diff --git a/CREDITS b/CREDITS index 5797e8f7e92b..df8d6946739f 100644 --- a/CREDITS +++ b/CREDITS @@ -2161,6 +2161,19 @@ N: Mike Kravetz E: mike.kravetz@oracle.com D: Maintenance and development of the hugetlb subsystem +N: Seth Jennings +E: sjenning@redhat.com +D: Creation and maintenance of zswap + +N: Dan Streetman +E: ddstreet@ieee.org +D: Maintenance and development of zswap +D: Creation and maintenance of the zpool API + +N: Vitaly Wool +E: vitaly.wool@konsulko.com +D: Maintenance and development of zswap + N: Andreas S. Krebs E: akrebs@altavista.net D: CYPRESS CY82C693 chipset IDE, Digital's PC-Alpha 164SX boards diff --git a/MAINTAINERS b/MAINTAINERS index 8999497011a2..32a47aa6aa76 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12903,6 +12903,8 @@ M: Alejandro Colomar L: linux-man@vger.kernel.org S: Maintained W: http://www.kernel.org/doc/man-pages +T: git git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git +T: git git://www.alejandro-colomar.es/src/alx/linux/man-pages/man-pages.git MANAGEMENT COMPONENT TRANSPORT PROTOCOL (MCTP) M: Jeremy Kerr @@ -24341,13 +24343,6 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs.git F: Documentation/filesystems/zonefs.rst F: fs/zonefs/ -ZPOOL COMPRESSED PAGE STORAGE API -M: Dan Streetman -L: linux-mm@kvack.org -S: Maintained -F: include/linux/zpool.h -F: mm/zpool.c - ZR36067 VIDEO FOR LINUX DRIVER M: Corentin Labbe L: mjpeg-users@lists.sourceforge.net @@ -24399,7 +24394,9 @@ M: Nhat Pham L: linux-mm@kvack.org S: Maintained F: Documentation/admin-guide/mm/zswap.rst +F: include/linux/zpool.h F: include/linux/zswap.h +F: mm/zpool.c F: mm/zswap.c THE REST diff --git a/arch/Kconfig b/arch/Kconfig index c91917b50873..a5af0edd3eb8 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -673,6 +673,7 @@ config SHADOW_CALL_STACK bool "Shadow Call Stack" depends on ARCH_SUPPORTS_SHADOW_CALL_STACK depends on DYNAMIC_FTRACE_WITH_ARGS || DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER + depends on MMU help This option enables the compiler's Shadow Call Stack, which uses a shadow stack to protect function return addresses from diff --git a/arch/x86/include/asm/kmsan.h b/arch/x86/include/asm/kmsan.h index 8fa6ac0e2d76..d91b37f5b4bb 100644 --- a/arch/x86/include/asm/kmsan.h +++ b/arch/x86/include/asm/kmsan.h @@ -64,6 +64,7 @@ static inline bool kmsan_virt_addr_valid(void *addr) { unsigned long x = (unsigned long)addr; unsigned long y = x - __START_KERNEL_map; + bool ret; /* use the carry flag to determine if x was < __START_KERNEL_map */ if (unlikely(x > y)) { @@ -79,7 +80,21 @@ static inline bool kmsan_virt_addr_valid(void *addr) return false; } - return pfn_valid(x >> PAGE_SHIFT); + /* + * pfn_valid() relies on RCU, and may call into the scheduler on exiting + * the critical section. However, this would result in recursion with + * KMSAN. Therefore, disable preemption here, and re-enable preemption + * below while suppressing reschedules to avoid recursion. + * + * Note, this sacrifices occasionally breaking scheduling guarantees. + * Although, a kernel compiled with KMSAN has already given up on any + * performance guarantees due to being heavily instrumented. + */ + preempt_disable(); + ret = pfn_valid(x >> PAGE_SHIFT); + preempt_enable_no_resched(); + + return ret; } #endif /* !MODULE */ diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index ea5b8e57d904..671664fed307 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -340,7 +340,7 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to) } else { folio_unlock(folio); - if (!folio_test_has_hwpoisoned(folio)) + if (!folio_test_hwpoison(folio)) want = nr; else { /* diff --git a/include/linux/mman.h b/include/linux/mman.h index 40d94411d492..dc7048824be8 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -156,6 +156,7 @@ calc_vm_flag_bits(unsigned long flags) return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) | + _calc_vm_trans(flags, MAP_STACK, VM_NOHUGEPAGE) | arch_calc_vm_flag_bits(flags); } diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4ed33b127821..a497f189d988 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -2013,9 +2013,9 @@ static inline int pfn_valid(unsigned long pfn) if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; ms = __pfn_to_section(pfn); - rcu_read_lock(); + rcu_read_lock_sched(); if (!valid_section(ms)) { - rcu_read_unlock(); + rcu_read_unlock_sched(); return 0; } /* @@ -2023,7 +2023,7 @@ static inline