From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) (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 66D8B156F3A; Tue, 25 Feb 2025 18:06:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740506797; cv=none; b=YDfASeEtKn/8SCRcpNTtmr8MPdKgU21cNMcF/+Tn2PgA+L/PUTEZitlayVIznqZ/RpD5DAYZGJqmeeNyBhRio1m9XG957mzr2heW2Px0QJ6+vz2PNEl1fwvhwHbJTRPzScWKGX6ily+7EzmZk0oLZyOa+i94rp4bQFe2osdwoM8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740506797; c=relaxed/simple; bh=zchtCEfEGcKd3MAmswqArfI+K6HNuL7Cz7XDtG3NbNA=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=omw6/bzf5Pe6xaULbxanKbDmdZ3z+FCMz5POjx50taJ6op7mYhFE8BllNZf5S7P/VQd5xeGvfSWHC4nA4VR2JEHGZY7XixRyswRp83RJJY+c3+VKB67pmT1Y1eypFxGS5z7xWhUEdvJ2wWHNsLkHx/zgJH5HvXDbiXTHJUJ2T/o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Y4oifWZd; arc=none smtp.client-ip=209.85.128.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Y4oifWZd" Received: by mail-wm1-f50.google.com with SMTP id 5b1f17b1804b1-43aac0390e8so15406255e9.2; Tue, 25 Feb 2025 10:06:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1740506793; x=1741111593; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=zchtCEfEGcKd3MAmswqArfI+K6HNuL7Cz7XDtG3NbNA=; b=Y4oifWZdg4UIF2bN0BfWa9urTM3jRZzoW1QN6DcLlXirvkiAKj6aDDGEBMjrfKlL+t xy+Lz7k6BMECbFed8A9wnsL1S4Oge1kJMqY9YTUET1/NUEiGbl0jAP86uCdoZ8UeUMEg HAm2NrCOaPHlheOnwOM9dAw0k7ZW//nadzEYUyUXfzygwjuqi4nlUt4YC4Zz67C4vw2f UJq6GrmNEkfmo5SZk5vRuOk5nwdPEEGi/rjNHs4pcJbSgqg5uAXokHPWlCxBrWmJBQBi 9aLvPPaKm3bNZ7BZTHvzMKFO5MauM8hzUS8+j9BKcwnAiQIDfzbwjTjmghel+fL1t12V LuMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740506793; x=1741111593; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zchtCEfEGcKd3MAmswqArfI+K6HNuL7Cz7XDtG3NbNA=; b=HP68725Feem9g5QDjwLjxfpAPzaRagT8+URSKDSvV+3axFBae72g8nabqztGn/+Og8 B4/UDbEEBqOO6SOB/di66VqvgYTJNRc3I/uCVuL6Xse+rVy7Ta57i4Rwh36fnIbXmpSq 4YXYhZD15pa+8up3ZqbxuBjwwt4bOAdOchrYd9S9OvNlK4VCFkXzuiIB1zQPCTYVdTyY oqoq4x4a3rRdLEmC/uBcrJWGGR1ONxHiL4aNkI/IAuP6fL3yAtEBuI45/NNcKGNYv+Qc AXT2x1+he3pc5iZIyngfRYOuEeV/K6eYRLg7fxqvuc32f2Eov5sFDALtCo2RBQevo4ah hxew== X-Forwarded-Encrypted: i=1; AJvYcCW4t5davvoATg/D+1oVAeqj/VUP7dnwfXP8f+0AKzxlsmSVeoD80FnfbzBO8GcR7Q7FNis=@vger.kernel.org, AJvYcCWl6QkI3dmc/XohEhTW5Y5IaLdwpSnX1LjQ7cEJY45szxpSMCA25gEqWT2lVCe4er8odv/ya4QdcjbQEbrk@vger.kernel.org, AJvYcCX7PjBgC546bUBAbYlyL7YYWEer8bvrCz4zaSUBaRUqKb7gxkGvA5ZWW991LSBTniRTFi3YrwkLq3TQtZjB3H4rN+Jg@vger.kernel.org X-Gm-Message-State: AOJu0Yyi7KIyi6TnoVNDeu48TmByxQzP/FKAX0Tm1LEuPyYYU5xQiff6 2HUK5ZhDC0EonB2HQNDHSjnDF4jzhPUi3fhm8AnvBQOM5hyeEFR3jzSdZvOCwTxoEa4PW1YyvD+ l3NXlYwk/LzCSLIGJpq+j/OS85L+WxMUB X-Gm-Gg: ASbGncuNiOaYT9OkRy/Bhrv490UDKGvP8MiamexKrP6162v+2xROlF2tJsP4Bi57vb8 VEcT/QIs9U3hY2xZ6lRwYTbeI5oG8FOEEY30HhJxAiObYKsnauIoqLXyIfvvsQooVTqvgDtU+lP jefdjSLAksVdarprttrpV+sXs= X-Google-Smtp-Source: AGHT+IGlwkwtt8yLazHetKUrxIo1z6pDXtJnI2CGJXL07EgtfUktZVrpKCWsb3EHD1nsxtvSR1Y7t73KP/dUgPFF8CA= X-Received: by 2002:a05:6000:1fae:b0:38d:cbc2:29f6 with SMTP id ffacd0b85a97d-38f6e947434mr14144173f8f.17.1740506793340; Tue, 25 Feb 2025 10:06:33 -0800 (PST) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250224140151.667679-1-jolsa@kernel.org> <20250224140151.667679-9-jolsa@kernel.org> In-Reply-To: From: Alexei Starovoitov Date: Tue, 25 Feb 2025 10:06:19 -0800 X-Gm-Features: AQ5f1JonQ3bzFeYH2MPwYc-bN0juQN4SqNxsA6Q12e74EuGvHeE7xiA9aTlZ6Xg Message-ID: Subject: Re: [PATCH RFCv2 08/18] uprobes/x86: Add uprobe syscall to speed up uprobe To: Jiri Olsa Cc: Oleg Nesterov , Peter Zijlstra , Andrii Nakryiko , bpf , LKML , linux-trace-kernel , X86 ML , Song Liu , Yonghong Song , John Fastabend , Hao Luo , Steven Rostedt , Masami Hiramatsu , Alan Maguire , David Laight , =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, Feb 25, 2025 at 5:35=E2=80=AFAM Jiri Olsa wrot= e: > > > In later patches I see nop5 is replaced with a call to > > uprobe_trampoline_entry, but which part saves > > rdi and other regs? > > Compiler doesn't automatically spill/fill around USDT's nop/nop5. > > Selftest is doing: > > +__naked noinline void uprobe_test(void) > > so just lucky ? > > if you mean registers that would carry usdt arguments, ebpf programs > access those based on assembler operand string stored in usdt record: No. I'm talking about all normal registers that trap-style uprobe preserves, but this nop5->call will scratch. Instead of void uprobe_test(void) add some arguments to it, and read them before and after nop5 uprobe. They must remain the same.