linux-stable.git/Documentation, branch v5.4.129

mm/slub: clarify verification reporting

2021-06-23T12:41:30+00:00

commit 8669dbab2ae56085c128894b181c2aa50f97e368 upstream.

Patch series "Actually fix freelist pointer vs redzoning", v4.

This fixes redzoning vs the freelist pointer (both for middle-position
and very small caches).  Both are "theoretical" fixes, in that I see no
evidence of such small-sized caches actually be used in the kernel, but
that's no reason to let the bugs continue to exist, especially since
people doing local development keep tripping over it.  :)

This patch (of 3):

Instead of repeating "Redzone" and "Poison", clarify which sides of
those zones got tripped.  Additionally fix column alignment in the
trailer.

Before:

  BUG test (Tainted: G    B            ): Redzone overwritten
  ...
  Redzone (____ptrval____): bb bb bb bb bb bb bb bb      ........
  Object (____ptrval____): f6 f4 a5 40 1d e8            ...@..
  Redzone (____ptrval____): 1a aa                        ..
  Padding (____ptrval____): 00 00 00 00 00 00 00 00      ........

After:

  BUG test (Tainted: G    B            ): Right Redzone overwritten
  ...
  Redzone  (____ptrval____): bb bb bb bb bb bb bb bb      ........
  Object   (____ptrval____): f6 f4 a5 40 1d e8            ...@..
  Redzone  (____ptrval____): 1a aa                        ..
  Padding  (____ptrval____): 00 00 00 00 00 00 00 00      ........

The earlier commits that slowly resulted in the "Before" reporting were:

  d86bd1bece6f ("mm/slub: support left redzone")
  ffc79d288000 ("slub: use print_hex_dump")
  2492268472e7 ("SLUB: change error reporting format to follow lockdep loosely")

Link: https://lkml.kernel.org/r/20210608183955.280836-1-keescook@chromium.org
Link: https://lkml.kernel.org/r/20210608183955.280836-2-keescook@chromium.org
Link: https://lore.kernel.org/lkml/cfdb11d7-fb8e-e578-c939-f7f5fb69a6bd@suse.cz/
Signed-off-by: Kees Cook 
Acked-by: Vlastimil Babka 
Cc: Marco Elver 
Cc: "Lin, Zhenpeng" 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Cc: Roman Gushchin 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

XArray: add xas_split

2021-06-10T11:37:14+00:00

commit 8fc75643c5e14574c8be59b69182452ece28315a upstream

In order to use multi-index entries for huge pages in the page cache, we
need to be able to split a multi-index entry (eg if a file is truncated in
the middle of a huge page entry).  This version does not support splitting
more than one level of the tree at a time.  This is an acceptable
limitation for the page cache as we do not expect to support order-12
pages in the near future.

[akpm@linux-foundation.org: export xas_split_alloc() to modules]
[willy@infradead.org: fix xarray split]
  Link: https://lkml.kernel.org/r/20200910175450.GV6583@casper.infradead.org
[willy@infradead.org: fix xarray]
  Link: https://lkml.kernel.org/r/20201001233943.GW20115@casper.infradead.org

Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton 
Cc: "Kirill A . Shutemov" 
Cc: Qian Cai 
Cc: Song Liu 
Link: https://lkml.kernel.org/r/20200903183029.14930-3-willy@infradead.org
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Documentation: seccomp: Fix user notification documentation

2021-06-03T06:59:03+00:00

commit aac902925ea646e461c95edc98a8a57eb0def917 upstream.

The documentation had some previously incorrect information about how
userspace notifications (and responses) were handled due to a change
from a previously proposed patchset.

Signed-off-by: Sargun Dhillon 
Acked-by: Tycho Andersen 
Acked-by: Christian Brauner 
Signed-off-by: Kees Cook 
Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210517193908.3113-2-sargun@sargun.me
Signed-off-by: Greg Kroah-Hartman

tweewide: Fix most Shebang lines

2021-05-22T09:38:30+00:00

commit c25ce589dca10d64dde139ae093abc258a32869c upstream.

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

Signed-off-by: Finn Behrens 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Greg Kroah-Hartman

ARM: 9012/1: move device tree mapping out of linear region

2021-05-19T08:08:32+00:00

commit 7a1be318f5795cb66fa0dc86b3ace427fe68057f upstream

On ARM, setting up the linear region is tricky, given the constraints
around placement and alignment of the memblocks, and how the kernel
itself as well as the DT are placed in physical memory.

Let's simplify matters a bit, by moving the device tree mapping to the
top of the address space, right between the end of the vmalloc region
and the start of the the fixmap region, and create a read-only mapping
for it that is independent of the size of the linear region, and how it
is organized.

