Files
android_kernel_xiaomi_sm8450/arch/powerpc/lib/memcpy_64.S
Ulrich Weigand 752a6422fe powerpc: Fix unsafe accesses to parameter area in ELFv2
Some of the assembler files in lib/ make use of the fact that in the
ELFv1 ABI, the caller guarantees to provide stack space to save the
parameter registers r3 ... r10.  This guarantee is no longer present
in ELFv2 for functions that have no variable argument list and no
more than 8 arguments.

Change the affected routines to temporarily store registers in the
red zone and/or the top of their own stack frame (in the space
provided to save r31 .. r29, which is actually not used in these
routines).

In opal_query_takeover, simply always allocate a stack frame;
the routine is not performance critical.

Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
2014-04-23 10:05:24 +10:00

206 lines
3.8 KiB
ArmAsm

/*
* Copyright (C) 2002 Paul Mackerras, IBM Corp.
*
* This program 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
* 2 of the License, or (at your option) any later version.
*/
#include <asm/processor.h>
#include <asm/ppc_asm.h>
.align 7
_GLOBAL(memcpy)
BEGIN_FTR_SECTION
std r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* save destination pointer for return value */
FTR_SECTION_ELSE
#ifndef SELFTEST
b memcpy_power7
#endif
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY)
PPC_MTOCRF(0x01,r5)
cmpldi cr1,r5,16
neg r6,r3 # LS 3 bits = # bytes to 8-byte dest bdry
andi. r6,r6,7
dcbt 0,r4
blt cr1,.Lshort_copy
/* Below we want to nop out the bne if we're on a CPU that has the
CPU_FTR_UNALIGNED_LD_STD bit set and the CPU_FTR_CP_USE_DCBTZ bit
cleared.
At the time of writing the only CPU that has this combination of bits
set is Power6. */
BEGIN_FTR_SECTION
nop
FTR_SECTION_ELSE
bne .Ldst_unaligned
ALT_FTR_SECTION_END(CPU_FTR_UNALIGNED_LD_STD | CPU_FTR_CP_USE_DCBTZ, \
CPU_FTR_UNALIGNED_LD_STD)
.Ldst_aligned:
addi r3,r3,-16
BEGIN_FTR_SECTION
andi. r0,r4,7
bne .Lsrc_unaligned
END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
srdi r7,r5,4
ld r9,0(r4)
addi r4,r4,-8
mtctr r7
andi. r5,r5,7
bf cr7*4+0,2f
addi r3,r3,8
addi r4,r4,8
mr r8,r9
blt cr1,3f
1: ld r9,8(r4)
std r8,8(r3)
2: ldu r8,16(r4)
stdu r9,16(r3)
bdnz 1b
3: std r8,8(r3)
beq 3f
addi r3,r3,16
.Ldo_tail:
bf cr7*4+1,1f
lwz r9,8(r4)
addi r4,r4,4
stw r9,0(r3)
addi r3,r3,4
1: bf cr7*4+2,2f
lhz r9,8(r4)
addi r4,r4,2
sth r9,0(r3)
addi r3,r3,2
2: bf cr7*4+3,3f
lbz r9,8(r4)
stb r9,0(r3)
3: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
blr
.Lsrc_unaligned:
srdi r6,r5,3
addi r5,r5,-16
subf r4,r0,r4
srdi r7,r5,4
sldi r10,r0,3
cmpdi cr6,r6,3
andi. r5,r5,7
mtctr r7
subfic r11,r10,64
add r5,r5,r0
bt cr7*4+0,0f
ld r9,0(r4) # 3+2n loads, 2+2n stores
ld r0,8(r4)
sld r6,r9,r10
ldu r9,16(r4)
srd r7,r0,r11
sld r8,r0,r10
or r7,r7,r6
blt cr6,4f
ld r0,8(r4)
# s1<< in r8, d0=(s0<<|s1>>) in r7, s3 in r0, s2 in r9, nix in r6 & r12
b 2f
0: ld r0,0(r4) # 4+2n loads, 3+2n stores
ldu r9,8(r4)
sld r8,r0,r10
addi r3,r3,-8
blt cr6,5f
ld r0,8(r4)
srd r12,r9,r11
sld r6,r9,r10
ldu r9,16(r4)
or r12,r8,r12
srd r7,r0,r11
sld r8,r0,r10
addi r3,r3,16
beq cr6,3f
# d0=(s0<<|s1>>) in r12, s1<< in r6, s2>> in r7, s2<< in r8, s3 in r9
1: or r7,r7,r6
ld r0,8(r4)
std r12,8(r3)
2: srd r12,r9,r11
sld r6,r9,r10
ldu r9,16(r4)
or r12,r8,r12
stdu r7,16(r3)
srd r7,r0,r11
sld r8,r0,r10
bdnz 1b
3: std r12,8(r3)
or r7,r7,r6
4: std r7,16(r3)
5: srd r12,r9,r11
or r12,r8,r12
std r12,24(r3)
beq 4f
cmpwi cr1,r5,8
addi r3,r3,32
sld r9,r9,r10
ble cr1,6f
ld r0,8(r4)
srd r7,r0,r11
or r9,r7,r9
6:
bf cr7*4+1,1f
rotldi r9,r9,32
stw r9,0(r3)
addi r3,r3,4
1: bf cr7*4+2,2f
rotldi r9,r9,16
sth r9,0(r3)
addi r3,r3,2
2: bf cr7*4+3,3f
rotldi r9,r9,8
stb r9,0(r3)
3: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
blr
.Ldst_unaligned:
PPC_MTOCRF(0x01,r6) # put #bytes to 8B bdry into cr7
subf r5,r6,r5
li r7,0
cmpldi cr1,r5,16
bf cr7*4+3,1f
lbz r0,0(r4)
stb r0,0(r3)
addi r7,r7,1
1: bf cr7*4+2,2f
lhzx r0,r7,r4
sthx r0,r7,r3
addi r7,r7,2
2: bf cr7*4+1,3f
lwzx r0,r7,r4
stwx r0,r7,r3
3: PPC_MTOCRF(0x01,r5)
add r4,r6,r4
add r3,r6,r3
b .Ldst_aligned
.Lshort_copy:
bf cr7*4+0,1f
lwz r0,0(r4)
lwz r9,4(r4)
addi r4,r4,8
stw r0,0(r3)
stw r9,4(r3)
addi r3,r3,8
1: bf cr7*4+1,2f
lwz r0,0(r4)
addi r4,r4,4
stw r0,0(r3)
addi r3,r3,4
2: bf cr7*4+2,3f
lhz r0,0(r4)
addi r4,r4,2
sth r0,0(r3)
addi r3,r3,2
3: bf cr7*4+3,4f
lbz r0,0(r4)
stb r0,0(r3)
4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
blr