{PATCH] parisc: Revise gateway LWS calls to probe user read access

{PATCH] parisc: Revise gateway LWS calls to probe user read access

[John David Anglin]

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parisc: Revise gateway LWS calls to probe user read access

Signed-off-by: John David Anglin <dave.anglin@bell.net>
---

diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 0fa81bf1466b..4a9d7a08ecf9 100644
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -613,6 +613,9 @@ lws_compare_and_swap32:
 lws_compare_and_swap:
 	/* Trigger memory reference interruptions without writing to memory */
 1:	ldw	0(%r26), %r28
+	proberi	(%r26), 3, %r28
+	comb,=,n	%r28, %r0, lws_fault /* backwards, likely not taken */
+	nop
 2:	stbys,e	%r0, 0(%r26)
 
 	/* Calculate 8-bit hash index from virtual address */
@@ -767,6 +770,9 @@ cas2_lock_start:
 	copy	%r26, %r28
 	depi_safe	0, 31, 2, %r28
 10:	ldw	0(%r28), %r1
+	proberi	(%r28), 3, %r1
+	comb,=,n	%r1, %r0, lws_fault /* backwards, likely not taken */
+	nop
 11:	stbys,e	%r0, 0(%r28)
 
 	/* Calculate 8-bit hash index from virtual address */
@@ -951,41 +957,47 @@ atomic_xchg_begin:
 
 	/* 8-bit exchange */
 1:	ldb	0(%r24), %r20
+	proberi	(%r24), 3, %r20
+	comb,=,n	%r20, %r0, lws_fault /* backwards, likely not taken */
+	nop
 	copy	%r23, %r20
 	depi_safe	0, 31, 2, %r20
 	b	atomic_xchg_start
 2:	stbys,e	%r0, 0(%r20)
-	nop
-	nop
-	nop
 
 	/* 16-bit exchange */
 3:	ldh	0(%r24), %r20
+	proberi	(%r24), 3, %r20
+	comb,=,n	%r20, %r0, lws_fault /* backwards, likely not taken */
+	nop
 	copy	%r23, %r20
 	depi_safe	0, 31, 2, %r20
 	b	atomic_xchg_start
 4:	stbys,e	%r0, 0(%r20)
-	nop
-	nop
-	nop
 
 	/* 32-bit exchange */
 5:	ldw	0(%r24), %r20
+	proberi	(%r24), 3, %r20
+	comb,=,n	%r20, %r0, lws_fault /* backwards, likely not taken */
+	nop
 	b	atomic_xchg_start
 6:	stbys,e	%r0, 0(%r23)
 	nop
 	nop
-	nop
-	nop
-	nop
 
 	/* 64-bit exchange */
 #ifdef CONFIG_64BIT
 7:	ldd	0(%r24), %r20
+	proberi	(%r24), 3, %r20
+	comb,=,n	%r20, %r0, lws_fault /* backwards, likely not taken */
+	nop
 8:	stdby,e	%r0, 0(%r23)
 #else
 7:	ldw	0(%r24), %r20
 8:	ldw	4(%r24), %r20
+	proberi	(%r24), 3, %r20
+	comb,=,n	%r20, %r0, lws_fault /* backwards, likely not taken */
+	nop
 	copy	%r23, %r20
 	depi_safe	0, 31, 2, %r20
 9:	stbys,e	%r0, 0(%r20)

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