The unaligned local in __aeabi_uidivmod leads to a store to a 64bit
value at an address that is not divisible by 8 (in grub_divmod64).
The compiler most likely generates a STRD instruction to store it and
this causes an exception.
Fixes Savannah bug #43632.
This includes improvements done by Leif Lindholm.
---
ChangeLog | 6 ++++++
grub-core/kern/arm/misc.S | 14 +++++++-------
2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 6fbec06..8728c04 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-11-21 David Kozub <zub....@gmail.com>
+
+ * grub-core/kern/arm/misc.S: fix unaligned 64bit local variable
+ in __aeabi_uidivmod
+ Fixes Savannah bug #43632.
+
2014-11-20 Andrei Borzenkov <arvidj...@gmail.com>
* tests/util/grub-fs-tester.in: Consistently print output
diff --git a/grub-core/kern/arm/misc.S b/grub-core/kern/arm/misc.S
index 8943cc3..16b6f8e 100644
--- a/grub-core/kern/arm/misc.S
+++ b/grub-core/kern/arm/misc.S
@@ -60,17 +60,17 @@ FUNCTION(__aeabi_lmul)
.macro division parent
- stmfd sp!, {lr}
- sub sp, sp, #12
+ sub sp, sp, #8 @ Allocate naturally aligned 64-bit space
+ stmfd sp!, {r3,lr} @ Dummy r3 to maintain stack alignment
+ add r3, sp, #8 @ Set r3 to address of 64-bit space
+ str r3, [sp] @ Stack parameter, pointer to 64-bit space
mov r2, r1
- add r1, sp, #4
- str r1, [sp, #0]
mov r1, #0
mov r3, #0
bl \parent
- ldr r1, [sp, #4]
- add sp, sp, #12
- ldmfd sp!, {lr}
+ ldr r1, [sp, #8] @ Extract remainder
+ ldmfd sp!, {r3,lr} @ Pop into an unused arg/scratch register
+ add sp, sp, #8
bx lr
.endm
--
2.1.1
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