diff options
Diffstat (limited to 'mm')
-rw-r--r-- | mm/backing-dev.c | 13 | ||||
-rw-r--r-- | mm/gup.c | 44 | ||||
-rw-r--r-- | mm/huge_memory.c | 7 | ||||
-rw-r--r-- | mm/kasan/Makefile | 8 | ||||
-rw-r--r-- | mm/kasan/generic.c | 1 | ||||
-rw-r--r-- | mm/kasan/tags.c | 1 | ||||
-rw-r--r-- | mm/khugepaged.c | 1 | ||||
-rw-r--r-- | mm/memcontrol.c | 15 | ||||
-rw-r--r-- | mm/mremap.c | 12 | ||||
-rw-r--r-- | mm/page_alloc.c | 9 | ||||
-rw-r--r-- | mm/ptdump.c | 17 | ||||
-rw-r--r-- | mm/shmem.c | 7 | ||||
-rw-r--r-- | mm/slab_common.c | 3 | ||||
-rw-r--r-- | mm/slub.c | 4 | ||||
-rw-r--r-- | mm/util.c | 18 | ||||
-rw-r--r-- | mm/z3fold.c | 11 |
16 files changed, 136 insertions, 35 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 62f05f605fb5..3f2480e4c5af 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -21,7 +21,7 @@ struct backing_dev_info noop_backing_dev_info = { EXPORT_SYMBOL_GPL(noop_backing_dev_info); static struct class *bdi_class; -const char *bdi_unknown_name = "(unknown)"; +static const char *bdi_unknown_name = "(unknown)"; /* * bdi_lock protects bdi_tree and updates to bdi_list. bdi_list has RCU @@ -938,7 +938,8 @@ int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args) if (bdi->dev) /* The driver needs to use separate queues per device */ return 0; - dev = device_create_vargs(bdi_class, NULL, MKDEV(0, 0), bdi, fmt, args); + vsnprintf(bdi->dev_name, sizeof(bdi->dev_name), fmt, args); + dev = device_create(bdi_class, NULL, MKDEV(0, 0), bdi, bdi->dev_name); if (IS_ERR(dev)) return PTR_ERR(dev); @@ -1043,6 +1044,14 @@ void bdi_put(struct backing_dev_info *bdi) } EXPORT_SYMBOL(bdi_put); +const char *bdi_dev_name(struct backing_dev_info *bdi) +{ + if (!bdi || !bdi->dev) + return bdi_unknown_name; + return bdi->dev_name; +} +EXPORT_SYMBOL_GPL(bdi_dev_name); + static wait_queue_head_t congestion_wqh[2] = { __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]), __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1]) @@ -176,13 +176,22 @@ static int follow_pfn_pte(struct vm_area_struct *vma, unsigned long address, } /* - * FOLL_FORCE can write to even unwritable pte's, but only - * after we've gone through a COW cycle and they are dirty. + * FOLL_FORCE or a forced COW break can write even to unwritable pte's, + * but only after we've gone through a COW cycle and they are dirty. */ static inline bool can_follow_write_pte(pte_t pte, unsigned int flags) { - return pte_write(pte) || - ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pte_dirty(pte)); + return pte_write(pte) || ((flags & FOLL_COW) && pte_dirty(pte)); +} + +/* + * A (separate) COW fault might break the page the other way and + * get_user_pages() would return the page from what is now the wrong + * VM. So we need to force a COW break at GUP time even for reads. + */ +static inline bool should_force_cow_break(struct vm_area_struct *vma, unsigned int flags) +{ + return is_cow_mapping(vma->vm_flags) && (flags & (FOLL_GET | FOLL_PIN)); } static struct page *follow_page_pte(struct vm_area_struct *vma, @@ -848,12 +857,18 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, goto out; } if (is_vm_hugetlb_page(vma)) { + if (should_force_cow_break(vma, foll_flags)) + foll_flags |= FOLL_WRITE; i = follow_hugetlb_page(mm, vma, pages, vmas, &start, &nr_pages, i, - gup_flags, nonblocking); + foll_flags, nonblocking); continue; } } + + if (should_force_cow_break(vma, foll_flags)) + foll_flags |= FOLL_WRITE; + retry: /* * If we have a pending SIGKILL, don't keep faulting pages and @@ -2364,6 +2379,10 @@ static bool gup_fast_permitted(unsigned long start, unsigned long end) * * If the architecture does not support this function, simply return with no * pages pinned. + * + * Careful, careful! COW breaking can go either way, so a non-write + * access can get ambiguous page results. If you call this function without + * 'write' set, you'd better be sure that you're ok with that ambiguity. */ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) @@ -2391,6 +2410,12 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, * * We do not adopt an rcu_read_lock(.) here as we also want to * block IPIs that come from THPs splitting. + * + * NOTE! We allow read-only gup_fast() here, but you'd better be + * careful about possible COW pages. You'll get _a_ COW page, but + * not necessarily the one you intended to get depending on what + * COW event happens after this. COW may break the page copy in a + * random direction. */ if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) && @@ -2448,10 +2473,17 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages, if (unlikely(!access_ok((void __user *)start, len))) return -EFAULT; + /* + * The FAST_GUP case requires FOLL_WRITE even for pure reads, + * because get_user_pages() may need to cause an early COW in + * order to avoid confusing the normal COW routines. So only + * targets that are already writable are safe to do by just + * looking at the page tables. + */ if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) && gup_fast_permitted(start, end)) { local_irq_disable(); - gup_pgd_range(addr, end, gup_flags, pages, &nr); + gup_pgd_range(addr, end, gup_flags | FOLL_WRITE, pages, &nr); local_irq_enable(); ret = nr; } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 24ad53b4dfc0..4ffaeb9dd4af 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1465,13 +1465,12 @@ out_unlock: } /* - * FOLL_FORCE can write to even unwritable pmd's, but only - * after we've gone through a COW cycle and they are dirty. + * FOLL_FORCE or a forced COW break can write even to unwritable pmd's, + * but only after we've gone through a COW cycle and they are dirty. */ static inline bool can_follow_write_pmd(pmd_t pmd, unsigned int flags) { - return pmd_write(pmd) || - ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pmd_dirty(pmd)); + return pmd_write(pmd) || ((flags & FOLL_COW) && pmd_dirty(pmd)); } struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index 08b43de2383b..f36ffc090f5f 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -14,10 +14,10 @@ CFLAGS_REMOVE_tags.o = $(CC_FLAGS_FTRACE) # Function splitter causes unnecessary splits in __asan_load1/__asan_store1 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 -CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) +CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING +CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING +CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING +CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING obj-$(CONFIG_KASAN) := common.o init.o report.o obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 616f9dd82d12..76a80033e0b7 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -15,7 +15,6 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#define DISABLE_BRANCH_PROFILING #include <linux/export.h> #include <linux/interrupt.h> diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index 0e987c9ca052..caf4efd9888c 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -12,7 +12,6 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#define DISABLE_BRANCH_PROFILING #include <linux/export.h> #include <linux/interrupt.h> diff --git a/mm/khugepaged.c b/mm/khugepaged.c index b679908743cb..ba059e68cf50 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1673,6 +1673,7 @@ static void collapse_file(struct mm_struct *mm, if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) { result = SCAN_PAGE_HAS_PRIVATE; + putback_lru_page(page); goto out_unlock; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 615d73acd0da..537eae162ed3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4977,19 +4977,22 @@ static struct mem_cgroup *mem_cgroup_alloc(void) unsigned int size; int node; int __maybe_unused i; + long error = -ENOMEM; size = sizeof(struct mem_cgroup); size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); memcg = kzalloc(size, GFP_KERNEL); if (!memcg) - return NULL; + return