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[34.22.131.218]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-42707b482b3sm2142688f8f.50.2025.10.17.01.36.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Oct 2025 01:36:30 -0700 (PDT) Date: Fri, 17 Oct 2025 09:36:27 +0100 From: Vincent Donnefort To: Steven Rostedt Cc: mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 14/28] tracing: Add a trace remote module for testing Message-ID: References: <20251003133825.2068970-1-vdonnefort@google.com> <20251003133825.2068970-15-vdonnefort@google.com> <20251016170645.15416c8a@gandalf.local.home> <20251016171155.0d871fc3@gandalf.local.home> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251016171155.0d871fc3@gandalf.local.home> On Thu, Oct 16, 2025 at 05:11:55PM -0400, Steven Rostedt wrote: > On Thu, 16 Oct 2025 17:06:45 -0400 > Steven Rostedt wrote: > > > On Fri, 3 Oct 2025 14:38:11 +0100 > > Vincent Donnefort wrote: > > > > > diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig > > > index 918afcc1fcaf..52131d89993c 100644 > > > --- a/kernel/trace/Kconfig > > > +++ b/kernel/trace/Kconfig > > > @@ -1244,4 +1244,12 @@ config TRACE_REMOTE > > > config SIMPLE_RING_BUFFER > > > bool > > > > > > +config TRACE_REMOTE_TEST > > > + tristate "Test module for remote tracing" > > > + select TRACE_REMOTE > > > + select SIMPLE_RING_BUFFER > > > + help > > > + This trace remote includes a ring-buffer writer implementation using > > > + "simple_ring_buffer". This is solely intending for testing. > > > + > > > > Nit, this should go up a few places so that it's with the other "test module" selections. > > And when I tried to build it, I hit this: > > GEN .vmlinux.objs > MODPOST Module.symvers > ERROR: modpost: "simple_ring_buffer_reserve" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "simple_ring_buffer_commit" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "simple_ring_buffer_unload" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "trace_remote_free_buffer" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "trace_remote_alloc_buffer" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "simple_ring_buffer_init" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "trace_remote_register" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "simple_ring_buffer_reset" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "simple_ring_buffer_swap_reader_page" [kernel/trace/remote_test.ko] undefined! > ERROR: modpost: "simple_ring_buffer_enable_tracing" [kernel/trace/remote_test.ko] undefined! > WARNING: modpost: suppressed 1 unresolved symbol warnings because there were too many) > make[3]: *** [/work/git/linux-trace.git/scripts/Makefile.modpost:147: Module.symvers] Error 1 > make[2]: *** [/work/git/linux-trace.git/Makefile:1960: modpost] Error 2 > make[1]: *** [/work/git/linux-trace.git/Makefile:248: __sub-make] Error 2 > make[1]: Leaving directory '/work/build/nobackup/debiantesting-x86-64' > make: *** [Makefile:248: __sub-make] Error 2 And of course, I forgot to check CONFIG_REMOTE_TEST=M ... The following snippet should do. Do you want a v8 now (and with your previous comment) or shall I wait a bit more? -- diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 0c023941a316..aa305be834f9 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -665,6 +665,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, fsnotify_create(d_inode(dentry->d_parent), dentry); return tracefs_end_creating(dentry); } +EXPORT_SYMBOL_GPL(tracefs_create_file); static struct dentry *__create_dir(const char *name, struct dentry *parent, const struct inode_operations *ops) diff --git a/kernel/trace/simple_ring_buffer.c b/kernel/trace/simple_ring_buffer.c index c2ec6017c37c..02303161aab7 100644 --- a/kernel/trace/simple_ring_buffer.c +++ b/kernel/trace/simple_ring_buffer.c @@ -162,6 +162,7 @@ int simple_ring_buffer_swap_reader_page(struct simple_rb_per_cpu *cpu_buffer) return 0; } +EXPORT_SYMBOL_GPL(simple_ring_buffer_swap_reader_page); static struct simple_buffer_page *simple_rb_move_tail(struct simple_rb_per_cpu *cpu_buffer) { @@ -267,6 +268,7 @@ void *simple_ring_buffer_reserve(struct simple_rb_per_cpu *cpu_buffer, unsigned return &rb_event->array[1]; } +EXPORT_SYMBOL_GPL(simple_ring_buffer_reserve); void simple_ring_buffer_commit(struct simple_rb_per_cpu *cpu_buffer) { @@ -280,6 +282,7 @@ void simple_ring_buffer_commit(struct simple_rb_per_cpu *cpu_buffer) */ smp_store_release(&cpu_buffer->status, SIMPLE_RB_READY); } +EXPORT_SYMBOL_GPL(simple_ring_buffer_commit); static u32 simple_rb_enable_tracing(struct simple_rb_per_cpu *cpu_buffer, bool enable) { @@ -337,6 +340,7 @@ int simple_ring_buffer_reset(struct simple_rb_per_cpu *cpu_buffer) return 0; } +EXPORT_SYMBOL_GPL(simple_ring_buffer_reset); int __simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_buffer_page *bpages, @@ -427,6 +431,7 @@ int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_ { return __simple_ring_buffer_init(cpu_buffer, bpages, desc, __load_page, __unload_page); } +EXPORT_SYMBOL_GPL(simple_ring_buffer_init); void __simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer, void (*unload_page)(void *)) @@ -449,6 +454,7 @@ void simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer) { return __simple_ring_buffer_unload(cpu_buffer, __unload_page); } +EXPORT_SYMBOL_GPL(simple_ring_buffer_unload); int simple_ring_buffer_enable_tracing(struct simple_rb_per_cpu *cpu_buffer, bool enable) { @@ -459,3 +465,4 @@ int simple_ring_buffer_enable_tracing(struct simple_rb_per_cpu *cpu_buffer, bool return 0; } +EXPORT_SYMBOL_GPL(simple_ring_buffer_enable_tracing); diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index dc6bc387ebca..e54cc3e75dc5 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -895,6 +895,7 @@ int trace_remote_register(const char *name, struct trace_remote_callbacks *cbs, return ret; } +EXPORT_SYMBOL_GPL(trace_remote_register); void trace_remote_free_buffer(struct trace_buffer_desc *desc) { @@ -910,6 +911,7 @@ void trace_remote_free_buffer(struct trace_buffer_desc *desc) free_page(rb_desc->page_va[id]); } } +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) @@ -960,6 +962,7 @@ int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, trace_remote_free_buffer(desc); return ret; } +EXPORT_SYMBOL_GPL(trace_remote_alloc_buffer); static int trace_remote_enable_event(struct trace_remote *remote, struct remote_event *evt, bool enable)