From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 2613B425A4; Fri, 15 Sep 2023 13:49:03 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id A2630402DE; Fri, 15 Sep 2023 13:49:02 +0200 (CEST) Received: from inbox.dpdk.org (inbox.dpdk.org [95.142.172.178]) by mails.dpdk.org (Postfix) with ESMTP id 81E3D402D7 for ; Fri, 15 Sep 2023 13:49:01 +0200 (CEST) Received: by inbox.dpdk.org (Postfix, from userid 33) id 6C516425A5; Fri, 15 Sep 2023 13:49:01 +0200 (CEST) From: bugzilla@dpdk.org To: dev@dpdk.org Subject: [Bug 1289] rte_table: lookup functions have UB for ctz Date: Fri, 15 Sep 2023 11:49:01 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: DPDK X-Bugzilla-Component: other X-Bugzilla-Version: 23.11 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: qrealka@gmail.com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: Normal X-Bugzilla-Assigned-To: dev@dpdk.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: multipart/alternative; boundary=16947785410.ab7CcE.233457 Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://bugs.dpdk.org/ Auto-Submitted: auto-generated X-Auto-Response-Suppress: All MIME-Version: 1.0 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org --16947785410.ab7CcE.233457 Date: Fri, 15 Sep 2023 13:49:01 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://bugs.dpdk.org/ Auto-Submitted: auto-generated X-Auto-Response-Suppress: All https://bugs.dpdk.org/show_bug.cgi?id=3D1289 Bug ID: 1289 Summary: rte_table: lookup functions have UB for ctz Product: DPDK Version: 23.11 Hardware: x86 OS: Linux Status: UNCONFIRMED Severity: normal Priority: Normal Component: other Assignee: dev@dpdk.org Reporter: qrealka@gmail.com Target Milestone: --- Macros 'lookup2_stage0_with_odd_support' can call rte_ctz with zero value (pkt_mask), which is undefined behaviour based on the GCC manual: https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html Quote: " Built-in Function: int __builtin_ctz (unsigned int x) Returns the number of trailing 0-bits in x, starting at the least significa= nt bit position. If x is 0, the result is undefined. " It is confirmed by checking this code in GCC-13 with ASAN. --=20 You are receiving this mail because: You are the assignee for the bug.= --16947785410.ab7CcE.233457 Date: Fri, 15 Sep 2023 13:49:01 +0200 MIME-Version: 1.0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://bugs.dpdk.org/ Auto-Submitted: auto-generated X-Auto-Response-Suppress: All
Bug ID 1289
Summary rte_table: lookup functions have UB for ctz
Product DPDK
Version 23.11
Hardware x86
OS Linux
Status UNCONFIRMED
Severity normal
Priority Normal
Component other
Assignee dev@dpdk.org
Reporter qrealka@gmail.com
Target Milestone --- 

Macros 'lookup2_stage0_with_odd_su=
pport' can call rte_ctz with zero value
(pkt_mask), which is undefined behaviour based on the GCC manual:
 https:/=
/gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html

Quote: "
Built-in Function: int __builtin_ctz (unsigned int x)
Returns the number of trailing 0-bits in x, starting at the least significa=
nt
bit position. If x is 0, the result is undefined.
"

It is confirmed by checking this code in GCC-13 with ASAN.

You are receiving this mail because:
  • You are the assignee for the bug.
=20=20=20=20=20=20=20=20=20=20
= --16947785410.ab7CcE.233457--