Implement copyin32().

ok deraadt@

diff --git a/sys/arch/riscv64/riscv64/copy.S b/sys/arch/riscv64/riscv64/copy.S
index 54ab2d2..96a4fa8 100644 (file)
--- a/sys/arch/riscv64/riscv64/copy.S
+++ b/sys/arch/riscv64/riscv64/copy.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: copy.S,v 1.4 2021/05/15 20:14:05 deraadt Exp $        */
+/*     $OpenBSD: copy.S,v 1.5 2021/06/28 09:35:09 kettenis Exp $       */
 
 /*
  * Copyright (c) 2020 Brian Bamsch <bbamsch@google.com>
@@ -62,7 +62,7 @@ ENTRY(copyin)
        EXIT_USER_ACCESS(a4)
        SET_FAULT_HANDLER(a3, a4)
 .Lcopyiodone:
-       mv      a0, x0
+       mv      a0, zero
        RETGUARD_CHECK(copyio, a6)
        ret
 
@@ -76,6 +76,33 @@ ENTRY(copyin)
        ret
 END(copyin)
 
+/*
+ * a0 = user space address
+ * a1 = kernel space address
+ *
+ * Atomically copies a 32-bit word from user space to kernel space
+ */
+ENTRY(copyin32)
+       RETGUARD_SETUP(copyio, a6)
+       /* Check source alignment. */
+       andi    a2, a0, 3
+       bnez    a2, .Lcopyiofault_nopcb
+       /* Check that source is in userspace. */
+       li      a4, VM_MAXUSER_ADDRESS
+       bgeu    a0, a4, .Lcopyiofault_nopcb
+
+       la      a3, .Lcopyiofault_user
+       SWAP_FAULT_HANDLER(a3, a4, a5)
+       ENTER_USER_ACCESS(a4)
+
+       lw      a2, 0(a0)
+       sw      a2, 0(a1)
+
+       EXIT_USER_ACCESS(a4)
+       SET_FAULT_HANDLER(a3, a4)
+       j       .Lcopyiodone
+END(copyin)
+
 /*
  * a0 = kernel space address
  * a1 = user space address