unimore/kernel-hacking-2024-linux-steffo
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Code Pull requests 5 Wiki Activity

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

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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: cf9f0f7c4c ("tracing: Allow user-space mapping of the ring-buffer")
Link: https://lore.kernel.org/20240702153354.367861db@rorschach.local.home
Reported-by: "Dmitry V. Levin" <ldv@strace.io>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Google) 2024-07-02 15:33:54 -04:00
parent 22a40d14b5
commit 4ecaf7e98a
2 changed files with 2 additions and 1 deletions
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1
Documentation/userspace-api/ioctl/ioctl-number.rst
View file

@ -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!

2
include/uapi/linux/trace_mmap.h
View file

@ -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_ */