On 20.10.2025 09:11, Benjamin Gaignard wrote:
Le 16/10/2025 à 13:11, Marek Szyprowski a écrit :
create_bufs and remove_bufs ioctl calls manipulate queue internal buffer list, potentially overwriting some pointers used by the legacy fileio access mode. Simply forbid those calls when fileio is active to protect internal queue state between subsequent read/write calls.
Hi Marek,
I may be wrong but using fileio API and create/remove API at the same time sound incorrect from application point of view, right ? If that not the case maybe we should also add a test in v4l2-compliance.
Definitely that's incorrect and v4l2-core must forbid such calls. The standard reqbufs/qbuf/dqbuf API is also forbidden. Extending v4l2-compliance tools is probably a good idea. I also wonder if its a good time to add a kernel option to completely disable legacy fileio access mode, as it is not really needed for most of the systems nowadays.
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Best regards