]> www.infradead.org Git - users/jedix/linux-maple.git/commitdiff
mm: Remove rb tree.
authorLiam R. Howlett <Liam.Howlett@Oracle.com>
Fri, 24 Jul 2020 19:06:25 +0000 (15:06 -0400)
committerLiam R. Howlett <Liam.Howlett@Oracle.com>
Thu, 14 Jan 2021 01:33:54 +0000 (20:33 -0500)
Remove the RB tree and start using the maple tree for vm_area_struct
tracking.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
arch/x86/kernel/tboot.c
drivers/firmware/efi/efi.c
include/linux/mm.h
include/linux/mm_types.h
kernel/fork.c
mm/init-mm.c
mm/mmap.c
mm/util.c

index 52fab58e4b07f9ba7b80614ffdebb379b21e2b70..53d0d3d8ff38df70a13bc31913e9a45c6019ca0d 100644 (file)
@@ -89,7 +89,6 @@ void __init tboot_probe(void)
 
 static pgd_t *tboot_pg_dir;
 static struct mm_struct tboot_mm = {
-       .mm_rb          = RB_ROOT,
        .mm_mt          = MTREE_INIT(mm_mt, MAPLE_ALLOC_RANGE),
        .pgd            = swapper_pg_dir,
        .mm_users       = ATOMIC_INIT(2),
index 03b07aa3df5e0c0c951bc5959b7dda255519f16f..aab326ade34d0bec24ae635fdc015586878096f4 100644 (file)
@@ -54,7 +54,6 @@ static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
 static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
 
 struct mm_struct efi_mm = {
-       .mm_rb                  = RB_ROOT,
        .mm_mt                  = MTREE_INIT(mm_mt, MAPLE_ALLOC_RANGE),
        .mm_users               = ATOMIC_INIT(2),
        .mm_count               = ATOMIC_INIT(1),
index 0270ce6fec3a99bce44c5451769394db2594f2e0..ad82ab61bebab7fd7e510b60858a82ed56241ddb 100644 (file)
@@ -2468,8 +2468,6 @@ extern bool arch_has_descending_max_zone_pfns(void);
 /* nommu.c */
 extern atomic_long_t mmap_pages_allocated;
 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
-/* maple_tree */
-void vma_store(struct mm_struct *mm, struct vm_area_struct *vma);
 
 /* interval_tree.c */
 void vma_interval_tree_insert(struct vm_area_struct *node,
@@ -2525,8 +2523,6 @@ extern int __split_vma(struct mm_struct *, struct vm_area_struct *,
 extern int split_vma(struct mm_struct *, struct vm_area_struct *,
        unsigned long addr, int new_below);
 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
-extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
-       struct rb_node **, struct rb_node *);
 extern void unlink_file_vma(struct vm_area_struct *);
 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
        unsigned long addr, unsigned long len, pgoff_t pgoff,
index 085ebbbb91ba4d2c4ea6d9521e27240e08bde84d..59707a68e3cf0d44bc061cee737e58021a2799ca 100644 (file)
@@ -272,7 +272,6 @@ typedef unsigned long vm_flags_t;
  * map parts of them.
  */
 struct vm_region {
-       struct rb_node  vm_rb;          /* link in global region tree */
        vm_flags_t      vm_flags;       /* VMA vm_flags */
        unsigned long   vm_start;       /* start address of region */
        unsigned long   vm_end;         /* region initialised to here */
@@ -310,19 +309,6 @@ struct vm_area_struct {
 
        /* linked list of VM areas per task, sorted by address */
        struct vm_area_struct *vm_next, *vm_prev;
-
-       struct rb_node vm_rb;
-
-       /*
-        * Largest free memory gap in bytes to the left of this VMA.
-        * Either between this VMA and vma->vm_prev, or between one of the
-        * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
-        * get_unmapped_area find a free area of the right size.
-        */
-       unsigned long rb_subtree_gap;
-
-       /* Second cache line starts here. */
-
        struct mm_struct *vm_mm;        /* The address space we belong to. */
 
        /*
@@ -332,6 +318,12 @@ struct vm_area_struct {
        pgprot_t vm_page_prot;
        unsigned long vm_flags;         /* Flags, see mm.h. */
 
+       /* Information about our backing store: */
+       unsigned long vm_pgoff;         /* Offset (within vm_file) in PAGE_SIZE
+                                        * units
+                                        */
+       /* Second cache line starts here. */
+       struct file *vm_file;           /* File we map to (can be NULL). */
        /*
         * For areas with an address space and backing store,
         * linkage into the address_space->i_mmap interval tree.
@@ -350,16 +342,14 @@ struct vm_area_struct {
        struct list_head anon_vma_chain; /* Serialized by mmap_lock &
                                          * page_table_lock */
        struct anon_vma *anon_vma;      /* Serialized by page_table_lock */
+       /* Third cache line starts here. */
 
        /* Function pointers to deal with this struct. */
        const struct vm_operations_struct *vm_ops;
 
-       /* Information about our backing store: */
-       unsigned long vm_pgoff;         /* Offset (within vm_file) in PAGE_SIZE
-                                          units */
-       struct file * vm_file;          /* File we map to (can be NULL). */
        void * vm_private_data;         /* was vm_pte (shared mem) */
 
