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 008AE390CA7; Mon, 5 May 2025 23:16:43 +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=1746487005; cv=none; b=uXnkWReAd83Syk9l5K9MWt7526lfrvOhO2aOJ8zX2KIMhpribjLeWo5QtfUWZ0Wo4P8EVyGlPdm7FNmHD/CiHTAHO+SrSYyr/AaTUJmlJy7evSYv97VKYEIqjFrnGkrBo0LZk8GloNR/pWiszdPHiIsskISpkIemFmx6vUjmsxU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746487005; c=relaxed/simple; bh=3u8xB5OTX/oGLpUbG3arB7SHSe3UaZLuPCMX6ZCHerg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=QENjXFXOzvogpPklomqCDcwMbLgoyC6NI5PcimHI78EMCZbk0n9HWiWaWyl7El0q+Ih6Lf+dRXDVH2Bt12UKVtN12mxFlgCrVjMzlvrp4YmJPohexvVPPYB4MnSCE7tUGJoD63RWOp3rhpo69ljJC1CbtX/1RUn/FD/UUhl7WXA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KDsD6hwR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KDsD6hwR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00B09C4CEF1; Mon, 5 May 2025 23:16:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746487003; bh=3u8xB5OTX/oGLpUbG3arB7SHSe3UaZLuPCMX6ZCHerg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KDsD6hwRpqdvA5maLklfKoJ6xhrtniAXiX/qcuX5J8Mp3aVcnvwHZZxuT2gHYd98Y tWoPZ1oQtY4VUzcDW8i6oUFTm+VFmYYvSrzcEqvAzUy5F16axZbkn3+ItJiEXCFwFc WwfDwIchMFFDU6jlSbTIUKn/cpRBOUqKfYdleOErbmxxcs5VAghB0fH7vqClE3HG4y ZDyeijMvL8qbsQZgjtBJTr/9YiD6Jd0cNwuePLZHQBoXU8Hx1jKsK2+gRsDhtG0aDw clWM6+I9NiyUqG1Obuf2niRMmJqkYAXnUVA+QpC+vFb2eeIJU23NN+xmqHSJvi8jxf ba9OowbQRE2Dg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arnd Bergmann , Jason Baron , Tony Luck , Sasha Levin , bp@alien8.de, linux-edac@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 103/153] EDAC/ie31200: work around false positive build warning Date: Mon, 5 May 2025 19:12:30 -0400 Message-Id: <20250505231320.2695319-103-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505231320.2695319-1-sashal@kernel.org> References: <20250505231320.2695319-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-edac@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.181 Content-Transfer-Encoding: 8bit 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