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 56C611DDCE; Tue, 16 Jul 2024 16:08:10 +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=1721146090; cv=none; b=SqZvgU98j26gnlwUv2WiCtuGnzCFd5TUI/wLrJZPC2svDNIF7Ug6bjl7+EeZuZ42oG1sbzIPQAXY0IjJrAD9Ge+6OGS6c9eIIwwN/XTRM8JzCW1LEcRH00TqdloyexiwMCqAbF9jIsX462zyl63ftr8q6x1CeAINUUJ0IH3eMIE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721146090; c=relaxed/simple; bh=wgk+j4U8P31Ia0nOCWu6kVu/ZbsZJDAdMZzhu0FKulM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iE3680Hhi1E7bglHlHhs9OQZjQ8lQBL+Lx9soOl2BlqE8OPdFZ3TIgsl7k1Lcg4ZeQMXys+fyPUc1fZvYyf6EurhXFaPaIIsCEA2VGFonsoQLtPz5NuRUeA6UAyKu+JuutjY3fZyxH5XrK+k5b6FxyZ5x6B19ktXLXU3YVOoAGY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CFZI1FcC; 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="CFZI1FcC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD60CC116B1; Tue, 16 Jul 2024 16:08:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721146090; bh=wgk+j4U8P31Ia0nOCWu6kVu/ZbsZJDAdMZzhu0FKulM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CFZI1FcC4+0prd7Ohx4e/x0R8d2Z1+rKurlqhM+4ZXvbLU5OcIb/ur4LVOz6QEfXZ 6vbCio9UbQUkcc3TnFXmxwd26JmGCbYI85CQKEAvWebVmQTfn9dauQw4cGwOyCHxKn YWAtpQ696OoJljJ77+DgwUWlXMU5LCtSIPHSYG+4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Jose E. Marchesi" , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.15 027/144] bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD Date: Tue, 16 Jul 2024 17:31:36 +0200 Message-ID: <20240716152753.583666396@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240716152752.524497140@linuxfoundation.org> References: <20240716152752.524497140@linuxfoundation.org> User-Agent: quilt/0.67 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jose E. Marchesi [ Upstream commit 009367099eb61a4fc2af44d4eb06b6b4de7de6db ] [Changes from V1: - Use a default branch in the switch statement to initialize `val'.] GCC warns that `val' may be used uninitialized in the BPF_CRE_READ_BITFIELD macro, defined in bpf_core_read.h as: [...] unsigned long long val; \ [...] \ switch (__CORE_RELO(s, field, BYTE_SIZE)) { \ case 1: val = *(const unsigned char *)p; break; \ case 2: val = *(const unsigned short *)p; break; \ case 4: val = *(const unsigned int *)p; break; \ case 8: val = *(const unsigned long long *)p; break; \ } \ [...] val; \ } \ This patch adds a default entry in the switch statement that sets `val' to zero in order to avoid the warning, and random values to be used in case __builtin_preserve_field_info returns unexpected values for BPF_FIELD_BYTE_SIZE. Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240508101313.16662-1-jose.marchesi@oracle.com Signed-off-by: Sasha Levin --- tools/lib/bpf/bpf_core_read.h | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h index e4aa9996a5501..b8e68a17f3f1b 100644 --- a/tools/lib/bpf/bpf_core_read.h +++ b/tools/lib/bpf/bpf_core_read.h @@ -101,6 +101,7 @@ enum bpf_enum_value_kind { case 2: val = *(const unsigned short *)p; break; \ case 4: val = *(const unsigned int *)p; break; \ case 8: val = *(const unsigned long long *)p; break; \ + default: val = 0; break; \ } \ val <<= __CORE_RELO(s, field, LSHIFT_U64); \ if (__CORE_RELO(s, field, SIGNED)) \ -- 2.43.0