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AJvYcCUu8EGvKS50dUeEWAMTgEgNFZpEVn4D/b24M3X4mXAcZH1yRThZ7xRgRaz5q3W9jOl6ivjOytt6PZfA3avrIh4=@vger.kernel.org X-Gm-Message-State: AOJu0YxJq0m6x/G9F7SvpP/gcxbESbyFlsHtsiyKAqvHVOenX2BmATUj uBx5L9kBDqcCIR2k4rLnfDdAGP/UIR0Lon5Au2mPSr04H12SsEuuOqz9bcC50KB5UhEvBhv6RF7 spiQ8PKcVPtfxvD1eEZvqgw== X-Google-Smtp-Source: AGHT+IFmFQ2+ilc/frkLStjSQyf19IpIYrW2nD/6coGLs4CVgqbF3qEYdPRbZm6F8+l8PBqgjQXpJziq3HiTUEpEQg== X-Received: from kalesh.mtv.corp.google.com ([2a00:79e0:2e3f:8:ad9b:6cde:2e57:6aff]) (user=kaleshsingh job=sendgmr) by 2002:a5b:d4c:0:b0:e30:bdc8:567f with SMTP id 3f1490d57ef6-e30c190221cmr60305276.4.1730308857554; Wed, 30 Oct 2024 10:20:57 -0700 (PDT) Date: Wed, 30 Oct 2024 10:17:49 -0700 In-Reply-To: <20241030171928.4168869-1-kaleshsingh@google.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241030171928.4168869-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.47.0.163.g1226f6d8fa-goog Message-ID: <20241030171928.4168869-3-kaleshsingh@google.com> Subject: [PATCH v2 2/3] tracing: Document tracefs gid mount option From: Kalesh Singh To: dhowells@redhat.com, rostedt@goodmis.org, mhiramat@kernel.org, sandeen@redhat.com Cc: surenb@google.com, jyescas@google.com, kernel-team@android.com, android-mm@google.com, Kalesh Singh , Mathieu Desnoyers , Shuah Khan , Ali Zahraee , Christian Brauner , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Commit ee7f3666995d ("tracefs: Have new files inherit the ownership of their parent") and commit 48b27b6b5191 ("tracefs: Set all files to the same group ownership as the mount option") introduced a new gid mount option that allows specifying a group to apply to all entries in tracefs. Document this in the tracing readme. Cc: Eric Sandeen Cc: David Howells Cc: Steven Rostedt Cc: Masami Hiramatsu Signed-off-by: Kalesh Singh --- Changes in v2: - Reference commits instead of lore links, per Steve kernel/trace/trace.c | 4 ++++ 1 file changed, 4 insertions(+) -- 2.47.0.163.g1226f6d8fa-goog diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a8f52b6527ca..2b64b3ec67d9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5501,6 +5501,10 @@ static const struct file_operations tracing_iter_fops = { static const char readme_msg[] = "tracing mini-HOWTO:\n\n" + "By default tracefs removes all OTH file permission bits.\n" + "When mounting tracefs an optional group id can be specified\n" + "which adds the group to every directory and file in tracefs:\n\n" + "\t e.g. mount -t tracefs [-o [gid=]] nodev /sys/kernel/tracing\n\n" "# echo 0 > tracing_on : quick way to disable tracing\n" "# echo 1 > tracing_on : quick way to re-enable tracing\n\n" " Important files:\n"