[PATCH] kni: fix build with Linux 6.3

[Ferruh Yigit]

KNI calls `get_user_pages_remote()` API which is using `FOLL_TOUCH`
flag, but `FOLL_TOUCH` is no more in public headers since v6.3,
causing a build error.

`FOLL_*` defines in Linux kernel first moved to another header [1],
later some of them moved to memory subsystem internal header [2] for 6.3

Quickly fixing build error by defining it in KNI compatibility header
when it is not defined in Linux headers.

There is a risk in this approach that if Linux kernel updates flags
value and it diverges from the value defined in KNI.

[1]
Commit b5054174ac7c ("mm: move FOLL_* defs to mm_types.h")

[2]
Commit 2c2241081f7d ("mm/gup: move private gup FOLL_ flags to internal.h")

Signed-off-by: Ferruh Yigit <ferruh.yigit at amd.com>
---
 kernel/linux/kni/compat.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/linux/kni/compat.h b/kernel/linux/kni/compat.h
index 7aa6cd9fca75..42305799ebbd 100644
--- a/kernel/linux/kni/compat.h
+++ b/kernel/linux/kni/compat.h
@@ -151,3 +151,8 @@
 	 RHEL_RELEASE_VERSION(9, 1) <= RHEL_RELEASE_CODE))
 #define HAVE_NETIF_RX_NI
 #endif
+
+/* defined in 'mm/internal.h' since v6.3 */
+#ifndef FOLL_TOUCH
+#define FOLL_TOUCH (1 << 16)
+#endif
-- 
2.34.1