* [PATCH] Try to make sure struct _mcontext is 16-byte aligned
@ 2015-04-02 16:25 Jon TURNEY
2015-04-02 17:01 ` Corinna Vinschen
0 siblings, 1 reply; 2+ messages in thread
From: Jon TURNEY @ 2015-04-02 16:25 UTC (permalink / raw)
To: cygwin-patches; +Cc: Jon TURNEY
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 <jon.turney@dronecode.org.uk>
---
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 9871b96..3b0e111 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+2015-04-02 Jon TURNEY <jon.turney@dronecode.org.uk>
+
+ * include/cygwin/signal.h (struct __mcontext): 16-byte align.
+ * include/sys/ucontext.h (ucontext_t): Ditto.
+
2015-04-02 Corinna Vinschen <corinna@vinschen.de>
* sec_acl.cc (CYG_ACE_ISBITS_TO_WIN): Fix typo.
diff --git a/winsup/cygwin/include/cygwin/signal.h b/winsup/cygwin/include/cygwin/signal.h
index 04e65aa..f2a6fa3 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
+ __attribute__ ((aligned (16))) struct __mcontext
{
__uint64_t p1home;
__uint64_t p2home;
diff --git a/winsup/cygwin/include/sys/ucontext.h b/winsup/cygwin/include/sys/ucontext.h
index 9362d90..859eb29 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;
--
2.1.4
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] Try to make sure struct _mcontext is 16-byte aligned
2015-04-02 16:25 [PATCH] Try to make sure struct _mcontext is 16-byte aligned Jon TURNEY
@ 2015-04-02 17:01 ` Corinna Vinschen
0 siblings, 0 replies; 2+ messages in thread
From: Corinna Vinschen @ 2015-04-02 17:01 UTC (permalink / raw)
To: cygwin-patches
[-- Attachment #1: Type: text/plain, Size: 786 bytes --]
On Apr 2 17:24, Jon TURNEY wrote:
> 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.
The __attribute__ should follow the "struct" keyword. With this
change, ok to apply.
Thanks,
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2015-04-02 17:01 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-04-02 16:25 [PATCH] Try to make sure struct _mcontext is 16-byte aligned Jon TURNEY
2015-04-02 17:01 ` Corinna Vinschen
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).