powerpc: Fix 64bit __copy_tofrom_user() regression
This fixes a regression introduced by commit
a4e22f02f5b6518c1484faea1f88d81802b9feac ("powerpc: Update 64bit
__copy_tofrom_user() using CPU_FTR_UNALIGNED_LD_STD").
The same bug that existed in the 64bit memcpy() also exists here so fix
it here too. The fix is the same as that applied to memcpy() with the
addition of fixes for the exception handling code required for
__copy_tofrom_user().
This stops us reading beyond the end of the source region we were told
to copy.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/lib/copyuser_64.S b/arch/powerpc/lib/copyuser_64.S
index 70693a5..693b14a 100644
--- a/arch/powerpc/lib/copyuser_64.S
+++ b/arch/powerpc/lib/copyuser_64.S
@@ -62,18 +62,19 @@
72: std r8,8(r3)
beq+ 3f
addi r3,r3,16
-23: ld r9,8(r4)
.Ldo_tail:
bf cr7*4+1,1f
- rotldi r9,r9,32
+23: lwz r9,8(r4)
+ addi r4,r4,4
73: stw r9,0(r3)
addi r3,r3,4
1: bf cr7*4+2,2f
- rotldi r9,r9,16
+44: lhz r9,8(r4)
+ addi r4,r4,2
74: sth r9,0(r3)
addi r3,r3,2
2: bf cr7*4+3,3f
- rotldi r9,r9,8
+45: lbz r9,8(r4)
75: stb r9,0(r3)
3: li r3,0
blr
@@ -141,11 +142,24 @@
6: cmpwi cr1,r5,8
addi r3,r3,32
sld r9,r9,r10
- ble cr1,.Ldo_tail
+ ble cr1,7f
34: ld r0,8(r4)
srd r7,r0,r11
or r9,r7,r9
- b .Ldo_tail
+7:
+ bf cr7*4+1,1f
+ rotldi r9,r9,32
+94: stw r9,0(r3)
+ addi r3,r3,4
+1: bf cr7*4+2,2f
+ rotldi r9,r9,16
+95: sth r9,0(r3)
+ addi r3,r3,2
+2: bf cr7*4+3,3f
+ rotldi r9,r9,8
+96: stb r9,0(r3)
+3: li r3,0
+ blr
.Ldst_unaligned:
PPC_MTOCRF 0x01,r6 /* put #bytes to 8B bdry into cr7 */
@@ -218,7 +232,6 @@
121:
132:
addi r3,r3,8
-123:
134:
135:
138:
@@ -226,6 +239,9 @@
140:
141:
142:
+123:
+144:
+145:
/*
* here we have had a fault on a load and r3 points to the first
@@ -309,6 +325,9 @@
187:
188:
189:
+194:
+195:
+196:
1:
ld r6,-24(r1)
ld r5,-8(r1)
@@ -329,7 +348,9 @@
.llong 72b,172b
.llong 23b,123b
.llong 73b,173b
+ .llong 44b,144b
.llong 74b,174b
+ .llong 45b,145b
.llong 75b,175b
.llong 24b,124b
.llong 25b,125b
@@ -347,6 +368,9 @@
.llong 79b,179b
.llong 80b,180b
.llong 34b,134b
+ .llong 94b,194b
+ .llong 95b,195b
+ .llong 96b,196b
.llong 35b,135b
.llong 81b,181b
.llong 36b,136b