[vbox-dev] [PATCH] Fix compilation of host modules on Linux kernel 5.0

[Kyle Laker]

The API for the access_ok() macro has changed in 5.0 to remove the first 
argument. Which means the host modules do not compile on the 5.0 kernel. 
I was able to resolve it with the following patch. I did not find any 
other instances where access_ok() is used.

I have not signed the CA; however, this code is contributed under the 
terms of the MIT License.

- Kyle


Index: src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c
===================================================================
--- src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c	(revision 
76826)
+++ src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c	(working copy)
@@ -66,7 +66,11 @@
  RTR0DECL(bool) RTR0MemUserIsValidAddr(RTR3PTR R3Ptr)
  {
      IPRT_LINUX_SAVE_EFL_AC();
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
+    bool fRc = access_ok((void *)R3Ptr, 1);
+#else
      bool fRc = access_ok(VERIFY_READ, (void *)R3Ptr, 1);
+#endif
      IPRT_LINUX_RESTORE_EFL_AC();
      return fRc;
  }
@@ -82,7 +86,11 @@
      return (uintptr_t)pv >= PAGE_OFFSET;
  #else
  # error "PORT ME"
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
+    return !access_ok(pv, 1);
+#else
      return !access_ok(VERIFY_READ, pv, 1);
+#endif /* LINUX_VERSION_CODE */
  #endif
  }
  RT_EXPORT_SYMBOL(RTR0MemKernelIsValidAddr);