Part of the intention during the definition of the RISC-V kernel image
header was to lay the groundwork for a future merge with the ARM64
image header.  One error during my original review was not noticing
that the RISC-V header's "magic" field was at a different size and
position than the ARM64's "magic" field.  If the existing ARM64 Image
header parsing code were to attempt to parse an existing RISC-V kernel
image header format, it would see a magic number 0.  This is
undesirable, since it's our intention to align as closely as possible
with the ARM64 header format.  Another problem was that the original
"res3" field was not being initialized correctly to zero.

Address these issues by creating a 32-bit "magic2" field in the RISC-V
header which matches the ARM64 "magic" field.  RISC-V binaries will
store "RSC\x05" in this field.  The intention is that the use of the
existing 64-bit "magic" field in the RISC-V header will be deprecated
over time.  Increment the minor version number of the file format to
indicate this change, and update the documentation accordingly.  Fix
the assembler directives in head.S to ensure that reserved fields are
properly zero-initialized.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reported-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Karsten Merker <merker@debian.org>
Link: https://lore.kernel.org/linux-riscv/194c2f10c9806720623430dbf0cc59a965e50448.camel@wdc.com/T/#u
Link: https://lore.kernel.org/linux-riscv/mhng-755b14c4-8f35-4079-a7ff-e421fd1b02bc@palmer-si-x1e/T/#t

Pull section attribute fix from Miguel Ojeda:
 "Fix Oops in Clang-compiled kernels (Nick Desaulniers)"

* tag 'compiler-attributes-for-linus-v5.3-rc8' of git://github.com/ojeda/linux:
  include/linux/compiler.h: fix Oops for Clang-compiled kernels

Pull GPIO fixes from Linus Walleij:
 "All related to the PCA953x driver when handling chips with more than 8
  ports, now that works again"

* tag 'gpio-v5.3-5' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: pca953x: use pca953x_read_regs instead of regmap_bulk_read
  gpio: pca953x: correct type of reg_direction

GCC unescapes escaped string section names while Clang does not. Because
__section uses the `#` stringification operator for the section name, it
doesn't need to be escaped.

This fixes an Oops observed in distro's that use systemd and not
net.core.bpf_jit_enable=1, when their kernels are compiled with Clang.

Link: https://github.com/ClangBuiltLinux/linux/issues/619
Link: https://bugs.llvm.org/show_bug.cgi?id=42950
Link: https://marc.info/?l=linux-netdev&m=156412960619946&w=2
Link: https://lore.kernel.org/lkml/20190904181740.GA19688@gmail.com/
Acked-by: Will Deacon <will@kernel.org>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[Cherry-picked from the __section cleanup series for 5.3]
[Adjusted commit message]
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>

This reverts commit 558682b5

.

Chris Wilson reports that it breaks his CPU hotplug test scripts.  In
particular, it breaks offlining and then re-onlining the boot CPU, which
we treat specially (and the BIOS does too).

The symptoms are that we can offline the CPU, but it then does not come
back online again:

    smpboot: CPU 0 is now offline
    smpboot: Booting Node 0 Processor 0 APIC 0x0
    smpboot: do_boot_cpu failed(-1) to wakeup CPU#0

Thomas says he knows why it's broken (my personal suspicion: our magic
handling of the "cpu0_logical_apicid" thing), but for 5.3 the right fix
is to just revert it, since we've never touched the LDR bits before, and
it's not worth the risk to do anything else at this stage.

[ Hotpluging of the boot CPU is special anyway, and should be off by
  default. See the "BOOTPARAM_HOTPLUG_CPU0" config option and the
  cpu0_hotplug kernel parameter.

  In general you should not do it, and it has various known limitations
  (hibernate and suspend require the boot CPU, for example).

  But it should work, even if the boot CPU is special and needs careful
  treatment       - Linus ]

Link: https://lore.kernel.org/lkml/156785100521.13300.14461504732265570003@skylake-alporthouse-com/
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bandan Das <bsd@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull Documentation updates from Greg KH:
 "A few small patches for the documenation file that came in through the
  char-misc tree in -rc7 for your tree.

  They fix the mistake in the .rst format that kept the table of
  companies from showing up in the html output, and most importantly,
  add people's names to the list showing support for our process"

* tag 'char-misc-5.3-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Documentation/process: Add Qualcomm process ambassador for hardware security issues
  Documentation/process/embargoed-hardware-issues: Microsoft ambassador
  Documentation/process: Add Google contact for embargoed hardware issues
  Documentation/process: Volunteer as the ambassador for Xen

Add Trilok Soni as process ambassador for hardware security issues
from Qualcomm.

Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
Link: https://lore.kernel.org/r/1567796517-8964-1-git-send-email-tsoni@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull dmaengine fixes from Vinod Koul:
 "Some late fixes for drivers:

   - memory leak in ti crossbar dma driver

   - cleanup of omap dma probe

   - Fix for link list configuration in sprd dma driver

   - Handling fixed for DMACHCLR if iommu is mapped in rcar dma"

* tag 'dmaengine-fix-5.3' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: rcar-dmac: Fix DMACHCLR handling if iommu is mapped
  dmaengine: sprd: Fix the DMA link-list configuration
  dmaengine: ti: omap-dma: Add cleanup in omap_dma_probe()
  dmaengine: ti: dma-crossbar: Fix a memory leak bug

Pull SCSI fix from James Bottomley:
 "Just a single lpfc fix adjusting the number of available queues for
  high CPU count systems"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: lpfc: Raise config max for lpfc_fcp_mq_threshold variable

Pull libnvdimm fix from Dan Williams:
 "Restore support for 1GB alignment namespaces, truncate the end of
  misaligned namespaces"

* tag 'libnvdimm-fix-5.3-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/pfn: Fix namespace creation on misaligned addresses

Pull input fix from Dmitry Torokhov:
 "A tiny update from Benjamin removing a mistakenly added Elan PNP ID so
  that the device is again handled by hid-multitouch"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: elan_i2c - remove Lenovo Legion Y7000 PnpID

Looks like the Bios of the Lenovo Legion Y7000 is using ELAN061B
when the actual device is supposed to be used with hid-multitouch.

Remove it from the list of the supported device, hoping that
no one will complain about the loss in functionality.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=203467
Fixes: 738c06d0

 ("Input: elan_i2c - add hardware ID for multiple Lenovo laptops")
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Pull ARM SoC fixes from Arnd Bergmann:
 "There are three more fixes for this week:

   - The Windows-on-ARM laptops require a workaround to prevent crashing
     at boot from ACPI

   - The Renesas 'draak' board needs one bugfix for the backlight
     regulator

   - Also for Renesas, the 'hihope' board accidentally had its eMMC
     turned off in the 5.3 merge window"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  soc: qcom: geni: Provide parameter error checking
  arm64: dts: renesas: hihope-common: Fix eMMC status
  arm64: dts: renesas: r8a77995: draak: Fix backlight regulator name

Pull configfs fixes from Christoph Hellwig:
 "Late configfs fixes from Al that fix pretty nasty removal vs attribute
  access races"

* tag 'configfs-for-5.3' of git://git.infradead.org/users/hch/configfs:
  configfs: provide exclusion between IO and removals
  configfs: new object reprsenting tree fragments
  configfs_register_group() shouldn't be (and isn't) called in rmdirable parts
  configfs: stash the data we need into configfs_buffer at open time

Pull IOMMU fixes from Joerg Roedel:

 - Revert an Intel VT-d patch that caused problems for some users.

 - Removal of a feature in the Intel VT-d driver that was never
   supported in hardware. This qualifies as a fix because the code for
   this feature sets reserved bits in the invalidation queue descriptor,
   causing failed invalidations on real hardware.

 - Two fixes for AMD IOMMU driver to fix a race condition and to add a
   missing IOTLB flush when kernel is booted in kdump mode.

* tag 'iommu-fixes-v5.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Fix race in increase_address_space()
  iommu/amd: Flush old domains in kdump kernel
  iommu/vt-d: Remove global page flush support
  Revert "iommu/vt-d: Avoid duplicated pci dma alias consideration"

Pull MMC fix from Ulf Hansson:
 "Revert in order to fix card init for some eMMCs that need retries for
  CMD6"

* tag 'mmc-v5.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  Revert "mmc: core: do not retry CMD6 in __mmc_switch()"

Pull drm fixes from Dave Airlie:
 "Live from my friend's couch in Barcelona, latest round of drm fixes.

