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Howlett" To: maple-tree@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Song Liu , Davidlohr Bueso , "Paul E . McKenney" , Matthew Wilcox , Jerome Glisse , David Rientjes , Axel Rasmussen , Suren Baghdasaryan , Vlastimil Babka , Rik van Riel , Peter Zijlstra Subject: [PATCH v2 12/70] mm: Remove rb tree. Date: Tue, 12 Jan 2021 11:11:42 -0500 Message-Id: <20210112161240.2024684-13-Liam.Howlett@Oracle.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210112161240.2024684-1-Liam.Howlett@Oracle.com> References: <20210112161240.2024684-1-Liam.Howlett@Oracle.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9862 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 bulkscore=0 malwarescore=0 suspectscore=0 adultscore=0 spamscore=0 mlxlogscore=999 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101120092 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9862 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=0 clxscore=1015 impostorscore=0 spamscore=0 priorityscore=1501 mlxscore=0 phishscore=0 mlxlogscore=999 bulkscore=0 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101120092 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Remove the RB tree and start using the maple tree for vm_area_struct tracking. Signed-off-by: Liam R. Howlett --- arch/x86/kernel/tboot.c | 1 - drivers/firmware/efi/efi.c | 1 - include/linux/mm.h | 4 - include/linux/mm_types.h | 27 +- kernel/fork.c | 8 - mm/init-mm.c | 2 - mm/mmap.c | 527 ++++++++----------------------------- mm/util.c | 8 + 8 files changed, 132 insertions(+), 446 deletions(-) diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index d9b1cc30976c4..9b97ffa23e0b0 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -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), diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index e40effbf028a6..665796649c23d 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -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), diff --git a/include/linux/mm.h b/include/linux/mm.h index 9cbbbbc3043a9..dbb83118eba09 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2467,8 +2467,6 @@ 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, @@ -2524,8 +2522,6 @@ 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, diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index f2c725e1052f8..fa3cf29f01f21 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -274,7 +274,6 @@ 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 */ @@ -312,19 +311,6 @@ 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. */ /* @@ -334,6 +320,12 @@ 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. @@ -352,16 +344,14 @@ 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 @@ -390,7 +380,6 @@ 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, diff --git a/kernel/fork.c b/kernel/fork.c index 8fcbd970666c3..0ef4c4fa66c1b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -470,7 +470,6 @@ 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); @@ -497,8 +496,6 @@ 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) @@ -591,10 +588,6 @@ 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; @@ -1017,7 +1010,6 @@ 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); diff --git a/mm/init-mm.c b/mm/init-mm.c index 27229044a0702..49d803fc4cdea 100644 --- a/mm/init-mm.c +++ b/mm/init-mm.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include #include #include #include @@ -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), diff --git a/mm/mmap.c b/mm/mmap.c index 3b3084ee309b7..a2b32202191d6 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -38,7 +38,6 @@ #include #include #include -#include #include #include #include @@ -286,93 +285,6 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) return retval; } -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); @@ -401,17 +313,25 @@ 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) { @@ -437,20 +357,6 @@ 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; @@ -458,6 +364,8 @@ 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; @@ -482,80 +390,12 @@ 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 @@ -589,38 +429,26 @@ 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; + struct vm_area_struct *existing; - __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; - } - } - - *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; } /* @@ -647,8 +475,6 @@ 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. @@ -657,76 +483,41 @@ 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; @@ -774,19 +565,8 @@ static inline void vma_mt_store(struct mm_struct *mm, struct vm_area_struct *vma GFP_KERNEL); } -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) -{ - vma_mt_store(mm, vma); - __vma_link_list(mm, vma, prev); - __vma_link_rb(mm, vma, rb_link, rb_parent); -} - 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; @@ -795,7 +575,8 @@ 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) @@ -807,30 +588,19 @@ 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; - 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)) BUG(); - __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. @@ -848,13 +618,10 @@ 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; @@ -980,21 +747,23 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, } 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; @@ -1012,25 +781,9 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, } 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) { @@ -1040,15 +793,6 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, * (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) { @@ -1106,10 +850,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 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. @@ -1136,8 +877,6 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, uprobe_mmap(insert); validate_mm(mm); - validate_mm_mt(mm); - return 0; } @@ -1284,7 +1023,6 @@ 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. @@ -1360,7 +1098,6 @@ 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 +1268,7 @@ 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 +1589,8 @@ 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 +1606,8 @@ 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 +1697,16 @@ 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 +1725,7 @@ 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 +1762,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma_set_page_prot(vma); - validate_mm_mt(mm); return addr; unmap_and_free_vma: @@ -2036,7 +1781,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, unacct_error: if (charged) vm_unacct_memory(charged); - validate_mm_mt(mm); return error; } @@ -2054,7 +1798,6 @@ static unsigned long unmapped_area(struct vm_unmapped_area_info *info) unsigned long length, gap; MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); - validate_mm(current->mm); /* Adjust search length to account for worst case alignment overhead */ length = info->length + info->align_mask; @@ -2085,7 +1828,6 @@ static unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info) unsigned long length, gap; MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); - validate_mm_mt(current->mm); /* Adjust search length to account for worst case alignment overhead */ length = info->length + info->align_mask; if (length < info->length) @@ -2324,9 +2066,6 @@ 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; @@ -2390,7 +2129,6 @@ 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; @@ -2437,15 +2175,13 @@ 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) @@ -2453,10 +2189,9 @@ 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); @@ -2467,7 +2202,6 @@ 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 */ @@ -2482,7 +2216,6 @@ 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; @@ -2519,15 +2252,13 @@ 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) @@ -2539,7 +2270,6 @@ 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); @@ -2681,16 +2411,14 @@ 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; @@ -2821,11 +2549,7 @@ 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 */ @@ -2833,7 +2557,7 @@ 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) @@ -2893,7 +2617,7 @@ 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; @@ -3057,11 +2781,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, * 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; @@ -3080,8 +2804,8 @@ 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... */ @@ -3115,7 +2839,7 @@ 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; @@ -3235,26 +2959,10 @@ 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; @@ -3276,7 +2984,7 @@ 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; } @@ -3292,9 +3000,7 @@ 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); /* @@ -3306,10 +3012,9 @@ 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); @@ -3350,7 +3055,7 @@ 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); diff --git a/mm/util.c b/mm/util.c index 4ddb6e186dd5c..48c79f2784eca 100644 --- 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 */