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 816EA390CB7; Mon, 5 May 2025 23:02:35 +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=1746486156; cv=none; b=cNRmHzutRKsPrp1PyP7SVRQPoHASQlhUDKAHds7A2xH1y4W2ZLqZUDBJxoAndTo4MHImLdWRCrboncrKlOVtEFKM7PEZFiyxaG0gOPL/vcyElH2AscflKeaUtj23VFJ0O3fBIz6+OUJZX7hEzhLoqQbs+YVsH0f6ZzOL0usZE28= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746486156; c=relaxed/simple; bh=dhyDtTy5Z6RWp/Mjf/6pkAtEPg5sjXajgUbTlAbaBXk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=U/rjtATbj2JgHiCZpt74yg0f/XhqjPvKZP3Ec57qTt3u8481t9zUrNralh/h+DojwuuTAnmp9wOvw1uUIm+QTREOXwLCtJJLO2Ff/xD3hLzwDODIO7WY8D9AHu06g4wDrAoPAEYbLerd0UhkJyVDfglLhqtM2fazq11DrRxe0Vs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SeHzG+9Z; 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="SeHzG+9Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CE11C4CEED; Mon, 5 May 2025 23:02:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746486155; bh=dhyDtTy5Z6RWp/Mjf/6pkAtEPg5sjXajgUbTlAbaBXk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SeHzG+9ZBJazIkd1iM7Mfzsm49A/KxBS0157QpK/buE+KOfTqeL+fksbAKKbAWaUI l7HwyUPX8s3LZ0/kR7BOqhuOnpgRsVk1Z1+mQPb9pdft9JQS3nJ1e+hpblMakaqghH pMrS3zUWVIgbzBXQ9lPCmDccOOIXa2aEVaVeN19XQ0DNvYpyQz5dTzFeuk/OU2+pGe l/quXyPZFK9Cw33AR20m0mKuVi3LF+829RQgQp4wNubiKKNz9A9j4GqSuWBQrHBbak lAu2oIcPxRoJurGdA7e5ik+9eYmQ4CFvoLgjkX2R0PN0f1DMK5oh/9IyCoBal+bs20 vuwQw5v/KnUqQ== 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 6.6 182/294] EDAC/ie31200: work around false positive build warning Date: Mon, 5 May 2025 18:54:42 -0400 Message-Id: <20250505225634.2688578-182-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505225634.2688578-1-sashal@kernel.org> References: <20250505225634.2688578-1-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 6.6.89 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 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