[Xen-devel] [PATCH] linux-2.6.18/mm: properly frame Xen additions with CONFIG_XEN conditionals

["Jan Beulich" <JBeulich@xxxxxxxx>]

There's no need and no good reason to affect native kernels built from
the same sources.

Also eliminate a compiler warning triggered by various versions, and
adjust some white space.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -209,14 +209,15 @@ struct vm_operations_struct {
        /* notification that a previously read-only page is about to become
         * writable, if an error is returned it will cause a SIGBUS */
        int (*page_mkwrite)(struct vm_area_struct *vma, struct page *page);
+#ifdef CONFIG_XEN
        /* Area-specific function for clearing the PTE at @ptep. Returns the
         * original value of @ptep. */
-       pte_t (*zap_pte)(struct vm_area_struct *vma, 
+       pte_t (*zap_pte)(struct vm_area_struct *vma,
                         unsigned long addr, pte_t *ptep, int is_fullmm);
 
-        /* called before close() to indicate no more pages should be mapped */
-        void (*unmap)(struct vm_area_struct *area);
-
+       /* called before close() to indicate no more pages should be mapped */
+       void (*unmap)(struct vm_area_struct *area);
+#endif
 #ifdef CONFIG_NUMA
        int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
        struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -409,7 +409,9 @@ struct page *vm_normal_page(struct vm_ar
         * and that the resulting page looks ok.
         */
        if (unlikely(!pfn_valid(pfn))) {
+#ifdef CONFIG_XEN
                if (!(vma->vm_flags & VM_RESERVED))
+#endif
                        print_bad_pte(vma, pte, addr);
                return NULL;
        }
@@ -665,10 +667,12 @@ static unsigned long zap_pte_range(struc
                                     page->index > details->last_index))
                                        continue;
                        }
+#ifdef CONFIG_XEN
                        if (unlikely(vma->vm_ops && vma->vm_ops->zap_pte))
                                ptent = vma->vm_ops->zap_pte(vma, addr, pte,
                                                             tlb->fullmm);
                        else
+#endif
                                ptent = ptep_get_and_clear_full(mm, addr, pte,
                                                                tlb->fullmm);
                        tlb_remove_tlb_entry(tlb, pte, addr);
@@ -1425,7 +1429,7 @@ static inline int apply_to_pte_range(str
        spinlock_t *ptl;
 
        pte = (mm == &init_mm) ?
-               pte_alloc_kernel(pmd, addr) :
+               ptl = NULL, pte_alloc_kernel(pmd, addr) :
                pte_alloc_map_lock(mm, pmd, addr, &ptl);
        if (!pte)
                return -ENOMEM;
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1689,8 +1689,10 @@ static void unmap_region(struct mm_struc
 
 static inline void unmap_vma(struct vm_area_struct *vma)
 {
+#ifdef CONFIG_XEN
        if (unlikely(vma->vm_ops && vma->vm_ops->unmap))
                vma->vm_ops->unmap(vma);
+#endif
 }
 
 /*
@@ -1966,7 +1968,7 @@ EXPORT_SYMBOL(do_brk);
 void exit_mmap(struct mm_struct *mm)
 {
        struct mmu_gather *tlb;
-       struct vm_area_struct *vma_tmp, *vma = mm->mmap;
+       struct vm_area_struct *vma = mm->mmap;
        unsigned long nr_accounted = 0;
        unsigned long end;
 
@@ -1974,8 +1976,11 @@ void exit_mmap(struct mm_struct *mm)
        arch_exit_mmap(mm);
 #endif
 
-       for (vma_tmp = mm->mmap; vma_tmp; vma_tmp = vma_tmp->vm_next)
-               unmap_vma(vma_tmp);
+#ifdef CONFIG_XEN
+       for (; vma; vma = vma->vm_next)
+               unmap_vma(vma);
+       vma = mm->mmap;
+#endif
 
        lru_add_drain();
        flush_cache_mm(mm);

Attachment: xen-mm-conditionals.patch
Description: Text document

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