+
 #ifdef CONFIG_SWAP
        atomic_long_t swap_readahead_info;
 #endif
@@ -388,7 +378,6 @@ struct mm_struct {
        struct {
                struct vm_area_struct *mmap;            /* list of VMAs */
                struct maple_tree mm_mt;
-               struct rb_root mm_rb;
                u64 vmacache_seqnum;                   /* per-thread vmacache */
 #ifdef CONFIG_MMU
                unsigned long (*get_unmapped_area) (struct file *filp,
index b0e60038d8444606eb5ab00d937a6772a78d248c..698ecfa055881ba8c3f5638bc15bb2fea2532d35 100644 (file)
@@ -471,7 +471,6 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
                                        struct mm_struct *oldmm)
 {
        struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
-       struct rb_node **rb_link, *rb_parent;
        int retval;
        unsigned long charge = 0;
        MA_STATE(old_mas, &oldmm->mm_mt, 0, 0);
@@ -498,8 +497,6 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
        mm->exec_vm = oldmm->exec_vm;
        mm->stack_vm = oldmm->stack_vm;
 
-       rb_link = &mm->mm_rb.rb_node;
-       rb_parent = NULL;
        pprev = &mm->mmap;
        retval = ksm_fork(mm, oldmm);
        if (retval)
@@ -592,10 +589,6 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
                tmp->vm_prev = prev;
                prev = tmp;
 
-               __vma_link_rb(mm, tmp, rb_link, rb_parent);
-               rb_link = &tmp->vm_rb.rb_right;
-               rb_parent = &tmp->vm_rb;
-
                /* Link the vma into the MT */
                mas.index = tmp->vm_start;
                mas.last = tmp->vm_end - 1;
@@ -1020,7 +1013,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
        struct user_namespace *user_ns)
 {
        mm->mmap = NULL;
-       mm->mm_rb = RB_ROOT;
        mt_init_flags(&mm->mm_mt, MAPLE_ALLOC_RANGE);
        mm->vmacache_seqnum = 0;
        atomic_set(&mm->mm_users, 1);
index 2014d4b822944743dee2b6767b791959cf0c7e6f..04bbe5172b72b11792ba88638b66684adb90ee7f 100644 (file)
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/mm_types.h>
-#include <linux/rbtree.h>
 #include <linux/maple_tree.h>
 #include <linux/rwsem.h>
 #include <linux/spinlock.h>
@@ -28,7 +27,6 @@
  * and size this cpu_bitmask to NR_CPUS.
  */
 struct mm_struct init_mm = {
-       .mm_rb          = RB_ROOT,
        .mm_mt          = MTREE_INIT(mm_mt, MAPLE_ALLOC_RANGE),
        .pgd            = swapper_pg_dir,
        .mm_users       = ATOMIC_INIT(2),
index 1aec52aa90e4b5dff619c383553048bb183fdccf..1cbfb80f5ed3158ccc14c5e990e35c615b85f2f4 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -38,7 +38,6 @@
 #include <linux/audit.h>
 #include <linux/khugepaged.h>
 #include <linux/uprobes.h>
-#include <linux/rbtree_augmented.h>
 #include <linux/notifier.h>
 #include <linux/memory.h>
 #include <linux/printk.h>
@@ -284,93 +283,6 @@ out:
        return origbrk;
 }
 
