CVS commit: src/sys/crypto/chacha/arch/arm

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Sun Aug 23 16:39:06 UTC 2020

Modified Files:
        src/sys/crypto/chacha/arch/arm: chacha_neon_32.S

Log Message:
Adjust sp, not fp, to allocate a 32-byte temporary.

Costs another couple MOV instructions, but we can't skimp on this --
there's no red zone below sp for interrupts on arm, so we can't touch
anything there.  So just use fp to save sp and then adjust sp itself,
rather than using fp as a temporary register to point just below sp.

Should fix PR port-arm/55598 -- previously the ChaCha self-test
failed 33/10000 trials triggered by sysctl during running system;
with the patch it has failed 0/10000 trials.

(Presumably it happened more often at boot time, leading to 5/26
failures in the test bed, because we just enabled interrupts and some
devices are starting to deliver interrupts.)


To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/sys/crypto/chacha/arch/arm/chacha_neon_32.S

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.