[Devel] [PATCH RHEL10 COMMIT] redhat: rh_waived: add a stub for CONFIG_RHEL_DIFFERENCES=n

[Konstantin Khorenko <khorenko@virtuozzo.com>]

The commit is pushed to "branch-rh10-6.12.0-211.39.1.16.x.vz10-ovz" and will appear at git at bitbucket.org:openvz/vzkernel.git
after rh10-6.12.0-211.39.1.16.6.vz10
------>
commit 01feec3c519a85a9979fdbed970138ebd312c26c
Author: Konstantin Khorenko <khorenko@virtuozzo.com>
Date:   Fri Aug 21 18:37:16 2026 +0200

    redhat: rh_waived: add a stub for CONFIG_RHEL_DIFFERENCES=n
    
    is_rh_waived() is compiled as part of kernel/rh_waived.c, which is built
    only with CONFIG_RHEL_DIFFERENCES, but huge_pmd_unshare() calls it
    unconditionally, so a kernel built without that option does not link:
    
      ld: vmlinux.o: in function 'huge_pmd_unshare':
          undefined reference to 'is_rh_waived'
    
    x86_64 defconfig is one such kernel.  Add a stub returning false: with no
    way to pass
    rh_waived= there is nothing waived, so every mitigation stays enabled.
    
    Fixes: 9f055df11343 ("rh10: import RHEL10 kernel-6.12.0-211.16.1.el10")
    Feature: fix rh/waived
    https://virtuozzo.atlassian.net/browse/VSTOR-134732
    Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
---
 include/linux/rh_waived.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/rh_waived.h b/include/linux/rh_waived.h
index 8ec7aabab3ab7..e6aab88182411 100644
--- a/include/linux/rh_waived.h
+++ b/include/linux/rh_waived.h
@@ -15,6 +15,13 @@ enum rh_waived_items {
 	RH_WAIVED_ITEMS,
 };
 
+#ifdef CONFIG_RHEL_DIFFERENCES
 bool is_rh_waived(enum rh_waived_items feat);
+#else
+static inline bool is_rh_waived(enum rh_waived_items feat)
+{
+	return false;
+}
+#endif
 
 #endif /* _RH_WAIVED_H */