mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-02-16 02:07:55 -05:00
2c2ca3416b
Currently alternative_has_cap_unlikely() can be used in VDSO code, but
alternative_has_cap_likely() cannot as it references alt_cb_patch_nops,
which is not available when linking the VDSO. This is unfortunate as it
would be useful to have alternative_has_cap_likely() available in VDSO
code.
The use of alt_cb_patch_nops was added in commit:
d926079f17 ("arm64: alternatives: add shared NOP callback")
... as removing duplicate NOPs within the kernel Image saved areasonable
amount of space.
Given the VDSO code will have nowhere near as many alternative branches
as the main kernel image, this isn't much of a concern, and a few extra
nops isn't a massive problem.
Change alternative_has_cap_likely() to only use alt_cb_patch_nops for
the main kernel image, and allow duplicate NOPs in VDSO code.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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.