Mercurial > illumos > illumos-gate
changeset 14127:8d9ae184cc0d
3912 crti needs to make sure _init and _fini are 16-byte stack aligned
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Keith M Wesolowski <wesolows@foobazco.org>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
| author | Robert Mustacchi <rm@joyent.com> |
|---|---|
| date | Tue, 23 Jul 2013 21:24:17 +0000 |
| parents | 62364715172d |
| children | 615580eeb3d8 |
| files | usr/src/lib/common/i386/crti.s |
| diffstat | 1 files changed, 17 insertions(+), 1 deletions(-) [+] |
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--- a/usr/src/lib/common/i386/crti.s Thu Jan 17 00:48:10 2013 +0000 +++ b/usr/src/lib/common/i386/crti.s Tue Jul 23 21:24:17 2013 +0000 @@ -23,6 +23,9 @@ * Copyright (c) 2001 by Sun Microsystems, Inc. * All rights reserved. */ +/* + * Copyright (c) 2013, Joyent, Inc. All rights reserved. + */ /* * These crt*.o modules are provided as the bare minimum required @@ -34,10 +37,19 @@ * For further details - see bug#4433015 */ - .ident "%Z%%M% %I% %E% SMI" .file "crti.s" /* + * Note that when _init and _fini are called we have 16-byte alignment per the + * ABI. We need to make sure that our asm leaves it such that subsequent calls + * will be aligned. gcc expects stack alignment before the call instruction is + * executed. Specifically if we call function foo(), the stack pointer will be + * 0xc aligned after executing the call instruction and before executing foo's + * prologue. Note that because 16-byte alignment also ensures 4-byte alignment + * we will not be breaking compatibility with older applications. + */ + +/* * _init function prologue */ .section .init,"ax" @@ -47,6 +59,8 @@ _init: pushl %ebp movl %esp, %ebp + andl $-16,%esp + subl $12,%esp pushl %ebx call .L1 .L1: popl %ebx @@ -62,6 +76,8 @@ _fini: pushl %ebp movl %esp, %ebp + andl $-16,%esp + subl $12,%esp pushl %ebx call .L2 .L2: popl %ebx