From ca71676fe9906efdc910094ed5d53e6b06845789 Mon Sep 17 00:00:00 2001
From: kib <kib@FreeBSD.org>
Date: Wed, 2 Nov 2011 18:08:30 +0000
Subject: Despite official i386 ABI does not mandate any stack alignment
 besides the word alignment, some versions of gcc do require 16-byte
 alignment. Make sure the stack is 16-byte aligned before calling a
 subroutine.

Inspired by:	PR amd64/162214
MFC after:	1 week
---
 lib/libc/i386/gen/setjmp.S    | 14 ++++++++++++++
 lib/libc/i386/gen/sigsetjmp.S | 14 ++++++++++++++
 2 files changed, 28 insertions(+)

(limited to 'lib/libc/i386/gen')

diff --git a/lib/libc/i386/gen/setjmp.S b/lib/libc/i386/gen/setjmp.S
index 5d0ddc4..a409e35 100644
--- a/lib/libc/i386/gen/setjmp.S
+++ b/lib/libc/i386/gen/setjmp.S
@@ -51,12 +51,19 @@ __FBSDID("$FreeBSD$");
 ENTRY(setjmp)
 	movl	4(%esp),%ecx
 	PIC_PROLOGUE
+#ifdef PIC
+	subl	$12,%esp		/* make the stack 16-byte aligned */
+#endif
 	leal	28(%ecx), %eax
 	pushl	%eax			/* (sigset_t*)oset */
 	pushl	$0			/* (sigset_t*)set  */
 	pushl	$1			/* SIG_BLOCK       */
 	call	PIC_PLT(CNAME(_sigprocmask))
+#ifdef PIC
+	addl	$24,%esp
+#else
 	addl	$12,%esp
+#endif
 	PIC_EPILOGUE
 	movl	4(%esp),%ecx
 	movl	0(%esp),%edx
@@ -76,12 +83,19 @@ END(setjmp)
 ENTRY(__longjmp)
 	movl	4(%esp),%edx
 	PIC_PROLOGUE
+#ifdef PIC
+	subl	$12,%esp		/* make the stack 16-byte aligned */
+#endif
 	pushl	$0			/* (sigset_t*)oset */
 	leal	28(%edx), %eax
 	pushl	%eax			/* (sigset_t*)set  */
 	pushl	$3			/* SIG_SETMASK     */
 	call	PIC_PLT(CNAME(_sigprocmask))
+#ifdef PIC
+	addl	$24,%esp
+#else
 	addl	$12,%esp
+#endif
 	PIC_EPILOGUE
 	movl	4(%esp),%edx
 	movl	8(%esp),%eax
diff --git a/lib/libc/i386/gen/sigsetjmp.S b/lib/libc/i386/gen/sigsetjmp.S
index 6487745..936edba 100644
--- a/lib/libc/i386/gen/sigsetjmp.S
+++ b/lib/libc/i386/gen/sigsetjmp.S
@@ -60,12 +60,19 @@ ENTRY(sigsetjmp)
 	testl	%eax,%eax
 	jz	2f
 	PIC_PROLOGUE
+#ifdef PIC
+	subl	$12,%esp		/* make the stack 16-byte aligned */
+#endif
 	leal	28(%ecx), %eax
 	pushl	%eax			/* (sigset_t*)oset */
 	pushl	$0			/* (sigset_t*)set  */
 	pushl	$1			/* SIG_BLOCK       */
 	call	PIC_PLT(CNAME(_sigprocmask))
+#ifdef PIC
+	addl	$24,%esp
+#else
 	addl	$12,%esp
+#endif
 	PIC_EPILOGUE
 	movl	4(%esp),%ecx
 2:	movl	0(%esp),%edx
@@ -87,12 +94,19 @@ ENTRY(__siglongjmp)
 	cmpl	$0,44(%edx)
 	jz	2f
 	PIC_PROLOGUE
+#ifdef PIC
+	subl	$12,%esp		/* make the stack 16-byte aligned */
+#endif
 	pushl	$0			/* (sigset_t*)oset */
 	leal	28(%edx), %eax
 	pushl	%eax			/* (sigset_t*)set  */
 	pushl	$3			/* SIG_SETMASK     */
 	call	PIC_PLT(CNAME(_sigprocmask))
+#ifdef PIC
+	addl	$24,%esp
+#else
 	addl	$12,%esp
+#endif
 	PIC_EPILOGUE
 	movl	4(%esp),%edx
 2:	movl	8(%esp),%eax
-- 
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