-static inline unsigned long vma_compute_gap(struct vm_area_struct *vma)
-{
-       unsigned long gap, prev_end;
-
-       /*
-        * Note: in the rare case of a VM_GROWSDOWN above a VM_GROWSUP, we
-        * allow two stack_guard_gaps between them here, and when choosing
-        * an unmapped area; whereas when expanding we only require one.
-        * That's a little inconsistent, but keeps the code here simpler.
-        */
-       gap = vm_start_gap(vma);
-       if (vma->vm_prev) {
-               prev_end = vm_end_gap(vma->vm_prev);
-               if (gap > prev_end)
-                       gap -= prev_end;
-               else
-                       gap = 0;
-       }
-       return gap;
-}
-
-#ifdef CONFIG_DEBUG_VM_RB
-static unsigned long vma_compute_subtree_gap(struct vm_area_struct *vma)
-{
-       unsigned long max = vma_compute_gap(vma), subtree_gap;
-       if (vma->vm_rb.rb_left) {
-               subtree_gap = rb_entry(vma->vm_rb.rb_left,
-                               struct vm_area_struct, vm_rb)->rb_subtree_gap;
-               if (subtree_gap > max)
-                       max = subtree_gap;
-       }
-       if (vma->vm_rb.rb_right) {
-               subtree_gap = rb_entry(vma->vm_rb.rb_right,
-                               struct vm_area_struct, vm_rb)->rb_subtree_gap;
-               if (subtree_gap > max)
-                       max = subtree_gap;
-       }
-       return max;
-}
-
-static int browse_rb(struct mm_struct *mm)
-{
-       struct rb_root *root = &mm->mm_rb;
-       int i = 0, j, bug = 0;
-       struct rb_node *nd, *pn = NULL;
-       unsigned long prev = 0, pend = 0;
-
-       for (nd = rb_first(root); nd; nd = rb_next(nd)) {
-               struct vm_area_struct *vma;
-               vma = rb_entry(nd, struct vm_area_struct, vm_rb);
-               if (vma->vm_start < prev) {
-                       pr_emerg("vm_start %lx < prev %lx\n",
-                                 vma->vm_start, prev);
-                       bug = 1;
-               }
-               if (vma->vm_start < pend) {
-                       pr_emerg("vm_start %lx < pend %lx\n",
-                                 vma->vm_start, pend);
-                       bug = 1;
-               }
-               if (vma->vm_start > vma->vm_end) {
-                       pr_emerg("vm_start %lx > vm_end %lx\n",
-                                 vma->vm_start, vma->vm_end);
-                       bug = 1;
-               }
-               spin_lock(&mm->page_table_lock);
-               if (vma->rb_subtree_gap != vma_compute_subtree_gap(vma)) {
-                       pr_emerg("free gap %lx, correct %lx\n",
-                              vma->rb_subtree_gap,
-                              vma_compute_subtree_gap(vma));
-                       bug = 1;
-               }
-               spin_unlock(&mm->page_table_lock);
-               i++;
-               pn = nd;
-               prev = vma->vm_start;
-               pend = vma->vm_end;
-       }
-       j = 0;
-       for (nd = pn; nd; nd = rb_prev(nd))
-               j++;
-       if (i != j) {
-               pr_emerg("backwards %d, forwards %d\n", j, i);
-               bug = 1;
-       }
-       return bug ? -1 : i;
-}
 #if defined(CONFIG_DEBUG_MAPLE_TREE)
 extern void mt_validate(struct maple_tree *mt);
 extern void mt_dump(const struct maple_tree *mt);
@@ -399,17 +311,25 @@ static void validate_mm_mt(struct mm_struct *mm)
                        dump_stack();
 #ifdef CONFIG_DEBUG_VM
                        dump_vma(vma_mt);
-                       pr_emerg("and next in rb\n");
+                       pr_emerg("and vm_next\n");
                        dump_vma(vma->vm_next);
-#endif
+#endif // CONFIG_DEBUG_VM
                        pr_emerg("mt piv: %px %lu - %lu\n", vma_mt,
                                 mas.index, mas.last);
                        pr_emerg("mt vma: %px %lu - %lu\n", vma_mt,
                                 vma_mt->vm_start, vma_mt->vm_end);
-                       pr_emerg("rb vma: %px %lu - %lu\n", vma,
+                       if (vma->vm_prev) {
+                               pr_emerg("ll prev: %px %lu - %lu\n",
+                                        vma->vm_prev, vma->vm_prev->vm_start,
+                                        vma->vm_prev->vm_end);
+                       }
+                       pr_emerg("ll vma: %px %lu - %lu\n", vma,
                                 vma->vm_start, vma->vm_end);
-                       pr_emerg("rb->next = %px %lu - %lu\n", vma->vm_next,
-                                       vma->vm_next->vm_start, vma->vm_next->vm_end);
+                       if (vma->vm_next) {
+                               pr_emerg("ll next: %px %lu - %lu\n",
+                                        vma->vm_next, vma->vm_next->vm_start,
+                                        vma->vm_next->vm_end);
+                       }
 
                        mt_dump(mas.tree);
                        if (vma_mt->vm_end != mas.last + 1) {
@@ -435,20 +355,6 @@ static void validate_mm_mt(struct mm_struct *mm)
        rcu_read_unlock();
        mt_validate(&mm->mm_mt);
 }
-#endif
-static void validate_mm_rb(struct rb_root *root, struct vm_area_struct *ignore)
-{
-       struct rb_node *nd;
-
-       for (nd = rb_first(root); nd; nd = rb_next(nd)) {
-               struct vm_area_struct *vma;
-               vma = rb_entry(nd, struct vm_area_struct, vm_rb);
-               VM_BUG_ON_VMA(vma != ignore &&
-                       vma->rb_subtree_gap != vma_compute_subtree_gap(vma),
-                       vma);
-       }
-}
-
 static void validate_mm(struct mm_struct *mm)
 {
        int bug = 0;
@@ -456,6 +362,8 @@ static void validate_mm(struct mm_struct *mm)
        unsigned long highest_address = 0;
        struct vm_area_struct *vma = mm->mmap;
 
