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 39F9422F1D; Fri, 24 Nov 2023 18:58:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zvo8K0tw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52250C433C8; Fri, 24 Nov 2023 18:58:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700852337; bh=6YLbCEG3+7wCgJYPmhtEiadT50uYh/IQKZfGyYYuObw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zvo8K0twjUvbbKhw2IgH6K7OogS4AX0i9J/WEVmHRg9PHg5cGoOHmoM6nvidw1R0t r2R0j8tRnz1ChxTTR27D6azLsenpbyD+X9ZFDmvCJMo1uaubs34UBGqSh2cVe7UJqM fDmx9lpDakAwFzwXTtHB3uc4cZ6sFWgBDDh8bniY= 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 , Sasha Levin Subject: [PATCH 6.1 298/372] cxl/region: Do not try to cleanup after cxl_region_setup_targets() fails Date: Fri, 24 Nov 2023 17:51:25 +0000 Message-ID: <20231124172020.362219786@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124172010.413667921@linuxfoundation.org> References: <20231124172010.413667921@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jim Harris [ Upstream commit 0718588c7aaa7a1510b4de972370535b61dddd0d ] 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: Sasha Levin --- drivers/cxl/core/region.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 1ee51327e989d..13b1b18612d3f 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1291,6 +1291,12 @@ static int cxl_region_attach(struct cxl_region *cxlr, 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); @@ -1339,7 +1345,7 @@ static int cxl_region_attach(struct cxl_region *cxlr, 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; } @@ -1351,12 +1357,6 @@ static int cxl_region_attach(struct cxl_region *cxlr, }; 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) -- 2.42.0