Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"14 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm, page_alloc: do not wake kswapd with zone lock held
hugetlbfs: revert "use i_mmap_rwsem for more pmd sharing synchronization"
hugetlbfs: revert "Use i_mmap_rwsem to fix page fault/truncate race"
mm: page_mapped: don't assume compound page is huge or THP
mm/memory.c: initialise mmu_notifier_range correctly
tools/vm/page_owner: use page_owner_sort in the use example
kasan: fix krealloc handling for tag-based mode
kasan: make tag based mode work with CONFIG_HARDENED_USERCOPY
kasan, arm64: use ARCH_SLAB_MINALIGN instead of manual aligning
mm, memcg: fix reclaim deadlock with writeback
mm/usercopy.c: no check page span for stack objects
slab: alien caches must not be initialized if the allocation of the alien cache failed
fork, memcg: fix cached_stacks case
zram: idle writeback fixes and cleanup
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h
index bc8191a..a44682c 100644
--- a/arch/openrisc/include/asm/uaccess.h
+++ b/arch/openrisc/include/asm/uaccess.h
@@ -58,8 +58,12 @@
/* Ensure that addr is below task's addr_limit */
#define __addr_ok(addr) ((unsigned long) addr < get_fs())
-#define access_ok(addr, size) \
- __range_ok((unsigned long)addr, (unsigned long)size)
+#define access_ok(addr, size) \
+({ \
+ unsigned long __ao_addr = (unsigned long)(addr); \
+ unsigned long __ao_size = (unsigned long)(size); \
+ __range_ok(__ao_addr, __ao_size); \
+})
/*
* These are the main single-value transfer routines. They automatically
diff --git a/kernel/fork.c b/kernel/fork.c
index 5ad60d4..b69248e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1834,8 +1834,6 @@ static __latent_entropy struct task_struct *copy_process(
posix_cpu_timers_init(p);
- p->start_time = ktime_get_ns();
- p->real_start_time = ktime_get_boot_ns();
p->io_context = NULL;
audit_set_context(p, NULL);
cgroup_fork(p);
@@ -2002,6 +2000,17 @@ static __latent_entropy struct task_struct *copy_process(
goto bad_fork_free_pid;
/*
+ * From this point on we must avoid any synchronous user-space
+ * communication until we take the tasklist-lock. In particular, we do
+ * not want user-space to be able to predict the process start-time by
+ * stalling fork(2) after we recorded the start_time but before it is
+ * visible to the system.
+ */
+
+ p->start_time = ktime_get_ns();
+ p->real_start_time = ktime_get_boot_ns();
+
+ /*
* Make it visible to the rest of the system, but dont wake it up yet.
* Need tasklist lock for parent etc handling!
*/