Commit 4ecaf7e9 authored by Steven Rostedt (Google)'s avatar Steven Rostedt (Google)
Browse files

tracing: Have memmapped ring buffer use ioctl of "R" range 0x20-2F 

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.

Link: https://lore.kernel.org/linux-trace-kernel/20240630105322.GA17573@altlinux.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240630213626.GA23566@altlinux.org/

Cc: Jonathan Corbet <corbet@lwn.net>
Fixes: cf9f0f7c ("tracing: Allow user-space mapping of the ring-buffer")
Link: https://lore.kernel.org/20240702153354.367861db@rorschach.local.home


Reported-by: default avatar"Dmitry V. Levin" <ldv@strace.io>
Reviewed-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 22a40d14

Documentation/userspace-api/ioctl/ioctl-number.rst

+1 −0
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ Code Seq# Include File Comments 
'Q'   all    linux/soundcard.h

'R'   00-1F  linux/random.h                                          conflict!

'R'   01     linux/rfkill.h                                          conflict!

'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                                           conflict!

include/uapi/linux/trace_mmap.h

+1 −1
Original line number Diff line number Diff line
@@ -43,6 +43,6 @@ struct trace_buffer_meta { 
	__u64	Reserved2;

};



#define TRACE_MMAP_IOCTL_GET_READER		_IO('T', 0x1)

#define TRACE_MMAP_IOCTL_GET_READER		_IO('R', 0x20)



#endif /* _TRACE_MMAP_H_ */