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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-17 21:58:52 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-17 21:58:52 +0100
commit0cbeafb245ca568bc0765645aa64f0451b716657 (patch)
tree663c09ff5a62a1b2b66a17c4dfe0413603530a36 /kernel
parentMerge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linu... (diff)
parentprintk: change recursion_bug type to bool (diff)
downloadlinux-0cbeafb245ca568bc0765645aa64f0451b716657.tar.xz
linux-0cbeafb245ca568bc0765645aa64f0451b716657.zip
Merge branch 'akpm' (patches from Andrew)
Merge second patch-bomb from Andrew Morton: - more MM stuff: - Kirill's page-flags rework - Kirill's now-allegedly-fixed THP rework - MADV_FREE implementation - DAX feature work (msync/fsync). This isn't quite complete but DAX is new and it's good enough and the guys have a handle on what needs to be done - I expect this to be wrapped in the next week or two. - some vsprintf maintenance work - various other misc bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (145 commits) printk: change recursion_bug type to bool lib/vsprintf: factor out %pN[F] handler as netdev_bits() lib/vsprintf: refactor duplicate code to special_hex_number() printk-formats.txt: remove unimplemented %pT printk: help pr_debug and pr_devel to optimize out arguments lib/test_printf.c: test dentry printing lib/test_printf.c: add test for large bitmaps lib/test_printf.c: account for kvasprintf tests lib/test_printf.c: add a few number() tests lib/test_printf.c: test precision quirks lib/test_printf.c: check for out-of-bound writes lib/test_printf.c: don't BUG lib/kasprintf.c: add sanity check to kvasprintf lib/vsprintf.c: warn about too large precisions and field widths lib/vsprintf.c: help gcc make number() smaller lib/vsprintf.c: expand field_width to 24 bits lib/vsprintf.c: eliminate potential race in string() lib/vsprintf.c: move string() below widen_string() lib/vsprintf.c: pull out padding code from dentry_name() printk: do cond_resched() between lines while outputting to consoles ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/uprobes.c11
-rw-r--r--kernel/futex.c65
-rw-r--r--kernel/memremap.c219
-rw-r--r--kernel/panic.c3
-rw-r--r--kernel/printk/printk.c67
-rw-r--r--kernel/stop_machine.c4
6 files changed, 294 insertions, 75 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index bb0669169716..0167679182c0 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -161,7 +161,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
const unsigned long mmun_end = addr + PAGE_SIZE;
struct mem_cgroup *memcg;
- err = mem_cgroup_try_charge(kpage, vma->vm_mm, GFP_KERNEL, &memcg);
+ err = mem_cgroup_try_charge(kpage, vma->vm_mm, GFP_KERNEL, &memcg,
+ false);
if (err)
return err;
@@ -175,8 +176,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
goto unlock;
get_page(kpage);
- page_add_new_anon_rmap(kpage, vma, addr);
- mem_cgroup_commit_charge(kpage, memcg, false);
+ page_add_new_anon_rmap(kpage, vma, addr, false);
+ mem_cgroup_commit_charge(kpage, memcg, false, false);
lru_cache_add_active_or_unevictable(kpage, vma);
if (!PageAnon(page)) {
@@ -188,7 +189,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
ptep_clear_flush_notify(vma, addr, ptep);
set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
- page_remove_rmap(page);
+ page_remove_rmap(page, false);
if (!page_mapped(page))
try_to_free_swap(page);
pte_unmap_unlock(ptep, ptl);
@@ -199,7 +200,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
err = 0;
unlock:
- mem_cgroup_cancel_charge(kpage, memcg);
+ mem_cgroup_cancel_charge(kpage, memcg, false);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
unlock_page(page);
return err;
diff --git a/kernel/futex.c b/kernel/futex.c
index 8a310e240cda..c6f514573b28 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -469,7 +469,8 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
{
unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
- struct page *page, *page_head;
+ struct page *page;
+ struct address_space *mapping;
int err, ro = 0;
/*
@@ -519,46 +520,9 @@ again:
else
err = 0;
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- page_head = page;
- if (unlikely(PageTail(page))) {
- put_page(page);
- /* serialize against __split_huge_page_splitting() */
- local_irq_disable();
- if (likely(__get_user_pages_fast(address, 1, !ro, &page) == 1)) {
- page_head = compound_head(page);
- /*
- * page_head is valid pointer but we must pin
- * it before taking the PG_lock and/or
- * PG_compound_lock. The moment we re-enable
- * irqs __split_huge_page_splitting() can
- * return and the head page can be freed from
- * under us. We can't take the PG_lock and/or
- * PG_compound_lock on a page that could be
- * freed from under us.
