From 7213a5bfa3bd9f360d6be01e6dbd59d91095a0fd Mon Sep 17 00:00:00 2001
From: Bruce Ashfield <bruce.ashfield@gmail.com>
Date: Thu, 4 Nov 2021 14:53:46 -0400
Subject: [PATCH] utils: fix build against 5.15 libc-headers headers

In kernel v5.15+ stdarg.h is part of the kernel source, and the
upstream project has a change to prefer that stdarg.h to the
c-library variant and hence includes it as <linux/stdarg.h>, which
leads to the following build error:

   | In file included from ../vboxsf/include/iprt/types.h:34,
   |                  from ../vboxsf/include/iprt/string.h:33,
   |                  from mount.vboxsf.c:53:
   | ../vboxsf/include/iprt/stdarg.h:49:13: fatal error: linux/stdarg.h: No such file or directory
   |    49 | #   include <linux/stdarg.h>
   |       |             ^~~~~~~~~~~~~~~~

If we modify our build of the vboxdrivers to have the kernel source
directory on the include path (to find linux/stdarg.h, that leads
to the following errors:

   In file included from build/tmp/work/qemux86_64-poky-linux/vboxguestdrivers/6.1.28-r0/recipe-sysroot/usr/include/stdlib.h:394,
   |                  from mount.vboxsf.c:36:
   | build/tmp/work/qemux86_64-poky-linux/vboxguestdrivers/6.1.28-r0/recipe-sysroot/usr/include/sys/types.h:192:20: note: previous declaration of 'blkcnt_t' with type 'blkcnt_t' {aka 'long int'}
   |   192 | typedef __blkcnt_t blkcnt_t;     /* Type to count number of disk blocks.  */
   |       |                    ^~~~~~~~
   | In file included from build/tmp/work-shared/qemux86-64/kernel-source/include/linux/time.h:5,
   |                  from poky/build/tmp/work-shared/qemux86-64/kernel-source/include/linux/stat.h:19,
   |                  from build/tmp/work/qemux86_64-poky-linux/vboxguestdrivers/6.1.28-r0/recipe-sysroot/usr/include/bits/statx.h:31,

Our libc-headers are safe and don't lead to the potential conflicing
information that the upstream commit is guarding against. The easiest
solution is to revert the upstream change and trust our headers.

Upstream-Status: Inappropriate [OE specific]

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
---
 vboxsf/include/iprt/stdarg.h | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/include/iprt/stdarg.h b/include/iprt/stdarg.h
index c73093c..7bffde5 100644
--- a/include/iprt/stdarg.h
+++ b/include/iprt/stdarg.h
@@ -44,12 +44,7 @@
 #   define __builtin_stdarg_start __builtin_va_start
 #  endif
 # elif defined(RT_OS_LINUX) && defined(IN_RING0)
-#  include "linux/version.h"
-#  if RTLNX_VER_MIN(5,15,0) || RTLNX_RHEL_MAJ_PREREQ(9,1)
-#   include <linux/stdarg.h>
-#  else
-#   include <stdarg.h>
-#  endif
+#  include <stdarg.h>
 # else
 #  include <stdarg.h>
 # endif
-- 
2.19.1