grub/grub-core/kern/arm/misc.S
David Kozub 17328db3b3 grub-core/kern/arm/misc.S: fix unaligned grub_uint64_t local variable
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.
2014-12-07 20:16:29 +03:00

89 lines
2.3 KiB
ArmAsm

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2013 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/symbol.h>
#include <grub/dl.h>
.file "misc.S"
.text
.syntax unified
#if !defined (__thumb2__)
.arm
#else
.thumb
#endif
.align 2
FUNCTION(__muldi3)
FUNCTION(__aeabi_lmul)
stmfd sp!, {r4, fp}
add fp, sp, #4
sub sp, sp, #16
str r0, [fp, #-12]
str r1, [fp, #-8]
str r2, [fp, #-20]
str r3, [fp, #-16]
ldr r3, [fp, #-8]
ldr r2, [fp, #-20]
mul r2, r3, r2
ldr r3, [fp, #-16]
ldr r1, [fp, #-12]
mul r3, r1, r3
add r2, r2, r3
ldr r0, [fp, #-12]
ldr r1, [fp, #-20]
umull r3, r4, r0, r1
add r2, r2, r4
mov r4, r2
mov r0, r3
mov r1, r4
mov sp, fp
sub sp, sp, #4
ldmfd sp!, {r4, fp}
bx lr
.macro division parent
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
mov r1, #0
mov r3, #0
bl \parent
ldr r1, [sp, #8] @ Extract remainder
ldmfd sp!, {r3,lr} @ Pop into an unused arg/scratch register
add sp, sp, #8
bx lr
.endm
FUNCTION(__aeabi_uidivmod)
division grub_divmod64
/*
* Null divide-by-zero handler
*/
FUNCTION(__aeabi_unwind_cpp_pr0)
FUNCTION(raise)
mov r0, #0
bx lr
END