+       validate_mm_mt(mm);
+
        while (vma) {
                struct anon_vma *anon_vma = vma->anon_vma;
                struct anon_vma_chain *avc;
@@ -480,80 +388,12 @@ static void validate_mm(struct mm_struct *mm)
                          mm->highest_vm_end, highest_address);
                bug = 1;
        }
-       i = browse_rb(mm);
-       if (i != mm->map_count) {
-               if (i != -1)
-                       pr_emerg("map_count %d rb %d\n", mm->map_count, i);
-               bug = 1;
-       }
        VM_BUG_ON_MM(bug, mm);
 }
-#else
-#define validate_mm_rb(root, ignore) do { } while (0)
+#else // !CONFIG_DEBUG_MAPLE_TREE
 #define validate_mm_mt(root) do { } while (0)
 #define validate_mm(mm) do { } while (0)
-#endif
-
-RB_DECLARE_CALLBACKS_MAX(static, vma_gap_callbacks,
-                        struct vm_area_struct, vm_rb,
-                        unsigned long, rb_subtree_gap, vma_compute_gap)
-
-/*
- * Update augmented rbtree rb_subtree_gap values after vma->vm_start or
- * vma->vm_prev->vm_end values changed, without modifying the vma's position
- * in the rbtree.
- */
-static void vma_gap_update(struct vm_area_struct *vma)
-{
-       /*
-        * As it turns out, RB_DECLARE_CALLBACKS_MAX() already created
-        * a callback function that does exactly what we want.
-        */
-       vma_gap_callbacks_propagate(&vma->vm_rb, NULL);
-}
-
-static inline void vma_rb_insert(struct vm_area_struct *vma,
-                                struct rb_root *root)
-{
-       /* All rb_subtree_gap values must be consistent prior to insertion */
-       validate_mm_rb(root, NULL);
-
-       rb_insert_augmented(&vma->vm_rb, root, &vma_gap_callbacks);
-}
-
-static void __vma_rb_erase(struct vm_area_struct *vma, struct rb_root *root)
-{
-       /*
-        * Note rb_erase_augmented is a fairly large inline function,
-        * so make sure we instantiate it only once with our desired
-        * augmented rbtree callbacks.
-        */
-       rb_erase_augmented(&vma->vm_rb, root, &vma_gap_callbacks);
-}
-
-static __always_inline void vma_rb_erase_ignore(struct vm_area_struct *vma,
-                                               struct rb_root *root,
-                                               struct vm_area_struct *ignore)
-{
-       /*
-        * All rb_subtree_gap values must be consistent prior to erase,
-        * with the possible exception of
-        *
-        * a. the "next" vma being erased if next->vm_start was reduced in
-        *    __vma_adjust() -> __vma_unlink()
-        * b. the vma being erased in detach_vmas_to_be_unmapped() ->
-        *    vma_rb_erase()
-        */
-       validate_mm_rb(root, ignore);
-
-       __vma_rb_erase(vma, root);
-}
-
-static __always_inline void vma_rb_erase(struct vm_area_struct *vma,
-                                        struct rb_root *root)
-{
-       vma_rb_erase_ignore(vma, root, vma);
-}
+#endif // CONFIG_DEBUG_MAPLE_TREE
 
 /*
  * vma has some anon_vma assigned, and is already inserted on that
@@ -587,38 +427,26 @@ anon_vma_interval_tree_post_update_vma(struct vm_area_struct *vma)
                anon_vma_interval_tree_insert(avc, &avc->anon_vma->rb_root);
 }
 
-static int find_vma_links(struct mm_struct *mm, unsigned long addr,
-               unsigned long end, struct vm_area_struct **pprev,
-               struct rb_node ***rb_link, struct rb_node **rb_parent)
+/* Private
+ * range_has_overlap() - Check the @start - @end range for overlapping VMAs and
+ * sets up a pointer to the previous VMA
+ *
+ * @mm - the mm struct
+ * @start - the start address of the range
+ * @end - the end address of the range
+ * @pprev - the pointer to the pointer of the previous VMA
+ *
+ * Returns: True if there is an overlapping VMA, false otherwise
+ */
+static bool range_has_overlap(struct mm_struct *mm, unsigned long start,
+                             unsigned long end, struct vm_area_struct **pprev)
 {
-       struct rb_node **__rb_link, *__rb_parent, *rb_prev;
-
-       __rb_link = &mm->mm_rb.rb_node;
-       rb_prev = __rb_parent = NULL;
-
-       while (*__rb_link) {
-               struct vm_area_struct *vma_tmp;
-
-               __rb_parent = *__rb_link;
-               vma_tmp = rb_entry(__rb_parent, struct vm_area_struct, vm_rb);
-
-               if (vma_tmp->vm_end > addr) {
-                       /* Fail if an existing vma overlaps the area */
-                       if (vma_tmp->vm_start < end)
-                               return -ENOMEM;
-                       __rb_link = &__rb_parent->rb_left;
-               } else {
-                       rb_prev = __rb_parent;
-                       __rb_link = &__rb_parent->rb_right;
-               }
-       }
+       struct vm_area_struct *existing;
 
-       *pprev = NULL;
-       if (rb_prev)
-               *pprev = rb_entry(rb_prev, struct vm_area_struct, vm_rb);
-       *rb_link = __rb_link;
-       *rb_parent = __rb_parent;
-       return 0;
+       MA_STATE(mas, &mm->mm_mt, start, start);
+       existing = mas_find(&mas, end - 1);
+       *pprev = mas_prev(&mas, 0);
+       return existing ? true : false;
 }
 
 /*
@@ -645,8 +473,6 @@ static inline struct vm_area_struct *vma_next(struct mm_struct *mm,
  * @start: The start of the range.
  * @len: The length of the range.
  * @pprev: pointer to the pointer that will be set to previous vm_area_struct
- * @rb_link: the rb_node
- * @rb_parent: the parent rb_node
  *
  * Find all the vm_area_struct that overlap from @start to
  * @end and munmap them.  Set @pprev to the previous vm_area_struct.
@@ -655,76 +481,41 @@ static inline struct vm_area_struct *vma_next(struct mm_struct *mm,
  */
 static inline int
 munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len,
-                struct vm_area_struct **pprev, struct rb_node ***link,
-                struct rb_node **parent, struct list_head *uf)
+                struct vm_area_struct **pprev, struct list_head *uf)
 {
-
-       while (find_vma_links(mm, start, start + len, pprev, link, parent))
+       // Needs optimization.
+       while (range_has_overlap(mm, start, start + len, pprev))
                if (do_munmap(mm, start, len, uf))
                        return -ENOMEM;
-
        return 0;
 }
 static unsigned long count_vma_pages_range(struct mm_struct *mm,
                unsigned long addr, unsigned long end)
 {
        unsigned long nr_pages = 0;
-       unsigned long nr_mt_pages = 0;
        struct vm_area_struct *vma;
+       unsigned long vm_start, vm_end;
+       MA_STATE(mas, &mm->mm_mt, addr, addr);
 
