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Levin" , Vincent Donnefort , mhiramat@kernel.org, kernel-team@android.com, rdunlap@infradead.org, rppt@kernel.org, david@redhat.com, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds References: <20240510140435.3550353-1-vdonnefort@google.com> <20240510140435.3550353-4-vdonnefort@google.com> <20240630105322.GA17573@altlinux.org> <20240630084053.0b506916@rorschach.local.home> <9a9c8ea4-8e17-4e7e-95fe-7b51441a228c@efficios.com> <20240702111807.13d2dd2c@rorschach.local.home> Content-Language: en-US From: Mathieu Desnoyers In-Reply-To: <20240702111807.13d2dd2c@rorschach.local.home> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 41E031C001C X-Stat-Signature: 63sbmqco5momuyp341j8zwhr9qoo34d1 X-Rspam-User: X-HE-Tag: 1719934356-359224 X-HE-Meta: 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 QohkQEX0 D2JSWHkUbP6sip5t7TsHzDU/kpOWSBzJBv6JzlFJm8LU/1yqdu5NszG2C9pPdchUL6wCuI4B7R3mQfdcZT1LejDhSDBTMixLJ0gw9JIgUTdpslg0OVbXyTya8K7C4L/AAtONa+GdWMmgoL2razvQRva0N9kfZB+58GtU/teR9Jh6Z4XxqjshZ7VACj0dzU0FpObsBfmbvVyJhJH8ZJQaYeeoTh9BVdpW/KczRFelr/7+RAQIN2fEbIZwVHrcfalp/v36xGcjiUUeMlYu4pHis+ypDGG7+vP7Nc/LaUwNHMiZNkvx31t17e9HCqdwircRr58YQ087zteSRPY4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2024-07-02 11:18, Steven Rostedt wrote: > On Tue, 2 Jul 2024 10:36:03 -0400 > Mathieu Desnoyers wrote: > >>> I can send a patch this week to update it. Or feel free to send a patch >>> yourself. >> >> You need to reserve an unused ioctl Code and Seq# range within: >> >> Documentation/userspace-api/ioctl/ioctl-number.rst > > Ug, it's been so long, I completely forgot about that file. > > Thanks for catching this. > >> >> Otherwise this duplicate will confuse all system call instrumentation >> tooling. > > Agreed, what if we did this then: > > -- Steve > > diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/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 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! > diff --git a/include/uapi/linux/trace_mmap.h b/include/uapi/linux/trace_mmap.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; > }; > > -#define TRACE_MMAP_IOCTL_GET_READER _IO('T', 0x1) > +#define TRACE_MMAP_IOCTL_GET_READER _IO('R', 0x20) Note that user events also has this issue: the ioctl is not reserved in the ioctl-number.rst list. See include/uapi/linux/user_events.h: #define DIAG_IOC_MAGIC '*' /* Request to register a user_event */ #define DIAG_IOCSREG _IOWR(DIAG_IOC_MAGIC, 0, struct user_reg *) /* Request to delete a user_event */ #define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char *) /* Requests to unregister a user_event */ #define DIAG_IOCSUNREG _IOW(DIAG_IOC_MAGIC, 2, struct user_unreg*) Where '*' maps to Code 0x2A. Looking at the list I don't see any conflicts there, but we should definitely add it. If we use '*' for user events already, perhaps we'd want to consider using the same range for the ring buffer ioctls ? Arguably one is about instrumentation and the other is about ring buffer interaction (data transport), but those are both related to tracing. Thanks, Mathieu > > #endif /* _TRACE_MMAP_H_ */ -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com