57c3bb725a
Currently the way to pass result from BPF helper to BPF program is to provide memory area defined by pointer and size: func(void *, size_t). It works great for generic use-case, but for simple types, such as int, it's overkill and consumes two arguments when it could use just one. Introduce new argument types ARG_PTR_TO_INT and ARG_PTR_TO_LONG to be able to pass result from helper to program via pointer to int and long correspondingly: func(int *) or func(long *). New argument types are similar to ARG_PTR_TO_MEM with the following differences: * they don't require corresponding ARG_CONST_SIZE argument, predefined access sizes are used instead (32bit for int, 64bit for long); * it's possible to use more than one such an argument in a helper; * provided pointers have to be aligned. It's easy to introduce similar ARG_PTR_TO_CHAR and ARG_PTR_TO_SHORT argument types. It's not done due to lack of use-case though. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.