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 9484B18A6A5; Tue, 27 May 2025 17:01:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748365285; cv=none; b=QVCcUnBlxHTZwgrxs6FT89oMRmkRIxQZttf/p2aoBk5k06t8GHavUmbA9M9zOKaTuk4CF89IzboFSWD8xzHoy6koeh17W8EGQvwp+nkK6UqTyqj1m3wP6Po0MiWyq38UwmJY/ACu+HVgqWtwk5mXdQl9BPv3WtxeooRnRoVJWuU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748365285; c=relaxed/simple; bh=GhmIQga9h/ixJkqAIlcDDN5ntm9A1BYy1Jl+soduspM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e7LQ41O4HwjdHrxXsFd0uPfOwchQr2rqelX6NOva0Bi9sQanZelpvKNoYDpEU08/yYhpyAsfCLGMxEzhY2gxi7dPzT53J3Okwuz6PPi459xtr34vBaloZMtz6Pzh7gq6HTqPbnEbZG7QUxwzDwLgBnsR0bCXVjLJ1bBpDPbf3pI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wB9dSiWK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wB9dSiWK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 252BEC4CEE9; Tue, 27 May 2025 17:01:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748365285; bh=GhmIQga9h/ixJkqAIlcDDN5ntm9A1BYy1Jl+soduspM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wB9dSiWKPHcppMb8NhdsrF0q5EMfyoJvPLuvkzV7q8d52G8qcqKni52Jc18Yvd1nE CbGHJr40lIuNkxsWsFev2ouW2XQ4Ro334tFaI7sYa9F+hnT6Iy78+c6Ys/EAo0U7bh +txxeCEdH5tXCTBAwz4QY++IsqjU9+cEbPzzD9JQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Arnd Bergmann , Jason Baron , Tony Luck , Sasha Levin Subject: [PATCH 6.12 327/626] EDAC/ie31200: work around false positive build warning Date: Tue, 27 May 2025 18:23:40 +0200 Message-ID: <20250527162458.316927629@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250527162445.028718347@linuxfoundation.org> References: <20250527162445.028718347@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann [ Upstream commit c29dfd661fe2f8d1b48c7f00590929c04b25bf40 ] gcc-14 produces a bogus warning in some configurations: drivers/edac/ie31200_edac.c: In function 'ie31200_probe1.isra': drivers/edac/ie31200_edac.c:412:26: error: 'dimm_info' is used uninitialized [-Werror=uninitialized] 412 | struct dimm_data dimm_info[IE31200_CHANNELS][IE31200_DIMMS_PER_CHANNEL]; | ^~~~~~~~~ drivers/edac/ie31200_edac.c:412:26: note: 'dimm_info' declared here 412 | struct dimm_data dimm_info[IE31200_CHANNELS][IE31200_DIMMS_PER_CHANNEL]; | ^~~~~~~~~ I don't see any way the unintialized access could really happen here, but I can see why the compiler gets confused by the two loops. Instead, rework the two nested loops to only read the addr_decode registers and then keep only one instance of the dimm info structure. [Tony: Qiuxu pointed out that the "populate DIMM info" comment was left behind in the refactor and suggested moving it. I deleted the comment as unnecessry in front os a call to populate_dimm_info(). That seems pretty self-describing.] Signed-off-by: Arnd Bergmann Acked-by: Jason Baron Signed-off-by: Tony Luck Link: https://lore.kernel.org/all/20250122065031.1321015-1-arnd@kernel.org Signed-off-by: Sasha Levin --- drivers/edac/ie31200_edac.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/drivers/edac/ie31200_edac.c b/drivers/edac/ie31200_edac.c index 56be8ef40f376..e3635fba63b49 100644 --- a/drivers/edac/ie31200_edac.c +++ b/drivers/edac/ie31200_edac.c @@ -405,10 +405,9 @@ static int ie31200_probe1(struct pci_dev *pdev, int dev_idx) int i, j, ret; struct mem_ctl_info *mci = NULL; struct edac_mc_layer layers[2]; - struct dimm_data dimm_info[IE31200_CHANNELS][IE31200_DIMMS_PER_CHANNEL]; void __iomem *window; struct ie31200_priv *priv; - u32 addr_decode, mad_offset; + u32 addr_decode[IE31200_CHANNELS], mad_offset; /* * Kaby Lake, Coffee Lake seem to work like Skylake. Please re-visit @@ -466,19 +465,10 @@ static int ie31200_probe1(struct pci_dev *pdev, int dev_idx) mad_offset = IE31200_MAD_DIMM_0_OFFSET; } - /* populate DIMM info */ for (i = 0; i < IE31200_CHANNELS; i++) { - addr_decode = readl(window + mad_offset + + addr_decode[i] = readl(window + mad_offset + (i * 4)); - edac_dbg(0, "addr_decode: 0x%x\n", addr_decode); - for (j = 0; j < IE31200_DIMMS_PER_CHANNEL; j++) { - populate_dimm_info(&dimm_info[i][j], addr_decode, j, - skl); - edac_dbg(0, "size: 0x%x, rank: %d, width: %d\n", - dimm_info[i][j].size, - dimm_info[i][j].dual_rank, - dimm_info[i][j].x16_width); - } + edac_dbg(0, "addr_decode: 0x%x\n", addr_decode[i]); } /* @@ -489,14 +479,22 @@ static int ie31200_probe1(struct pci_dev *pdev, int dev_idx) */ for (i = 0; i < IE31200_DIMMS_PER_CHANNEL; i++) { for (j = 0; j < IE31200_CHANNELS; j++) { + struct dimm_data dimm_info; struct dimm_info *dimm; unsigned long nr_pages; - nr_pages = IE31200_PAGES(dimm_info[j][i].size, skl); + populate_dimm_info(&dimm_info, addr_decode[j], i, + skl); + edac_dbg(0, "size: 0x%x, rank: %d, width: %d\n", + dimm_info.size, + dimm_info.dual_rank, + dimm_info.x16_width); + + nr_pages = IE31200_PAGES(dimm_info.size, skl); if (nr_pages == 0) continue; - if (dimm_info[j][i].dual_rank) { + if (dimm_info.dual_rank) { nr_pages = nr_pages / 2; dimm = edac_get_dimm(mci, (i * 2) + 1, j, 0); dimm->nr_pages = nr_pages; -- 2.39.5