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=1794184134; b=z9d06Vb7df6o6n54jBYP05TAUb617592GMf0RU6q52dGarsFiCQmgsELMLm4wXYdelvo zEOM60pzM6CBScAK22Un7qB5p07ys73BIluVBrypdi/wZv6ZrO2wqQSItfw6r00aPpUlu wd9FzVI0ugOVDuEisawN5dVUfngdDlPCZaeP+dwOarPJkMESV/L4KHSeQZZC320F6Dh9i mj3hbareXJ3geOoIUO5YT0Tsi2kj4t2FLYM9YU3LI/kMUbA4qt2oyxSU0Xb7RONGAjuGS EgtMoTjMhRHGxcjgZQ5Xc2MrPQUkQfEWfJW3+ThHMTrE7wGI36KgCvWeXCTuYvrUV1g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794184134; 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=IhzINCA1oF6W+yH/Lb8kr/1ZeCYibumXBmXCoUbE6KFxMGmVYB4bRdcpSJZ6UZJGL1nj vfnHVvF8e6GxF/dY/xT731maj43+OxTcq1AVNE6Bd6afepn5LQ8qEIPd7qxepWdP5N75P mF4QkhZe9nrYlMa1E+rX6BnZwhaZFTdYBZovFqhxpr7/hrdYo8wzbpK/Vzh3axsdDG7d1 5GCMhTyOlOa9NHYpAqM+oxsMPgEpgxIZj9LVFX6XoDJ84lElGhei/WI+eENXToYyV0GZk AJN4C343bkqS7EPLvy0F580WdYv0uPzvypiCNe1ISXgXTQm3EcvYGCxiob0sVyG7VtQ== 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=YdN0nqEH; 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 CA32A606A33B; Mon, 9 Nov 2026 00:28:53 +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=YdN0nqEH Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47B1B1F008BD; Mon, 9 Nov 2026 00:28:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794184133; bh=gCrBj/L0nVk0Y4rofc9IruZOjajTmVyTiEHWsaHrV40=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YdN0nqEHYHW9IXIIsnukUYR498thAEYe0E3NNUWCEYGQcnBOQtjqQwbcKU1x6hb99 4E0S9MMwiMpPuaTwelBuoTh8hR8g7bvfF+hwuPIcLcJZZo6IzItRD0bLBQ+tVrxnUX HTjFJU79GhZmpQ2QFSJe3QH5FCsF6adP2129vmS/OO7WBS8C7HZKUEK32sxI6CazEV I0Q5ZaMTRB6Az2Sq//9Hg3lF1iPe6v+ks8z1NyTn9PQxfji2Xh7JTxJ8RSHvTAfTKS 8Qy10cEg6u8Ri03JlMRSss977NeDMO/OLWw7bgisz5XPL7Kx80LlgPhW/QRdzeuelS dYt81GL4H1aYQ== 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 05/12] tracing/eprobe: Fix 1-byte signed field fetch in get_event_field() Date: Mon, 9 Nov 2026 09:28:49 +0900 Message-ID: <179418412989.227715.15975346868609035820.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <179418408457.227715.1485179201014819821.stgit@devnote2> References: <179418408457.227715.1485179201014819821.stgit@devnote2> User-Agent: StGit/0.19 X-Mailing-List: linux-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)) {