int pfn_valid(unsigned long pfn) * the entire section-sized span. */ ret = early_section(ms) || pfn_section_valid(ms, pfn); - rcu_read_unlock(); + rcu_read_unlock_sched(); return ret; } diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 485bb0389b48..929e98c62965 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -537,7 +537,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, } } - ret = __replace_page(vma, vaddr, old_page, new_page); + ret = __replace_page(vma, vaddr & PAGE_MASK, old_page, new_page); if (new_page) put_page(new_page); put_old: diff --git a/lib/stackdepot.c b/lib/stackdepot.c index a0be5d05c7f0..5caa1f566553 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) "stackdepot: " fmt +#include #include #include #include @@ -21,8 +22,9 @@ #include #include #include -#include #include +#include +#include #include #include #include @@ -67,12 +69,28 @@ union handle_parts { }; struct stack_record { - struct list_head list; /* Links in hash table or freelist */ + struct list_head hash_list; /* Links in the hash table */ u32 hash; /* Hash in hash table */ u32 size; /* Number of stored frames */ - union handle_parts handle; + union handle_parts handle; /* Constant after initialization */ refcount_t count; - unsigned long entries[CONFIG_STACKDEPOT_MAX_FRAMES]; /* Frames */ + union { + unsigned long entries[CONFIG_STACKDEPOT_MAX_FRAMES]; /* Frames */ + struct { + /* + * An important invariant of the implementation is to + * only place a stack record onto the freelist iff its + * refcount is zero. Because stack records with a zero + * refcount are never considered as valid, it is safe to + * union @entries and freelist management state below. + * Conversely, as soon as an entry is off the freelist + * and its refcount becomes non-zero, the below must not + * be accessed until being placed back on the freelist. + */ + struct list_head free_list; /* Links in the freelist */ + unsigned long rcu_state; /* RCU cookie */ + }; + }; }; #define DEPOT_STACK_RECORD_SIZE \ @@ -112,8 +130,25 @@ static LIST_HEAD(free_stacks); * yet allocated or if the limit on the number of pools is reached. */ static bool new_pool_required = true; -/* Lock that protects the variables above. */ -static DEFINE_RWLOCK(pool_rwlock); +/* The lock must be held when performing pool or freelist modifications. */ +static DEFINE_RAW_SPINLOCK(pool_lock); + +/* Statistics counters for debugfs. */ +enum depot_counter_id { + DEPOT_COUNTER_ALLOCS, + DEPOT_COUNTER_FREES, + DEPOT_COUNTER_INUSE, + DEPOT_COUNTER_FREELIST_SIZE, + DEPOT_COUNTER_COUNT, +}; +static long counters[DEPOT_COUNTER_COUNT]; +static const char *const counter_names[] = { + [DEPOT_COUNTER_ALLOCS] = "allocations", + [DEPOT_COUNTER_FREES] = "frees", + [DEPOT_COUNTER_INUSE] = "in_use", + [DEPOT_COUNTER_FREELIST_SIZE] = "freelist_size", +}; +static_assert(ARRAY_SIZE(counter_names) == DEPOT_COUNTER_COUNT); static int __init disable_stack_depot(char *str) { @@ -258,14 +293,15 @@ int stack_depot_init(void) } EXPORT_SYMBOL_GPL(stack_depot_init); -/* Initializes a stack depol pool. */ +/* + * Initializes new stack depot @pool, release all its entries to the freelist, + * and update the list of pools. + */ static void depot_init_pool(void *pool) { int offset; - lockdep_assert_held_write(&pool_rwlock); - - WARN_ON(!list_empty(&free_stacks)); + lockdep_assert_held(&pool_lock); /* Initialize handles and link stack records into the freelist. */ for (offset = 0; offset <= DEPOT_POOL_SIZE - DEPOT_STACK_RECORD_SIZE; @@ -276,18 +312,36 @@ static void depot_init_pool(void *pool) stack->handle.offset = offset >> DEPOT_STACK_ALIGN; stack->handle.extra = 0; - list_add(&stack->list, &free_stacks); + /* + * Stack traces of size 0 are never saved, and we can simply use + * the size field as an indicator if this is a new unused stack + * record in the freelist. + */ + stack->size = 0; + + INIT_LIST_HEAD(&stack->hash_list); + /* + * Add to the freelist front to prioritize never-used entries: + * required in case there are entries in the freelist, but their + * RCU cookie still belongs to the current RCU grace period + * (there can still be concurrent readers). + */ + list_add(&stack->free_list, &free_stacks); + counters[DEPOT_COUNTER_FREELIST_SIZE]++; } /* Save reference to the pool to be used by depot_fetch_stack(). */ stack_pools[pools_num] = pool; - pools_num++; + + /* Pairs with concurrent READ_ONCE() in depot_fetch_stack(). */ + WRITE_ONCE(pools_num, pools_num + 1); + ASSERT_EXCLUSIVE_WRITER(pools_num); } /* Keeps the preallocated memory to be used for a new stack depot pool. */ static void depot_keep_new_pool(void **prealloc) { - lockdep_assert_held_write(&pool_rwlock); + lockdep_assert_held(&pool_lock); /* * If a new pool is already saved or the maximum number of @@ -310,17 +364,16 @@ static void depot_keep_new_pool(void **prealloc) * number of pools is reached. In either case, take note that * keeping another pool is not required. */ - new_pool_required = false; + WRITE_ONCE(new_pool_required, false); } -/* Updates references to the current and the next stack depot pools. */ -static bool depot_update_pools(void **prealloc) +/* + * Try to initialize a new stack depot pool from either a previous or the + * current pre-allocation, and release all its entries to the freelist. + */ +static bool depot_try_init_pool(void **prealloc) { - lockdep_assert_held_write(&pool_rwlock); - - /* Check if we still have objects in the freelist. */ - if (!list_empty(&free_stacks)) - goto out_keep_prealloc; + lockdep_assert_held(&pool_lock); /* Check if we have a new pool saved and use it. */ if (new_pool) { @@ -329,10 +382,9 @@ static bool depot_update_pools(void **prealloc) /* Take note that we might need a new new_pool. */ if (pools_num < DEPOT_MAX_POOLS) - new_pool_required = true; + WRITE_ONCE(new_pool_required, true); - /* Try keeping the preallocated memory for new_pool. */ - goto out_keep_prealloc; + return true; } /* Bail out if we reached the pool limit. */ @@ -349,12 +401,32 @@ static bool depot_update_pools(void **prealloc) } return false; +} -out_keep_prealloc: - /* Keep the preallocated memory for a new pool if required. */ - if (*prealloc) - depot_keep_new_pool(prealloc); - return true; +/* Try to find next free usable entry. */ +static struct stack_record *depot_pop_free(void) +{ + struct stack_record *stack; + + lockdep_assert_held(&pool_lock); + + if (list_empty(&free_stacks)) + return NULL; + + /* + * We maintain the invariant that the elements in front are least + * recently used, and are therefore more likely to be associated with an + * RCU grace period in the past. Consequently it is sufficient to only + * check the first entry. + */ + stack = list_first_entry(&free_stacks, struct stack_record, free_list); + if (stack->size && !poll_state_synchronize_rcu(stack->rcu_state)) + return NULL; + + list_del(&stack->free_list); + counters[DEPOT_COUNTER_FREELIST_SIZE]--; + + return stack; } /* Allocates a new stack in a stack depot pool. */ @@ -363,19 +435,22 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc) { struct stack_record *stack; - lockdep_assert_held_write(&pool_rwlock); + lockdep_assert_held(&pool_lock); - /* Update current and new pools if required and possible. */ - if (!depot_update_pools(prealloc)) + /* This should already be checked by public API entry points. */ + if (WARN_ON_ONCE(!size)) return NULL; /* Check if we have a stack record to save the stack trace. */ - if (list_empty(&free_stacks)) - return NULL; - - /* Get and unlink the first entry from the freelist. */ - stack = list_first_entry(&free_stacks, struct stack_record, list); - list_del(&stack->list); + stack = depot_pop_free(); + if (!stack) { + /* No usable entries on the freelist - try to refill the freelist. */ + if (!depot_try_init_pool(prealloc)) + return NULL; + stack = depot_pop_free(); + if (WARN_ON(!stack)) + return NULL; + } /* Limit number of saved frames to CONFIG_STACKDEPOT_MAX_FRAMES. */ if (size > CONFIG_STACKDEPOT_MAX_FRAMES) @@ -394,38 +469,80 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc) */ kmsan_unpoison_memory(stack, DEPOT_STACK_RECORD_SIZE); + counters[DEPOT_COUNTER_ALLOCS]++; + counters[DEPOT_COUNTER_INUSE]++; return stack; } static struct stack_record *depot_fetch_stack(depot_stack_handle_t handle) { + const int pools_num_cached = READ_ONCE(pools_num); union handle_parts parts = { .handle = handle }; void *pool; size_t offset = parts.offset << DEPOT_STACK_ALIGN; struct stack_record *stack; - lockdep_assert_held(&pool_rwlock); + lockdep_assert_not_held(&pool_lock); - if (parts.pool_index > pools_num) { + if (parts.pool_index > pools_num_cached) { WARN(1, "pool index %d out of bounds (%d) for stack id %08x\n", - parts.pool_index, pools_num, handle); + parts.pool_index, pools_num_cached, handle); return NULL; } pool = stack_pools[parts.pool_index]; - if (!pool) + if (WARN_ON(!pool)) return NULL; stack = pool + offset; + if (WARN_ON(!refcount_read(&stack->count))) + return NULL; + return stack; } /* Links stack into the freelist. */ static void depot_free_stack(struct stack_record *stack) { - lockdep_assert_held_write(&pool_rwlock); + unsigned long flags; - list_add(&stack->list, &free_stacks); + lockdep_assert_not_held(&pool_lock); + + raw_spin_lock_irqsave(&pool_lock, flags); + printk_deferred_enter(); + + /* + * Remove the entry from the hash list. Concurrent list traversal may + * still observe the entry, but since the refcount is zero, this entry + * will no longer be considered as valid. + */ + list_del_rcu(&stack->hash_list); + + /* + * Due to being used from constrained contexts such as the allocators, + * NMI, or even RCU itself, stack depot cannot rely on primitives that + * would sleep (such as synchronize_rcu()) or recursively call into + * stack depot again (such as call_rcu()). + * + * Instead, get an RCU cookie, so that we can ensure this entry isn't + * moved onto another list until the next grace period, and concurrent + * RCU list traversal remains safe. + */ + stack->rcu_state = get_state_synchronize_rcu(); + + /* + * Add the entry to the freelist tail, so that older entries are + * considered first - their RCU cookie is more likely to no longer be + * associated with the current grace period. + */ + list_add_tail(&stack->free_list, &free_stacks); + + counters[DEPOT_COUNTER_FREELIST_SIZE]++; + counters[DEPOT_COUNTER_FREES]++; + counters[DEPOT_COUNTER_INUSE]--; + + printk_deferred_exit(); + raw_spin_unlock_irqrestore(&pool_lock, flags); } /* Calculates the hash for a stack. */ @@ -453,22 +570,52 @@ int stackdepot_memcmp(const unsigned long *u1, const unsigned long *u2, /* Finds a stack in a bucket of the hash table. */ static inline struct stack_record *find_stack(struct list_head *bucket, - unsigned long *entries, int size, - u32 hash) + unsigned long *entries, int size, + u32 hash, depot_flags_t flags) { - struct list_head *pos; - struct stack_record *found; + struct stack_record *stack, *ret = NULL; - lockdep_assert_held(&pool_rwlock); + /* + * Stack depot may be used from instrumentation that instruments RCU or + * tracing itself; use variant that does not call into RCU and cannot be + * traced. + * + * Note: Such use cases must take care when using refcounting to evict + * unused entries, because the stack record free-then-reuse code paths + * do call into RCU. + */ + rcu_read_lock_sched_notrace(); - list_for_each(pos, bucket) { - found = list_entry(pos, struct stack_record, list); - if (found->hash == hash && - found->size == size && - !stackdepot_memcmp(entries, found->entries, size)) - return found; + list_for_each_entry_rcu(stack, bucket, hash_list) { + if (stack->hash != hash || stack->size != size) + continue; + + /* + * This may race with depot_free_stack() accessing the freelist + * management state unioned with @entries. The refcount is zero + * in that case and the below refcount_inc_not_zero() will fail. + */ + if (data_race(stackdepot_memcmp(entries, stack->entries, size))) + continue; + + /* + * Try to increment refcount. If this succeeds, the stack record + * is valid and has not yet been freed. + * + * If STACK_DEPOT_FLAG_GET is not used, it is undefined behavior + * to then call stack_depot_put() later, and we can assume that + * a stack record is never placed back on the freelist. + */ + if ((flags & STACK_DEPOT_FLAG_GET) && !refcount_inc_not_zero(&stack->count)) + continue; + + ret = stack; + break; } - return NULL; + + rcu_read_unlock_sched_notrace(); + + return ret; } depot_stack_handle_t stack_depot_save_flags(unsigned long *entries, @@ -482,7 +629,6 @@ depot_stack_handle_t stack_depot_save_flags(unsigned long *entries, struct page *page = NULL; void *prealloc = NULL; bool can_alloc = depot_flags & STACK_DEPOT_FLAG_CAN_ALLOC; - bool need_alloc = false; unsigned long flags; u32 hash; @@ -505,31 +651,16 @@ depot_stack_handle_t stack_depot_save_flags(unsigned long *entries, hash = hash_stack(entries, nr_entries); bucket = &stack_table[hash & stack_hash_mask]; - read_lock_irqsave(&pool_rwlock, flags); - printk_deferred_enter(); - - /* Fast path: look the stack trace up without full locking. */ - found = find_stack(bucket, entries, nr_entries, hash); - if (found) { - if (depot_flags & STACK_DEPOT_FLAG_GET) - refcount_inc(&found->count); - printk_deferred_exit(); - read_unlock_irqrestore(&pool_rwlock, flags); + /* Fast path: look