[PATCH 16/33] powerpc: Fix unsafe accesses to parameter area in ELFv2
Anton Blanchard
anton at samba.org
Tue Mar 25 22:44:22 EST 2014
From: Ulrich Weigand <ulrich.weigand at de.ibm.com>
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 at de.ibm.com>
Signed-off-by: Anton Blanchard <anton at samba.org>
---
arch/powerpc/lib/copypage_power7.S | 8 ++++----
arch/powerpc/lib/copyuser_power7.S | 24 ++++++++++++------------
arch/powerpc/lib/memcpy_64.S | 8 ++++----
arch/powerpc/lib/memcpy_power7.S | 20 ++++++++++----------
arch/powerpc/platforms/powernv/opal-takeover.S | 2 ++
5 files changed, 32 insertions(+), 30 deletions(-)
diff --git a/arch/powerpc/lib/copypage_power7.S b/arch/powerpc/lib/copypage_power7.S
index affc6d3..d7dafb3 100644
--- a/arch/powerpc/lib/copypage_power7.S
+++ b/arch/powerpc/lib/copypage_power7.S
@@ -56,15 +56,15 @@ _GLOBAL(copypage_power7)
#ifdef CONFIG_ALTIVEC
mflr r0
- std r3,STK_PARAM(R3)(r1)
- std r4,STK_PARAM(R4)(r1)
+ std r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
+ std r4,-STACKFRAMESIZE+STK_REG(R30)(r1)
std r0,16(r1)
stdu r1,-STACKFRAMESIZE(r1)
bl enter_vmx_copy
cmpwi r3,0
ld r0,STACKFRAMESIZE+16(r1)
- ld r3,STACKFRAMESIZE+STK_PARAM(R3)(r1)
- ld r4,STACKFRAMESIZE+STK_PARAM(R4)(r1)
+ ld r3,STK_REG(R31)(r1)
+ ld r4,STK_REG(R30)(r1)
mtlr r0
li r0,(PAGE_SIZE/128)
diff --git a/arch/powerpc/lib/copyuser_power7.S b/arch/powerpc/lib/copyuser_power7.S
index db0fcbc..c46c876 100644
--- a/arch/powerpc/lib/copyuser_power7.S
+++ b/arch/powerpc/lib/copyuser_power7.S
@@ -85,9 +85,9 @@
.Lexit:
addi r1,r1,STACKFRAMESIZE
.Ldo_err1:
- ld r3,STK_PARAM(R3)(r1)
- ld r4,STK_PARAM(R4)(r1)
- ld r5,STK_PARAM(R5)(r1)
+ ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
+ ld r4,-STACKFRAMESIZE+STK_REG(R30)(r1)
+ ld r5,-STACKFRAMESIZE+STK_REG(R29)(r1)
b __copy_tofrom_user_base
@@ -96,18 +96,18 @@ _GLOBAL(__copy_tofrom_user_power7)
cmpldi r5,16
cmpldi cr1,r5,4096
- std r3,STK_PARAM(R3)(r1)
- std r4,STK_PARAM(R4)(r1)
- std r5,STK_PARAM(R5)(r1)
+ std r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
+ std r4,-STACKFRAMESIZE+STK_REG(R30)(r1)
+ std r5,-STACKFRAMESIZE+STK_REG(R29)(r1)
blt .Lshort_copy
bgt cr1,.Lvmx_copy
#else
cmpldi r5,16
- std r3,STK_PARAM(R3)(r1)
- std r4,STK_PARAM(R4)(r1)
- std r5,STK_PARAM(R5)(r1)
+ std r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
+ std r4,-STACKFRAMESIZE+STK_REG(R30)(r1)
+ std r5,-STACKFRAMESIZE+STK_REG(R29)(r1)
blt .Lshort_copy
#endif
@@ -298,9 +298,9 @@ err1; stb r0,0(r3)
bl enter_vmx_usercopy
cmpwi cr1,r3,0
ld r0,STACKFRAMESIZE+16(r1)
- ld r3,STACKFRAMESIZE+STK_PARAM(R3)(r1)
- ld r4,STACKFRAMESIZE+STK_PARAM(R4)(r1)
- ld r5,STACKFRAMESIZE+STK_PARAM(R5)(r1)
+ ld r3,STK_REG(R31)(r1)
+ ld r4,STK_REG(R30)(r1)
+ ld r5,STK_REG(R29)(r1)
mtlr r0
/*
diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
index 01da956..9d3960c 100644
--- a/arch/powerpc/lib/memcpy_64.S
+++ b/arch/powerpc/lib/memcpy_64.S
@@ -12,7 +12,7 @@
.align 7
_GLOBAL(memcpy)
BEGIN_FTR_SECTION
- std r3,STK_PARAM(R3)(r1) /* save destination pointer for return value */
+ std r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* save destination pointer for return value */