- */
- if (page != page_head) {
- get_page(page_head);
- put_page(page);
- }
- local_irq_enable();
- } else {
- local_irq_enable();
- goto again;
- }
- }
-#else
- page_head = compound_head(page);
- if (page != page_head) {
- get_page(page_head);
- put_page(page);
- }
-#endif
-
- lock_page(page_head);
-
+ lock_page(page);
/*
- * If page_head->mapping is NULL, then it cannot be a PageAnon
+ * If page->mapping is NULL, then it cannot be a PageAnon
* page; but it might be the ZERO_PAGE or in the gate area or
* in a special mapping (all cases which we are happy to fail);
* or it may have been a good file page when get_user_pages_fast
@@ -570,12 +534,13 @@ again:
*
* The case we do have to guard against is when memory pressure made
* shmem_writepage move it from filecache to swapcache beneath us:
- * an unlikely race, but we do need to retry for page_head->mapping.
+ * an unlikely race, but we do need to retry for page->mapping.
*/
- if (!page_head->mapping) {
- int shmem_swizzled = PageSwapCache(page_head);
- unlock_page(page_head);
- put_page(page_head);
+ mapping = compound_head(page)->mapping;
+ if (!mapping) {
+ int shmem_swizzled = PageSwapCache(page);
+ unlock_page(page);
+ put_page(page);
if (shmem_swizzled)
goto again;
return -EFAULT;
@@ -588,7 +553,7 @@ again:
* it's a read-only handle, it's expected that futexes attach to
* the object not the particular process.
*/
- if (PageAnon(page_head)) {
+ if (PageAnon(page)) {
/*
* A RO anonymous page will never change and thus doesn't make
* sense for futex operations.
@@ -603,15 +568,15 @@ again:
key->private.address = address;
} else {
key->both.offset |= FUT_OFF_INODE; /* inode-based key */
- key->shared.inode = page_head->mapping->host;
+ key->shared.inode = mapping->host;
key->shared.pgoff = basepage_index(page);
}
get_futex_key_refs(key); /* implies MB (B) */
out:
- unlock_page(page_head);
- put_page(page_head);
+ unlock_page(page);
+ put_page(page);
return err;
}
@@ -639,7 +604,7 @@ static int fault_in_user_writeable(u32 __user *uaddr)
down_read(&mm->mmap_sem);
ret = fixup_user_fault(current, mm, (unsigned long)uaddr,
- FAULT_FLAG_WRITE);
+ FAULT_FLAG_WRITE, NULL);
up_read(&mm->mmap_sem);
return ret < 0 ? ret : 0;
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 7658d32c5c78..e517a16cb426 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -10,8 +10,11 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
+#include <linux/radix-tree.h>
+#include <linux/memremap.h>
#include <linux/device.h>
#include <linux/types.h>
+#include <linux/pfn_t.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/memory_hotplug.h>
@@ -147,24 +150,127 @@ void devm_memunmap(struct device *dev, void *addr)
}
EXPORT_SYMBOL(devm_memunmap);
+pfn_t phys_to_pfn_t(dma_addr_t addr, unsigned long flags)
+{
+ return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags);
+}
+EXPORT_SYMBOL(phys_to_pfn_t);
+
#ifdef CONFIG_ZONE_DEVICE
+static DEFINE_MUTEX(pgmap_lock);
+static RADIX_TREE(pgmap_radix, GFP_KERNEL);
+#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)
+#define SECTION_SIZE (1UL << PA_SECTION_SHIFT)
+
