From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 1B2993836C5D; Mon, 7 Dec 2020 20:47:10 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1B2993836C5D From: "agentzh at gmail dot com" To: systemtap@sourceware.org Subject: [Bug bpf/27032] New: bpf: -c CMD option does not work Date: Mon, 07 Dec 2020 20:47:09 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: systemtap X-Bugzilla-Component: bpf X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: agentzh at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: systemtap at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: systemtap@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Systemtap mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Dec 2020 20:47:10 -0000 https://sourceware.org/bugzilla/show_bug.cgi?id=3D27032 Bug ID: 27032 Summary: bpf: -c CMD option does not work Product: systemtap Version: unspecified Status: UNCONFIRMED Severity: normal Priority: P2 Component: bpf Assignee: systemtap at sourceware dot org Reporter: agentzh at gmail dot com Target Milestone: --- I've noticed that stap's `-c CMD` option does not work as expected in the b= pf backend. Tested the latest master branch on Fedora 32 x86_64: ``` [agentzh@fed32-min ~/git/systemtap 0 (master)]$ cat a.c long a =3D 0xdeadbeef; int main (void) { return 0; } [agentzh@fed32-min ~/git/systemtap 0 (master)]$ gcc -g a.c -o /tmp/a.out [agentzh@fed32-min ~/git/systemtap 0 (master)]$ /opt/stap/bin/stap --bpf -c /tmp/a.out -e 'probe process("/tmp/a.out").function("main") { warn("Hit") exit() }' ``` The last command hangs forever which means that the `/tmp/a.out` command specified in the `-c` option never gets traced. If I run that command in another terminal of the same machine, then that `stap` command prints and q= uits immediately: ``` [agentzh@fed32-min ~/git/systemtap 0 (master)]$ /opt/stap/bin/stap --bpf -c /tmp/a.out -e 'probe process("/tmp/a.out").function("main") { warn("Hit") exit() }' WARNING: Hit ``` More info about my stap and kernel: ``` [agentzh@fed32-min ~/git/systemtap 130 (master)]$ /opt/stap/bin/stap -V Systemtap translator/driver (version 4.5/0.182, commit release-4.4-24-g3e0d449fe427 + changes) Copyright (C) 2005-2020 Red Hat, Inc. and others This is free software; see the source for copying conditions. tested kernel versions: 2.6.32 ... 5.10.0-rc enabled features: BPF NLS [agentzh@fed32-min ~/git/systemtap 0 (master)]$ cat /proc/version Linux version 5.9.11-100.fc32.x86_64 (mockbuild@bkernel01.iad2.fedoraproject.org) (gcc (GCC) 10.2.1 20201016 (Red Hat 10.2.1-6), GNU ld version 2.34-6.fc32) #1 SMP Tue Nov 24 19:16:53 UTC 2= 020 ``` Tested the same example on Fedora 28 with an older kernel. Same thing: ``` [agentzh@glass ~/git/systemtap.new 0 (master)]$ /opt/stap/bin/stap --bpf -c /tmp/a.out -e 'probe process("/tmp/a.out").function("main") { warn("Hit") exit() }' [agentzh@glass ~/git/systemtap.new 134 (master)]$ cat /proc/version Linux version 5.0.16-100.fc28.x86_64 (mockbuild@bkernel04.phx2.fedoraproject.org) (gcc version 8.3.1 20190223 (R= ed Hat 8.3.1-2) (GCC)) #1 SMP Tue May 14 18:22:28 UTC 2019 ``` --=20 You are receiving this mail because: You are the assignee for the bug.=