FTR_SECTION_ELSE
#ifndef SELFTEST
b memcpy_power7
@@ -73,7 +73,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
2: bf cr7*4+3,3f
lbz r9,8(r4)
stb r9,0(r3)
-3: ld r3,STK_PARAM(R3)(r1) /* return dest pointer */
+3: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
blr
.Lsrc_unaligned:
@@ -156,7 +156,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
2: bf cr7*4+3,3f
rotldi r9,r9,8
stb r9,0(r3)
-3: ld r3,STK_PARAM(R3)(r1) /* return dest pointer */
+3: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
blr
.Ldst_unaligned:
@@ -201,5 +201,5 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
3: bf cr7*4+3,4f
lbz r0,0(r4)
stb r0,0(r3)
-4: ld r3,STK_PARAM(R3)(r1) /* return dest pointer */
+4: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1) /* return dest pointer */
blr
diff --git a/arch/powerpc/lib/memcpy_power7.S b/arch/powerpc/lib/memcpy_power7.S
index 87d8eec..2ff5c14 100644
--- a/arch/powerpc/lib/memcpy_power7.S
+++ b/arch/powerpc/lib/memcpy_power7.S
@@ -33,14 +33,14 @@ _GLOBAL(memcpy_power7)
cmpldi r5,16
cmpldi cr1,r5,4096
- std r3,STK_PARAM(R1)(r1)
+ std r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
blt .Lshort_copy
bgt cr1,.Lvmx_copy
#else
cmpldi r5,16
- std r3,STK_PARAM(R1)(r1)
+ std r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
blt .Lshort_copy
#endif
@@ -216,7 +216,7 @@ _GLOBAL(memcpy_power7)
lbz r0,0(r4)
stb r0,0(r3)
-15: ld r3,STK_PARAM(R3)(r1)
+15: ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
blr
.Lunwind_stack_nonvmx_copy:
@@ -226,16 +226,16 @@ _GLOBAL(memcpy_power7)
#ifdef CONFIG_ALTIVEC
.Lvmx_copy:
mflr r0
- std r4,STK_PARAM(R4)(r1)
- std r5,STK_PARAM(R5)(r1)
+ std r4,-STACKFRAMESIZE+STK_REG(R30)(r1)
+ std r5,-STACKFRAMESIZE+STK_REG(R29)(r1)
std r0,16(r1)
stdu r1,-STACKFRAMESIZE(r1)
bl enter_vmx_copy
cmpwi cr1,r3,0
ld r0,STACKFRAMESIZE+16(r1)
- ld r3,STACKFRAMESIZE+STK_PARAM(R3)(r1)
- ld r4,STACKFRAMESIZE+STK_PARAM(R4)(r1)
- ld r5,STACKFRAMESIZE+STK_PARAM(R5)(r1)
+ ld r3,STK_REG(R31)(r1)
+ ld r4,STK_REG(R30)(r1)
+ ld r5,STK_REG(R29)(r1)
mtlr r0
/*
@@ -447,7 +447,7 @@ _GLOBAL(memcpy_power7)
stb r0,0(r3)
15: addi r1,r1,STACKFRAMESIZE
- ld r3,STK_PARAM(R3)(r1)
+ ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
b exit_vmx_copy /* tail call optimise */
.Lvmx_unaligned_copy:
@@ -651,6 +651,6 @@ _GLOBAL(memcpy_power7)
stb r0,0(r3)
15: addi r1,r1,STACKFRAMESIZE
- ld r3,STK_PARAM(R3)(r1)
+ ld r3,-STACKFRAMESIZE+STK_REG(R31)(r1)
b exit_vmx_copy /* tail call optimise */
#endif /* CONFiG_ALTIVEC */
diff --git a/arch/powerpc/platforms/powernv/opal-takeover.S b/arch/powerpc/platforms/powernv/opal-takeover.S
index 3cd2628..11a3169 100644
--- a/arch/powerpc/platforms/powernv/opal-takeover.S
+++ b/arch/powerpc/platforms/powernv/opal-takeover.S
@@ -21,11 +21,13 @@
_GLOBAL(opal_query_takeover)
mfcr r0
stw r0,8(r1)
+ stdu r1,-STACKFRAMESIZE(r1)
std r3,STK_PARAM(R3)(r1)
std r4,STK_PARAM(R4)(r1)
li r3,H_HAL_TAKEOVER
li r4,H_HAL_TAKEOVER_QUERY_MAGIC
HVSC
+ addi r1,r1,STACKFRAMESIZE
ld r10,STK_PARAM(R3)(r1)
std r4,0(r10)
ld r10,STK_PARAM(R4)(r1)
--
1.8.3.2
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