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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-29 10:40:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-29 10:40:31 -0700
commit570203ec830dd451b8804cdef8036f7fca9f0311 (patch)
treecebdd249624e00d5aed6f24e94f0b743944ccfba
parentab93e984dbb41578b41208cee52ce4e709951eb2 (diff)
parentb943f045a9af9fd02f923e43fe8d7517e9961701 (diff)
downloadlinux-sh-570203ec830dd451b8804cdef8036f7fca9f0311.tar.gz
Merge branch 'akpm' (patches from Andrew)
Merge vm fixes from Andrew Morton: "5 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm/sparse: fix kernel crash with pfn_section_valid check mm: fork: fix kernel_stack memcg stats for various stack implementations hugetlb_cgroup: fix illegal access to memory drivers/base/memory.c: indicate all memory blocks as removable mm/swapfile.c: move inode_lock out of claim_swapfile
-rw-r--r--drivers/base/memory.c23
-rw-r--r--include/linux/memcontrol.h12
-rw-r--r--kernel/fork.c4
-rw-r--r--mm/hugetlb_cgroup.c3
-rw-r--r--mm/memcontrol.c38
-rw-r--r--mm/sparse.c6
-rw-r--r--mm/swapfile.c41
7 files changed, 82 insertions, 45 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b9f474c11393..4086718f6876 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -97,30 +97,13 @@ static ssize_t phys_index_show(struct device *dev,
}
/*
- * Show whether the memory block is likely to be offlineable (or is already
- * offline). Once offline, the memory block could be removed. The return
- * value does, however, not indicate that there is a way to remove the
- * memory block.
+ * Legacy interface that we cannot remove. Always indicate "removable"
+ * with CONFIG_MEMORY_HOTREMOVE - bad heuristic.
*/
static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
- struct memory_block *mem = to_memory_block(dev);
- unsigned long pfn;
- int ret = 1, i;
-
- if (mem->state != MEM_ONLINE)
- goto out;
-
- for (i = 0; i < sections_per_block; i++) {
- if (!present_section_nr(mem->start_section_nr + i))
- continue;
- pfn = section_nr_to_pfn(mem->start_section_nr + i);
- ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
- }
-
-out:
- return sprintf(buf, "%d\n", ret);
+ return sprintf(buf, "%d\n", (int)IS_ENABLED(CONFIG_MEMORY_HOTREMOVE));
}
/*
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index a7a0a1a5c8d5..e9ba01336d4e 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -695,6 +695,7 @@ static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
int val);
void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val);
+void mod_memcg_obj_state(void *p, int idx, int val);
static inline void mod_lruvec_state(struct lruvec *lruvec,
enum node_stat_item idx, int val)
@@ -1123,6 +1124,10 @@ static inline void __mod_lruvec_slab_state(void *p, enum node_stat_item idx,
__mod_node_page_state(page_pgdat(page), idx, val);
}
+static inline void mod_memcg_obj_state(void *p, int idx, int val)
+{
+}
+
static inline
unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
gfp_t gfp_mask,
@@ -1427,6 +1432,8 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg)
return memcg ? memcg->kmemcg_id : -1;
}
+struct mem_cgroup *mem_cgroup_from_obj(void *p);
+
#else
static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
@@ -1468,6 +1475,11 @@ static inline void memcg_put_cache_ids(void)
{
}
+static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
+{
+ return NULL;
+}
+
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/kernel/fork.c b/kernel/fork.c
index 86425305cd4a..d90af13431c7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -397,8 +397,8 @@ static void account_kernel_stack(struct task_struct *tsk, int account)
mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB,
THREAD_SIZE / 1024 * account);
- mod_memcg_page_state(first_page, MEMCG_KERNEL_STACK_KB,
- account * (THREAD_SIZE / 1024));
+ mod_memcg_obj_state(stack, MEMCG_KERNEL_STACK_KB,
+ account * (THREAD_SIZE / 1024));
}
}
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index e434b05416c6..5280bcf459af 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -240,8 +240,7 @@ again:
if (!page_counter_try_charge(&h_cg->hugepage[idx], nr_pages,
&counter)) {
ret = -ENOMEM;
- hugetlb_event(hugetlb_cgroup_from_counter(counter, idx), idx,
- HUGETLB_MAX);
+ hugetlb_event(h_cg, idx, HUGETLB_MAX);
}
css_put(&h_cg->css);
done:
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7a4bd8b9adc2..7ddf91c4295f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -777,6 +777,17 @@ void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val)
rcu_read_unlock();
}
+void mod_memcg_obj_state(void *p, int idx, int val)
+{
+ struct mem_cgroup *memcg;
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_obj(p);
+ if (memcg)
+ mod_memcg_state(memcg, idx, val);
+ rcu_read_unlock();
+}
+
/**
* __count_memcg_events - account VM events in a cgroup
* @memcg: the memory cgroup
@@ -2661,6 +2672,33 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg,
}
#ifdef CONFIG_MEMCG_KMEM
+/*
+ * Returns a pointer to the memory cgroup to which the kernel object is charged.
