From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 4A0FF47A6A for ; Sun, 25 Aug 2024 22:40:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724625643; cv=none; b=N1lGNMNzrqRUab0SVrIZyLszgeb6JKhyvgalk7yubYMwV1cUix/QO1sP+6s8L/TqWF+Vk68iFzH9olesirObr6DA+NYUTJi21w30CCicPxKoM2yyBshwBF37ZJhGD/HwUUKyFem79gw0BcuEoK1ObztdBrZCj+O/ZIhmO+EnQQE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724625643; c=relaxed/simple; bh=E2b6S42am7FxdDCGzlzr8xGm8Shd9IcqwtlxU9KAQQg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JC2+elolVUFuREkkvE419M/xovlysxokJluOx18Y9co01Ac5QHX74MzIFXU5tqfPKpKr2xRU1iUDgHomoWj2jveohIj7WI7bkByJHOA4OjS1Xo5+krnj4SrBumUWoI1GFO09V5qBaVCf/zWfvmdgbj4xw5LTAJm48ffjC3VLUNo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=LTOOCamv; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LTOOCamv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724625640; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=XldHedHtO4bPQ+b6KANXtOgQ6JTZqedmNWOSSS/IrRY=; b=LTOOCamvvSFkWPiZ0xHTh8xTfpeQ2krGoGaEDEYZ4K43aj6ljpPUg3EMhGK31dWgNZ8iog V7Y74Ty9MATMteMWsWblPcqdNkbnf26nm4G2L2DBjGkGuK3PWRZ1qb7t6AGAwFw9MRZmq5 EVKlHSX98jpnQGiJfvvcEw228RskoUQ= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-271-aL8pZNnGOpSWp99MLDxDhw-1; Sun, 25 Aug 2024 18:40:34 -0400 X-MC-Unique: aL8pZNnGOpSWp99MLDxDhw-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 78E9E1956080; Sun, 25 Aug 2024 22:40:32 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.12]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 14FC91955DDD; Sun, 25 Aug 2024 22:40:27 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 26 Aug 2024 00:40:25 +0200 (CEST) Date: Mon, 26 Aug 2024 00:40:18 +0200 From: Oleg Nesterov To: Tianyi Liu Cc: andrii.nakryiko@gmail.com, mhiramat@kernel.org, ajor@meta.com, albancrequy@linux.microsoft.com, bpf@vger.kernel.org, flaniel@linux.microsoft.com, jolsa@kernel.org, linux-trace-kernel@vger.kernel.org, linux@jordanrome.com, mathieu.desnoyers@efficios.com Subject: Re: [PATCH v2] tracing/uprobe: Add missing PID filter for uretprobe Message-ID: <20240825224018.GD3906@redhat.com> References: <20240825171417.GB3906@redhat.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240825171417.GB3906@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 On 08/25, Oleg Nesterov wrote: > > At least I certainly disagree with "Fixes: c1ae5c75e103" ;) > > uretprobe_perf_func/etc was designed for perf, and afaics this code still > works fine even if you run 2 perf-record's with -p PID1/PID2 at the same > time. > > BPF hacks/hooks were added later, so perhaps this should be fixed in the > bpf code, but I have no idea what bpftrace does... And I can't install bpftrace on my old Fedora 23 working laptop ;) Yes, yes, I know, I should upgrade it. For the moment, please forget about ret-probes. Could you compile this program #define _GNU_SOURCE #include #include #include int func(int i) { return i; } int test(void *arg) { int i; for (i = 0;; ++i) { sleep(1); func(i); } return 0; } int main(void) { static char stack[65536]; clone(test, stack + sizeof(stack)/2, CLONE_VM|SIGCHLD, NULL); test(NULL); return 0; } and then do something like $ ./test & $ bpftrace -p $! -e 'uprobe:./test:func { printf("%d\n", pid); }' I hope that the syntax of the 2nd command is correct... I _think_ that it will print 2 pids too. But "perf-record -p" works as expected. Oleg.