From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 229941C8603; Sat, 20 Jun 2026 15:17:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781968629; cv=none; b=cyiP7ye3mqk5GOepsToKfK5b4G7B4siHETxDpo99tPwgN3a4QWReCD5uxTUOWtz1K9mOXwBuKasiDldBST+8oZX4yxCvyIY+Fa/y/bnELM8iKPuh1vJYBYJlRJwDHCdARqfzCLnuCE0MesxaVn95HY8vL7i79xZqW7g8wP2Gp14= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781968629; c=relaxed/simple; bh=jeJsoZHHjsHCB1QaVDspMd45ZNErBfh+X4RXxFkMx0A=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=j0JlQ48Ds/2s2ZdENPA35FOqvjbxZh2wfcS8iCc+v+sTrNE6lhL4uEuJjKv55txtMmYGmRZ4o79BL2kF8j5f5ocUaTSoeTdOe4sb3LSn7cCPn8FjNcRb4PRBZSQp93HDS8ustut8Sn/85O7+f0wPDPofmroOAu8ePvLS6C+PodU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e1HvPZUn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e1HvPZUn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 851181F000E9; Sat, 20 Jun 2026 15:17:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781968627; bh=eyiRJczF7wbhF8VDuUywOe9gqRXCgnMSHEuOuFReqC4=; h=From:To:Cc:Subject:Date; b=e1HvPZUnit82bOtHf4Nsw/c5vzf2zO9M5MoLqZGJ9PD1PiaEonJR7AZu5sY1LDaDe vtvr6TgurTH6InKTuoS7E/TkrlUbESkOA+lRz/r5RVs/7plmB2xG5j5x60V/O1rESb hnuq+RTjiT2/Y9Hd22X41CPlvhkKzDwpERD7nas9TO1AXCMuuVpv6bA+3zJPVxakzk usSIBbDNdFMM7GfeF/8g58fhn1xDPQj584m8h44G1jnCo3nPnlQrsb0l4C8x+FaOwK FqRmqdoPKUX5/Suh/41tky1V9QCuCiZI+silB6HI1RPuzjtESxOryuNfXx2lej76c1 KPslwesEaL8Gg== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Mathieu Desnoyers Cc: Jonathan Corbet , Shuah Khan , Masami Hiramatsu , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v6 0/8] tracing/probes: Add more typecast features Date: Sun, 21 Jun 2026 00:17:02 +0900 Message-ID: <178196862271.560995.5255615288323003663.stgit@devnote2> X-Mailer: git-send-email 2.43.0 User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Hi, Here is the 6th version of series to introduce more typecast features to probe events. The previous version is here: In this version, I fixed some issues found by Sashiko reviews (again), drop the first bugfix which is merged to probes/core, add new fetcharg dump patch[1/8] and make typecast always nested[3/8]. This version also allows all probe events to use $current. Steve introduced BTF typecast feature for eprobe[1]. This series extends it and add more options: 1. Expanding BTF typecast to kprobe and fprobe. (currently only function entry/exit) 2. Introduce container_of like typecast. This adds a "assigned member" option to the typecast. (STRUCT,MEMBER)VAR->ANOTHER_MEMBER This casts VAR to STRUCT type but the VAR is as the address of STRUCT.MEMBER. In C, it is: container_of(VAR, STRUCT, MEMBER)->ANOTHER_MEMBER 3. Support nested typecast, e.g. (STRUCT)((STRUCT2)VAR->MEMBER2)->MEMBER the nest level must be smaller than 3. 4. Add $current variable to point "current" task_struct. This is useful with typecast, e.g. (task_struct)$current->pid 5. per-cpu dereference support. Intrdouce this_cpu_read(VAR) and this_cpu_ptr(VAR) to access per-cpu data on the current CPU (accessing other CPU data is not stable, because it can be changed.) You can access the member of per-cpu data structure using typecast like: (STRUCT)this_cpu_ptr(VAR)->MEMBER And added fetcharg dump feature (for debug) and updated test scripts to test part of them. Thanks, --- base-id: cfae4cb90fc8113d52fea1f0a62cd6a36d9df149 Masami Hiramatsu (Google) (8): tracing/probes: Support dumping fetcharg program for debugging dynamic events tracing/probes: Support typecast for various probe events tracing/probes: Support nested typecast tracing/probes: Type casting always involves nested calls tracing/probes: Support field specifier option for typecast tracing/probes: Add $current variable support tracing/probes: Add this_cpu_read() and this_cpu_ptr() dereference method to fetcharg tracing/probes: Add a new testcase for BTF typecasts Documentation/trace/eprobetrace.rst | 9 Documentation/trace/fprobetrace.rst | 10 Documentation/trace/kprobetrace.rst | 11 kernel/trace/Kconfig | 11 kernel/trace/trace.c | 8 kernel/trace/trace_eprobe.c | 2 kernel/trace/trace_fprobe.c | 2 kernel/trace/trace_kprobe.c | 2 kernel/trace/trace_probe.c | 571 ++++++++++++++++---- kernel/trace/trace_probe.h | 95 ++- kernel/trace/trace_probe_tmpl.h | 25 + kernel/trace/trace_uprobe.c | 3 samples/trace_events/trace-events-sample.c | 40 + samples/trace_events/trace-events-sample.h | 34 + .../ftrace/test.d/dynevent/btf_probe_event.tc | 51 ++ .../ftrace/test.d/dynevent/fprobe_syntax_errors.tc | 11 .../ftrace/test.d/kprobe/kprobe_syntax_errors.tc | 11 .../ftrace/test.d/kprobe/uprobe_syntax_errors.tc | 5 18 files changed, 747 insertions(+), 154 deletions(-) create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/btf_probe_event.tc -- Masami Hiramatsu (Google)