struct page_map {
struct resource res;
+ struct percpu_ref *ref;
+ struct dev_pagemap pgmap;
+ struct vmem_altmap altmap;
};
-static void devm_memremap_pages_release(struct device *dev, void *res)
+void get_zone_device_page(struct page *page)
+{
+ percpu_ref_get(page->pgmap->ref);
+}
+EXPORT_SYMBOL(get_zone_device_page);
+
+void put_zone_device_page(struct page *page)
+{
+ put_dev_pagemap(page->pgmap);
+}
+EXPORT_SYMBOL(put_zone_device_page);
+
+static void pgmap_radix_release(struct resource *res)
+{
+ resource_size_t key;
+
+ mutex_lock(&pgmap_lock);
+ for (key = res->start; key <= res->end; key += SECTION_SIZE)
+ radix_tree_delete(&pgmap_radix, key >> PA_SECTION_SHIFT);
+ mutex_unlock(&pgmap_lock);
+}
+
+static unsigned long pfn_first(struct page_map *page_map)
+{
+ struct dev_pagemap *pgmap = &page_map->pgmap;
+ const struct resource *res = &page_map->res;
+ struct vmem_altmap *altmap = pgmap->altmap;
+ unsigned long pfn;
+
+ pfn = res->start >> PAGE_SHIFT;
+ if (altmap)
+ pfn += vmem_altmap_offset(altmap);
+ return pfn;
+}
+
+static unsigned long pfn_end(struct page_map *page_map)
+{
+ const struct resource *res = &page_map->res;
+
+ return (res->start + resource_size(res)) >> PAGE_SHIFT;
+}
+
+#define for_each_device_pfn(pfn, map) \
+ for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++)
+
+static void devm_memremap_pages_release(struct device *dev, void *data)
{
- struct page_map *page_map = res;
+ struct page_map *page_map = data;
+ struct resource *res = &page_map->res;
+ resource_size_t align_start, align_size;
+ struct dev_pagemap *pgmap = &page_map->pgmap;
+
+ if (percpu_ref_tryget_live(pgmap->ref)) {
+ dev_WARN(dev, "%s: page mapping is still live!\n", __func__);
+ percpu_ref_put(pgmap->ref);
+ }
+
+ pgmap_radix_release(res);
/* pages are dead and unused, undo the arch mapping */
- arch_remove_memory(page_map->res.start, resource_size(&page_map->res));
+ align_start = res->start & ~(SECTION_SIZE - 1);
+ align_size = ALIGN(resource_size(res), SECTION_SIZE);
+ arch_remove_memory(align_start, align_size);
+ dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc,
+ "%s: failed to free all reserved pages\n", __func__);
+}
+
+/* assumes rcu_read_lock() held at entry */
+struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
+{
+ struct page_map *page_map;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ page_map = radix_tree_lookup(&pgmap_radix, phys >> PA_SECTION_SHIFT);
+ return page_map ? &page_map->pgmap : NULL;
}
-void *devm_memremap_pages(struct device *dev, struct resource *res)
+/**
+ * devm_memremap_pages - remap and provide memmap backing for the given resource
+ * @dev: hosting device for @res
+ * @res: "host memory" address range
+ * @ref: a live per-cpu reference count
+ * @altmap: optional descriptor for allocating the memmap from @res
+ *
+ * Notes:
+ * 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time
+ * (or devm release event).
+ *
+ * 2/ @res is expected to be a host memory range that could feasibly be
+ * treated as a "System RAM" range, i.e. not a device mmio range, but
+ * this is not enforced.
