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 110D222A1E9; Mon, 2 Jun 2025 14:56:54 +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=1748876214; cv=none; b=VKqhefmL143h2Eej7g3V5ljN/+bSdXt1lYUadG8elEe4FMUbX3l/S9ZarPzWb9NsAIcOy49obIe1vn4b0hegZUSVhxqA04kwSxQdSp5FM6jmfb17MKvZ+XdCstHSLvCmHX+CTEOda5yK3aCcpBi8zRtweWud/0GdGK6UAEZTM0s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748876214; c=relaxed/simple; bh=fedeNau8pW769+qRPB477/JQiCQcbiTmHS1hmeVEayg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=g0K7130f1+zD0U9ICvlEvDolOexxWVAD8eq3yqBFcMlm0nlN+KFUoUMi3F+B8BM4zjVRoZRge5GZSV0Ywmy4UES6tz1XF/tOCymcuOQWjX2zc6Ny+5JvQUpvYIm0NH8pHdWd+LieOhEJPb0q0Fx1UrdzqdCrYCILuc7vaoPhrjw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nmDSZo1t; 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="nmDSZo1t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75662C4CEEE; Mon, 2 Jun 2025 14:56:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748876213; bh=fedeNau8pW769+qRPB477/JQiCQcbiTmHS1hmeVEayg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nmDSZo1t2Wkj4nToR1/pBIhCqbjqFal0gqRlRGzRVe+sOCoB48VhBqHXd30H34MJW aHESrANZY3JJbVXn8p6UrnEEQmcVqU6qxLUxxt3Kr3i0Zzdm5xFrXhkZk33FTJtZr0 qlxU5c7eKaWjFnmZIIP+bewHjICF2BZ+FfBmsvE8= 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 5.15 107/207] EDAC/ie31200: work around false positive build warning Date: Mon, 2 Jun 2025 15:47:59 +0200 Message-ID: <20250602134302.925043625@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134258.769974467@linuxfoundation.org> References: <20250602134258.769974467@linuxfoundation.org> User-Agent: quilt/0.68 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 5.15-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 acb011cfd8c4f..5e61ca1b72e00 100644 --- a/drivers/edac/ie31200_edac.c +++ b/drivers/edac/ie31200_edac.c @@ -397,10 +397,9 @@ 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 @@ -458,19 +457,10 @@ 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]); } /* @@ -481,14 +471,22 @@ 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