powerpc: Fix parameter clobber in csum_partial_copy_generic()

commit d9813c3 upstream. The csum_partial_copy_generic() uses register r7 to adjust the remaining bytes to process. Unfortunately, r7 also holds a parameter, namely the address of the flag to set in case of access exceptions while reading the source buffer. Lacking a quantum implementation of PowerPC, this commit instead uses register r9 to do the adjusting, leaving r7's pointer uncorrupted. Signed-off-by: Paul E. McKenney <[email protected]> Signed-off-by: Anton Blanchard <[email protected]> Signed-off-by: Benjamin Herrenschmidt <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
cm12-amami · Oct 13, 2013 · 77ddd59 · 77ddd59
1 parent ff9c3c0
commit 77ddd59
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S
@@ -272,8 +272,8 @@ _GLOBAL(csum_partial_copy_generic)
 	rldicl. r6,r3,64-1,64-2		/* r6 = (r3 & 0x3) >> 1 */
 	beq	.Lcopy_aligned
 
-	li	r7,4
-	sub	r6,r7,r6
+	li	r9,4
+	sub	r6,r9,r6
 	mtctr	r6
 
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