1 files changed, 10 insertions, 2 deletions

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 987d4648aad9..370c66ce187a 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -96,7 +96,9 @@ relocate:
 
         /*
          * Load trampoline page directory, which will cause us to trap to
-         * stvec if VA != PA, or simply fall through if VA == PA
+         * stvec if VA != PA, or simply fall through if VA == PA.  We need a
+         * full fence here because setup_vm() just wrote these PTEs and we need
+         * to ensure the new translations are in use.
          */
         la a0, trampoline_pg_dir
         srl a0, a0, PAGE_SHIFT
@@ -115,8 +117,14 @@ relocate:
         la gp, __global_pointer$
 .option pop
 
-        /* Switch to kernel page tables */
+        /*
+         * Switch to kernel page tables.  A full fence is necessary in order to
+         * avoid using the trampoline translations, which are only correct for
+         * the first superpage.  Fetching the fence is guarnteed to work
+         * because that first superpage is translated the same way.
+         */
         csrw CSR_SATP, a2
+        sfence.vma
 
         ret