hugetlb: pass struct vm_fault through to hugetlb_handle_userfault()

Now that hugetlb_fault() has a struct vm_fault, have
hugetlb_handle_userfault() use it instead of creating one of its own.

This lets us reduce the number of arguments passed to
hugetlb_handle_userfault() from 7 to 3, cleaning up the code and stack.

Link: https://lkml.kernel.org/r/20240221234732.187629-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 02673926b3bb071c666f7ebb00f16be3b4dd7923..fa695e71152cdd4579257d0e600f8bcf02e4cd70 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6085,39 +6085,21 @@ int hugetlb_add_to_page_cache(struct folio *folio, struct address_space *mapping
        return 0;
 }
 
-static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma,
+static inline vm_fault_t hugetlb_handle_userfault(struct vm_fault *vmf,
                                                  struct address_space *mapping,
-                                                 pgoff_t idx,
-                                                 unsigned int flags,
-                                                 unsigned long haddr,
-                                                 unsigned long addr,
                                                  unsigned long reason)
 {
        u32 hash;
-       struct vm_fault vmf = {
-               .vma = vma,
-               .address = haddr,
-               .real_address = addr,
-               .flags = flags,
-
-               /*
-                * Hard to debug if it ends up being
-                * used by a callee that assumes
-                * something about the other
-                * uninitialized fields... same as in
-                * memory.c
-                */
-       };
 
        /*
         * vma_lock and hugetlb_fault_mutex must be dropped before handling
         * userfault. Also mmap_lock could be dropped due to handling
         * userfault, any vma operation should be careful from here.
         */
-       hugetlb_vma_unlock_read(vma);
-       hash = hugetlb_fault_mutex_hash(mapping, idx);
+       hugetlb_vma_unlock_read(vmf->vma);
+       hash = hugetlb_fault_mutex_hash(mapping, vmf->pgoff);
        mutex_unlock(&hugetlb_fault_mutex_table[hash]);
-       return handle_userfault(&vmf, reason);
+       return handle_userfault(vmf, reason);
 }
 
 /*
@@ -6141,7 +6123,8 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
                        struct vm_area_struct *vma,
                        struct address_space *mapping, pgoff_t idx,
                        unsigned long address, pte_t *ptep,
-                       pte_t old_pte, unsigned int flags)
+                       pte_t old_pte, unsigned int flags,
+                       struct vm_fault *vmf)
 {
        struct hstate *h = hstate_vma(vma);
        vm_fault_t ret = VM_FAULT_SIGBUS;
@@ -6200,8 +6183,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
                                goto out;
                        }
 
-                       return hugetlb_handle_userfault(vma, mapping, idx, flags,
-                                                       haddr, address,
+                       return hugetlb_handle_userfault(vmf, mapping,
                                                        VM_UFFD_MISSING);
                }
 
@@ -6273,8 +6255,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
                                ret = 0;
                                goto out;
                        }
-                       return hugetlb_handle_userfault(vma, mapping, idx, flags,
-                                                       haddr, address,
+                       return hugetlb_handle_userfault(vmf, mapping,
                                                        VM_UFFD_MINOR);
                }
        }
@@ -6444,9 +6425,8 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 * hugetlb_no_page will drop vma lock and hugetlb fault
                 * mutex internally, which make us return immediately.
                 */
-
                return hugetlb_no_page(mm, vma, mapping, vmf.pgoff, address,
-                                       ptep, entry, flags);
+                                       ptep, entry, flags, &vmf);
        }
 
        ret = 0;