From 4dfb9c941132d7b10b897c678f360fd27d6f5c95 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 12 Jan 2017 01:52:37 +0000 Subject: [PATCH] Make fallback fegetexceptflag work with generic fetestexceptflag. The generic implementation of fetestexceptflag does: int fetestexceptflag (const fexcept_t *flagp, int excepts) { /* Most versions of fegetexceptflag store exceptions in a form such that this works. */ return *flagp & excepts & FE_ALL_EXCEPT; } In the case where FE_ALL_EXCEPT is nonzero but exceptions may not be supported at runtime, this only works if fegetexceptflag cleared all the bits of FE_ALL_EXCEPT in *flagp; otherwise it accesses uninitialized data. This showed up as a failure of math/test-fetestexceptflag for MIPS o32 soft-float. This patch makes the fallback fegetexceptflag store 0 (fexcept_t is an integer type everywhere) so that this works. (No bug report in Bugzilla because this wasn't user-visible - at least, without using tools to detect uninitialized memory use at runtime - without fetestexceptflag, which is new in 2.25.) Tested for MIPS o32 soft-float. * math/fgetexcptflg.c (__fegetexceptflag): Store 0 in fexcept_t object. --- ChangeLog | 5 +++++ math/fgetexcptflg.c | 1 + 2 files changed, 6 insertions(+) diff --git a/ChangeLog b/ChangeLog index d86a9c76f4..5b0601fa1b 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2017-01-12 Joseph Myers + + * math/fgetexcptflg.c (__fegetexceptflag): Store 0 in fexcept_t + object. + 2017-01-11 Joseph Myers [BZ #16458] diff --git a/math/fgetexcptflg.c b/math/fgetexcptflg.c index 8e16250e3b..95a9217198 100644 --- a/math/fgetexcptflg.c +++ b/math/fgetexcptflg.c @@ -24,6 +24,7 @@ int __fegetexceptflag (fexcept_t *flagp, int excepts) { /* Nothing to do. */ + *flagp = 0; return 0; } #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2) -- 2.43.5