From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) (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 4BB7D3911A2 for ; Wed, 12 Aug 2026 16:14:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786551245; cv=none; b=ue++defLUSLW6y4CVgCjtR0rhBrw0GjBvHPa2U0W+YdYESfniVqw7aJgH30EJccBqTgAp13bpTaxwcgtcLXTpVOg3ybLP4TZuJGFMsHjINB9TMOmstgRvJ92I5rFLdrIMNiuSNw5O4JJ/TKV1vCxYgb9cvebqTXQ+RDiWhXTa04= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786551245; c=relaxed/simple; bh=wsZEE9Zz0mqjuBsNamOoGhBoBuELzXWcnKGuADaQB2I=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=X5xtw7iyjJts38p1K/NJgaWi/bQZy3DvKcqIb5wleGopmJw3zEtWAb9GIGGq0q3Ckn5T/32hSghjMgN2QqmblgHFnQdq8uMlINFFKGU7qcn2fqZKrLtAuD2Z4ajznuHDCqKKy0yFGVAxtfqea7AiKUpCI/y8JtunwviQPMfOCtg= 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=KFiEJEJ7; arc=none smtp.client-ip=209.85.221.70 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="KFiEJEJ7" Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-47f6d70223dso831824f8f.1 for ; Wed, 12 Aug 2026 09:14:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786551242; x=1787156042; 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=Ji3tCFeKYvvU/YCTSwEXd6efxBELYIn3Hl3vNbltnQE=; b=KFiEJEJ7+2lxI4FZBZ9OtlAxr6Lyc6zh5KG5550PEm7hVX0dm2QuV3uLFim+ggcsuI GhnkSqNk+Sn9oaRHuaFl6DNagtiCSgiDLDI5QhoOVS0obTLKrDvFmIyR12MF5z221GkT 6Jpt5fvC9p1lGgV181J6FKP7YmvVyuB34M11NY8UC7v+buPNy0TNQ2HjJMdxok0HN1QQ f4Qqj41Xeur43ht/epBzO1dgus1n5RnfNTvjl5jAYBwjo3MQmq4Y2BMLxHbPwXUXI8j7 AuR9R4V5NRZsBQc/xxu7rU9hrrWZ7Qhwc9ccDJVKHlnVdiwBGRCVRKbuzjNyOO3cjBy8 Y+dA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786551242; x=1787156042; 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=Ji3tCFeKYvvU/YCTSwEXd6efxBELYIn3Hl3vNbltnQE=; b=SLabjrPS3exE1p8fizI9AVMqvl/kCNiOvYTLlb4GJbLl52LyijkxTkeAEdAx6CsGRH cVm0pDCr/HOlipl5oB2RFtkTtf1npD2sFUP1sabjshK6Wa/LTTJvYpyMX/+GgpZfV+3g QlFQA9ZDUWoR/NKBeDazwA6uFqaNSKIkYkHxjlTbuhxGKxYYEfG1e026XzhRLW0I6gSY sW8TxBCrZhEdFmL7G4hG+j5XfL+5taByayWFz1I41PHcfn3oNyIZBA0EGoKOHgNPuywP x37zdEhLIoUs24tSbvbcfJ+EvNtcezip+YgSdjis6lckcAjaTrONYIviRQo3FxGMpgdr FfDg== X-Forwarded-Encrypted: i=1; AHgh+RpzzyoIJTWe24PG3fDzZjf7I1s77zmw+oNvp7Ix0tDoaY06zxQLx9uJlvmhHdfeR7A4Y7SPGjHEfURy4ELFiqshqKA=@vger.kernel.org X-Gm-Message-State: AOJu0Yzz0WCSsEos25xUJ5C3kFE7ZRJOMG0q/K23L8RmKBCCNfvHUIKH Voz+Q1LjlrFFYpNiE7FmeYCh7YyBiBJRcjTGs3PTZP0yNrK+l2cKEcvAw+O3lknOHVhLTg2zfiX m4Y0JPSOlzJrg3zdxm2YR3Q== X-Received: from wrql16.prod.google.com ([2002:a5d:4810:0:b0:47f:90dd:e729]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:25e3:b0:47f:90a4:ff42 with SMTP id ffacd0b85a97d-48152b0a8ddmr9032868f8f.5.1786551241963; Wed, 12 Aug 2026 09:14:01 -0700 (PDT) Date: Wed, 12 Aug 2026 17:13:38 +0100 In-Reply-To: <20260812161340.2417322-1-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: <20260812161340.2417322-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.691.gc56d675ccc-goog Message-ID: <20260812161340.2417322-17-vdonnefort@google.com> Subject: [PATCH v5 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 b1c75666ab63..8764d0ed3909 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 +1171,124 @@ 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)) + continue; + + opts_cmdline = token; + events_cmdline = curr; + + 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 +1465,7 @@ 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 +1949,15 @@ 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; +} -- 2.55.0.691.gc56d675ccc-goog