summaryrefslogtreecommitdiffstats
path: root/toolchain/uClibc/uClibc-0.9.29-load-got-pointer-at-the-beginning-of-init-and-fini.patch
blob: 27aa5a59c78a0c3ab3cd3d196093772f0600dd8c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
From: Haavard Skinnemoen <hskinnemoen@atmel.com>
Date: Wed, 19 Sep 2007 10:03:35 +0200
Subject: [Avr-gnu-toolchain] [uClibc PATCH] Load GOT pointer at the
	beginning of .init and .fini

I don't know why this seems to have worked before, but the .init and
.fini sections typically consist of a bunch of mcalls using r6 as the
base pointer. This can cause "interesting" behaviour when r6 hasn't
been initialized to point to the GOT.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
---
 libc/sysdeps/linux/avr32/crti.S |   15 ++++++++++++---
 libc/sysdeps/linux/avr32/crtn.S |    4 ++--
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/libc/sysdeps/linux/avr32/crti.S b/libc/sysdeps/linux/avr32/crti.S
index 3e132d0..660f47c 100644
--- a/libc/sysdeps/linux/avr32/crti.S
+++ b/libc/sysdeps/linux/avr32/crti.S
@@ -4,14 +4,23 @@
 	.global	_init
 	.type	_init, @function
 _init:
-	/* Use a four-byte instruction to avoid NOPs */
-	stm	--sp, r0-r7,lr
+	stm	--sp, r6, lr
+	lddpc	r6, 2f
+1:	rsub	r6, pc
+	rjmp	3f
 	.align	2
+2:	.long	1b - _GLOBAL_OFFSET_TABLE_
+3:
 
 	.section .fini
 	.align	2
 	.global	_fini
 	.type	_fini, @function
 _fini:
-	stm	--sp, r0-r7,lr
+	stm	--sp, r6, lr
+	lddpc	r6, 2f
+1:	rsub	r6, pc
+	rjmp	3f
 	.align	2
+2:	.long	1b - _GLOBAL_OFFSET_TABLE_
+3:
diff --git a/libc/sysdeps/linux/avr32/crtn.S b/libc/sysdeps/linux/avr32/crtn.S
index 577adcc..f7d1040 100644
--- a/libc/sysdeps/linux/avr32/crtn.S
+++ b/libc/sysdeps/linux/avr32/crtn.S
@@ -3,12 +3,12 @@
 	.align	2
 	.global	_init
 	.type	_init, @function
-	ldm	sp++, r0-r7,pc
+	ldm	sp++, r6, pc
 	.size	_init, . - _init
 
 	.section .fini
 	.align	2
 	.global _fini
 	.type	_fini, @function
-	ldm	sp++, r0-r7,pc
+	ldm	sp++, r6, pc
 	.size	_fini, . - _fini
-- 
1.5.3.1