mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-05 02:21:52 +09:00
50edea7d4c
Commit 06fe9b1df1086b42718d632aa57e8f7cd1a66a21 upstream. If IORING_FEAT_SINGLE_MMAP is ignored, as can happen if an application uses an ancient liburing or does setup manually, then 3 mmap's are required to map the ring into userspace. The kernel will still have collapsed the mappings, however userspace may ask for mapping them individually. If so, then we should not use the full number of ring pages, as it may exceed the partial mapping. Doing so will yield an -EFAULT from vm_insert_pages(), as we pass in more pages than what the application asked for. Cap the number of pages to match what the application asked for, for the particular mapping operation. Reported-by: Lucas Mülling <lmulling@proton.me> Link: https://github.com/axboe/liburing/issues/1157 Fixes: 3ab1db3c6039 ("io_uring: get rid of remap_pfn_range() for mapping rings/sqes") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.