Since this region was formerly used as a guard region, which will now be
populated fully on LPAE builds by this read-only mapping (which will
still be able to function as a guard region for stray writes), bump the
start of the [underutilized] fixmap region by 512 KB as well, to ensure
that there is always a proper guard region here. Doing so still leaves
ample room for the fixmap space, even with NR_CPUS set to its maximum
value of 32.

Tested-by: Linus Walleij 
Reviewed-by: Linus Walleij 
Reviewed-by: Nicolas Pitre 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Russell King 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

dt-bindings: net: ethernet-controller: fix typo in NVMEM

2021-04-14T06:24:18+00:00

commit af9d316f3dd6d1385fbd1631b5103e620fc4298a upstream.

The correct property name is "nvmem-cell-names". This is what:
1. Was originally documented in the ethernet.txt
2. Is used in DTS files
3. Matches standard syntax for phandles
4. Linux net subsystem checks for

Fixes: 9d3de3c58347 ("dt-bindings: net: Add YAML schemas for the generic Ethernet options")
Signed-off-by: Rafał Miłecki 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Reject VM creation when the default IPA size is unsupported

2021-03-17T16:03:57+00:00

Commit 7d717558dd5ef10d28866750d5c24ff892ea3778 upstream.

KVM/arm64 has forever used a 40bit default IPA space, partially
due to its 32bit heritage (where the only choice is 40bit).

However, there are implementations in the wild that have a *cough*
much smaller *cough* IPA space, which leads to a misprogramming of
VTCR_EL2, and a guest that is stuck on its first memory access
if userspace dares to ask for the default IPA setting (which most
VMMs do).

Instead, blundly reject the creation of such VM, as we can't
satisfy the requirements from userspace (with a one-off warning).
Also clarify the boot warning, and document that the VM creation
will fail when an unsupported IPA size is provided.

Although this is an ABI change, it doesn't really change much
for userspace:

- the guest couldn't run before this change, but no error was
  returned. At least userspace knows what is happening.

- a memory slot that was accepted because it did fit the default
  IPA space now doesn't even get a chance to be registered.

The other thing that is left doing is to convince userspace to
actually use the IPA space setting instead of relying on the
antiquated default.

Fixes: 233a7cb23531 ("kvm: arm64: Allow tuning the physical address size for VM")
Signed-off-by: Marc Zyngier 
Cc: stable@vger.kernel.org
Reviewed-by: Andrew Jones 
Reviewed-by: Eric Auger 
Link: https://lore.kernel.org/r/20210311100016.3830038-2-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman

sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output

2021-03-07T11:20:48+00:00

commit 2efc459d06f1630001e3984854848a5647086232 upstream.

Output defects can exist in sysfs content using sprintf and snprintf.

sprintf does not know the PAGE_SIZE maximum of the temporary buffer
used for outputting sysfs content and it's possible to overrun the
PAGE_SIZE buffer length.

Add a generic sysfs_emit function that knows that the size of the
temporary buffer and ensures that no overrun is done.

Add a generic sysfs_emit_at function that can be used in multiple
call situations that also ensures that no overrun is done.

Validate the output buffer argument to be page aligned.
Validate the offset len argument to be within the PAGE_SIZE buf.

Signed-off-by: Joe Perches 
Link: https://lore.kernel.org/r/884235202216d464d61ee975f7465332c86f76b2.1600285923.git.joe@perches.com
Signed-off-by: Greg Kroah-Hartman

dt-bindings: net: btusb: DT fix s/interrupt-name/interrupt-names/

2021-03-07T11:20:43+00:00

commit f288988930e93857e0375bdf88bb670c312b82eb upstream.

The standard DT property name is "interrupt-names".

Fixes: fd913ef7ce619467 ("Bluetooth: btusb: Add out-of-band wakeup support")
Signed-off-by: Geert Uytterhoeven 
Acked-by: Rob Herring 
Reviewed-by: Brian Norris 
Acked-by: Rajat Jain 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

dt-bindings: ethernet-controller: fix fixed-link specification

2021-03-07T11:20:43+00:00

commit 322322d15b9b912bc8710c367a95a7de62220a72 upstream.

The original fixed-link.txt allowed a pause property for fixed link.
This has been missed in the conversion to yaml format.

Fixes: 9d3de3c58347 ("dt-bindings: net: Add YAML schemas for the generic Ethernet options")
Signed-off-by: Russell King 
Reviewed-by: Andrew Lunn 
Link: https://lore.kernel.org/r/E1l6W2G-0002Ga-0O@rmk-PC.armlinux.org.uk
Signed-off-by: Rob Herring 
Signed-off-by: Greg Kroah-Hartman