the stack trace up without locking. */ + found = find_stack(bucket, entries, nr_entries, hash, depot_flags); + if (found) goto exit; - } - - /* Take note if another stack pool needs to be allocated. */ - if (new_pool_required) - need_alloc = true; - - printk_deferred_exit(); - read_unlock_irqrestore(&pool_rwlock, flags); /* * Allocate memory for a new pool if required now: * we won't be able to do that under the lock. */ - if (unlikely(can_alloc && need_alloc)) { + if (unlikely(can_alloc && READ_ONCE(new_pool_required))) { /* * Zero out zone modifiers, as we don't have specific zone * requirements. Keep the flags related to allocation in atomic @@ -543,31 +674,36 @@ depot_stack_handle_t stack_depot_save_flags(unsigned long *entries, prealloc = page_address(page); } - write_lock_irqsave(&pool_rwlock, flags); + raw_spin_lock_irqsave(&pool_lock, flags); printk_deferred_enter(); - found = find_stack(bucket, entries, nr_entries, hash); + /* Try to find again, to avoid concurrently inserting duplicates. */ + found = find_stack(bucket, entries, nr_entries, hash, depot_flags); if (!found) { struct stack_record *new = depot_alloc_stack(entries, nr_entries, hash, &prealloc); if (new) { - list_add(&new->list, bucket); + /* + * This releases the stack record into the bucket and + * makes it visible to readers in find_stack(). + */ + list_add_rcu(&new->hash_list, bucket); found = new; } - } else { - if (depot_flags & STACK_DEPOT_FLAG_GET) - refcount_inc(&found->count); + } + + if (prealloc) { /* - * Stack depot already contains this stack trace, but let's - * keep the preallocated memory for future. + * Either stack depot already contains this stack trace, or + * depot_alloc_stack() did not consume the preallocated memory. + * Try to keep the preallocated memory for future. */ - if (prealloc) - depot_keep_new_pool(&prealloc); + depot_keep_new_pool(&prealloc); } printk_deferred_exit(); - write_unlock_irqrestore(&pool_rwlock, flags); + raw_spin_unlock_irqrestore(&pool_lock, flags); exit: if (prealloc) { /* Stack depot didn't use this memory, free it. */ @@ -592,7 +728,6 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries) { struct stack_record *stack; - unsigned long flags; *entries = NULL; /* @@ -604,13 +739,13 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, if (!handle || stack_depot_disabled) return 0; - read_lock_irqsave(&pool_rwlock, flags); - printk_deferred_enter(); - stack = depot_fetch_stack(handle); - - printk_deferred_exit(); - read_unlock_irqrestore(&pool_rwlock, flags); + /* + * Should never be NULL, otherwise this is a use-after-put (or just a + * corrupt handle). + */ + if (WARN(!stack, "corrupt handle or use after stack_depot_put()")) + return 0; *entries = stack->entries; return stack->size; @@ -620,29 +755,20 @@ EXPORT_SYMBOL_GPL(stack_depot_fetch); void stack_depot_put(depot_stack_handle_t handle) { struct stack_record *stack; - unsigned long flags; if (!handle || stack_depot_disabled) return; - write_lock_irqsave(&pool_rwlock, flags); - printk_deferred_enter(); - stack = depot_fetch_stack(handle); - if (WARN_ON(!stack)) - goto out; + /* + * Should always be able to find the stack record, otherwise this is an + * unbalanced put attempt (or corrupt handle). + */ + if (WARN(!stack, "corrupt handle or unbalanced stack_depot_put()")) + return; - if (refcount_dec_and_test(&stack->count)) { - /* Unlink stack from the hash table. */ - list_del(&stack->list); - - /* Free stack. */ + if (refcount_dec_and_test(&stack->count)) depot_free_stack(stack); - } - -out: - printk_deferred_exit(); - write_unlock_irqrestore(&pool_rwlock, flags); } EXPORT_SYMBOL_GPL(stack_depot_put); @@ -690,3 +816,30 @@ unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle) return parts.extra; } EXPORT_SYMBOL(stack_depot_get_extra_bits); + +static int stats_show(struct seq_file *seq, void *v) +{ + /* + * data race ok: These are just statistics counters, and approximate + * statistics are ok for debugging. + */ + seq_printf(seq, "pools: %d\n", data_race(pools_num)); + for (int i = 0; i < DEPOT_COUNTER_COUNT; i++) + seq_printf(seq, "%s: %ld\n", counter_names[i], data_race(counters[i])); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(stats); + +static int depot_debugfs_init(void) +{ + struct dentry *dir; + + if (stack_depot_disabled) + return 0; + + dir = debugfs_create_dir("stackdepot", NULL); + debugfs_create_file("stats", 0444, dir, NULL, &stats_fops); + return 