  The command line parser regression fixes look a bit larger because
  they come with selftests included for the bugs they fix. Otherwise a
  single nouveau, single ingenic and single vmwgfx fix:

  nouveau:
   - add missing MODULE_FIRMWARE definitions

  igenic:
   - hardcode panel type DPI

  vmwgfx:
   - double free fix

  core:
   - command line mode parser fixes"

* tag 'drm-fixes-2019-09-06' of git://anongit.freedesktop.org/drm/drm:
  drm/vmwgfx: Fix double free in vmw_recv_msg()
  drm/nouveau/sec2/gp102: add missing MODULE_FIRMWAREs
  drm/selftests: modes: Add more unit tests for the cmdline parser
  drm/modes: Introduce a whitelist for the named modes
  drm/modes: Fix the command line parser to take force options into account
  drm/modes: Add a switch to differentiate free standing options
  drm/ingenic: Hardcode panel type to DPI

Pull virtio fixes from Michael Tsirkin:
 "virtio, vhost, and balloon bugfixes.

  A couple of last minute bugfixes. And a revert of a failed attempt at
  metadata access optimization - we'll try again in the next cycle"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  mm/balloon_compaction: suppress allocation warnings
  Revert "vhost: access vq metadata through kernel virtual address"
  vhost: Remove unnecessary variable
  virtio-net: lower min ring num_free for efficiency
  vhost/test: fix build for vhost test
  vhost/test: fix build for vhost test

Pull powerpc fixes from Michael Ellerman:
 "One fix for a boot hang on some Freescale machines when PREEMPT is
  enabled.

  Two CVE fixes for bugs in our handling of FP registers and
  transactional memory, both of which can result in corrupted FP state,
  or FP state leaking between processes.

  Thanks to: Chris Packham, Christophe Leroy, Gustavo Romero, Michael
  Neuling"

* tag 'powerpc-5.3-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts
  powerpc/tm: Fix FP/VMX unavailable exceptions inside a transaction
  powerpc/64e: Drop stale call to smp_processor_id() which hangs SMP startup

Add Sasha Levin as Microsoft's process ambassador.

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Link: https://lore.kernel.org/r/20190906095852.23568-1-sashal@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When booting with ACPI, the Geni Serial Engine is not set as the I2C/SPI
parent and thus, the wrapper (parent device) is unassigned.  This causes
the kernel to crash with a null dereference error.

Link: https://lore.kernel.org/r/20190905082555.15020-1-lee.jones@linaro.org
Fixes: 8bc529b2

 ("soc: qcom: geni: Add support for ACPI")
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

After the conversion to lock-less dma-api call the
increase_address_space() function can be called without any
locking. Multiple CPUs could potentially race for increasing
the address space, leading to invalid domain->mode settings
and invalid page-tables. This has been happening in the wild
under high IO load and memory pressure.

Fix the race by locking this operation. The function is
called infrequently so that this does not introduce
a performance regression in the dma-api path again.

Reported-by: Qian Cai <cai@lca.pw>
Fixes: 256e4621

 ('iommu/amd: Make use of the generic IOVA allocator')
Signed-off-by: Joerg Roedel <jroedel@suse.de>

When devices are attached to the amd_iommu in a kdump kernel, the old device
table entries (DTEs), which were copied from the crashed kernel, will be
overwritten with a new domain number.  When the new DTE is written, the IOMMU
is told to flush the DTE from its internal cache--but it is not told to flush
the translation cache entries for the old domain number.

Without this patch, AMD systems using the tg3 network driver fail when kdump
tries to save the vmcore to a network system, showing network timeouts and
(sometimes) IOMMU errors in the kernel log.

This patch will flush IOMMU translation cache entries for the old domain when
a DTE gets overwritten with a new domain number.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Fixes: 3ac3e5ee

 ('iommu/amd: Copy old trans table from old kernel')
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drm-misc-fixes for v5.3 final:
- Make ingenic panel type DPI insteado f unknown.
- Fixes for command line parser modes.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/606d87b2-1840-c893-eb30-d6c471c9e50a@linux.intel.com

Single vmwgfx double free fix.

Signed-off-by: Dave Airlie <airlied@redhat.com>

If a request_key authentication token key gets revoked, there's a window in
which request_key_auth_describe() can see it with a NULL payload - but it
makes no check for this and something like the following oops may occur:

	BUG: Kernel NULL pointer dereference at 0x00000038
	Faulting instruction address: 0xc0000000004ddf30
	Oops: Kernel access of bad area, sig: 11 [#1]
	...
	NIP [...] request_key_auth_describe+0x90/0xd0
	LR [...] request_key_auth_describe+0x54/0xd0
	Call Trace:
	[...] request_key_auth_describe+0x54/0xd0 (unreliable)
	[...] proc_keys_show+0x308/0x4c0
	[...] seq_read+0x3d0/0x540
	[...] proc_reg_read+0x90/0x110
	[...] __vfs_read+0x3c/0x70
	[...] vfs_read+0xb4/0x1b0
	[...] ksys_read+0x7c/0x130
	[...] system_call+0x5c/0x70

Fix this by checking for a NULL pointer when describing such a key.

Also make the read routine check for a NULL pointer to be on the safe side.

[DH: Modified to not take already-held rcu lock and modifie...

Pull sound fixes from Takashi Iwai:
 "A collection of small HD-audio fixes:

   - A regression fix for Realtek codecs due to the recent
     initialization procedure change

   - A fix for potential endless loop at the quirk table lookup

   - Quirks for Lenovo, ASUS and HP machines"

* tag 'sound-5.3-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Fix the problem of two front mics on a ThinkCentre
  ALSA: hda/realtek - Enable internal speaker & headset mic of ASUS UX431FL
  ALSA: hda/realtek - Add quirk for HP Pavilion 15
  ALSA: hda/realtek - Fix overridden device-specific initialization
  ALSA: hda - Fix potential endless loop at applying quirks

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - EFI boot fix for signed kernels

   - an AC flags fix related to UBSAN

   - Hyper-V infinite loop fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/hyper-v: Fix overflow bug in fill_gva_list()
  x86/uaccess: Don't leak the AC flags into __get_user() argument evaluation
  x86/boot: Preserve boot_params.secure_boot from sanitizing

Pull scheduler fixes from Ingo Molnar:
 "This fixes an ABI bug introduced this cycle, plus fixes a throttling
  bug"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Fix uclamp ABI bug, clean up and robustify sched_read_attr() ABI logic and code
  sched/fair: Don't assign runtime for throttled cfs_rq

Pull clang-format update from Miguel Ojeda:
 "Update with the latest for_each macro list"

* tag 'clang-format-for-linus-v5.3-rc8' of git://github.com/ojeda/linux:
  clang-format: Update with the latest for_each macro list

Merge tag 'renesas-fixes2-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into arm/fixes

Second Round of Renesas ARM Based SoC Fixes for v5.3

* RZ/G2M based HiHope main board
  - Re-enabled accidently disabled SDHI3 (eMMC) support

* tag 'renesas-fixes2-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  arm64: dts: renesas: hihope-common: Fix eMMC status

Link: https://lore.kernel.org/r/cover.1567675986.git.horms+renesas@verge.net.au
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

We recently added a kfree() after the end of the loop:

	if (retries == RETRIES) {
		kfree(reply);
		return -EINVAL;
	}

There are two problems.  First the test is wrong and because retries
equals RETRIES if we succeed on the last iteration through the loop.
Second if we fail on the last iteration through the loop then the kfree
is a double free.

When you're reading this code, please note the break statement at the
end of the while loop.  This patch changes the loop so that if it's not
successful then "reply" is NULL and we can test for that afterward.

Cc: <stable@vger.kernel.org>
Fixes: 6b7c3b86

 ("drm/vmwgfx: fix memory leak when too many retries have occurred")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>

This adds myself as the Google contact for embargoed hardware security
issues and fixes some small typos.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matt Linton <amuse@google.com>
Cc: Matthew Garrett <mjg59@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/201909040922.56496BF70@keescook
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Link: https://lore.kernel.org/r/20190904181702.19788-1-andrew.cooper3@citrix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure that attribute methods are not called after the item
has been removed from the tree.  To do so, we
	* at the point of no return in removals, grab ->frag_sem
exclusive and mark the fragment dead.
	* call the methods of attributes with ->frag_sem taken
shared and only after having verified that the fragment is still
alive.

	The main benefit is for method instances - they are
guaranteed that the objects they are accessing *and* all ancestors
are still there.  Another win is that we don't need to bother
with extra refcount on config_item when opening a file -
the item will be alive for as long as it stays in the tree, and
we won't touch it/attributes/any associated data after it's
been removed from the tree.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Pull NFS client bugfix from Trond Myklebust:
 "Regression fix inode fileid checks in attribute revalidation code"

* tag 'nfs-for-5.3-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix inode fileid checks in attribute revalidation code

Thadeu Lima de Souza Cascardo reported that 'chrt' broke on recent kernels:

  $ chrt -p $$
  chrt: failed to get pid 26306's policy: Argument list too long

and he has root-caused the bug to the following commit increasing sched_attr
size and breaking sched_read_attr() into returning -EFBIG:

  a509a7cd

 ("sched/uclamp: Extend sched_setattr() to support utilization clamping")

The other, bigger bug is that the whole sched_getattr() and sched_read_attr()
logic of checking non-zero bits in new ABI components is arguably broken,
and pretty much any extension of the ABI will spuriously break the ABI.
That's way too fragile.

Instead implement the perf syscall's extensible ABI instead, which we
already implement on the sched_setattr() side:

 - if user-attributes have the same size as kernel attributes then the
   logic is unchanged.

 - if user-attributes are larger than the kernel knows about then simply
   skip the extra bits, but set attr->size to the (smaller) kernel size
   so that tooling can (in principle) handle older kernel as well.

 - if user-attributes are smaller than the kernel knows about then just
   copy whatever user-space can accept.

Also clean up the whole logic:

 - Simplify the code flow - there's no need for 'ret' for example.

 - Standardize on 'kattr/uattr' and 'ksize/usize' naming to make sure we
   always know which side we are dealing with.

 - Why is it called 'read' when what it does is to copy to user? This
   code is so far away from VFS read() semantics that the naming is
   actively confusing. Name it sched_attr_copy_to_user() instead, which
   mirrors other copy_to_user() functionality.

 - Move the attr->size assignment from the head of sched_getattr() to the
   sched_attr_copy_to_user() function. Nothing else within the kernel
   should care about the size of the structure.

With these fixes the sched_getattr() syscall now nicely supports an
extensible ABI in both a forward and backward compatible fashion, and
will also fix the chrt bug.

As an added bonus the bogus -EFBIG return is removed as well, which as
Thadeu noted should have been -E2BIG to begin with.

Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: a509a7cd

 ("sched/uclamp: Extend sched_setattr() to support utilization clamping")
Link: https://lkml.kernel.org/r/20190904075532.GA26751@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'renesas-fixes-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into arm/fixes

Renesas ARM Based SoC Fixes for v5.3

* R-Car D3 (r8a77995) based Draak Board
  - Correct backlight regulator name in device tree

* tag 'renesas-fixes-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  arm64: dts: renesas: r8a77995: draak: Fix backlight regulator name

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

When in userspace and MSR FP=0 the hardware FP state is unrelated to
the current process. This is extended for transactions where if tbegin
is run with FP=0, the hardware checkpoint FP state will also be
unrelated to the current process. Due to this, we need to ensure this
hardware checkpoint is updated with the correct state before we enable
FP for this process.

Unfortunately we get this wrong when returning to a process from a
hardware interrupt. A process that starts a transaction with FP=0 can
take an interrupt. When the kernel returns back to that process, we
change to FP=1 but with hardware checkpoint FP state not updated. If
this transaction is then rolled back, the FP registers now contain the
wrong state.

The process looks like this:
   Userspace:                      Kernel

               Start userspace
                with MSR FP=0 TM=1
                  < -----
   ...
   tbegin
   bne
               Hardware interrupt
                   ---- >
                                    <do_IRQ...>
                                    ....
                                    ret_from_except
                                      restore_math()
				        /* sees FP=0 */
                                        restore_fp()
                                          tm_active_with_fp()
					    /* sees FP=1 (Incorrect) */
                                          load_fp_state()
                                        FP = 0 -> 1
                  < -----
               Return to userspace
                 with MSR TM=1 FP=1
                 with junk in the FP TM checkpoint
   TM rollback
   reads FP junk

When returning from the hardware exception, tm_active_with_fp() is
incorrectly making restore_fp() call load_fp_state() which is setting
FP=1.

The fix is to remove tm_active_with_fp().

tm_active_with_fp() is attempting to handle the case where FP state
has been changed inside a transaction. In this case the checkpointed
and transactional FP state is different and hence we must restore the
FP state (ie. we can't do lazy FP restore inside a transaction that's
used FP). It's safe to remove tm_active_with_fp() as this case is
handled by restore_tm_state(). restore_tm_state() detects if FP has
been using inside a transaction and will set load_fp and call
restore_math() to ensure the FP state (checkpoint and transaction) is
restored.

This is a data integrity problem for the current process as the FP
registers are corrupted. It's also a security problem as the FP
registers from one process may be leaked to another.

Similarly for VMX.

A simple testcase to replicate this will be posted to
tools/testing/selftests/powerpc/tm/tm-poison.c

This fixes CVE-2019-15031.

Fixes: a7771176

 ("powerpc: Don't enable FP/Altivec if not checkpointed")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Gustavo Romero <gromero@linux.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904045529.23002-2-gromero@linux.vnet.ibm.com