On Mar 24 10:28, Takashi Yano wrote: > x86_64 ABI requires the direction flag in CPU flags register cleared. > https://learn.microsoft.com/en-us/cpp/build/x64-software-conventions > However, currently that flag is not maintained in signal handler. > Therefore, if the signal handler is called when that flag is set, it > destroys the data and may crash if rep instruction is used in the > signal handler. With this patch, the direction flag is cleared in > sigdelayed() by adding cld instruction. > > Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257704.html > Fixes: 1fd5e000ace5 ("import winsup-2000-02-17 snapshot") > Reported-by: Christian Franke <christian.fra...@t-online.de> > Reviewed-by: > Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp> > --- > winsup/cygwin/scripts/gendef | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/winsup/cygwin/scripts/gendef b/winsup/cygwin/scripts/gendef > index a2f0392bc..861a2405b 100755 > --- a/winsup/cygwin/scripts/gendef > +++ b/winsup/cygwin/scripts/gendef > @@ -179,6 +179,7 @@ sigdelayed: > movq %rsp,%rbp > pushf > .seh_pushreg %rax # fake, there's no .seh_pushreg > for the flags > + cld # x86_64 ABI requires direction > flag cleared > # stack is aligned or unaligned on entry! > # make sure it is aligned from here on > # We could be called from an interrupted thread which doesn't know > -- > 2.45.1
GTG, of course! Thanks, Corinna
