From 61655555aa8c2cd5f5351ef7d0aea6dfce046135 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 12 Jul 2016 06:29:54 -0700
Subject: x86-64: Properly align stack in _dl_tlsdesc_dynamic [BZ #20309]

Since _dl_tlsdesc_dynamic is called via PLT, we need to add 8 bytes for
push in the PLT entry to align the stack.

	[BZ #20309]
	* configure.ac (have-mtls-dialect-gnu2): Set to yes if
	-mtls-dialect=gnu2 works.
	* configure: Regenerated.
	* elf/Makefile [have-mtls-dialect-gnu2 = yes]
	(tests): Add tst-gnu2-tls1.
	(modules-names): Add tst-gnu2-tls1mod.
	($(objpfx)tst-gnu2-tls1): New.
	(tst-gnu2-tls1mod.so-no-z-defs): Likewise.
	(CFLAGS-tst-gnu2-tls1mod.c): Likewise.
	* elf/tst-gnu2-tls1.c: New file.
	* elf/tst-gnu2-tls1mod.c: Likewise.
	* sysdeps/x86_64/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Add 8
	bytes for push in the PLT entry to align the stack.
---
 sysdeps/x86_64/dl-tlsdesc.S | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

(limited to 'sysdeps')

diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S
index 3cb7c3d..777f30b 100644
--- a/sysdeps/x86_64/dl-tlsdesc.S
+++ b/sysdeps/x86_64/dl-tlsdesc.S
@@ -163,14 +163,15 @@ _dl_tlsdesc_dynamic:
 	/* The PLT entry will have pushed the link_map pointer.  */
 _dl_tlsdesc_resolve_rela:
 	cfi_adjust_cfa_offset (8)
-	/* Save all call-clobbered registers.  */
-	subq	$72, %rsp
-	cfi_adjust_cfa_offset (72)
+	/* Save all call-clobbered registers.  Add 8 bytes for push in
+	   the PLT entry to align the stack.  */
+	subq	$80, %rsp
+	cfi_adjust_cfa_offset (80)
 	movq	%rax, (%rsp)
 	movq	%rdi, 8(%rsp)
 	movq	%rax, %rdi	/* Pass tlsdesc* in %rdi.  */
 	movq	%rsi, 16(%rsp)
-	movq	72(%rsp), %rsi	/* Pass link_map* in %rsi.  */
+	movq	80(%rsp), %rsi	/* Pass link_map* in %rsi.  */
 	movq	%r8, 24(%rsp)
 	movq	%r9, 32(%rsp)
 	movq	%r10, 40(%rsp)
@@ -187,8 +188,8 @@ _dl_tlsdesc_resolve_rela:
 	movq	48(%rsp), %r11
 	movq	56(%rsp), %rdx
 	movq	64(%rsp), %rcx
-	addq	$80, %rsp
-	cfi_adjust_cfa_offset (-80)
+	addq	$88, %rsp
+	cfi_adjust_cfa_offset (-88)
 	jmp	*(%rax)
 	cfi_endproc
 	.size	_dl_tlsdesc_resolve_rela, .-_dl_tlsdesc_resolve_rela
-- 
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