From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) (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 1D04846E013 for ; Tue, 4 Aug 2026 14:04:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785852254; cv=none; b=dX4jRI4sWHsodXpIh+YJV131i5jOlG8nyZY1OsFG4EuBoU+pJmEakfQkCHry0WAj5LqUBzyBNwij1bbqINesk8RCaQ6k3QbtUIwgGvLB0MdeGmEjEYFdqiSFC0OHc0WVBLCkJtnCYAxvginK8IbzZG3dQRdr/oS5aiCN5zqjR3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785852254; c=relaxed/simple; bh=QGatgsAET/5XqKb3+hsGKw6QkVZbzk2Z1c+qVO2iegI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=h3yX9O/gjzoDu1+KGD1cYA2Mx/psw83YIhiLYoSS8DlKgievzLfjYHLSj5U+cX3ecnAmwmUjK8Kq7KdCtLis9CXJz13UPMlySJhngvW+H/6PODvBEWfBIS4W2LefYSDWnzVutd/aKUQ+O5uVtzfbwIqKnfPlxVwesFk5HfzepTU= 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=abI1O0cp; arc=none smtp.client-ip=209.85.218.70 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="abI1O0cp" Received: by mail-ej1-f70.google.com with SMTP id a640c23a62f3a-c1c25c44d15so293918266b.1 for ; Tue, 04 Aug 2026 07:04:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785852251; x=1786457051; 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=/J+xPvL9n08cw0WZxmpDgbasEs5MnLj6R6UWekeMZ2w=; b=abI1O0cpP1+s1pKItgbKz39T+ViRvX1XlxtuwgQudkSI7VPOtR7pSmIR8LNszvVYOb ApLStjOC5QEezOeqG6LNHiihX0D3QFd6zmTaGqX/UFN2K3WZPK9UatBv3c/xsqjGP3Hu KbQIpuP3s841S4K+c3uTEFzog/ZvDcco1Li6rbwgeHvEUl4I5X5irodrYHkVl0ihJOpY 9VH4vRkdaA7dRr6sEBG9sIYcWjtxKTQpHEruiI5yhuN8j4JG3AjElruKjUWOeaLvkq11 PwjIrOPvZ8xUsw5UII0npUmLHlG1ipEaJILYa3qb7RtHtPEpD0VpUp8SfDkG6GIdvT8F BWpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785852251; x=1786457051; 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=/J+xPvL9n08cw0WZxmpDgbasEs5MnLj6R6UWekeMZ2w=; b=DUA7ipjitnWrI+90mtNMY40/4i486ZvoJr+cmJebBHTEbUFdUoCNdAQUTbU5oVlGPc 0QRpqD/8k5B8osaBfRfWBzJyy2MpzJAAXXVon9S/orzIrdylAIu5sRQptCWfmx5N1Did Xlmw2D2LOnSXp3MEmqtouUsxP5Tna6XFyH59Bz4laK7ZIVsWl9Dh7lKR0kXHhLkR6UFm 2yOLOlzoen36Q0dffBL7upGMke8zXszALW+Q3UNxGlgtlzMuDy74JD7sP3HuzL7d0Myj NfugSU4gRkPvNLwNp2W+GRC96d12lzFrNsS1+47NmUG98O7LIssctMnlxDCWtcbZk/5r Im7w== X-Forwarded-Encrypted: i=1; AHgh+Rp9szxw9e8wC6U0PVtDoVe9tfjwWQ88y2EyMucWI7VtZ9hzM58uxGGITGLNskvNi9zNJxBbygYRjtOkzt3sNznXjSI=@vger.kernel.org X-Gm-Message-State: AOJu0YySTfTStIlFL0XmPf2oJsElgJ0y9j8091HQat0sP1vLKJBqiXbg GVfOB0n96Xb9059zAIg4G9TxVysZSZf73xRFRWxrGl2XnJJgiW90eJ9umMLfdaiCAwNvLn7UMKb RVFfvVdxIrsncg+6B+MFjCA== X-Received: from ejbgz12.prod.google.com ([2002:a17:906:f2cc:b0:c12:5011:7092]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a17:907:987:b0:c12:5a0e:3e0 with SMTP id a640c23a62f3a-c20283c4a01mr317099666b.19.1785852251065; Tue, 04 Aug 2026 07:04:11 -0700 (PDT) Date: Tue, 4 Aug 2026 15:03:31 +0100 In-Reply-To: <20260804140333.797210-1-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: <20260804140333.797210-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.571.g244d577d93-goog Message-ID: <20260804140333.797210-17-vdonnefort@google.com> Subject: [PATCH v4 16/18] tracing/remotes: Add trace_remote cmdline options 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 Content-Type: text/plain; charset="UTF-8" Following the same format as trace_instance, add a cmdline to configure a trace remote on registration: trace_remote=^^,, Enabling events automatically turns on tracing. Signed-off-by: Vincent Donnefort diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index ccdac9fa106a..e72ee6ecf473 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -13,6 +13,8 @@ #include #include +#include + #include "trace.h" #define TRACEFS_DIR "remotes" @@ -1169,6 +1171,125 @@ static int poll_ms_show(struct seq_file *s, void *unused) } DEFINE_TRACE_REMOTE_ATTRIBUTE(poll_ms); +static char trace_remote_cmdline[COMMAND_LINE_SIZE]; + +static int __init set_trace_remote_cmdline(char *str) +{ + trace_append_boot_param(trace_remote_cmdline, str, '\t', COMMAND_LINE_SIZE); + return 1; +} +__setup("trace_remote=", set_trace_remote_cmdline); + +static void trace_remote_apply_cmdline_opts(struct trace_remote *remote, char *cmdline) +{ + bool dmesg_on = false; + char *opt; + int ret; + + while ((opt = strsep(&cmdline, "^"))) { + if (!