        /* Find first overlaping mapping */
-       vma = find_vma_intersection(mm, addr, end);
+       vma = mas_find(&mas, end - 1);
        if (!vma)
                return 0;
 
-       nr_pages = (min(end, vma->vm_end) -
-               max(addr, vma->vm_start)) >> PAGE_SHIFT;
+       vm_start = vma->vm_start;
+       vm_end = vma->vm_end;
+       nr_pages = (min(end, vm_end) - max(addr, vm_start)) >> PAGE_SHIFT;
 
        /* Iterate over the rest of the overlaps */
-       for (vma = vma->vm_next; vma; vma = vma->vm_next) {
-               unsigned long overlap_len;
-
-               if (vma->vm_start > end)
-                       break;
-
-               overlap_len = min(end, vma->vm_end) - vma->vm_start;
-               nr_pages += overlap_len >> PAGE_SHIFT;
+       mas_for_each(&mas, vma, end) {
+               vm_start = vma->vm_start;
+               vm_end = vma->vm_end;
+               nr_pages += (min(end, vm_end) - vm_start) >> PAGE_SHIFT;
        }
 
-       mt_for_each(&mm->mm_mt, vma, addr, end) {
-               nr_mt_pages +=
-                       (min(end, vma->vm_end) - vma->vm_start) >> PAGE_SHIFT;
-       }
-
-       VM_BUG_ON_MM(nr_pages != nr_mt_pages, mm);
-
        return nr_pages;
 }
 
-void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,
-               struct rb_node **rb_link, struct rb_node *rb_parent)
-{
-       /* Update tracking information for the gap following the new vma. */
-       if (vma->vm_next)
-               vma_gap_update(vma->vm_next);
-       else
-               mm->highest_vm_end = vm_end_gap(vma);
-
-       /*
-        * vma->vm_prev wasn't known when we followed the rbtree to find the
-        * correct insertion point for that vma. As a result, we could not
-        * update the vma vm_rb parents rb_subtree_gap values on the way down.
-        * So, we first insert the vma with a zero rb_subtree_gap value
-        * (to be consistent with what we did on the way down), and then
-        * immediately update the gap to the correct value. Finally we
-        * rebalance the rbtree after all augmented values have been set.
-        */
-       rb_link_node(&vma->vm_rb, rb_parent, rb_link);
-       vma->rb_subtree_gap = 0;
-       vma_gap_update(vma);
-       vma_rb_insert(vma, &mm->mm_rb);
-}
-
 static void __vma_link_file(struct vm_area_struct *vma)
 {
        struct file *file;
@@ -787,8 +578,7 @@ __vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
 }
 
 static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
-                       struct vm_area_struct *prev, struct rb_node **rb_link,
-                       struct rb_node *rb_parent)
+                       struct vm_area_struct *prev)
 {
        struct address_space *mapping = NULL;
 
@@ -797,7 +587,8 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
                i_mmap_lock_write(mapping);
        }
 
-       __vma_link(mm, vma, prev, rb_link, rb_parent);
+       vma_mt_store(mm, vma);
+       __vma_link_list(mm, vma, prev);
        __vma_link_file(vma);
 
        if (mapping)
@@ -809,29 +600,19 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
 
 /*
  * Helper for vma_adjust() in the split_vma insert case: insert a vma into the
- * mm's list and rbtree.  It has already been inserted into the interval tree.
+ * mm's list and the mm tree.  It has already been inserted into the interval tree.
  */
 static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
 {
        struct vm_area_struct *prev;
-       struct rb_node **rb_link, *rb_parent;
 
        BUG_ON(find_vma_links(mm, vma->vm_start, vma->vm_end,
                           &prev, &rb_link, &rb_parent));
-       __vma_link(mm, vma, prev, rb_link, rb_parent);
+       vma_mt_store(mm, vma);
+       __vma_link_list(mm, vma, prev);
        mm->map_count++;
 }
 
-static __always_inline void __vma_unlink(struct mm_struct *mm,
-                                               struct vm_area_struct *vma,
-                                               struct vm_area_struct *ignore)
-{
-       vma_rb_erase_ignore(vma, &mm->mm_rb, ignore);
-       __vma_unlink_list(mm, vma);
-       /* Kill the cache */
-       vmacache_invalidate(mm);
-}
-
 /*
  * We cannot adjust vm_start, vm_end, vm_pgoff fields of a vma that
  * is already present in an i_mmap tree without adjusting the tree.
@@ -849,13 +630,10 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
        struct rb_root_cached *root = NULL;
        struct anon_vma *anon_vma = NULL;
        struct file *file = vma->vm_file;
-       bool start_changed = false, end_changed = false;
+       bool vma_changed = false;
        long adjust_next = 0;
        int remove_next = 0;
 
-       validate_mm(mm);
-       validate_mm_mt(mm);
-
        if (next && !insert) {
                struct vm_area_struct *exporter = NULL, *importer = NULL;
 
