From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91709CD1288 for ; Wed, 3 Apr 2024 14:11:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0CBC96B0087; Wed, 3 Apr 2024 10:11:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 07C7A6B0088; Wed, 3 Apr 2024 10:11:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E85C16B0089; Wed, 3 Apr 2024 10:11:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id CB1426B0087 for ; Wed, 3 Apr 2024 10:11:38 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 3B1761C0CC2 for ; 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x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 79FDD1C0024 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: b6ifj3dd5srhh9xni9dcrgjt8dy4puag X-HE-Tag: 1712153495-157795 X-HE-Meta: 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 QSY8zgNr qzNw4RUTkRtYBAuHFYjySttwcONAI33vClLHRJOG23srj7xYxBigRd6rLF4E615VKlqcVS6NHhRcLGFRM7CiWUJab9I1MrWWJjkGibtWTU1xse9oIWlUwBxTJu+1glCL0t4wt5KNHkwlhphDjdFrOP4ZvlJxX5PS5ZrsKt6IWIxlsSHXwsXC7NoeSClKFZKSDPFjij66L5nC7ljt/+466nmgXhe3X6GGlC0Mu/IfMo7j6NAmvsuBK/xbAbf8Si1yQC5yx8wUfxV8rX+XnmGBlvg5VQu2S8F2LFV4ecMqCHIsjQbCn+lLfwEFX4w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, 29 Mar 2024 14:40:55 -0400 Steven Rostedt wrote: > > +static vm_fault_t tracing_buffers_mmap_fault(struct vm_fault *vmf) > > +{ > > + return VM_FAULT_SIGBUS; > > +} > > If this is all it does, I don't believe it's needed. > > > + > > +#ifdef CONFIG_TRACER_MAX_TRACE > > +static int get_snapshot_map(struct trace_array *tr) > > +{ > > + int err = 0; > > + > > + /* > > + * Called with mmap_lock held. lockdep would be unhappy if we would now > > + * take trace_types_lock. Instead use the specific > > + * snapshot_trigger_lock. > > + */ > > + spin_lock(&tr->snapshot_trigger_lock); > > + > > + if (tr->snapshot || tr->mapped == UINT_MAX) > > + err = -EBUSY; > > + else > > + tr->mapped++; > > + > > + spin_unlock(&tr->snapshot_trigger_lock); > > + > > + /* Wait for update_max_tr() to observe iter->tr->mapped */ > > + if (tr->mapped == 1) > > + synchronize_rcu(); > > + > > + return err; > > + > > +} > > +static void put_snapshot_map(struct trace_array *tr) > > +{ > > + spin_lock(&tr->snapshot_trigger_lock); > > + if (!WARN_ON(!tr->mapped)) > > + tr->mapped--; > > + spin_unlock(&tr->snapshot_trigger_lock); > > +} > > +#else > > +static inline int get_snapshot_map(struct trace_array *tr) { return 0; } > > +static inline void put_snapshot_map(struct trace_array *tr) { } > > +#endif > > + > > +static void tracing_buffers_mmap_close(struct vm_area_struct *vma) > > +{ > > + struct ftrace_buffer_info *info = vma->vm_file->private_data; > > + struct trace_iterator *iter = &info->iter; > > + > > + WARN_ON(ring_buffer_unmap(iter->array_buffer->buffer, iter->cpu_file)); > > + put_snapshot_map(iter->tr); > > +} > > + > > +static void tracing_buffers_mmap_open(struct vm_area_struct *vma) { } > > Same for the open. > > > > + > > +static const struct vm_operations_struct tracing_buffers_vmops = { > > + .open = tracing_buffers_mmap_open, > > + .close = tracing_buffers_mmap_close, > > + .fault = tracing_buffers_mmap_fault, > > +}; > > I replaced this with: > > static const struct vm_operations_struct tracing_buffers_vmops = { > .close = tracing_buffers_mmap_close, > }; > > And it appears to work just fine. The mm code handles the NULL cases for > .open and .fault. > > Is there any reason to do something different than the mm defaults? Hi Vincent, Do you plan on sending out a v20 series? -- Steve