*opt) + continue; + + if (!strcmp(opt, "dump_on_panic")) { + remote->panic_on = true; + } else if (!strcmp(opt, "dmesg")) { + dmesg_on = true; + } else if (!strncmp(opt, "buf_size=", 9)) { + /* buf_size can only be applied if the buffer is unloaded */ + if (!WARN_ON(trace_remote_loaded(remote))) + remote->trace_buffer_size = memparse(opt + 9, NULL); + } else if (!strncmp(opt, "poll=", 5)) { + unsigned int poll_ms; + + if (!kstrtouint(opt + 5, 10, &poll_ms) && poll_ms > 0) + remote->poll_ms = poll_ms; + else + pr_warn("Invalid trace remote poll '%s'\n", opt); + } else { + pr_warn("Unknown trace remote option '%s'\n", opt); + } + } + + if (dmesg_on) { + ret = trace_remote_enable_dmesg(remote, true); + if (ret) + pr_warn("Failed to enable trace remote dmesg (%d)\n", ret); + } +} + +static struct remote_event * +trace_remote_find_event_by_name(struct trace_remote *remote, const char *name); + +static int +trace_remote_enable_event(struct trace_remote *remote, struct remote_event *evt, bool enable); + +static void trace_remote_apply_cmdline_events(struct trace_remote *remote, char *cmdline) +{ + bool tracing_on = false; + char *token; + int ret; + + while ((token = strsep(&cmdline, ","))) { + struct remote_event *evt; + + if (!*token) + continue; + + evt = trace_remote_find_event_by_name(remote, token); + if (!evt) { + pr_warn("trace remote event '%s' not found\n", token); + continue; + } + + ret = trace_remote_enable_event(remote, evt, true); + if (ret) + pr_warn("Failed to enable trace remote event '%s' (%d)\n", token, ret); + else + tracing_on = true; + } + + if (tracing_on) { + ret = trace_remote_enable_tracing(remote); + if (ret) + pr_warn("Failed to enable trace remote tracing (%d)\n", ret); + } +} + +static void trace_remote_apply_cmdline(const char *name, struct trace_remote *remote) +{ + char *cmdline __free(kfree) = NULL; + char *events_cmdline = NULL; + char *opts_cmdline = NULL; + char *curr, *next; + + if (!trace_remote_cmdline[0]) + return; + + cmdline = kstrdup(trace_remote_cmdline, GFP_KERNEL); + if (!cmdline) + return; + + next = cmdline; + while ((curr = strsep(&next, "\t"))) { + char *token = strsep(&curr, ","); + char *rname = strsep(&token, "^"); + + if (strcmp(rname, name) == 0) { + opts_cmdline = token; + events_cmdline = curr; + break; + } + } + + guard(mutex)(&remote->lock); + + if (opts_cmdline) + trace_remote_apply_cmdline_opts(remote, opts_cmdline); + if (events_cmdline) + trace_remote_apply_cmdline_events(remote, events_cmdline); +} + + static int trace_remote_init_tracefs(const char *name, struct trace_remote *remote) { struct dentry *remote_d, *percpu_d, *d; @@ -1345,6 +1466,7 @@ int trace_remote_register(const char *name, struct trace_remote_callbacks *cbs, } list_add(&remote->node, &trace_remotes); + trace_remote_apply_cmdline(name, remote); retain_and_null_ptr(remote); return 0; @@ -1828,3 +1950,15 @@ static struct remote_event *trace_remote_find_event(struct trace_remote *remote, return bsearch((const void *)(unsigned long)id, remote->events, remote->nr_events, sizeof(*remote->events), __cmp_events); } + +static struct remote_event * +trace_remote_find_event_by_name(struct trace_remote *remote, const char *name) +{ + int i; + + for (i = 0; i < remote->nr_events; i++) { + if (!strcmp(remote->events[i].name, name)) + return &remote->events[i]; + } + return NULL; +} -- 2.55.0.571.g244d577d93-goog