@@ -981,21 +759,23 @@ again:
        }
 
        if (start != vma->vm_start) {
-               unsigned long old_start = vma->vm_start;
+               if (vma->vm_start < start)
+                       vma_mt_szero(mm, vma->vm_start, start);
+               else
+                       vma_changed = true;
                vma->vm_start = start;
-               if (old_start < start)
-                       vma_mt_szero(mm, old_start, start);
-               start_changed = true;
        }
        if (end != vma->vm_end) {
-               unsigned long old_end = vma->vm_end;
+               if (vma->vm_end > end)
+                       vma_mt_szero(mm, end, vma->vm_end);
+               else
+                       vma_changed = true;
                vma->vm_end = end;
-               if (old_end > end)
-                       vma_mt_szero(mm, end, old_end);
-               end_changed = true;
+               if (!next)
+                       mm->highest_vm_end = vm_end_gap(vma);
        }
 
-       if (end_changed || start_changed)
+       if (vma_changed)
                vma_mt_store(mm, vma);
 
        vma->vm_pgoff = pgoff;
@@ -1013,25 +793,9 @@ again:
        }
 
        if (remove_next) {
-               /*
-                * vma_merge has merged next into vma, and needs
-                * us to remove next before dropping the locks.
-                * Since we have expanded over this vma, the maple tree will
-                * have overwritten by storing the value
-                */
-               if (remove_next != 3)
-                       __vma_unlink(mm, next, next);
-               else
-                       /*
-                        * vma is not before next if they've been
-                        * swapped.
-                        *
-                        * pre-swap() next->vm_start was reduced so
-                        * tell validate_mm_rb to ignore pre-swap()
-                        * "next" (which is stored in post-swap()
-                        * "vma").
-                        */
-                       __vma_unlink(mm, next, vma);
+               __vma_unlink_list(mm, next);
+               /* Kill the cache */
+               vmacache_invalidate(mm);
                if (file)
                        __remove_shared_vm_struct(next, file, mapping);
        } else if (insert) {
@@ -1041,15 +805,6 @@ again:
                 * (it may either follow vma or precede it).
                 */
                __insert_vm_struct(mm, insert);
-       } else {
-               if (start_changed)
-                       vma_gap_update(vma);
-               if (end_changed) {
-                       if (!next)
-                               mm->highest_vm_end = vm_end_gap(vma);
-                       else if (!adjust_next)
-                               vma_gap_update(next);
-               }
        }
 
        if (anon_vma) {
@@ -1107,10 +862,7 @@ again:
                        remove_next = 1;
                        end = next->vm_end;
                        goto again;
-               }
-               else if (next)
-                       vma_gap_update(next);
-               else {
+               } else if (!next) {
                        /*
                         * If remove_next == 2 we obviously can't
                         * reach this path.
@@ -1137,8 +889,6 @@ again:
                uprobe_mmap(insert);
 
        validate_mm(mm);
-       validate_mm_mt(mm);
-
        return 0;
 }
 
@@ -1285,7 +1035,6 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
        struct vm_area_struct *area, *next;
        int err;
 
-       validate_mm_mt(mm);
        /*
         * We later require that vma->vm_flags == vm_flags,
         * so this tests vma->vm_flags & VM_SPECIAL, too.
@@ -1361,7 +1110,6 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
                khugepaged_enter_vma_merge(area, vm_flags);
                return area;
        }
-       validate_mm_mt(mm);
 
        return NULL;
 }
@@ -1531,6 +1279,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
        vm_flags_t vm_flags;
        int pkey = 0;
 
+       validate_mm(mm);
        *populate = 0;
 
        if (!len)
@@ -1851,10 +1600,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma, *prev, *merge;
        int error;
-       struct rb_node **rb_link, *rb_parent;
        unsigned long charged = 0;
 
-       validate_mm_mt(mm);
        /* Check against address space limit. */
        if (!may_expand_vm(mm, vm_flags, len >> PAGE_SHIFT)) {
                unsigned long nr_pages;
@@ -1870,8 +1617,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
                        return -ENOMEM;
        }
 
-       /* Clear old maps, set up prev, rb_link, rb_parent, and uf */
-       if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf))
+       /* Clear old maps, set up prev and uf */
+       if (munmap_vma_range(mm, addr, len, &prev, uf))
                return -ENOMEM;
        /*
         * Private writable mapping: check memory availability
@@ -1961,6 +1708,16 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
                        }
                }
 
+               /* Can addr have changed??
+                *
+                * Answer: Yes, several device drivers can do it in their
+                *         f_op->mmap method. -DaveM
+                * Bug: If addr is changed, prev and the maple tree data  should
+                * be updated for vma_link()
+                */
+               WARN_ON_ONCE(addr != vma->vm_start);
+
+               addr = vma->vm_start;
                vm_flags = vma->vm_flags;
        } else if (vm_flags & VM_SHARED) {
                error = shmem_zero_setup(vma);
@@ -1979,7 +1736,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
                        goto free_vma;
        }
 
-       vma_link(mm, vma, prev, rb_link, rb_parent);
+       vma_link(mm, vma, prev);
        /* Once vma denies write, undo our temporary denial count */
        if (file) {
 unmap_writable:
@@ -2016,7 +1773,6 @@ out:
 
        vma_set_page_prot(vma);
 
-       validate_mm_mt(mm);
        return addr;
 
 unmap_and_free_vma:
@@ -2036,7 +1792,6 @@ free_vma:
 unacct_error:
        if (charged)
                vm_unacct_memory(charged);
-       validate_mm_mt(mm);
        return error;
 }
 
