7db6c0f1d8
The current BPF store/load instruction is translated by the JIT into two instructions. The first instruction moves the immediate offset into a temporary register. The second instruction uses this temporary register to do the real store/load. In fact, arm64 supports addressing with immediate offsets. So This patch introduces optimization that uses arm64 str/ldr instruction with immediate offset when the offset fits. Example of generated instuction for r2 = *(u64 *)(r1 + 0): without optimization: mov x10, 0 ldr x1, [x0, x10] with optimization: ldr x1, [x0, 0] If the offset is negative, or is not aligned correctly, or exceeds max value, rollback to the use of temporary register. Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220321152852.2334294-3-xukuohai@huawei.com |
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| 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.