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| author |   visa <visa@openbsd.org> | 2017-10-15 12:07:27 +0000 |
|---|---|---|
| committer | visa <visa@openbsd.org> | 2017-10-15 12:07:27 +0000 |
| commit | 4b2bdc8087a6474b1b8dfaaf34f7e2e6fdf9364a (patch) | |
| tree | fa9dadb058941bb4a85d29436e41d83186a4710c | |
| parent | locore0: remove an unused variable (diff) | |
| download | wireguard-openbsd-4b2bdc8087a6474b1b8dfaaf34f7e2e6fdf9364a.tar.xz wireguard-openbsd-4b2bdc8087a6474b1b8dfaaf34f7e2e6fdf9364a.zip | |
Do not use an uninitialized value when determining the sign
of a denormal result of ldexp(3).
The bug was found when investigating why denormal results
of pow(3) can have an incorrect sign on loongson.
pow(3) misbehaviour reported and fix tested by juanfra@
No objection from deraadt@
| -rw-r--r-- | lib/libc/arch/mips64/gen/ldexp.S | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/lib/libc/arch/mips64/gen/ldexp.S b/lib/libc/arch/mips64/gen/ldexp.S index ba934bee580..8844078ceff 100644 --- a/lib/libc/arch/mips64/gen/ldexp.S +++ b/lib/libc/arch/mips64/gen/ldexp.S @@ -1,4 +1,4 @@ -/* $OpenBSD: ldexp.S,v 1.7 2015/10/27 05:54:49 guenther Exp $ */ +/* $OpenBSD: ldexp.S,v 1.8 2017/10/15 12:07:27 visa Exp $ */ /*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. @@ -143,20 +143,20 @@ LEAF(ldexp, 0) xori t2, 1 1: dmtc1 t2, $f0 # save denormalized result (LSW) - bge v1, zero, 1f # should result be negative? + bge t3, zero, 1f # should result be negative? neg.d $f0, $f0 # negate result 1: j ra 7: dmtc1 zero, $f0 # result is zero - beq t0, zero, 1f # is result positive? + bge t3, zero, 1f # is result positive? neg.d $f0, $f0 # negate result 1: j ra 8: dli t1, 0x7ff0000000000000 # result is infinity (MSW) dmtc1 t1, $f0 - bge v1, zero, 1f # should result be negative infinity? + bge t3, zero, 1f # should result be negative infinity? neg.d $f0, $f0 # result is negative infinity 1: add.d $f0, $f0 # cause overflow faults if enabled |