From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794558484; b=wpCAV5M99KzmfKkRLfYJBWA7wiaUmIJs7VZLz2rkukp8GJXV2JhkOyQrMSrlOgbsP8Pg mAd/owJhWr/Ui31MsYWyAyvZpnEJjTSSJtxsKL3cqF0xpvwc3YnXmZZOCHwD54rbrhKM/ rFGVkcof4Uc1CcrmLn3D+MniQN6NXdDU3KveTgws8ZGzfaGNlgqfjrnPJvMrs7PAcE40O NlSGNgN7D+rymz5NNqRJiwGOa9NqaKQK6dWLP8aAoxswsyMHYUZrrPYgCCO35ea1qdz4y VHQSEoDuLtSeRBD26HqRmtN3PqAassX1NF5qjhPivOUxfkRjZzOopeYpuOgpKpNRaUA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794558484; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: User-Agent:MIME-Version:Content-Type:Content-Transfer-Encoding; bh=0iN/FKxYUCGEpOFSamodvC5PzKD9DC9piKtcytUlbUY=; b=soRHgiynGn69R3UU9/jzDjE031PkWrJtCEyhyOTcNKI45s5plTQhG+x99/J4CYknjAip L26Vhv0Jp/ZR8KSI5MQLDk3Drxgu+b6P0gILtj0U4an9ZdYNHfut8MtSArGtvkXaVkzde cW2Kx7Z7001qB1xoGLiDf6hC55XR2cffo+bwhzUgR1ygVcMzT/hXZuVkIGwmPe4vrYYoI XeyiUmIqWRgXLRSSYd8ZSs0dJgtWDNnR26RJ2HLxTVB4B2eiuZLIvcFTpvSg5VPT7+y1h DKYLmV/2X8yW7skRtrVaclbic5DPef7g2xy0y0iWNsmqkatD/GFLo7AB2biMSHSp7aw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=D3auLbta; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 12E07606B61A; Fri, 13 Nov 2026 08:28:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=D3auLbta Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8262B1F000C5; Fri, 13 Nov 2026 08:28:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794558483; bh=0iN/FKxYUCGEpOFSamodvC5PzKD9DC9piKtcytUlbUY=; h=From:To:Cc:Subject:Date; b=D3auLbtaoNC3obhBxtpiu3oU8BuKyySWZDDHdk7MaeLlgoDYBULCEq+OQ7d8O3Dsc wR6Vyh4xe0mC+gv20X6+zyOhnL1YVbG+oX0aYJ4yjiGkbPVgKkyHkg9IcMCivwjHBc suUk+hqXjYJ3ZCQSijiQpjkBOynfqWGOSjYgqUXy+nkUFNC47GkI6u8py0mYw0ohRZ SOKYlF6/CYXPWqba7aMeYI5/c2Bm5xIjKs/wfaan/DL4rFfwC2b2gwdClP+3XTVObd oWi+LFMt9z5zGWlVDIh7Dl5zyQz8Qz0l8mdLjuoO61eewkaQ++qj9v9BGYfcOxlOTs TB019cZof4Odw== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH v3 00/13] tracing/probes: Fix various bugs in dynamic probe events Date: Fri, 13 Nov 2026 17:27:59 +0900 Message-ID: <179455847934.403392.15146485751358774349.stgit@devnote2> X-Mailer: git-send-email 2.43.0 User-Agent: StGit/0.19 X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Hi, This is the 3rd version of the series fixing several bugs in dynamic probe events (kprobe, fprobe, uprobe, and eprobe) and BTF/fetch-argument handling. Here is the previous version: https://lore.kernel.org/all/179444679892.345731.5271591537517106679.stgit@devnote2/ This version updates [03/13] to fix BTF bitfield handling for kflag=0 bit offsets, non-power-of-2 container sizes, and big-endian bitfields pointed out by Sashiko. - [01/13] Check whether the target event is enabled or busy before unlinking a sibling probe during multiprobe unregistration, and add the missing checks to trace_uprobe and trace_eprobe. - [02/13] Enable newly appended fprobes and uprobes immediately when the target multiprobe event is already enabled, matching trace_kprobe behavior. - [03/13] Fix BTF bitfield parsing for non-kflag bitfields (such as enum bitfields, non-byte-aligned offsets, and non-power-of-2 sizes), select a narrow container fetch type to avoid out-of-bounds buffer writes, and compute bitfield extraction parameters from the container width for both big- and little-endian bitfields. - [04/13] Add missing BTF_KIND_PTR, NULL, and BTF_KIND_INT checks