@@ -2338,9 +2093,6 @@ find_vma_prev(struct mm_struct *mm, unsigned long addr,
 
        rcu_read_lock();
        vma = mas_find(&mas, ULONG_MAX);
-       if (!vma)
-               mas_reset(&mas);
-
        *pprev = mas_prev(&mas, 0);
        rcu_read_unlock();
        return vma;
@@ -2404,7 +2156,6 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
        unsigned long gap_addr;
        int error = 0;
 
-       validate_mm_mt(mm);
        if (!(vma->vm_flags & VM_GROWSUP))
                return -EFAULT;
 
@@ -2451,15 +2202,13 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
                        error = acct_stack_growth(vma, size, grow);
                        if (!error) {
                                /*
-                                * vma_gap_update() doesn't support concurrent
-                                * updates, but we only hold a shared mmap_lock
-                                * lock here, so we need to protect against
-                                * concurrent vma expansions.
-                                * anon_vma_lock_write() doesn't help here, as
-                                * we don't guarantee that all growable vmas
-                                * in a mm share the same root anon vma.
-                                * So, we reuse mm->page_table_lock to guard
-                                * against concurrent vma expansions.
+                                * We only hold a shared mmap_lock lock here, so
+                                * we need to protect against concurrent vma
+                                * expansions.  anon_vma_lock_write() doesn't
+                                * help here, as we don't guarantee that all
+                                * growable vmas in a mm share the same root
+                                * anon vma.  So, we reuse mm->page_table_lock
+                                * to guard against concurrent vma expansions.
                                 */
                                spin_lock(&mm->page_table_lock);
                                if (vma->vm_flags & VM_LOCKED)
@@ -2467,10 +2216,9 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
                                vm_stat_account(mm, vma->vm_flags, grow);
                                anon_vma_interval_tree_pre_update_vma(vma);
                                vma->vm_end = address;
+                               vma_mt_store(mm, vma);
                                anon_vma_interval_tree_post_update_vma(vma);
-                               if (vma->vm_next)
-                                       vma_gap_update(vma->vm_next);
-                               else
+                               if (!vma->vm_next)
                                        mm->highest_vm_end = vm_end_gap(vma);
                                spin_unlock(&mm->page_table_lock);
 
@@ -2481,7 +2229,6 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
        anon_vma_unlock_write(vma->anon_vma);
        khugepaged_enter_vma_merge(vma, vma->vm_flags);
        validate_mm(mm);
-       validate_mm_mt(mm);
        return error;
 }
 #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
@@ -2496,7 +2243,6 @@ int expand_downwards(struct vm_area_struct *vma,
        struct vm_area_struct *prev;
        int error = 0;
 
-       validate_mm(mm);
        address &= PAGE_MASK;
        if (address < mmap_min_addr)
                return -EPERM;
@@ -2533,15 +2279,13 @@ int expand_downwards(struct vm_area_struct *vma,
                        error = acct_stack_growth(vma, size, grow);
                        if (!error) {
                                /*
-                                * vma_gap_update() doesn't support concurrent
-                                * updates, but we only hold a shared mmap_lock
-                                * lock here, so we need to protect against
-                                * concurrent vma expansions.
-                                * anon_vma_lock_write() doesn't help here, as
-                                * we don't guarantee that all growable vmas
-                                * in a mm share the same root anon vma.
-                                * So, we reuse mm->page_table_lock to guard
-                                * against concurrent vma expansions.
+                                * We only hold a shared mmap_lock lock here, so
+                                * we need to protect against concurrent vma
+                                * expansions.  anon_vma_lock_write() doesn't
+                                * help here, as we don't guarantee that all
+                                * growable vmas in a mm share the same root
+                                * anon vma.  So, we reuse mm->page_table_lock
+                                * to guard against concurrent vma expansions.
                                 */
                                spin_lock(&mm->page_table_lock);
                                if (vma->vm_flags & VM_LOCKED)
@@ -2553,7 +2297,6 @@ int expand_downwards(struct vm_area_struct *vma,
                                /* Overwrite old entry in mtree. */
                                vma_mt_store(mm, vma);
                                anon_vma_interval_tree_post_update_vma(vma);
-                               vma_gap_update(vma);
                                spin_unlock(&mm->page_table_lock);
 
                                perf_event_mmap(vma);
@@ -2695,16 +2438,14 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
        vma->vm_prev = NULL;
        vma_mt_szero(mm, vma->vm_start, end);
        do {
-               vma_rb_erase(vma, &mm->mm_rb);
                mm->map_count--;
                tail_vma = vma;
                vma = vma->vm_next;
        } while (vma && vma->vm_start < end);
        *insertion_point = vma;
-       if (vma) {
+       if (vma)
                vma->vm_prev = prev;
-               vma_gap_update(vma);
-       } else
+       else
                mm->highest_vm_end = prev ? vm_end_gap(prev) : 0;
        tail_vma->vm_next = NULL;
 
@@ -2835,11 +2576,7 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
        if (len == 0)
                return -EINVAL;
 
-       /*
-        * arch_unmap() might do unmaps itself.  It must be called
-        * and finish any rbtree manipulation before this code
-        * runs and also starts to manipulate the rbtree.
-        */
+        /* arch_unmap() might do unmaps itself.  */
        arch_unmap(mm, start, end);
 
