From nobody Wed Dec 17 19:52:29 2025 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 19ABF1DC18B for ; Mon, 16 Dec 2024 23:25:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734391512; cv=none; b=mEwUM6fes/QHW0Atew1oClrlE/TdQfooF49sE53P5dTdCk/ctkt8oN2wOZrwiViBQKxGc5rcvVI991Fp25N/kjsZDo7qWEVNU77rdSo+U42r8hzzBgOBHCc7EETYhy7u7PcW2KvMQYdJQpMsRECO3zp+SDa7P8yjFrxkXBRSOO4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734391512; c=relaxed/simple; bh=BrUJvr7HXzMJyoNYnziI4wlrd5p8WOXp8dhXnVgi80k=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=G/kRG5ar7to8zCAPW0t4GuC5k/g/+gMVk5kjNwBp8NBSOM90Sfg8iH/8CpiNa0lVhRW423Gamq4/JL2I1Za/TR9yrcCX6LtVCU1tmekWYNi0HYrkTnQ1JHjNQofGmqamOIXVcoD3HNAAjPg6R3nzOKpbX17BY1WOGnwKDn/mOgU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=crfsoyi7; arc=none smtp.client-ip=209.85.219.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="crfsoyi7" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-e3c61a11a40so6887371276.2 for ; Mon, 16 Dec 2024 15:25:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1734391510; x=1734996310; darn=vger.kernel.org; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=cLJ1stvpEh/i9mxehEqquhSJV82oFfMq3Eq8V809bTo=; b=crfsoyi7TwlBKtEypJWDFUPLCQZE7GZG8G1J4ekb5xwxsMQ0YUQsntvGoZ2W/9eF8V Ge47PAvXRNdxG/btRXTCcoHaz2mi0tWQXyyrSELNgOqP84Z/+108CbQxiJQRsKuMj/32 MqbI/fcjg4KJSL4jYTuC/DH7yXWX7VAyxSOLUvd6RcZbao6MzDjJxTZ1DZiidybaHcYE AS4WSHO2xBUJay6sNfTSACc10D3nxH1HWxAFY80VWoIw3NCytTkBOwi+QqY2LasqR7EY fE/YbSqe6ZVbFPG3F6jRCiwE2WWmm6RX1tY0OYX7rP+840A7WWC42onW+dtOtyrgGTbC xx4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1734391510; x=1734996310; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cLJ1stvpEh/i9mxehEqquhSJV82oFfMq3Eq8V809bTo=; b=G0XFr5uzehEwVYCsgP0JZh+Huh5bWCeDLDxdEv9IPF761+3xFBgs5JzpzU4XGpYs2e DJwfOxL8VmT3WoBSUfvEDeiJT3PC7YNckWuxM7ysz49FxYW1+oqVFpEHIKU0LAeS2PQ5 CjZODNcPdpbgrDfS3GvjLz65iIleFIv4ZTDO2O89X/SYr4zC6jBQYpH7NgvS0vtV27ce QBLlpfZFR+/3bRjM37M36ycOMvYNZ29vI47LEnJ5YWlPT+vbXsiQ9ZHzAiRtEDqlxTB7 YUQ1CF5CIabLFhbwbyYGObh30vBVhyuzA81Txd8xoZjAnafejeNBHVAy0CrMiumZzQav GjtA== X-Forwarded-Encrypted: i=1; AJvYcCWLPoxUa1z7JPJub8OSlnyaYYEoIDDs+xIxAvx12JAFBuggcW2QjrE+A4Jol8VRtVFdtypSy8VqC3804rw=@vger.kernel.org X-Gm-Message-State: AOJu0YzqoorYu98i700+05wiGUmonZ8EMsnMLYwuy68sIuQlsDBu5tti YSvoW64UiPO1APrpT9bFff/UtMO64h/NrOeeXxPK81NA0nD3mnJE9MRL4YvOlt2R+NWpjixMB+I 2rlTsKw== X-Google-Smtp-Source: AGHT+IEBk2ZWqf3tvA5JHyC7+FOyJZXG8fvNRj78GZbr7laoh+Qh/+6h6VlNMjqZMzkUaxrw+ZzcYont7naS X-Received: from irogers.svl.corp.google.com ([2620:15c:2c5:11:b850:b916:18b9:17a7]) (user=irogers job=sendgmr) by 2002:a25:c74d:0:b0:e3c:88e3:b8ba with SMTP id 3f1490d57ef6-e434e9bfa53mr7252276.5.1734391509720; Mon, 16 Dec 2024 15:25:09 -0800 (PST) Date: Mon, 16 Dec 2024 15:24:57 -0800 In-Reply-To: <20241216232459.427642-1-irogers@google.com> Message-Id: <20241216232459.427642-4-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241216232459.427642-1-irogers@google.com> X-Mailer: git-send-email 2.47.1.613.gc27f4b7a9f-goog Subject: [PATCH v3 3/5] perf synthetic-events: Ensure features are aligned From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Sun Haiyong , Yanteng Si , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Features like hostname have arbitrary size and break the assumed 8-byte alignment of perf events. Pad all feature events until 8-byte alignment is restored. Rather than invent a new mechanism, reuse write_padded but pass an empty buffer as what to write. As no alignment may be necessary, update write_padded to be tolerant of 0 as a count and count_aligned value. Signed-off-by: Ian Rogers --- tools/perf/util/header.c | 7 ++++--- tools/perf/util/synthetic-events.c | 2 ++ 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 03e43a9894d4..d10703090e83 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -168,11 +168,12 @@ int write_padded(struct feat_fd *ff, const void *bf, size_t count, size_t count_aligned) { static const char zero_buf[NAME_ALIGN]; - int err =3D do_write(ff, bf, count); + int err =3D count > 0 ? do_write(ff, bf, count) : 0; =20 - if (!err) + if (!err && count_aligned > count) { + assert(count_aligned - count < sizeof(zero_buf)); err =3D do_write(ff, zero_buf, count_aligned - count); - + } return err; } =20 diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic= -events.c index f8ac2ac2da45..ee6e9c2fb11b 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -2401,6 +2401,8 @@ int perf_event__synthesize_features(const struct perf= _tool *tool, struct perf_se pr_debug("Error writing feature\n"); continue; } + write_padded(&ff, /*bf=3D*/NULL, /*count=3D*/0, + /*count_aligned=3D*/PERF_ALIGN(ff.offset, sizeof(u64)) - ff.offset= ); /* ff.buf may have changed due to realloc in do_write() */ fe =3D ff.buf; memset(fe, 0, sizeof(*fe)); --=20 2.47.1.613.gc27f4b7a9f-goog