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=1794446848; b=ZjYDEA+0e64727qAZB3BCfTgMTrGHSumKYL558M9ky+miqcrZaXhdVQ2rFeq5Xxgj0lE luFh5lXWlEsQ8wDEHLsXEQs3SZs5JRJMAqc6JqLEZZ2yOFqiFydCxz7jvkKDOzin5uL7N Q2ahHsn+Nvsr4qCwnpcVbpAChTxqpSc43nCKI1h3JQWpwlprHxI5j+/FU7N3dXCpIdIiG sZx7Vx1v0vpL+ogHga0/QJeQqQEhtZaBkuBaDjfzSvm/t2uncJl6oBhWrBgBTv14tsm+H Qz4bTL6SuRiVMyEsHZIOBd6lshaVYPLGALOKth1VQA4+ZCJFbr+MsAXldTM7+Zz8AhQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794446848; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=gCrBj/L0nVk0Y4rofc9IruZOjajTmVyTiEHWsaHrV40=; b=ZrlAuyKbf5VGrTEdC2bCQgsg3QE43OyHG6Ia4GQW13k5PnHJOphibZjNmcsd2RhUcKfi xijd36l4l808FYdQVSa06KwbHOsf4vnRoQfr5LM36hvAFhdWf5h6bJ9rgRJZ+grm86clA ylTxZvjcaE3T9LqAcLeaHUsNqwE+mzvcqh4VFsi2DyWSJDk9wV/GpDgzNw/kUvbzgSgE4 IST5WZ48QgtUrX+BhWKPlOcBvg0suTF4ljIblpslkNDmgXTbY8CJnPidFSi+dmWZo31Uu GCdBFNAZC4/SD0CkeVc1rB1nCWtyMh7ce1q/mWDvlvMWFWNTv9v+db5uNWFFOwZqUwg== 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=oeizNkiE; 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 421B8606A31C; Thu, 12 Nov 2026 01:27:28 +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=oeizNkiE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97EBC1F00A0A; Thu, 12 Nov 2026 01:27:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794446847; bh=gCrBj/L0nVk0Y4rofc9IruZOjajTmVyTiEHWsaHrV40=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=oeizNkiEanCwVfNBW8cDUMRCoudYoAXgDzGG5RkrrJX052IikEJOfbSPZ8VTo93Au s5b5pjHSKOo9Jis0XUbivT2BCOehjwMgcHPcGIlvS0hf4EQGK2FrqE15Flv6CueGkS bMzxFEGRRWdp6knvGp7UthDL59bjCaOAWc3xBQYH/ONPH+AHUvdFUofvM/Ch5thLBT N8db2pKn8zRZdodgl4gAv5Cer1af3EBUJLtEF+7vMYtnGXL/XLU3u5xcd+xf3rsaxY sUxaa3tMk5S/924Ua6ewi81UG/wHNzZZzjcbQFaWswWuqEmgsLkXAW4Q8tMt94EJCp fbOwV6bkDKFww== 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 v2 05/13] tracing/eprobe: Fix 1-byte signed field fetch in get_event_field() Date: Thu, 12 Nov 2026 10:27:24 +0900 Message-ID: <179444684450.345731.8324000135791531252.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <179444679892.345731.5271591537517106679.stgit@devnote2> References: <179444679892.345731.5271591537517106679.stgit@devnote2> 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 From: Masami Hiramatsu (Google) Because the kernel is built with -funsigned-char, plain 'char' is unsigned on all architectures. Reading 1-byte signed trace event fields via *(char *)addr in get_event_field() therefore zero-extends instead of sign-extending negative s8 values. Use explicit fixed-width integer types (s8/u8, s16/u16, s32/u32) when reading event fields. Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_eprobe.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index f1590c9af6b2..9defe86f4e8f 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -334,21 +334,21 @@ get_event_field(struct fetch_insn *code, void *rec) switch (field->size) { case 1: if (field->is_signed) - val = *(char *)addr; + val = *(s8 *)addr; else - val = *(unsigned char *)addr; + val = *(u8 *)addr; break; case 2: if (field->is_signed) - val = *(short *)addr; + val = *(s16 *)addr; else - val = *(unsigned short *)addr; + val = *(u16 *)addr; break; case 4: if (field->is_signed) - val = *(int *)addr; + val = *(s32 *)addr; else - val = *(unsigned int *)addr; + val = *(u32 *)addr; break; default: if (field->size == sizeof(long)) {