+ *
+ * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(),
+ * cgroup_mutex, etc.
+ */
+struct mem_cgroup *mem_cgroup_from_obj(void *p)
+{
+ struct page *page;
+
+ if (mem_cgroup_disabled())
+ return NULL;
+
+ page = virt_to_head_page(p);
+
+ /*
+ * Slab pages don't have page->mem_cgroup set because corresponding
+ * kmem caches can be reparented during the lifetime. That's why
+ * memcg_from_slab_page() should be used instead.
+ */
+ if (PageSlab(page))
+ return memcg_from_slab_page(page);
+
+ /* All other pages use page->mem_cgroup */
+ return page->mem_cgroup;
+}
+
static int memcg_alloc_cache_id(void)
{
int id, size;
diff --git a/mm/sparse.c b/mm/sparse.c
index aadb7298dcef..65599e8bd636 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -781,6 +781,12 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
ms->usage = NULL;
}
memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+ /*
+ * Mark the section invalid so that valid_section()
+ * return false. This prevents code from dereferencing
+ * ms->usage array.
+ */
+ ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;
}
if (section_is_early && memmap)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index b2a2e45c9a36..be33e6176cd9 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2899,10 +2899,6 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode)
p->bdev = inode->i_sb->s_bdev;
}
- inode_lock(inode);
- if (IS_SWAPFILE(inode))
- return -EBUSY;
-
return 0;
}
@@ -3157,36 +3153,41 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
mapping = swap_file->f_mapping;
inode = mapping->host;
- /* will take i_rwsem; */
error = claim_swapfile(p, inode);
if (unlikely(error))
goto bad_swap;
+ inode_lock(inode);
+ if (IS_SWAPFILE(inode)) {
+ error = -EBUSY;
+ goto bad_swap_unlock_inode;
+ }
+
/*
* Read the swap header.
*/
if (!mapping->a_ops->readpage) {
error = -EINVAL;
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
page = read_mapping_page(mapping, 0, swap_file);
if (IS_ERR(page)) {
error = PTR_ERR(page);
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
swap_header = kmap(page);
maxpages = read_swap_header(p, swap_header, inode);
if (unlikely(!maxpages)) {
error = -EINVAL;
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
/* OK, set up the swap map and apply the bad block list */
swap_map = vzalloc(maxpages);
if (!swap_map) {
error = -ENOMEM;
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
if (bdi_cap_stable_pages_required(inode_to_bdi(inode)))
@@ -3211,7 +3212,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
GFP_KERNEL);
if (!cluster_info) {
error = -ENOMEM;
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
for (ci = 0; ci < nr_cluster; ci++)
@@ -3220,7 +3221,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
p->percpu_cluster = alloc_percpu(struct percpu_cluster);
if (!p->percpu_cluster) {
error = -ENOMEM;
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
for_each_possible_cpu(cpu) {
struct percpu_cluster *cluster;
@@ -3234,13 +3235,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
error = swap_cgroup_swapon(p->type, maxpages);
if (error)
- goto bad_swap;
+ goto bad_swap_unlock_inode;
nr_extents = setup_swap_map_and_extents(p, swap_header, swap_map,
cluster_info, maxpages, &span);
if (unlikely(nr_extents < 0)) {
error = nr_extents;
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
/* frontswap enabled? set up bit-per-page map for frontswap */
if (IS_ENABLED(CONFIG_FRONTSWAP))
@@ -3280,7 +3281,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
error = init_swap_address_space(p->type, maxpages);
if (error)
- goto bad_swap;
+ goto bad_swap_unlock_inode;
/*
* Flush any pending IO and dirty mappings before we start using this
@@ -3290,7 +3291,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
error = inode_drain_writes(inode);
if (error) {
inode->i_flags &= ~S_SWAPFILE;
- goto bad_swap;
+ goto bad_swap_unlock_inode;
}
mutex_lock(&swapon_mutex);
@@ -3315,6 +3316,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
error = 0;
goto out;
+bad_swap_unlock_inode:
+ inode_unlock(inode);
bad_swap:
free_percpu(p->percpu_cluster);
p->percpu_cluster = NULL;
@@ -3322,6 +3325,7 @@ bad_swap:
set_blocksize(p->bdev, p->old_block_size);
blkdev_put(p->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
}
+ inode = NULL;
destroy_swap_extents(p);
swap_cgroup_swapoff(p->type);
spin_lock(&swap_lock);
@@ -3333,13 +3337,8 @@ bad_swap:
kvfree(frontswap_map);
if (inced_nr_rotate_swap)
atomic_dec(&nr_rotate_swap);
- if (swap_file) {
- if (inode) {
- inode_unlock(inode);
- inode = NULL;
- }
+ if (swap_file)
filp_close(swap_file, NULL);
- }
out:
if (page && !IS_ERR(page)) {
kunmap(page);