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 6A6A019FA6C; Tue, 16 Jul 2024 15:42:12 +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=1721144532; cv=none; b=mm8KIXHvsdSJhS8vgtTTjwAoa9tHfl00kSruILAS1Zeibpg4ZxwrleBsGlgtdrS79ByUAc/CGTTV+WEf+5F0mi5a/pWklSpKEDoLEmtB46zt6Bcyz8sSjWJaX+FkicIeuPaVKbhvWjXuSSaDu/TfKVYqSBwIfAAm3UQVfb2h0yo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721144532; c=relaxed/simple; bh=lxlqlOfrI8DPPAGMpDE3VD9AM6iyTSKPEjVOXBa2V+U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cyFsTPK2f+StfUpbVFzxJYh2ihzzdxjLj/Y4OUE9v0P0rgk5d5B37L0x+AKW5mDheGC9aMnqERM0jU+1IMatKgDCtFmOQAVPhLNo3Qjq8l8gItOQ6H6KhcfKJ7vpw0+tGY2j9Un9xrNADxDSe/w6dsv/ds8jUC3LfxhYaU5eFuQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=b+igSQv0; 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="b+igSQv0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1BEBC4AF0D; Tue, 16 Jul 2024 15:42:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721144532; bh=lxlqlOfrI8DPPAGMpDE3VD9AM6iyTSKPEjVOXBa2V+U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b+igSQv03UbJXujevzAHpEpQaQw7F12CvxGhCMsPDHoYogCviaLRyeGd+3LxzF3A+ GyQZ4yb7D+CJdfzn6L4kmc9saPbFfmwbWe+5YzmlkJFzd8h+gPUIBmZwtaYO7uuWXY QWAgh/IEqTIIvjctdq8RwCMER7a+yuWcQk45qRc8= 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 5.10 024/108] bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD Date: Tue, 16 Jul 2024 17:30:39 +0200 Message-ID: <20240716152746.931327629@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240716152745.988603303@linuxfoundation.org> References: <20240716152745.988603303@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 5.10-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 f05cfc082915d..4303b31498d81 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