        /* Find the first overlapping VMA */
@@ -2847,7 +2584,7 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
        if (!vma)
                return 0;
        prev = vma->vm_prev;
-       /* we have  start < vma->vm_end  */
+       /* we have start < vma->vm_end  */
 
        /* if it doesn't overlap, we have nothing.. */
        if (vma->vm_start >= end)
@@ -2907,7 +2644,7 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
        if (mm->locked_vm)
                unlock_range(vma, end);
 
-       /* Detach vmas from rbtree */
+       /* Detach vmas from the MM linked list and remove from the mm tree*/
        if (!detach_vmas_to_be_unmapped(mm, vma, prev, end))
                downgrade = false;
 
@@ -3071,11 +2808,11 @@ out:
  *  anonymous maps.  eventually we may be able to do some
  *  brk-specific accounting here.
  */
-static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long flags, struct list_head *uf)
+static int do_brk_flags(unsigned long addr, unsigned long len,
+                       unsigned long flags, struct list_head *uf)
 {
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma, *prev;
-       struct rb_node **rb_link, *rb_parent;
        pgoff_t pgoff = addr >> PAGE_SHIFT;
        int error;
        unsigned long mapped_addr;
@@ -3094,8 +2831,8 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
        if (error)
                return error;
 
-       /* Clear old maps, set up prev, rb_link, rb_parent, and uf */
-       if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf))
+       /* Clear old maps, set up prev and uf */
+       if (munmap_vma_range(mm, addr, len, &prev, uf))
                return -ENOMEM;
 
        /* Check against address space limits *after* clearing old maps... */
@@ -3129,7 +2866,7 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
        vma->vm_pgoff = pgoff;
        vma->vm_flags = flags;
        vma->vm_page_prot = vm_get_page_prot(flags);
-       vma_link(mm, vma, prev, rb_link, rb_parent);
+       vma_link(mm, vma, prev);
 out:
        perf_event_mmap(vma);
        mm->total_vm += len >> PAGE_SHIFT;
@@ -3249,26 +2986,10 @@ void exit_mmap(struct mm_struct *mm)
 int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
 {
        struct vm_area_struct *prev;
-       struct rb_node **rb_link, *rb_parent;
-       unsigned long start = vma->vm_start;
-       struct vm_area_struct *overlap = NULL;
 
-       if (find_vma_links(mm, vma->vm_start, vma->vm_end,
-                          &prev, &rb_link, &rb_parent))
+       if (range_has_overlap(mm, vma->vm_start, vma->vm_end, &prev))
                return -ENOMEM;
 
-       overlap = mt_find(&mm->mm_mt, &start, vma->vm_end - 1);
-       if (overlap) {
-
-               pr_err("Found vma ending at %lu\n", start - 1);
-               pr_err("vma : %lu => %lu-%lu\n", (unsigned long)overlap,
-                               overlap->vm_start, overlap->vm_end - 1);
-#if defined(CONFIG_DEBUG_MAPLE_TREE)
-               mt_dump(&mm->mm_mt);
-#endif
-               BUG();
-       }
-
        if ((vma->vm_flags & VM_ACCOUNT) &&
             security_vm_enough_memory_mm(mm, vma_pages(vma)))
                return -ENOMEM;
@@ -3290,7 +3011,7 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
                vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
        }
 
-       vma_link(mm, vma, prev, rb_link, rb_parent);
+       vma_link(mm, vma, prev);
        return 0;
 }
 
@@ -3306,9 +3027,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
        unsigned long vma_start = vma->vm_start;
        struct mm_struct *mm = vma->vm_mm;
        struct vm_area_struct *new_vma, *prev;
-       struct rb_node **rb_link, *rb_parent;
        bool faulted_in_anon_vma = true;
-       unsigned long index = addr;
 
        validate_mm_mt(mm);
        /*
@@ -3320,10 +3039,9 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
                faulted_in_anon_vma = false;
        }
 
-       if (find_vma_links(mm, addr, addr + len, &prev, &rb_link, &rb_parent))
+       if (range_has_overlap(mm, addr, addr + len, &prev))
                return NULL;    /* should never get here */
-       if (mt_find(&mm->mm_mt, &index, addr+len - 1))
-               BUG();
+
        new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
                            vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
                            vma->vm_userfaultfd_ctx);
@@ -3364,7 +3082,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
                        get_file(new_vma->vm_file);
                if (new_vma->vm_ops && new_vma->vm_ops->open)
                        new_vma->vm_ops->open(new_vma);
-               vma_link(mm, new_vma, prev, rb_link, rb_parent);
+               vma_link(mm, new_vma, prev);
                *need_rmap_locks = false;
        }
        validate_mm_mt(mm);
index 8c9b7d1e7c499828c429b93853af28e7299edcc1..f57a76b53b23a9ca7dc4dfff02cb35846fb1d167 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -287,6 +287,8 @@ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
        vma->vm_next = next;
        if (next)
                next->vm_prev = vma;
+       else
+               mm->highest_vm_end = vm_end_gap(vma);
 }
 
 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma)
@@ -301,6 +303,12 @@ void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma)
                mm->mmap = next;
        if (next)
                next->vm_prev = prev;
+       else {
+               if (prev)
+                       mm->highest_vm_end = vm_end_gap(prev);
+               else
+                       mm->highest_vm_end = 0;
+       }
 }
 
 /* Check if the vma is being used as a stack by this task */