ARM: KVM: Enforce sorting of all CP tables

Since we're obviously terrible at sorting the CP tables, make sure
we're going to do it properly (or fail to boot). arm64 has had the
same mechanism for a while, and nobody ever broke it...

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 17 insertions, 8 deletions

diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 9aa462ec9c56..40d6db1ca4a8 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -381,17 +381,26 @@ static const struct coproc_reg cp15_regs[] = {
 	{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
 };
 
+static int check_reg_table(const struct coproc_reg *table, unsigned int n)
+{
+	unsigned int i;
+
+	for (i = 1; i < n; i++) {
+		if (cmp_reg(&table[i-1], &table[i]) >= 0) {
+			kvm_err("reg table %p out of order (%d)\n", table, i - 1);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 /* Target specific emulation tables */
 static struct kvm_coproc_target_table *target_tables[KVM_ARM_NUM_TARGETS];
 
 void kvm_register_target_coproc_table(struct kvm_coproc_target_table *table)
 {
-	unsigned int i;
-
-	for (i = 1; i < table->num; i++)
-		BUG_ON(cmp_reg(&table->table[i-1],
-			       &table->table[i]) >= 0);
-
+	BUG_ON(check_reg_table(table->table, table->num));
 	target_tables[table->target] = table;
 }
 
@@ -1210,8 +1219,8 @@ void kvm_coproc_table_init(void)
 	unsigned int i;
 
 	/* Make sure tables are unique and in order. */
-	for (i = 1; i < ARRAY_SIZE(cp15_regs); i++)
-		BUG_ON(cmp_reg(&cp15_regs[i-1], &cp15_regs[i]) >= 0);
+	BUG_ON(check_reg_table(cp15_regs, ARRAY_SIZE(cp15_regs)));
+	BUG_ON(check_reg_table(invariant_cp15, ARRAY_SIZE(invariant_cp15)));
 
 	/* We abuse the reset function to overwrite the table itself. */
 	for (i = 0; i < ARRAY_SIZE(invariant_cp15); i++)