Merge tag 'v4.14-rc2' into patchwork

Linux 4.14-rc2

* tag 'v4.14-rc2': (12066 commits)
  Linux 4.14-rc2
  tpm: ibmvtpm: simplify crq initialization and document crq format
  tpm: replace msleep() with  usleep_range() in TPM 1.2/2.0 generic drivers
  Documentation: tpm: add powered-while-suspended binding documentation
  tpm: tpm_crb: constify acpi_device_id.
  tpm: vtpm: constify vio_device_id
  security: fix description of values returned by cap_inode_need_killpriv
  x86/asm: Fix inline asm call constraints for Clang
  objtool: Handle another GCC stack pointer adjustment bug
  inet: fix improper empty comparison
  net: use inet6_rcv_saddr to compare sockets
  net: set tb->fast_sk_family
  net: orphan frags on stand-alone ptype in dev_queue_xmit_nit
  MAINTAINERS: update git tree locations for ieee802154 subsystem
  SMB3: Don't ignore O_SYNC/O_DSYNC and O_DIRECT flags
  SMB3: handle new statx fields
  arch: remove unused *_segments() macros/functions
  parisc: Unbreak bootloader due to gcc-7 optimizations
  parisc: Reintroduce option to gzip-compress the kernel
  apparmor: fix apparmorfs DAC access permissions
  ...

1 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/oom.h b/include/linux/oom.h
index 8a266e2be5a6..76aac4ce39bc 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -6,6 +6,8 @@
 #include <linux/types.h>
 #include <linux/nodemask.h>
 #include <uapi/linux/oom.h>
+#include <linux/sched/coredump.h> /* MMF_* */
+#include <linux/mm.h> /* VM_FAULT* */
 
 struct zonelist;
 struct notifier_block;
@@ -63,6 +65,26 @@ static inline bool tsk_is_oom_victim(struct task_struct * tsk)
 	return tsk->signal->oom_mm;
 }
 
+/*
+ * Checks whether a page fault on the given mm is still reliable.
+ * This is no longer true if the oom reaper started to reap the
+ * address space which is reflected by MMF_UNSTABLE flag set in
+ * the mm. At that moment any !shared mapping would lose the content
+ * and could cause a memory corruption (zero pages instead of the
+ * original content).
+ *
+ * User should call this before establishing a page table entry for
+ * a !shared mapping and under the proper page table lock.
+ *
+ * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise.
+ */
+static inline int check_stable_address_space(struct mm_struct *mm)
+{
+	if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags)))
+		return VM_FAULT_SIGBUS;
+	return 0;
+}
+
 extern unsigned long oom_badness(struct task_struct *p,
 		struct mem_cgroup *memcg, const nodemask_t *nodemask,
 		unsigned long totalpages);