From nobody Fri Dec 19 10:48:36 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 72B8A1369A0 for ; Wed, 3 Jul 2024 20:42:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720039369; cv=none; b=MhyRrb84H0yLFYUujBqojWrKm9siTVbAUpA/Y5niSAEyHBd7oI5sb6Qz5ptkEZEVo8L2lSJ0aXvCxeqVatzZZcyZd5PZkNwTVYsW/GoTAsYFKy+ychMIaaezlGG2eu27Qvgd6VycEyCi5dByDThEhmLRLDqHXXizltxi16wdJkg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720039369; c=relaxed/simple; bh=wq+w7PujNWZnEd5aACvBTq2DLByFAXSVhKl1DS7FYEE=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=keQGObO86NoGA6zF7jZrZq3RDzHzJD2MVJTq/HEergjPw+90craYZKXE79AbciGzoe5662W48M4IJuurT0Nazy2e82t0jUuadWb8tJHVkFDIhPq1NEkc64d9lXH5/XQOnzS34DwmRiBVEgj7JRTzdPQthAcFl8peiplTgthrJNE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 364B3C2BD10; Wed, 3 Jul 2024 20:42:48 +0000 (UTC) Date: Wed, 3 Jul 2024 16:42:46 -0400 From: Steven Rostedt To: LKML Cc: Masami Hiramatsu , Mathieu Desnoyers , "Dmitry V. Levin" , Jonathan Corbet Subject: [for-linus][PATCH] tracing: Have memmapped ring buffer use ioctl of "R" range 0x20-2F Message-ID: <20240703164247.34096efa@rorschach.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" It was reported that the ioctl() number used to update the ring buffer memory mapping conflicted with the TCGETS ioctl causing strace to report: $ strace -e ioctl stty ioctl(0, TCGETS or TRACE_MMAP_IOCTL_GET_READER, {c_iflag=3DICRNL|IXON, c_= oflag=3DNL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=3DB38400|CS8|CREAD, c= _lflag=3DISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) =3D 0 Since this ioctl hasn't been in a full release yet, change it from "T", 0x1 to "R" 0x20, and also reserve 0x20-0x2F for future ioctl commands, as some more are being worked on for the future. git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git trace/urgent Head SHA1: 4ecaf7e98a3ae0c843d67c76649ecc694232834b Steven Rostedt (Google) (1): tracing: Have memmapped ring buffer use ioctl of "R" range 0x20-2F ---- Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + include/uapi/linux/trace_mmap.h | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) --------------------------- commit 4ecaf7e98a3ae0c843d67c76649ecc694232834b Author: Steven Rostedt (Google) Date: Tue Jul 2 15:33:54 2024 -0400 tracing: Have memmapped ring buffer use ioctl of "R" range 0x20-2F =20 To prevent conflicts with other ioctl numbers to allow strace to have an idea of what is happening, add the range of ioctls for the trace buffer mapping from _IO("T", 0x1) to the range of "R" 0x20 - 0x2F. =20 Link: https://lore.kernel.org/linux-trace-kernel/20240630105322.GA17573= @altlinux.org/ Link: https://lore.kernel.org/linux-trace-kernel/20240630213626.GA23566= @altlinux.org/ =20 Cc: Jonathan Corbet Fixes: cf9f0f7c4c5bb ("tracing: Allow user-space mapping of the ring-bu= ffer") Link: https://lore.kernel.org/20240702153354.367861db@rorschach.local.h= ome Reported-by: "Dmitry V. Levin" Reviewed-by: Mathieu Desnoyers Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documenta= tion/userspace-api/ioctl/ioctl-number.rst index a141e8e65c5d..9a97030c6c8d 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -186,6 +186,7 @@ Code Seq# Include File = Comments 'Q' all linux/soundcard.h 'R' 00-1F linux/random.h confl= ict! 'R' 01 linux/rfkill.h confl= ict! +'R' 20-2F linux/trace_mmap.h 'R' C0-DF net/bluetooth/rfcomm.h 'R' E0 uapi/linux/fsl_mc.h 'S' all linux/cdrom.h confl= ict! diff --git a/include/uapi/linux/trace_mmap.h b/include/uapi/linux/trace_mma= p.h index bd1066754220..c102ef35d11e 100644 --- a/include/uapi/linux/trace_mmap.h +++ b/include/uapi/linux/trace_mmap.h @@ -43,6 +43,6 @@ struct trace_buffer_meta { __u64 Reserved2; }; =20 -#define TRACE_MMAP_IOCTL_GET_READER _IO('T', 0x1) +#define TRACE_MMAP_IOCTL_GET_READER _IO('R', 0x20) =20 #endif /* _TRACE_MMAP_H_ */