0; +} +late_initcall(depot_debugfs_init); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 94ef5c02b459..94c958f7ebb5 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -809,7 +810,10 @@ static unsigned long __thp_get_unmapped_area(struct file *filp, { loff_t off_end = off + len; loff_t off_align = round_up(off, size); - unsigned long len_pad, ret; + unsigned long len_pad, ret, off_sub; + + if (IS_ENABLED(CONFIG_32BIT) || in_compat_syscall()) + return 0; if (off_end <= off_align || (off_end - off_align) < size) return 0; @@ -835,7 +839,13 @@ static unsigned long __thp_get_unmapped_area(struct file *filp, if (ret == addr) return addr; - ret += (off - ret) & (size - 1); + off_sub = (off - ret) & (size - 1); + + if (current->mm->get_unmapped_area == arch_get_unmapped_area_topdown && + !off_sub) + return ret + size; + + ret += off_sub; return ret; } @@ -2437,7 +2447,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, page = pmd_page(old_pmd); folio = page_folio(page); if (!folio_test_dirty(folio) && pmd_dirty(old_pmd)) - folio_set_dirty(folio); + folio_mark_dirty(folio); if (!folio_test_referenced(folio) && pmd_young(old_pmd)) folio_set_referenced(folio); folio_remove_rmap_pmd(folio, page, vma); @@ -3563,7 +3573,7 @@ int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, } if (pmd_dirty(pmdval)) - folio_set_dirty(folio); + folio_mark_dirty(folio); if (pmd_write(pmdval)) entry = make_writable_migration_entry(page_to_pfn(page)); else if (anon_exclusive) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e4c8735e7c85..46d8d02114cf 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2623,8 +2623,9 @@ static unsigned long calculate_high_delay(struct mem_cgroup *memcg, } /* - * Scheduled by try_charge() to be executed from the userland return path - * and reclaims memory over the high limit. + * Reclaims memory over the high limit. Called directly from + * try_charge() (context permitting), as well as from the userland + * return path where reclaim is always able to block. */ void mem_cgroup_handle_over_high(gfp_t gfp_mask) { @@ -2643,6 +2644,17 @@ void mem_cgroup_handle_over_high(gfp_t gfp_mask) current->memcg_nr_pages_over_high = 0; retry_reclaim: + /* + * Bail if the task is already exiting. Unlike memory.max, + * memory.high enforcement isn't as strict, and there is no + * OOM killer involved, which means the excess could already + * be much bigger (and still growing) than it could for + * memory.max; the dying task could get stuck in fruitless + * reclaim for a long time, which isn't desirable. + */ + if (task_is_dying()) + goto out; + /* * The allocating task should reclaim at least the batch size, but for * subsequent retries we only want to do what's necessary to prevent oom @@ -2693,6 +2705,9 @@ void mem_cgroup_handle_over_high(gfp_t gfp_mask) } /* + * Reclaim didn't manage to push usage below the limit, slow + * this allocating task down. + * * If we exit early, we're guaranteed to die (since * schedule_timeout_killable sets TASK_KILLABLE). This means we don't * need to account for any ill-begotten jiffies to pay them off later. @@ -2887,11 +2902,17 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, } } while ((memcg = parent_mem_cgroup(memcg))); + /* + * Reclaim is set up above to be called from the userland + * return path. But also attempt synchronous reclaim to avoid + * excessive overrun while the task is still inside the + * kernel. If this is successful, the return path will see it + * when it rechecks the overage and simply bail out. + */ if (current->memcg_nr_pages_over_high > MEMCG_CHARGE_BATCH && !(current->flags & PF_MEMALLOC) && - gfpflags_allow_blocking(gfp_mask)) { + gfpflags_allow_blocking(gfp_mask)) mem_cgroup_handle_over_high(gfp_mask); - } return 0; } diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4f9b61f4a668..636280d04008 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -982,7 +982,7 @@ static bool has_extra_refcount(struct page_state *ps, struct page *p, int count = page_count(p) - 1; if (extra_pins) - count -= 1; + count -= folio_nr_pages(page_folio(p)); if (count > 0) { pr_err("%#lx: %s still referenced by %d users\n", diff --git a/mm/memory.c b/mm/memory.c index 7e1f4849463a..89bcae0b224d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1464,7 +1464,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, delay_rmap = 0; if (!folio_test_anon(folio)) { if (pte_dirty(ptent)) { - folio_set_dirty(folio); + folio_mark_dirty(folio); if (tlb_delay_rmap(tlb)) { delay_rmap = 1; force_flush = 1; diff --git a/mm/mmap.c b/mm/mmap.c index b78e83d351d2..d89770eaab6b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1825,15 +1825,17 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, /* * mmap_region() will call shmem_zero_setup() to create a file, * so use shmem's get_unmapped_area in case it can be huge. - * do_mmap() will clear pgoff, so match alignment. */ - pgoff = 0; get_area = shmem_get_unmapped_area; } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { /* Ensures that larger anonymous mappings are THP aligned. */ get_area = thp_get_unmapped_area; } + /* Always treat pgoff as zero for anonymous memory. */ + if (!file) + pgoff = 0; + addr = get_area(file, addr, len, pgoff, flags); if (IS_ERR_VALUE(addr)) return addr; diff --git a/mm/page-writeback.c b/mm/page-writeback.c index cd4e4ae77c40..02147b61712b 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1638,7 +1638,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc) */ dtc->wb_thresh = __wb_calc_thresh(dtc); dtc->wb_bg_thresh = dtc->thresh ? - div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0; + div64_u64(dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0; /* * In order to avoid the stacked BDI deadlock we need diff --git a/mm/readahead.c b/mm/readahead.c index 23620c57c122..2648ec4f0494 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -469,7 +469,7 @@ static inline int ra_alloc_folio(struct readahead_control *ractl, pgoff_t index, if (!folio) return -ENOMEM; - mark = round_up(mark, 1UL << order); + mark = round_down(mark, 1UL << order); if (index == mark) folio_set_readahead(folio); err = filemap_add_folio(ractl->mapping, folio, index, gfp); @@ -575,7 +575,7 @@ static void ondemand_readahead(struct readahead_control *ractl, * It's the expected callback index, assume sequential access. * Ramp up sizes, and push forward the readahead window. */ - expected = round_up(ra->start + ra->size - ra->async_size, + expected = round_down(ra->start + ra->size - ra->async_size, 1UL << order); if (index == expected || index == (ra->start + ra->size)) { ra->start += ra->size; diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 20e3b0d9cf7e..75fcf1f783bc 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -357,6 +357,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb( unsigned long dst_start, unsigned long src_start, unsigned long len, + atomic_t *mmap_changing, uffd_flags_t flags) { struct mm_struct *dst_mm = dst_vma->vm_mm; @@ -472,6 +473,15 @@ static __always_inline ssize_t mfill_atomic_hugetlb( goto out; } mmap_read_lock(dst_mm); + /* + * If memory mappings are changing because of non-cooperative + * operation (e.g. mremap) running in parallel, bail out and + * request the user to retry later + */ + if (mmap_changing && atomic_read(mmap_changing)) { + err = -EAGAIN; + break; + } dst_vma = NULL; goto retry; @@ -506,6 +516,7 @@ extern ssize_t mfill_atomic_hugetlb(struct vm_area_struct *dst_vma, unsigned long dst_start, unsigned long src_start, unsigned long len, + atomic_t *mmap_changing, uffd_flags_t flags); #endif /* CONFIG_HUGETLB_PAGE */ @@ -622,8 +633,8 @@ static __always_inline ssize_t mfill_atomic(struct mm_struct *dst_mm, * If this is a HUGETLB vma, pass off to appropriate routine */ if (is_vm_hugetlb_page(dst_vma)) - return mfill_atomic_hugetlb(dst_vma, dst_start, - src_start, len, flags); + return mfill_atomic_hugetlb(dst_vma, dst_start, src_start, + len, mmap_changing, flags); if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma)) goto out_unlock; diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh index 0899019a7fcb..e14bdd4455f2 100755 --- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh +++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh @@ -1,4 +1,4 @@ -#!/bin/sh +#!