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Anton Protopopov
dd3fd3c965
For v4 instruction set LLVM is allowed to generate indirect jumps for
switch statements and for 'goto *rX' assembly. Every such a jump will
be accompanied by necessary metadata, e.g. (`llvm-objdump -Sr ...`):
0: r2 = 0x0 ll
0000000000000030: R_BPF_64_64 BPF.JT.0.0
Here BPF.JT.1.0 is a symbol residing in the .jumptables section:
Symbol table:
4: 0000000000000000 240 OBJECT GLOBAL DEFAULT 4 BPF.JT.0.0
The -bpf-min-jump-table-entries llvm option may be used to control the
minimal size of a switch which will be converted to an indirect jumps.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251105090410.1250500-11-a.s.protopopov@gmail.com
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 reStructuredText 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.