Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:

 - Almost all of the rest of MM (memcg, slab-generic, slab, pagealloc,
   gup, hugetlb, pagemap, memremap)

 - Various other things (hfs, ocfs2, kmod, misc, seqfile)

* akpm: (34 commits)
  ipc/util.c: sysvipc_find_ipc() should increase position index
  kernel/gcov/fs.c: gcov_seq_next() should increase position index
  fs/seq_file.c: seq_read(): add info message about buggy .next functions
  drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings
  change email address for Pali Rohár
  selftests: kmod: test disabling module autoloading
  selftests: kmod: fix handling test numbers above 9
  docs: admin-guide: document the kernel.modprobe sysctl
  fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()
  kmod: make request_module() return an error when autoloading is disabled
  mm/memremap: set caching mode for PCI P2PDMA memory to WC
  mm/memory_hotplug: add pgprot_t to mhp_params
  powerpc/mm: thread pgprot_t through create_section_mapping()
  x86/mm: introduce __set_memory_prot()
  x86/mm: thread pgprot_t through init_memory_mapping()
  mm/memory_hotplug: rename mhp_restrictions to mhp_params
  mm/memory_hotplug: drop the flags field from struct mhp_restrictions
  mm/special: create generic fallbacks for pte_special() and pte_mkspecial()
  mm/vma: introduce VM_ACCESS_FLAGS
  mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS
  ...

1 files changed, 21 insertions, 0 deletions

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 335696d3360d..39c95c0e13d3 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -446,6 +446,27 @@ Notes:
      successful IPC object allocation. If an IPC object allocation syscall
      fails, it is undefined if the value remains unmodified or is reset to -1.
 
+modprobe:
+=========
+
+The path to the usermode helper for autoloading kernel modules, by
+default "/sbin/modprobe".  This binary is executed when the kernel
+requests a module.  For example, if userspace passes an unknown
+filesystem type to mount(), then the kernel will automatically request
+the corresponding filesystem module by executing this usermode helper.
+This usermode helper should insert the needed module into the kernel.
+
+This sysctl only affects module autoloading.  It has no effect on the
+ability to explicitly insert modules.
+
+If this sysctl is set to the empty string, then module autoloading is
+completely disabled.  The kernel will not try to execute a usermode
+helper at all, nor will it call the kernel_module_request LSM hook.
+
+If CONFIG_STATIC_USERMODEHELPER=y is set in the kernel configuration,
+then the configured static usermode helper overrides this sysctl,
+except that the empty string is still accepted to completely disable
+module autoloading as described above.
 
 nmi_watchdog
 ============