/bin/bash # SPDX-License-Identifier: GPL-2.0 # Kselftest framework requirement - SKIP code is 4. diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c index 380b691d3eb9..b748c48908d9 100644 --- a/tools/testing/selftests/mm/ksm_tests.c +++ b/tools/testing/selftests/mm/ksm_tests.c @@ -566,7 +566,7 @@ static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot, if (map_ptr_orig == MAP_FAILED) err(2, "initial mmap"); - if (madvise(map_ptr, len + HPAGE_SIZE, MADV_HUGEPAGE)) + if (madvise(map_ptr, len, MADV_HUGEPAGE)) err(2, "MADV_HUGEPAGE"); pagemap_fd = open("/proc/self/pagemap", O_RDONLY); diff --git a/tools/testing/selftests/mm/map_hugetlb.c b/tools/testing/selftests/mm/map_hugetlb.c index 193281560b61..86e8f2048a40 100644 --- a/tools/testing/selftests/mm/map_hugetlb.c +++ b/tools/testing/selftests/mm/map_hugetlb.c @@ -15,6 +15,7 @@ #include #include #include +#include "vm_util.h" #define LENGTH (256UL*1024*1024) #define PROTECTION (PROT_READ | PROT_WRITE) @@ -58,10 +59,16 @@ int main(int argc, char **argv) { void *addr; int ret; + size_t hugepage_size; size_t length = LENGTH; int flags = FLAGS; int shift = 0; + hugepage_size = default_huge_page_size(); + /* munmap with fail if the length is not page aligned */ + if (hugepage_size > length) + length = hugepage_size; + if (argc > 1) length = atol(argv[1]) << 20; if (argc > 2) { diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c index 1d4c1589c305..2f8b991f78cb 100644 --- a/tools/testing/selftests/mm/mremap_test.c +++ b/tools/testing/selftests/mm/mremap_test.c @@ -360,7 +360,8 @@ static long long remap_region(struct config c, unsigned int threshold_mb, char pattern_seed) { void *addr, *src_addr, *dest_addr, *dest_preamble_addr; - unsigned long long i; + int d; + unsigned long long t; struct timespec t_start = {0, 0}, t_end = {0, 0}; long long start_ns, end_ns, align_mask, ret, offset; unsigned long long threshold; @@ -378,8 +379,8 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Set byte pattern for source block. */ srand(pattern_seed); - for (i = 0; i < threshold; i++) - memset((char *) src_addr + i, (char) rand(), 1); + for (t = 0; t < threshold; t++) + memset((char *) src_addr + t, (char) rand(), 1); /* Mask to zero out lower bits of address for alignment */ align_mask = ~(c.dest_alignment - 1); @@ -420,8 +421,8 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Set byte pattern for the dest preamble block. */ srand(pattern_seed); - for (i = 0; i < c.dest_preamble_size; i++) - memset((char *) dest_preamble_addr + i, (char) rand(), 1); + for (d = 0; d < c.dest_preamble_size; d++) + memset((char *) dest_preamble_addr + d, (char) rand(), 1); } clock_gettime(CLOCK_MONOTONIC, &t_start); @@ -437,14 +438,14 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Verify byte pattern after remapping */ srand(pattern_seed); - for (i = 0; i < threshold; i++) { + for (t = 0; t < threshold; t++) { char c = (char) rand(); - if (((char *) dest_addr)[i] != c) { + if (((char *) dest_addr)[t] != c) { ksft_print_msg("Data after remap doesn't match at offset %llu\n", - i); + t); ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff, - ((char *) dest_addr)[i] & 0xff); + ((char *) dest_addr)[t] & 0xff); ret = -1; goto clean_up_dest; } @@ -453,14 +454,14 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Verify the dest preamble byte pattern after remapping */ if (c.dest_preamble_size) { srand(pattern_seed); - for (i = 0; i < c.dest_preamble_size; i++) { + for (d = 0; d < c.dest_preamble_size; d++) { char c = (char) rand(); - if (((char *) dest_preamble_addr)[i] != c) { + if (((char *) dest_preamble_addr)[d] != c) { ksft_print_msg("Preamble data after remap doesn't match at offset %d\n", - i); + d); ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff, - ((char *) dest_preamble_addr)[i] & 0xff); + ((char *) dest_preamble_addr)[d] & 0xff); ret = -1; goto clean_up_dest; } diff --git a/tools/testing/selftests/mm/va_high_addr_switch.sh b/tools/testing/selftests/mm/va_high_addr_switch.sh index 45cae7cab27e..a0a75f302904 100755 --- a/tools/testing/selftests/mm/va_high_addr_switch.sh +++ b/tools/testing/selftests/mm/va_high_addr_switch.sh @@ -29,9 +29,15 @@ check_supported_x86_64() # See man 1 gzip under '-f'. local pg_table_levels=$(gzip -dcfq "${config}" | grep PGTABLE_LEVELS | cut -d'=' -f 2) + local cpu_supports_pl5=$(awk '/^flags/ {if (/la57/) {print 0;} + else {print 1}; exit}' /proc/cpuinfo 2>/dev/null) + if [[ "${pg_table_levels}" -lt 5 ]]; then echo "$0: PGTABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test" exit $ksft_skip + elif [[ "${cpu_supports_pl5}" -ne 0 ]]; then + echo "$0: CPU does not have the necessary la57 flag to support page table level 5" + exit $ksft_skip fi } diff --git a/tools/testing/selftests/mm/write_hugetlb_memory.sh b/tools/testing/selftests/mm/write_hugetlb_memory.sh index 70a02301f4c2..3d2d2eb9d6ff 100755 --- a/tools/testing/selftests/mm/write_hugetlb_memory.sh +++ b/tools/testing/selftests/mm/write_hugetlb_memory.sh @@ -1,4 +1,4 @@ -#!/bin/sh +#!/bin/bash # SPDX-License-Identifier: GPL-2.0 set -e