Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "87 patches.

  Subsystems affected by this patch series: mm (pagecache and hugetlb),
  procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs,
  init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork,
  sysvfs, kcov, gdb, resource, selftests, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits)
  ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL
  ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
  selftests/kselftest/runner/run_one(): allow running non-executable files
  virtio-mem: disallow mapping virtio-mem memory via /dev/mem
  kernel/resource: disallow access to exclusive system RAM regions
  kernel/resource: clean up and optimize iomem_is_exclusive()
  scripts/gdb: handle split debug for vmlinux
  kcov: replace local_irq_save() with a local_lock_t
  kcov: avoid enable+disable interrupts if !in_task()
  kcov: allocate per-CPU memory on the relevant node
  Documentation/kcov: define `ip' in the example
  Documentation/kcov: include types.h in the example
  sysv: use BUILD_BUG_ON instead of runtime check
  kernel/fork.c: unshare(): use swap() to make code cleaner
  seq_file: fix passing wrong private data
  seq_file: move seq_escape() to a header
  signal: remove duplicate include in signal.h
  crash_dump: remove duplicate include in crash_dump.h
  crash_dump: fix boolreturn.cocci warning
  hfs/hfsplus: use WARN_ON for sanity check
  ...

1 files changed, 24 insertions, 6 deletions

diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 2618577a4d6d..620821549b23 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -8,8 +8,6 @@
 #include <linux/pgtable.h>
 #include <uapi/linux/vmcore.h>
 
-#include <linux/pgtable.h> /* for pgprot_t */
-
 /* For IS_ENABLED(CONFIG_CRASH_DUMP) */
 #define ELFCORE_ADDR_MAX	(-1ULL)
 #define ELFCORE_ADDR_ERR	(-2ULL)
@@ -91,12 +89,32 @@ static inline void vmcore_unusable(void)
 		elfcorehdr_addr = ELFCORE_ADDR_ERR;
 }
 
-#define HAVE_OLDMEM_PFN_IS_RAM 1
-extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
-extern void unregister_oldmem_pfn_is_ram(void);
+/**
+ * struct vmcore_cb - driver callbacks for /proc/vmcore handling
+ * @pfn_is_ram: check whether a PFN really is RAM and should be accessed when
+ *              reading the vmcore. Will return "true" if it is RAM or if the
+ *              callback cannot tell. If any callback returns "false", it's not
+ *              RAM and the page must not be accessed; zeroes should be
+ *              indicated in the vmcore instead. For example, a ballooned page
+ *              contains no data and reading from such a page will cause high
+ *              load in the hypervisor.
+ * @next: List head to manage registered callbacks internally; initialized by
+ *        register_vmcore_cb().
+ *
+ * vmcore callbacks allow drivers managing physical memory ranges to
+ * coordinate with vmcore handling code, for example, to prevent accessing
+ * physical memory ranges that should not be accessed when reading the vmcore,
+ * although included in the vmcore header as memory ranges to dump.
+ */
+struct vmcore_cb {
+	bool (*pfn_is_ram)(struct vmcore_cb *cb, unsigned long pfn);
+	struct list_head next;
+};
+extern void register_vmcore_cb(struct vmcore_cb *cb);
+extern void unregister_vmcore_cb(struct vmcore_cb *cb);
 
 #else /* !CONFIG_CRASH_DUMP */
-static inline bool is_kdump_kernel(void) { return 0; }
+static inline bool is_kdump_kernel(void) { return false; }
 #endif /* CONFIG_CRASH_DUMP */
 
 /* Device Dump information to be filled by drivers */