Merge tag 'v4.1.41' into 4.1-2.0.x-imx

Linux 4.1.41

* tag 'v4.1.41': (473 commits)
  Linux 4.1.41
  mm/huge_memory.c: respect FOLL_FORCE/FOLL_COW for thp
  xc2028: Fix use-after-free bug properly
  iio: proximity: as3935: fix as3935_write
  ipx: call ipxitf_put() in ioctl error path
  sched/fair: Initialize throttle_count for new task-groups lazily
  sched/fair: Do not announce throttled next buddy in dequeue_task_fair()
  iio: dac: ad7303: fix channel description
  mwifiex: pcie: fix cmd_buf use-after-free in remove/reset
  rtlwifi: rtl8821ae: setup 8812ae RFE according to device type
  ARM: tegra: paz00: Mark panel regulator as enabled on boot
  fs/xattr.c: zero out memory copied to userspace in getxattr
  vfio/type1: Remove locked page accounting workqueue
  crypto: algif_aead - Require setkey before accept(2)
  staging: gdm724x: gdm_mux: fix use-after-free on module unload
  drm/ttm: fix use-after-free races in vm fault handling
  f2fs: sanity check segment count
  ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf
  ipv6: initialize route null entry in addrconf_init()
  rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string
  ...

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>

2 files changed, 51 insertions, 15 deletions

diff --git a/Documentation/arm64/tagged-pointers.txt b/Documentation/arm64/tagged-pointers.txt
index d9995f1f51b3..a25a99e82bb1 100644
--- a/Documentation/arm64/tagged-pointers.txt
+++ b/Documentation/arm64/tagged-pointers.txt
@@ -11,24 +11,56 @@ in AArch64 Linux.
 The kernel configures the translation tables so that translations made
 via TTBR0 (i.e. userspace mappings) have the top byte (bits 63:56) of
 the virtual address ignored by the translation hardware. This frees up
-this byte for application use, with the following caveats:
+this byte for application use.
 
-	(1) The kernel requires that all user addresses passed to EL1
-	    are tagged with tag 0x00. This means that any syscall
-	    parameters containing user virtual addresses *must* have
-	    their top byte cleared before trapping to the kernel.
 
-	(2) Non-zero tags are not preserved when delivering signals.
-	    This means that signal handlers in applications making use
-	    of tags cannot rely on the tag information for user virtual
-	    addresses being maintained for fields inside siginfo_t.
-	    One exception to this rule is for signals raised in response
-	    to watchpoint debug exceptions, where the tag information
-	    will be preserved.
+Passing tagged addresses to the kernel
+--------------------------------------
 
-	(3) Special care should be taken when using tagged pointers,
-	    since it is likely that C compilers will not hazard two
-	    virtual addresses differing only in the upper byte.
+All interpretation of userspace memory addresses by the kernel assumes
+an address tag of 0x00.
+
+This includes, but is not limited to, addresses found in:
+
+ - pointer arguments to system calls, including pointers in structures
+   passed to system calls,
+
+ - the stack pointer (sp), e.g. when interpreting it to deliver a
+   signal,
+
+ - the frame pointer (x29) and frame records, e.g. when interpreting
+   them to generate a backtrace or call graph.
+
+Using non-zero address tags in any of these locations may result in an
+error code being returned, a (fatal) signal being raised, or other modes
+of failure.
+
+For these reasons, passing non-zero address tags to the kernel via
+system calls is forbidden, and using a non-zero address tag for sp is
+strongly discouraged.
+
+Programs maintaining a frame pointer and frame records that use non-zero
+address tags may suffer impaired or inaccurate debug and profiling
+visibility.
+
+
+Preserving tags
+---------------
+
+Non-zero tags are not preserved when delivering signals. This means that
+signal handlers in applications making use of tags cannot rely on the
+tag information for user virtual addresses being maintained for fields
+inside siginfo_t. One exception to this rule is for signals raised in
+response to watchpoint debug exceptions, where the tag information will
+be preserved.
 
 The architecture prevents the use of a tagged PC, so the upper byte will
 be set to a sign-extension of bit 55 on exception return.
+
+
+Other considerations
+--------------------
+
+Special care should be taken when using tagged pointers, since it is
+likely that C compilers will not hazard two virtual addresses differing
+only in the upper byte.
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7bcd7a26f885..fa7ac8614038 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1200,6 +1200,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			When zero, profiling data is discarded and associated
 			debugfs files are removed at module unload time.
 
+	goldfish	[X86] Enable the goldfish android emulator platform.
+			Don't use this when you are not running on the
+			android emulator
+
 	gpt		[EFI] Forces disk with valid GPT signature but
 			invalid Protective MBR to be treated as GPT. If the
 			primary GPT is corrupted, it enables the backup/alternate