The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 188cb385bbf04d486df3e52f28c47b3961f5f0c0 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025081229-useable-overhung-5a62@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 188cb385bbf04d486df3e52f28c47b3961f5f0c0 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko andriy.shevchenko@linux.intel.com Date: Thu, 10 Jul 2025 11:23:53 +0300 Subject: [PATCH] mm/hmm: move pmd_to_hmm_pfn_flags() to the respective #ifdeffery

When pmd_to_hmm_pfn_flags() is unused, it prevents kernel builds with clang, `make W=1` and CONFIG_TRANSPARENT_HUGEPAGE=n:

mm/hmm.c:186:29: warning: unused function 'pmd_to_hmm_pfn_flags' [-Wunused-function]

Fix this by moving the function to the respective existing ifdeffery for its the only user.

See also:

6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build")

Link: https://lkml.kernel.org/r/20250710082403.664093-1-andriy.shevchenko@linux.in... Fixes: 992de9a8b751 ("mm/hmm: allow to mirror vma of a file on a DAX backed filesystem") Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Leon Romanovsky leonro@nvidia.com Reviewed-by: Alistair Popple apopple@nvidia.com Cc: Andriy Shevchenko andriy.shevchenko@linux.intel.com Cc: Bill Wendling morbo@google.com Cc: Jerome Glisse jglisse@redhat.com Cc: Justin Stitt justinstitt@google.com Cc: Nathan Chancellor nathan@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org

diff --git a/mm/hmm.c b/mm/hmm.c index f2415b4b2cdd..d545e2494994 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -183,6 +183,7 @@ static inline unsigned long hmm_pfn_flags_order(unsigned long order) return order << HMM_PFN_ORDER_SHIFT; }

+#ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline unsigned long pmd_to_hmm_pfn_flags(struct hmm_range *range, pmd_t pmd) { @@ -193,7 +194,6 @@ static inline unsigned long pmd_to_hmm_pfn_flags(struct hmm_range *range, hmm_pfn_flags_order(PMD_SHIFT - PAGE_SHIFT); }

-#ifdef CONFIG_TRANSPARENT_HUGEPAGE static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, unsigned long end, unsigned long hmm_pfns[], pmd_t pmd)