6dbae03b2e
Daniel Borkmann says:
====================
This gets rid of indirect jumps for BPF tail calls whenever possible.
The series adds emission for *direct* jumps for tail call maps in order
to avoid the retpoline overhead from a493a87f38cf ("bpf, x64: implement
retpoline for tail call") for situations that allow for it, meaning,
for known constant keys at verification time which are used as index
into the tail call map. See patch 7/8 for more general details.
Thanks!
v1 -> v2:
- added more test cases
- u8 ip_stable -> bool (Andrii)
- removed bpf_map_poke_{un,}lock and simplified the code (Andrii)
- added break into prog_array_map_poke_untrack since there's just
one prog (Andrii)
- fixed typo: for for in commit msg (Andrii)
- reworked __bpf_arch_text_poke (Andrii)
- added subtests, and comment on tests themselves, NULL-NULL
transistion (Andrii)
- in constant map key tracking I've moved the map_poke_track callback
to once we've finished creating the poke tab as otherwise concurrent
access from tail call map would blow up (since we realloc the table)
rfc -> v1:
- Applied Alexei's and Andrii's feeback from
https://lore.kernel.org/bpf/cover.1573779287.git.daniel@iogearbox.net/T/#t
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.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.