From 383ff5fc47123ab2914cffc9517df1071eb1dc6a Mon Sep 17 00:00:00 2001 From: Jon TURNEY Date: Thu, 2 Apr 2015 18:05:32 +0100 Subject: [PATCH] Try to make sure struct _mcontext is 16-byte aligned On x86_64, RtlCaptureContext() uses fxsave to save FPU/MMX/SSE state. fxsave requires that the destination address is 16-byte aligned, or it will fault. CONTEXT is already annotated __attribute__ ((aligned (16))), do the same with struct _mcontext. Rearrange ucontext_t so that it's struct _mcontext element is also correctly aligned. * include/cygwin/signal.h (struct __mcontext): 16-byte align. * include/sys/ucontext.h (ucontext_t): Ditto. Signed-off-by: Jon TURNEY --- winsup/cygwin/ChangeLog | 5 +++++ winsup/cygwin/include/cygwin/signal.h | 2 +- winsup/cygwin/include/sys/ucontext.h | 4 ++-- 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog index 72dfa6658..bcc7df874 100644 --- a/winsup/cygwin/ChangeLog +++ b/winsup/cygwin/ChangeLog @@ -1,3 +1,8 @@ +2015-04-02 Jon TURNEY + + * include/cygwin/signal.h (struct __mcontext): 16-byte align. + * include/sys/ucontext.h (ucontext_t): Ditto. + 2015-04-01 Corinna Vinschen * include/cygwin/types.h: Include sys/_stdint.h rather than stdint.h. diff --git a/winsup/cygwin/include/cygwin/signal.h b/winsup/cygwin/include/cygwin/signal.h index 04e65aa34..ef29baf7b 100644 --- a/winsup/cygwin/include/cygwin/signal.h +++ b/winsup/cygwin/include/cygwin/signal.h @@ -49,7 +49,7 @@ struct _fpstate __uint32_t padding[24]; }; -struct __mcontext +struct __attribute__ ((aligned (16))) __mcontext { __uint64_t p1home; __uint64_t p2home; diff --git a/winsup/cygwin/include/sys/ucontext.h b/winsup/cygwin/include/sys/ucontext.h index 9362d90cd..65485fbad 100644 --- a/winsup/cygwin/include/sys/ucontext.h +++ b/winsup/cygwin/include/sys/ucontext.h @@ -15,11 +15,11 @@ details. */ typedef struct __mcontext mcontext_t; -typedef struct __ucontext { +typedef __attribute__ ((aligned (16))) struct __ucontext { + mcontext_t uc_mcontext; struct __ucontext *uc_link; sigset_t uc_sigmask; stack_t uc_stack; - mcontext_t uc_mcontext; unsigned long int uc_flags; } ucontext_t;