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 5B36E30DE13; Mon, 5 May 2025 22:29:06 +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=1746484147; cv=none; b=BYTw9334tzTQJOUXP20eM2uP/0DmFVTz9FWJTIpbIST6nC5L4rtZL8FB5zkFsSybzRnT4C64KI3XGrF5JuF9NRpuKFCQlY7mP1PTYUvGBqqTtckThRoTQf6W7gAvbumTc7e5jKvJXXAiVbfnueNxEHJ3FfOzqraPkykUlIP8lZg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746484147; c=relaxed/simple; bh=xp7i7yrYfua8EgpoX9n1vKr200NGNNoWozeC3ptxk7o=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Pqvc5gBzaBM9O3vNAde6yWE5yIl2deGtWh1oI2B9Otbgosk4nWMDhSVb20KiyXHTw/wrxVrcSvggP2wKpMBygVdSTzPdbZsEdQwR00tGprwhmaeFL9xze2+ddxt9H4Sdsx6dYB+/OwXaW60Ry/xcxgB/INmmMl7kn/0ltHtCR5w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vp7IuXDG; 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="Vp7IuXDG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBA16C4CEE4; Mon, 5 May 2025 22:29:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746484146; bh=xp7i7yrYfua8EgpoX9n1vKr200NGNNoWozeC3ptxk7o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vp7IuXDGQZW+RFl8siIvYrEjEVe5K4nKVBVIu+0XNgnghJANe7JSJpdSrTBlS5Gio T7vw+9nbYedvcwSZC1kD/uoFDWZEsYIAWQtNqWonQNu5tEzW687ZwHz/hGZHy5d7Qo 0wTxPaVgY14vJefVQN+xxjLegP9zc9LtYBOAsZ3iFACxXxavET31ddAM+sJwz8amjB zgtZyravKCEgZeYC8lGNE09aMQuJ/xyWkCvUkhMdxZYLF+AlyTd2ot0LtyP/o60PcB r2aVJ0DF0H7SwjHYXi2UzEUm4pT0B6c/tYgwQj3LdSutS1HmIpO1iAfKi4PT7WoomC j6nfEd2OJ6dAA== 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 6.14 374/642] EDAC/ie31200: work around false positive build warning Date: Mon, 5 May 2025 18:09:50 -0400 Message-Id: <20250505221419.2672473-374-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505221419.2672473-1-sashal@kernel.org> References: <20250505221419.2672473-1-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 6.14.5 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 9b02a6b43ab58..a8dd55ec52cea 100644 --- a/drivers/edac/ie31200_edac.c +++ b/drivers/edac/ie31200_edac.c @@ -408,10 +408,9 @@ 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 @@ -469,19 +468,10 @@ 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]); } /* @@ -492,14 +482,22 @@ 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