in btf_type_is_char_ptr() and btf_type_is_char_array(). - [05/13] Use explicit fixed-width integer types (s8/u8, s16/u16, s32/u32) in eprobe get_event_field() so 1-byte signed fields are properly sign-extended under -funsigned-char. - [06/13] Disallow attaching eprobes to fprobe events to prevent potential recursion issues, matching kprobes and uprobes. - [07/13] Check FETCH_OP_UDEREF before advancing the fetch instruction pointer in finalize_fetch_insn() so user-space dereference string arrays emit FETCH_OP_ST_USTRING instead of FETCH_OP_ST_STRING. - [08/13] Reject array specifiers on non-dereference string sources (such as $comm or symstr) in finalize_fetch_insn(). - [09/13] Fix memory leak of tail in __trace_uprobe_create() when generating a default event name. Minor updates/cleanups: - [10/13] Allow the symstr type on function entry arguments ($argN) in return probes (FETCH_OP_EDATA). - [11/13] Reject empty fetch expressions before :%pd and :%pD in traceprobe_expand_dentry_args(). - [12/13] Validate the command prefix in kprobe, uprobe, and eprobe creation when the colon separator is omitted so invalid prefixes are rejected. - [13/13] Propagate actual error return codes in eprobe and fprobe creation paths instead of overwriting them with -EINVAL. Changes in v3: - [03/13] Use ctx->last_bitoffs as code->lshift on __BIG_ENDIAN_BITFIELD architectures in parse_btf_bitfield(), and fold BTF_INT_OFFSET(intdata) into bitoffs before checking alignment and !is_power_of_2(type->size) in get_bitoffset_of_field(). Changes in v2: - [03/13] Check (bitoffs % 8) in get_bitoffset_of_field() so unaligned byte-sized kflag=0 bitfields also record ctx->last_bitsize. - [08/13] Add Fixes and Cc: stable tags. - [09/13] Newly added to fix tail memory leak in __trace_uprobe_create(). Notes: - These bugs were identified and the fixes and cover letter were prepared with the assistance of an LLM coding assistant. Thank you, --- base-commit: be94710b1f6ba1bea33e73129c110af80e999b2d Masami Hiramatsu (Google) (13): tracing/probes: Check enabled and busy state before unlinking sibling probes tracing/probes: Enable newly appended probe when target event is enabled tracing/probes: Fix BTF bitfield parsing and out-of-bounds buffer write tracing/probes: Fix missing BTF kind checks in char pointer/array helpers tracing/eprobe: Fix 1-byte signed field fetch in get_event_field() tracing/eprobe: Disallow attaching eprobes to fprobe events tracing/probes: Fix user-space dereference string array store type tracing/probes: Reject array count on non-dereference string sources tracing/uprobes: Fix memory leak of tail in __trace_uprobe_create() tracing/probes: Allow symstr type for function entry arguments in return probes tracing/probes: Reject empty fetch expression for %pd and %pD tracing/probes: Validate command prefix in kprobe, uprobe, and eprobe tracing/probes: Propagate error codes in eprobe and fprobe creation kernel/trace/trace_eprobe.c | 39 +++++++++++------- kernel/trace/trace_fprobe.c | 26 +++++------- kernel/trace/trace_kprobe.c | 11 +++-- kernel/trace/trace_probe.c | 94 ++++++++++++++++++++++++++++++++++--------- kernel/trace/trace_uprobe.c | 79 ++++++++++++++++++++++++------------ 5 files changed, 171 insertions(+), 78 deletions(-) -- Masami Hiramatsu (Google)