+ */
+void *devm_memremap_pages(struct device *dev, struct resource *res,
+ struct percpu_ref *ref, struct vmem_altmap *altmap)
{
int is_ram = region_intersects(res->start, resource_size(res),
"System RAM");
+ resource_size_t key, align_start, align_size;
+ struct dev_pagemap *pgmap;
struct page_map *page_map;
+ unsigned long pfn;
int error, nid;
if (is_ram == REGION_MIXED) {
@@ -176,25 +282,120 @@ void *devm_memremap_pages(struct device *dev, struct resource *res)
if (is_ram == REGION_INTERSECTS)
return __va(res->start);
+ if (altmap && !IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) {
+ dev_err(dev, "%s: altmap requires CONFIG_SPARSEMEM_VMEMMAP=y\n",
+ __func__);
+ return ERR_PTR(-ENXIO);
+ }
+
+ if (!ref)
+ return ERR_PTR(-EINVAL);
+
page_map = devres_alloc_node(devm_memremap_pages_release,
sizeof(*page_map), GFP_KERNEL, dev_to_node(dev));
if (!page_map)
return ERR_PTR(-ENOMEM);
+ pgmap = &page_map->pgmap;
memcpy(&page_map->res, res, sizeof(*res));
+ pgmap->dev = dev;
+ if (altmap) {
+ memcpy(&page_map->altmap, altmap, sizeof(*altmap));
+ pgmap->altmap = &page_map->altmap;
+ }
+ pgmap->ref = ref;
+ pgmap->res = &page_map->res;
+
+ mutex_lock(&pgmap_lock);
+ error = 0;
+ for (key = res->start; key <= res->end; key += SECTION_SIZE) {
+ struct dev_pagemap *dup;
+
+ rcu_read_lock();
+ dup = find_dev_pagemap(key);
+ rcu_read_unlock();
+ if (dup) {
+ dev_err(dev, "%s: %pr collides with mapping for %s\n",
+ __func__, res, dev_name(dup->dev));
+ error = -EBUSY;
+ break;
+ }
+ error = radix_tree_insert(&pgmap_radix, key >> PA_SECTION_SHIFT,
+ page_map);
+ if (error) {
+ dev_err(dev, "%s: failed: %d\n", __func__, error);
+ break;
+ }
+ }
+ mutex_unlock(&pgmap_lock);
+ if (error)
+ goto err_radix;
+
nid = dev_to_node(dev);
if (nid < 0)
nid = numa_mem_id();
- error = arch_add_memory(nid, res->start, resource_size(res), true);
- if (error) {
- devres_free(page_map);
- return ERR_PTR(error);
- }
+ align_start = res->start & ~(SECTION_SIZE - 1);
+ align_size = ALIGN(resource_size(res), SECTION_SIZE);
+ error = arch_add_memory(nid, align_start, align_size, true);
+ if (error)
+ goto err_add_memory;
+ for_each_device_pfn(pfn, page_map) {
+ struct page *page = pfn_to_page(pfn);
+
+ /* ZONE_DEVICE pages must never appear on a slab lru */
+ list_force_poison(&page->lru);
+ page->pgmap = pgmap;
+ }
devres_add(dev, page_map);
return __va(res->start);
+
+ err_add_memory:
+ err_radix:
+ pgmap_radix_release(res);
+ devres_free(page_map);
+ return ERR_PTR(error);
}
EXPORT_SYMBOL(devm_memremap_pages);
+
+unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
+{
+ /* number of pfns from base where pfn_to_page() is valid */
+ return altmap->reserve + altmap->free;
+}
+
+void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns)
+{
+ altmap->alloc -= nr_pfns;
+}
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
+{
+ /*
+ * 'memmap_start' is the virtual address for the first "struct
+ * page" in this range of the vmemmap array. In the case of
+ * CONFIG_SPARSE_VMEMMAP a page_to_pfn conversion is simple
+ * pointer arithmetic, so we can perform this to_vmem_altmap()
+ * conversion without concern for the initialization state of
+ * the struct page fields.
+ */
+ struct page *page = (struct page *) memmap_start;
+ struct dev_pagemap *pgmap;
+
+ /*
+ * Uncoditionally retrieve a dev_pagemap associated with the
+ * given physical address, this is only for use in the
+ * arch_{add|remove}_memory() for setting up and tearing down
+ * the memmap.
+ */
+ rcu_read_lock();
+ pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page)));
+ rcu_read_unlock();
+
+ return pgmap ? pgmap->altmap : NULL;
+}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
#endif /* CONFIG_ZONE_DEVICE */
diff --git a/kernel/panic.c b/kernel/panic.c
index b333380c6bb2..d96469de72dc 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -180,8 +180,7 @@ void panic(const char *fmt, ...)
* panic() is not being callled from OOPS.
