From: Andy Polyakov <[email protected]>
Date: Fri, 31 May 2013 19:38:03 +0200

> No. SPARCV9_64BIT_STACK is Linux-specific thing. In the commentary
> section in crypto/bn/asm/sparct4-mont.pl you see paragraph that starts
> with "32-bit code is prone to performance degradation." This is what
> SPARCV9_64BIT_STACK is about.

For further clarification, how the thing works is that if a 32-bit
user process has an odd stack address in a register window, the kernel
interprets it as a 64-bit biased stack frame, and will save/restore
the local/in registers accordingly during spill/fill traps.

This eliminates all of the montmul/montsqr/mpmul "retry" logic outside
of hardware error cases.

Solaris supported these so-called "mixed mode" stacks, but only for
the sake of calling into the firmware from the kernel, not for
userspace usage as Linux does.
______________________________________________________________________
OpenSSL Project                                 http://www.openssl.org
Development Mailing List                       [email protected]
Automated List Manager                           [email protected]

Reply via email to