97eb31384a
When loading a BPF program with a pinned map, the loader checks whether the pinned map can be reused, i.e. their properties match. To derive such of the pinned map, the loader invokes BPF_OBJ_GET_INFO_BY_FD and then does the comparison. Unfortunately, on < 4.12 kernels the BPF_OBJ_GET_INFO_BY_FD is not available, so loading the program fails with the following error: libbpf: failed to get map info for map FD 5: Invalid argument libbpf: couldn't reuse pinned map at '/sys/fs/bpf/tc/globals/cilium_call_policy': parameter mismatch" libbpf: map 'cilium_call_policy': error reusing pinned map libbpf: map 'cilium_call_policy': failed to create: Invalid argument(-22) libbpf: failed to load object 'bpf_overlay.o' To fix this, fallback to derivation of the map properties via /proc/$PID/fdinfo/$MAP_FD if BPF_OBJ_GET_INFO_BY_FD fails with EINVAL, which can be used as an indicator that the kernel doesn't support the latter. Signed-off-by: Martynas Pumputis <m@lambda.lt> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210712125552.58705-1-m@lambda.lt |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| 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 | ||
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.