ERR_PTR(error); memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, 1, MEM_CGROUP_ID_MAX, GFP_KERNEL); - if (memcg->id.id < 0) + if (memcg->id.id < 0) { + error = memcg->id.id; goto fail; + } memcg->vmstats_local = alloc_percpu(struct memcg_vmstats_percpu); if (!memcg->vmstats_local) @@ -5033,7 +5036,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void) fail: mem_cgroup_id_remove(memcg); __mem_cgroup_free(memcg); - return NULL; + return ERR_PTR(error); } static struct cgroup_subsys_state * __ref @@ -5044,8 +5047,8 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) long error = -ENOMEM; memcg = mem_cgroup_alloc(); - if (!memcg) - return ERR_PTR(error); + if (IS_ERR(memcg)) + return ERR_CAST(memcg); memcg->high = PAGE_COUNTER_MAX; memcg->soft_limit = PAGE_COUNTER_MAX; @@ -5095,7 +5098,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) fail: mem_cgroup_id_remove(memcg); mem_cgroup_free(memcg); - return ERR_PTR(-ENOMEM); + return ERR_PTR(error); } static int mem_cgroup_css_online(struct cgroup_subsys_state *css) diff --git a/mm/mremap.c b/mm/mremap.c index af363063ea23..3a097e02cafe 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -266,7 +266,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr); if (!new_pmd) break; - if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd)) { + if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd) || pmd_devmap(*old_pmd)) { if (extent == HPAGE_PMD_SIZE) { bool moved; /* See comment in move_ptes() */ @@ -606,6 +606,16 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, LIST_HEAD(uf_unmap_early); LIST_HEAD(uf_unmap); + /* + * There is a deliberate asymmetry here: we strip the pointer tag + * from the old address but leave the new address alone. This is + * for consistency with mmap(), where we prevent the creation of + * aliasing mappings in userspace by leaving the tag bits of the + * mapping address intact. A non-zero tag will cause the subsequent + * range checks to reject the address as invalid. + * + * See Documentation/arm64/tagged-address-abi.rst for more information. + */ addr = untagged_addr(addr); if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3c4eb750a199..a97de355a13c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1555,6 +1555,7 @@ void set_zone_contiguous(struct zone *zone) if (!__pageblock_pfn_to_page(block_start_pfn, block_end_pfn, zone)) return; + cond_resched(); } /* We confirm that there is no hole */ @@ -2350,6 +2351,14 @@ static inline void boost_watermark(struct zone *zone) if (!watermark_boost_factor) return; + /* + * Don't bother in zones that are unlikely to produce results. + * On small machines, including kdump capture kernels running + * in a small area, boosting the watermark can cause an out of + * memory situation immediately. + */ + if ((pageblock_nr_pages * 4) > zone_managed_pages(zone)) + return; max_boost = mult_frac(zone->_watermark[WMARK_HIGH], watermark_boost_factor, 10000); diff --git a/mm/ptdump.c b/mm/ptdump.c index 26208d0d03b7..f4ce916f5602 100644 --- a/mm/ptdump.c +++ b/mm/ptdump.c @@ -36,6 +36,9 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr, return note_kasan_page_table(walk, addr); #endif + if (st->effective_prot) + st->effective_prot(st, 0, pgd_val(val)); + if (pgd_leaf(val)) st->note_page(st, addr, 0, pgd_val(val)); @@ -53,6 +56,9 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr, return note_kasan_page_table(walk, addr); #endif + if (st->effective_prot) + st->effective_prot(st, 1, p4d_val(val)); + if (p4d_leaf(val)) st->note_page(st, addr, 1, p4d_val(val)); @@ -70,6 +76,9 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr, return note_kasan_page_table(walk, addr); #endif + if (st->effective_prot) + st->effective_prot(st, 2, pud_val(val)); + if (pud_leaf(val)) st->note_page(st, addr, 2, pud_val(val)); @@ -87,6 +96,8 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr, return note_kasan_page_table(walk, addr); #endif + if (st->effective_prot) + st->effective_prot(st, 3, pmd_val(val)); if (pmd_leaf(val)) st->note_page(st, addr, 3, pmd_val(val)); @@ -97,8 +108,12 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr, unsigned long next, struct mm_walk *walk) { struct ptdump_state *st = walk->private; + pte_t val = READ_ONCE(*pte); + + if (st->effective_prot) + st->effective_prot(st, 4, pte_val(val)); - st->note_page(st, addr, 4, pte_val(READ_ONCE(*pte))); + st->note_page(st, addr, 4, pte_val(val)); return 0; } diff --git a/mm/shmem.c b/mm/shmem.c index 7406f91f8a52..153d889e32d1 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2184,7 +2184,11 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user) struct shmem_inode_info *info = SHMEM_I(inode); int retval = -ENOMEM; - spin_lock_irq(&info->lock); + /* + * What serializes the accesses to info->flags? + * ipc_lock_object() when called from shmctl_do_lock(), + * no serialization needed when called from shm_destroy(). + */ if (lock && !(info->flags & VM_LOCKED)) { if (!user_shm_lock(inode->i_size, user)) goto out_nomem; @@ -2199,7 +2203,6 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user) retval = 0; out_nomem: - spin_unlock_irq(&info->lock); return retval; } diff --git a/mm/slab_common.c b/mm/slab_common.c index 1907cb2903c7..4b045f12177f 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1303,7 +1303,8 @@ void __init create_kmalloc_caches(slab_flags_t flags) kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( kmalloc_info[i].name[KMALLOC_DMA], kmalloc_info[i].size, - SLAB_CACHE_DMA | flags, 0, 0); + SLAB_CACHE_DMA | flags, 0, + kmalloc_info[i].size); } } #endif diff --git a/mm/slub.c b/mm/slub.c index 3b17e774831a..fd886d24ee29 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5778,8 +5778,10 @@ static int sysfs_slab_add(struct kmem_cache *s) s->kobj.kset = kset; err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name); - if (err) + if (err) { + kobject_put(&s->kobj); goto out; + } err = sysfs_create_group(&s->kobj, &slab_attr_group); if (err) diff --git a/mm/util.c b/mm/util.c index 988d11e6c17c..dc1c877d5481 100644 --- a/mm/util.c +++ b/mm/util.c @@ -604,6 +604,24 @@ void kvfree(const void *addr) } EXPORT_SYMBOL(kvfree); +/** + * kvfree_sensitive - Free a data object containing sensitive information. + * @addr: address of the data object to be freed. + * @len: length of the data object. + * + * Use the special memzero_explicit() function to clear the content of a + * kvmalloc'ed object containing sensitive data to make sure that the + * compiler won't optimize out the data clearing. + */ +void kvfree_sensitive(const void *addr, size_t len) +{ + if (likely(!ZERO_OR_NULL_PTR(addr))) { + memzero_explicit((void *)addr, len); + kvfree(addr); + } +} +EXPORT_SYMBOL(kvfree_sensitive); + static inline void *__page_rmapping(struct page *page) { unsigned long mapping; diff --git a/mm/z3fold.c b/mm/z3fold.c index 42f31c4b53ad..8c3bb5e508b8 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -318,16 +318,16 @@ static inline void free_handle(unsigned long handle) slots = handle_to_slots(handle); write_lock(&slots->lock); *(unsigned long *)handle = 0; - write_unlock(&slots->lock); - if (zhdr->slots == slots) + if (zhdr->slots == slots) { + write_unlock(&slots->lock); return; /* simple case, nothing else to do */ + } /* we are freeing a foreign handle if we are here */ zhdr->foreign_handles--; is_free = true; - read_lock(&slots->lock); if (!test_bit(HANDLES_ORPHANED, &slots->pool)) { - read_unlock(&slots->lock); + write_unlock(&slots->lock); return; } for (i = 0; i <= BUDDY_MASK; i++) { @@ -336,7 +336,7 @@ static inline void free_handle(unsigned long handle) break; } } - read_unlock(&slots->lock); + write_unlock(&slots->lock); if (is_free) { struct z3fold_pool *pool = slots_to_pool(slots); @@ -422,6 +422,7 @@ static struct z3fold_header *init_z3fold_page(struct page *page, bool headless, zhdr->start_middle = 0; zhdr->cpu = -1; zhdr->foreign_handles = 0; + zhdr->mapped_count = 0; zhdr->slots = slots; zhdr->pool = pool; INIT_LIST_HEAD(&zhdr->buddy); |