jump_label: Provide CONFIG-driven build state defaults

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As shown in the comment in jump_label.h, choosing the initial state of
static branches changes the assembly layout. If the condition is expected
to be likely it's inline, and if unlikely it is out of line via a jump.

A few places in the kernel use (or could be using) a CONFIG to choose the
default state, which would give a small performance benefit to their
compile-time declared default. Provide the infrastructure to do this.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210401232347.2791257-2-keescook@chromium.org

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Kees Cook 2021-04-01 16:23:42 -07:00 • committed by Thomas Gleixner

parent e49d033bdd

commit 0d66ccc162

1 changed files with 19 additions and 0 deletions

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include/linux/jump_label.h

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