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 8E646377019; Tue, 23 Jun 2026 01:44:14 +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=1782179055; cv=none; b=J7+ULdMxo7u02bYZCr/uRxI5Jv3Uxe1idfrqoWZp5drRe6JYeopGRJtj/+QI9WgGkeif0+xwC4J3mdQWh5n3Lmz1SlgA/l4bSUPtO7CLVuW2LZII+hxXrsH42fqNFdaY2jiBc+kNDrFVyGxAADjp0LDKja1FnF5uifZ7mnqzk8A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782179055; c=relaxed/simple; bh=ty118v/GEIKgPHRF7FkPEb1YYTctfSyI9LDfVCc8uBw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=dnSrwMAR9M6GST8HTwJZa1YmHM/HP9vBALjheGdOgo/rZ7dw/pLS0LrOnxzJcRaD8Uwalvy/ucZ5RmY1Ewc70N/x9fm412hl26HOUsTbW1ofwYlIVwlX/bp+kU2e5EnBYRuzpNgCC/0afQEwEnyxha5fGOnwBBHDcnHSx365WcY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jZeo4cWT; 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="jZeo4cWT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 386DD1F000E9; Tue, 23 Jun 2026 01:44:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782179054; bh=vni5Lyip3mgwniFnSgkoIOM9DFuNAQmCprTMRCiORoU=; h=From:To:Cc:Subject:Date; b=jZeo4cWTbOi4j3PW944Wwi8m+/QXtToDpe7N3uOJzT60jex6ZikMn6LvXCqG7GHMv q9k0q1V+TgggdtJkR+aCiufi5rt/fgZrSmjZg2yMz5DbjelHq7a5ZGdG8F4hYM63kL zNOOn/gqW/fGF5KI216G5d0HNxPyz76ViI59nGSkKEq/JswvFhwQYkfA4EnL86hQDW dqetFDoeTneXCXBYOZy7LNfbWFsWbeZ0cEUFIgQF2DGUyo/KZZ0zkS4p3WnSoSU3eM yigvj8RMw3O1xC/N3il+KbSvokgRHsjUB+rirELEAYWl0f4sY9a/D75/ZVC8hxiY4X h7y2iyWUnWD3A== 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 v7 00/10] tracing/probes: Add more typecast features Date: Tue, 23 Jun 2026 10:44:10 +0900 Message-ID: <178217904992.643090.15726197350652241270.stgit@devnote2> X-Mailer: git-send-email 2.43.0 User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kernel@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 7th version of series to introduce more typecast features to probe events. The previous version is here: https://lore.kernel.org/all/178201238795.570818.15573963115625446598.stgit@devnote2/ In this version, I added 2 new fix and cleanup patches and update according to Sashiko's review. [1/10] is a long-lived issue about @+FOFFS, which was wrongly adding offset twice. [2/10] is a clean up patch for renaming fetch_op name (good to dump it). This is applicable against probes/core branch on linux-trace tree. 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-commit: 3ec75d0067f30eb5e0730f033766d6ab2feca7ae Masami Hiramatsu (Google) (10): tracing/probes: Fix double addition of offset for @+FOFFSET tracing/probes: Rename FETCH_OP_DATA to FETCH_OP_IMMSTR 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 | 582 ++++++++++++++++---- kernel/trace/trace_probe.h | 98 ++- kernel/trace/trace_probe_tmpl.h | 27 + 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, 756 insertions(+), 161 deletions(-) create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/btf_probe_event.tc -- Masami Hiramatsu (Google)