ARM: 6767/1: ptrace: fix register indexing in GETHBPREGS request

The GETHBPREGS ptrace request incorrectly maps its index argument onto
the thread's saved debug state when the index != 0. This has not yet
been seen from userspace because GDB (the only user of this request)
only reads from register 0.

This patch fixes the indexing.

Signed-off-by: Will Deacon <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/kernel/ptrace.c

···
 		while (!(arch_ctrl.len & 0x1))
 			arch_ctrl.len >>= 1;
 
-		if (idx & 0x1)
-			reg = encode_ctrl_reg(arch_ctrl);
-		else
+		if (num & 0x1)
 			reg = bp->attr.bp_addr;
+		else
+			reg = encode_ctrl_reg(arch_ctrl);
 	}
 
 put: