not try to cleanup after cxl_region_setup_targets() fails Date: Fri, 24 Nov 2023 17:49:11 +0000 Message-ID: <20231124172039.738273256@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124172028.107505484@linuxfoundation.org> References: <20231124172028.107505484@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jim Harris commit 0718588c7aaa7a1510b4de972370535b61dddd0d upstream. Commit 5e42bcbc3fef ("cxl/region: decrement ->nr_targets on error in cxl_region_attach()") tried to avoid 'eiw' initialization errors when ->nr_targets exceeded 16, by just decrementing ->nr_targets when cxl_region_setup_targets() failed. Commit 86987c766276 ("cxl/region: Cleanup target list on attach error") extended that cleanup to also clear cxled->pos and p->targets[pos]. The initialization error was incidentally fixed separately by: Commit 8d4285425714 ("cxl/region: Fix port setup uninitialized variable warnings") which was merged a few days after 5e42bcbc3fef. But now the original cleanup when cxl_region_setup_targets() fails prevents endpoint and switch decoder resources from being reused: 1) the cleanup does not set the decoder's region to NULL, which results in future dpa_size_store() calls returning -EBUSY 2) the decoder is not properly freed, which results in future commit errors associated with the upstream switch Now that the initialization errors were fixed separately, the proper cleanup for this case is to just return immediately. Then the resources associated with this target get cleanup up as normal when the failed region is deleted. The ->nr_targets decrement in the error case also helped prevent a p->targets[] array overflow, so add a new check to prevent against that overflow. Tested by trying to create an invalid region for a 2 switch * 2 endpoint topology, and then following up with creating a valid region. Fixes: 5e42bcbc3fef ("cxl/region: decrement ->nr_targets on error in cxl_region_attach()") Cc: Signed-off-by: Jim Harris Reviewed-by: Jonathan Cameron Acked-by: Dan Carpenter Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/169703589120.1202031.14696100866518083806.stgit@bgt-140510-bm03.eng.stellus.in Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- drivers/cxl/core/region.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1675,6 +1675,12 @@ static int cxl_region_attach(struct cxl_ return -ENXIO; } + if (p->nr_targets >= p->interleave_ways) { + dev_dbg(&cxlr->dev, "region already has %d endpoints\n", + p->nr_targets); + return -EINVAL; + } + ep_port = cxled_to_port(cxled); root_port = cxlrd_to_port(cxlrd); dport = cxl_find_dport_by_dev(root_port, ep_port->host_bridge); @@ -1767,7 +1773,7 @@ static int cxl_region_attach(struct cxl_ if (p->nr_targets == p->interleave_ways) { rc = cxl_region_setup_targets(cxlr); if (rc) - goto err_decrement; + return rc; p->state = CXL_CONFIG_ACTIVE; } @@ -1799,12 +1805,6 @@ static int cxl_region_attach(struct cxl_ } return 0; - -err_decrement: - p->nr_targets--; - cxled->pos = -1; - p->targets[pos] = NULL; - return rc; } static int cxl_region_detach(struct cxl_endpoint_decoder *cxled)