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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2013-10-01 17:11:35 +1000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-09 10:51:21 -0700
commit0b36b7f617524596dc8900c1f8c3ab051c6b9dc5 (patch)
treeebe7c2d1c2efaf5d962065cdd650b69ceca00f6b
parent58b9385170d93957a0518d4ee9c4b1c5068bc7ef (diff)
powerpc: Restore registers on error exit from csum_partial_copy_generic()
commit 8f21bd0090052e740944f9397e2be5ac7957ded7 upstream. The csum_partial_copy_generic() function saves the PowerPC non-volatile r14, r15, and r16 registers for the main checksum-and-copy loop. Unfortunately, it fails to restore them upon error exit from this loop, which results in silent corruption of these registers in the presumably rare event of an access exception within that loop. This commit therefore restores these register on error exit from the loop. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [bwh: Backported to 3.2: register name macros use lower-case 'r'] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/powerpc/lib/checksum_64.S54
1 files changed, 40 insertions, 14 deletions
diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S
index afa2ebaee174..3cdbc648d979 100644
--- a/arch/powerpc/lib/checksum_64.S
+++ b/arch/powerpc/lib/checksum_64.S
@@ -229,19 +229,35 @@ _GLOBAL(csum_partial)
blr
- .macro source
+ .macro srcnr
100:
.section __ex_table,"a"
.align 3
- .llong 100b,.Lsrc_error
+ .llong 100b,.Lsrc_error_nr
.previous
.endm
- .macro dest
+ .macro source
+150:
+ .section __ex_table,"a"
+ .align 3
+ .llong 150b,.Lsrc_error
+ .previous
+ .endm
+
+ .macro dstnr
200:
.section __ex_table,"a"
.align 3
- .llong 200b,.Ldest_error
+ .llong 200b,.Ldest_error_nr
+ .previous
+ .endm
+
+ .macro dest
+250:
+ .section __ex_table,"a"
+ .align 3
+ .llong 250b,.Ldest_error
.previous
.endm
@@ -277,11 +293,11 @@ _GLOBAL(csum_partial_copy_generic)
mtctr r6
1:
-source; lhz r6,0(r3) /* align to doubleword */
+srcnr; lhz r6,0(r3) /* align to doubleword */
subi r5,r5,2
addi r3,r3,2
adde r0,r0,r6
-dest; sth r6,0(r4)
+dstnr; sth r6,0(r4)
addi r4,r4,2
bdnz 1b
@@ -395,10 +411,10 @@ dest; std r16,56(r4)
mtctr r6
3:
-source; ld r6,0(r3)
+srcnr; ld r6,0(r3)
addi r3,r3,8
adde r0,r0,r6
-dest; std r6,0(r4)
+dstnr; std r6,0(r4)
addi r4,r4,8
bdnz 3b
@@ -408,10 +424,10 @@ dest; std r6,0(r4)
srdi. r6,r5,2
beq .Lcopy_tail_halfword
-source; lwz r6,0(r3)
+srcnr; lwz r6,0(r3)
addi r3,r3,4
adde r0,r0,r6
-dest; stw r6,0(r4)
+dstnr; stw r6,0(r4)
addi r4,r4,4
subi r5,r5,4
@@ -419,10 +435,10 @@ dest; stw r6,0(r4)
srdi. r6,r5,1
beq .Lcopy_tail_byte
-source; lhz r6,0(r3)
+srcnr; lhz r6,0(r3)
addi r3,r3,2
adde r0,r0,r6
-dest; sth r6,0(r4)
+dstnr; sth r6,0(r4)
addi r4,r4,2
subi r5,r5,2
@@ -430,10 +446,10 @@ dest; sth r6,0(r4)
andi. r6,r5,1
beq .Lcopy_finish
-source; lbz r6,0(r3)
+srcnr; lbz r6,0(r3)
sldi r9,r6,8 /* Pad the byte out to 16 bits */
adde r0,r0,r9
-dest; stb r6,0(r4)
+dstnr; stb r6,0(r4)
.Lcopy_finish:
addze r0,r0 /* add in final carry */
@@ -443,6 +459,11 @@ dest; stb r6,0(r4)
blr
.Lsrc_error:
+ ld r14,STK_REG(r14)(r1)
+ ld r15,STK_REG(r15)(r1)
+ ld r16,STK_REG(r16)(r1)
+ addi r1,r1,STACKFRAMESIZE
+.Lsrc_error_nr:
cmpdi 0,r7,0
beqlr
li r6,-EFAULT
@@ -450,6 +471,11 @@ dest; stb r6,0(r4)
blr
.Ldest_error:
+ ld r14,STK_REG(r14)(r1)
+ ld r15,STK_REG(r15)(r1)
+ ld r16,STK_REG(r16)(r1)
+ addi r1,r1,STACKFRAMESIZE
+.Ldest_error_nr:
cmpdi 0,r8,0
beqlr
li r6,-EFAULT