*/
debug_locks_off();
- console_trylock();
- console_unlock();
+ console_flush_on_panic();
if (!panic_blink)
panic_blink = no_blink;
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 2ce8826f1053..e79439134978 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -48,6 +48,7 @@
#include <linux/uio.h>
#include <asm/uaccess.h>
+#include <asm-generic/sections.h>
#define CREATE_TRACE_POINTS
#include <trace/events/printk.h>
@@ -1660,7 +1661,7 @@ asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
{
- static int recursion_bug;
+ static bool recursion_bug;
static char textbuf[LOG_LINE_MAX];
char *text = textbuf;
size_t text_len = 0;
@@ -1696,7 +1697,7 @@ asmlinkage int vprintk_emit(int facility, int level,
* it can be printed at the next appropriate moment:
*/
if (!oops_in_progress && !lockdep_recursing(current)) {
- recursion_bug = 1;
+ recursion_bug = true;
local_irq_restore(flags);
return 0;
}
@@ -1711,7 +1712,7 @@ asmlinkage int vprintk_emit(int facility, int level,
static const char recursion_msg[] =
"BUG: recent printk recursion!";
- recursion_bug = 0;
+ recursion_bug = false;
/* emit KERN_CRIT message */
printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
NULL, 0, recursion_msg,
@@ -2233,13 +2234,24 @@ void console_unlock(void)
static u64 seen_seq;
unsigned long flags;
bool wake_klogd = false;
- bool retry;
+ bool do_cond_resched, retry;
if (console_suspended) {
up_console_sem();
return;
}
+ /*
+ * Console drivers are called under logbuf_lock, so
+ * @console_may_schedule should be cleared before; however, we may
+ * end up dumping a lot of lines, for example, if called from
+ * console registration path, and should invoke cond_resched()
+ * between lines if allowable. Not doing so can cause a very long
+ * scheduling stall on a slow console leading to RCU stall and
+ * softlockup warnings which exacerbate the issue with more
+ * messages practically incapacitating the system.
+ */
+ do_cond_resched = console_may_schedule;
console_may_schedule = 0;
/* flush buffered message fragment immediately to console */
@@ -2311,6 +2323,9 @@ skip:
call_console_drivers(level, ext_text, ext_len, text, len);
start_critical_timings();
local_irq_restore(flags);
+
+ if (do_cond_resched)
+ cond_resched();
}
console_locked = 0;
@@ -2378,6 +2393,25 @@ void console_unblank(void)
console_unlock();
}
+/**
+ * console_flush_on_panic - flush console content on panic
+ *
+ * Immediately output all pending messages no matter what.
+ */
+void console_flush_on_panic(void)
+{
+ /*
+ * If someone else is holding the console lock, trylock will fail
+ * and may_schedule may be set. Ignore and proceed to unlock so
+ * that messages are flushed out. As this can be called from any
+ * context and we don't want to get preempted while flushing,
+ * ensure may_schedule is cleared.
+ */
+ console_trylock();
+ console_may_schedule = 0;
+ console_unlock();
+}
+
/*
* Return the console tty driver structure and its associated index
*/
@@ -2658,13 +2692,36 @@ int unregister_console(struct console *console)
}
EXPORT_SYMBOL(unregister_console);
+/*
+ * Some boot consoles access data that is in the init section and which will
+ * be discarded after the initcalls have been run. To make sure that no code
+ * will access this data, unregister the boot consoles in a late initcall.
+ *
+ * If for some reason, such as deferred probe or the driver being a loadable
+ * module, the real console hasn't registered yet at this point, there will
+ * be a brief interval in which no messages are logged to the console, which
+ * makes it difficult to diagnose problems that occur during this time.
+ *
+ * To mitigate this problem somewhat, only unregister consoles whose memory
+ * intersects with the init section. Note that code exists elsewhere to get
+ * rid of the boot console as soon as the proper console shows up, so there
+ * won't be side-effects from postponing the removal.
+ */
static int __init printk_late_init(void)
{
struct console *con;
for_each_console(con) {
if (!keep_bootcon && con->flags & CON_BOOT) {
- unregister_console(con);
+ /*
+ * Make sure to unregister boot consoles whose data
+ * resides in the init section before the init section
+ * is discarded. Boot consoles whose data will stick
+ * around will automatically be unregistered when the
+ * proper console replaces them.
+ */
+ if (init_section_intersects(con, sizeof(*con)))
+ unregister_console(con);
}
}
hotcpu_notifier(console_cpu_notify, 0);
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index edb6de4f5908..a467e6c28a3b 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -529,8 +529,6 @@ static int __init cpu_stop_init(void)
}
early_initcall(cpu_stop_init);
-#if defined(CONFIG_SMP) || defined(CONFIG_HOTPLUG_CPU)
-
static int __stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
{
struct multi_stop_data msdata = {
@@ -628,5 +626,3 @@ int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
mutex_unlock(&stop_cpus_mutex);
return ret ?: done.ret;
}
-
-#endif /* CONFIG_SMP || CONFIG_HOTPLUG_CPU */