From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (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 79D6B42E00A for ; Thu, 9 Jul 2026 16:00:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783612848; cv=none; b=oiThxxfiWh4sz6YlS0XWMYSDo7jew6WbT2aR6g4RW+NAhv67suBp34o8g/5nnq30x+PF3DMDIzlAuZ5rxnuUUdLYt6gDOOqpvY+rBIPp1HJPh8bAMoDYAXjATBLGY7Ge0oaZEkHoWTGeKpdkdQSSwNKYH5qt0oqXUdYilBCbeEg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783612848; c=relaxed/simple; bh=rLGcEWQLDsuBOlJtQaU04lVEFpTg/6Zm5TPaRWNb5r0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=klFWDCT4UyJ8q77ZaLkVJZe93qXcteSmxgDa/3TDpq4eSmRdEWwHgd9FkCvLI1fuY1yJmsd3MDCGpJY3Asn8MZssXsSPlLYpKwyf1DdOv2pEYnGYh2Wc38KVVRBltEIIfA/UUqhGkSCLyaTfp3lrIUzU3MAoBCqnwekuSfHQpMw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=VXNc0LW4; arc=none smtp.client-ip=209.85.221.74 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--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="VXNc0LW4" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-476608a9fefso830815f8f.1 for ; Thu, 09 Jul 2026 09:00:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1783612846; x=1784217646; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=Unj4WErTghUtss2IKhQJXeY0+igl+yHyxF7jgGiRQLQ=; b=VXNc0LW4FUqil+yJPfLaSxM6T1x6RhFjYWrpNqOccDPWIqoBqRFqkGSkLSpFPJqXNf xThvJN8+0PWM/JjqTHhbx6YkxKasy1RVHnV8wvWHoFWcEdNve/jpea9WqSB2LKQM2eAM 2nblQwRIFbap5YKsO9cewBT/GJwh3rZ2f/OVEa5Ky/VywfsLugQnc0gYQrPuac2Y9d8j GAqpWLBIY8JuN3GNAuGWh0Cupmu7eEXbU7Q3HJLXkDeNmc9Dzm1Ojrk5ByN3beXsZjZu E+ZcqwO2OBFijND/EWZtMrWIqWkvOeQjfCIkamckOKX+mSa61fXe3jJrX1WrRGdYhK0k 1u/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783612846; x=1784217646; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Unj4WErTghUtss2IKhQJXeY0+igl+yHyxF7jgGiRQLQ=; b=GVzSygWJ2n1XdMD7ixJWz8sqzI7ocdJS/uX3Asta46iW1TAOZ3A4Cg9WZ+wZ/tGNs6 xajSONC5LbxhiIH56rD1Y3/JVqM068QE22Gxw4t9GFU1T/uqMsA+nFm2Nm0YbLdso39c VSTecXToFQNhqo1fWZHuDJdDaQGq1rotc1sC2Jb3VoKwGxcz1E9wx4EVuLZz6roolJUU B5Puv7zu3aa94XDB7NVpGFSVNF4DiFc0qMAVcszsYhBIWiEtw7Z2DoREwFlHAVI/e+2h nj9dMBoS8ADtbBf9ilKYTg/WLHNWO3Y+WvlKHDreokxItMmLqsbYtA6rR0/Sx02crja+ HJ/A== X-Forwarded-Encrypted: i=1; AHgh+RrJrzlOisJMc0gv5Ec3cvpuRyVgTIH7Y74CyERpYHdRFjO97QGG0fZq9/Km9FJUaMw/L9yYmOZw32xTsOp+vB5UdF8=@vger.kernel.org X-Gm-Message-State: AOJu0Yy9+aUHFYoheFQ7mRjuVp3sK7azY6y+/OV+Uvmi18Fq/MI5LX3S Ar0FQIbcggjaAZfuqgJVftIbD4/1nC0VkMtdh7jldCMFdlYH0XzIuPCIJGeMBYKbpxbIzyyylaY uFHGe8+k4N3a0GmZKx+HvXw== X-Received: from wrbdl3.prod.google.com ([2002:a05:6000:b83:b0:470:4c2:a55f]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:2509:b0:475:da0e:744d with SMTP id ffacd0b85a97d-47df754dbc2mr4056983f8f.8.1783612845468; Thu, 09 Jul 2026 09:00:45 -0700 (PDT) Date: Thu, 9 Jul 2026 17:00:16 +0100 In-Reply-To: <20260709160017.1729517-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260709160017.1729517-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.795.g602f6c329a-goog Message-ID: <20260709160017.1729517-3-vdonnefort@google.com> Subject: [PATCH v2 2/3] tracing/remotes: Fix struct_len in trace_remote_alloc_buffer() From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, linux-trace-kernel@vger.kernel.org Cc: mathieu.desnoyers@efficios.com, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort , Sashiko Content-Type: text/plain; charset="UTF-8" Pre-calculate desc->struct_len up-front in trace_remote_alloc_buffer() with trace_buffer_desc_size() to fix double-counting. While at it, use the accessor __first_ring_buffer_desc(). Fixes: 96e43537af54 ("tracing: Introduce trace remotes") Reported-by: Sashiko Signed-off-by: Vincent Donnefort diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index d48042239d58..0f6ef5c36d84 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -979,27 +979,22 @@ EXPORT_SYMBOL_GPL(trace_remote_free_buffer); int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, size_t buffer_size, const struct cpumask *cpumask) { + size_t min_desc_size = trace_buffer_desc_size(buffer_size, cpumask_weight(cpumask)); unsigned int nr_pages = max(DIV_ROUND_UP(buffer_size, PAGE_SIZE), 2UL) + 1; - void *desc_end = desc + desc_size; struct ring_buffer_desc *rb_desc; int cpu, ret = -ENOMEM; - if (desc_size < struct_size(desc, __data, 0)) + if (desc_size < min_desc_size) return -EINVAL; desc->nr_cpus = 0; - desc->struct_len = struct_size(desc, __data, 0); + desc->struct_len = min_desc_size; - rb_desc = (struct ring_buffer_desc *)&desc->__data[0]; + rb_desc = __first_ring_buffer_desc(desc); for_each_cpu(cpu, cpumask) { unsigned int id; - if ((void *)rb_desc + struct_size(rb_desc, page_va, nr_pages) > desc_end) { - ret = -EINVAL; - goto err; - } - rb_desc->cpu = cpu; rb_desc->nr_page_va = 0; rb_desc->meta_va = (unsigned long)__get_free_page(GFP_KERNEL); @@ -1015,8 +1010,6 @@ int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, rb_desc->nr_page_va++; } - desc->struct_len += offsetof(struct ring_buffer_desc, page_va); - desc->struct_len += struct_size(rb_desc, page_va, rb_desc->nr_page_va); rb_desc = __next_ring_buffer_desc(rb_desc); } -- 2.55.0.795.g602f6c329a-goog