linux-stable.git/include, branch v4.14.255

block: introduce multi-page bvec helpers

2021-11-12T13:28:23+00:00

commit 3d75ca0adef4280650c6690a0c4702a74a6f3c95 upstream.

This patch introduces helpers of 'mp_bvec_iter_*' for multi-page bvec
support.

The introduced helpers treate one bvec as real multi-page segment,
which may include more than one pages.

The existed helpers of bvec_iter_* are interfaces for supporting current
bvec iterator which is thought as single-page by drivers, fs, dm and
etc. These introduced helpers will build single-page bvec in flight, so
this way won't break current bio/bvec users, which needn't any change.

Follows some multi-page bvec background:

- bvecs stored in bio->bi_io_vec is always multi-page style

- bvec(struct bio_vec) represents one physically contiguous I/O
  buffer, now the buffer may include more than one page after
  multi-page bvec is supported, and all these pages represented
  by one bvec is physically contiguous. Before multi-page bvec
  support, at most one page is included in one bvec, we call it
  single-page bvec.

- .bv_page of the bvec points to the 1st page in the multi-page bvec

- .bv_offset of the bvec is the offset of the buffer in the bvec

The effect on the current drivers/filesystem/dm/bcache/...:

- almost everyone supposes that one bvec only includes one single
  page, so we keep the sp interface not changed, for example,
  bio_for_each_segment() still returns single-page bvec

- bio_for_each_segment_all() will return single-page bvec too

- during iterating, iterator variable(struct bvec_iter) is always
  updated in multi-page bvec style, and bvec_iter_advance() is kept
  not changed

- returned(copied) single-page bvec is built in flight by bvec
  helpers from the stored multi-page bvec

Reviewed-by: Christoph Hellwig 
Reviewed-by: Omar Sandoval 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe 
Cc: Zubin Mithra 
Signed-off-by: Greg Kroah-Hartman

arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed

2021-11-12T13:28:22+00:00

[ Upstream commit cef397038167ac15d085914493d6c86385773709 ]

Stefan Agner reported a bug when using zsram on 32-bit Arm machines
with RAM above the 4GB address boundary:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = a27bd01c
  [00000000] *pgd=236a0003, *pmd=1ffa64003
  Internal error: Oops: 207 [#1] SMP ARM
  Modules linked in: mdio_bcm_unimac(+) brcmfmac cfg80211 brcmutil raspberrypi_hwmon hci_uart crc32_arm_ce bcm2711_thermal phy_generic genet
  CPU: 0 PID: 123 Comm: mkfs.ext4 Not tainted 5.9.6 #1
  Hardware name: BCM2711
  PC is at zs_map_object+0x94/0x338
  LR is at zram_bvec_rw.constprop.0+0x330/0xa64
  pc : []    lr : []    psr: 60000013
  sp : e376bbe0  ip : 00000000  fp : c1e2921c
  r10: 00000002  r9 : c1dda730  r8 : 00000000
  r7 : e8ff7a00  r6 : 00000000  r5 : 02f9ffa0  r4 : e3710000
  r3 : 000fdffe  r2 : c1e0ce80  r1 : ebf979a0  r0 : 00000000
  Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
  Control: 30c5383d  Table: 235c2a80  DAC: fffffffd
  Process mkfs.ext4 (pid: 123, stack limit = 0x495a22e6)
  Stack: (0xe376bbe0 to 0xe376c000)

As it turns out, zsram needs to know the maximum memory size, which
is defined in MAX_PHYSMEM_BITS when CONFIG_SPARSEMEM is set, or in
MAX_POSSIBLE_PHYSMEM_BITS on the x86 architecture.

The same problem will be hit on all 32-bit architectures that have a
physical address space larger than 4GB and happen to not enable sparsemem
and include asm/sparsemem.h from asm/pgtable.h.

After the initial discussion, I suggested just always defining
MAX_POSSIBLE_PHYSMEM_BITS whenever CONFIG_PHYS_ADDR_T_64BIT is
set, or provoking a build error otherwise. This addresses all
configurations that can currently have this runtime bug, but
leaves all other configurations unchanged.

I looked up the possible number of bits in source code and
datasheets, here is what I found:

 - on ARC, CONFIG_ARC_HAS_PAE40 controls whether 32 or 40 bits are used
 - on ARM, CONFIG_LPAE enables 40 bit addressing, without it we never
   support more than 32 bits, even though supersections in theory allow
   up to 40 bits as well.
 - on MIPS, some MIPS32r1 or later chips support 36 bits, and MIPS32r5
   XPA supports up to 60 bits in theory, but 40 bits are more than
   anyone will ever ship
 - On PowerPC, there are three different implementations of 36 bit
   addressing, but 32-bit is used without CONFIG_PTE_64BIT
 - On RISC-V, the normal page table format can support 34 bit
   addressing. There is no highmem support on RISC-V, so anything
   above 2GB is unused, but it might be useful to eventually support
   CONFIG_ZRAM for high pages.

Fixes: 61989a80fb3a ("staging: zsmalloc: zsmalloc memory allocation library")
Fixes: 02390b87a945 ("mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS")
Acked-by: Thomas Bogendoerfer 
Reviewed-by: Stefan Agner 
Tested-by: Stefan Agner 
Acked-by: Mike Rapoport 
Link: https://lore.kernel.org/linux-mm/bdfa44bf1c570b05d6c70898e2bbb0acf234ecdf.1604762181.git.stefan@agner.ch/
Signed-off-by: Arnd Bergmann 
Signed-off-by: Sasha Levin 
[florian: patch arch/powerpc/include/asm/pte-common.h for 4.14.y
removed arch/riscv/include/asm/pgtable.h which does not exist]
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

elfcore: correct reference to CONFIG_UML

2021-10-27T07:51:40+00:00

commit b0e901280d9860a0a35055f220e8e457f300f40a upstream.

Commit 6e7b64b9dd6d ("elfcore: fix building with clang") introduces
special handling for two architectures, ia64 and User Mode Linux.
However, the wrong name, i.e., CONFIG_UM, for the intended Kconfig
symbol for User-Mode Linux was used.

Although the directory for User Mode Linux is ./arch/um; the Kconfig
symbol for this architecture is called CONFIG_UML.

Luckily, ./scripts/checkkconfigsymbols.py warns on non-existing configs:

  UM
  Referencing files: include/linux/elfcore.h
  Similar symbols: UML, NUMA

Correct the name of the config to the intended one.

[akpm@linux-foundation.org: fix um/x86_64, per Catalin]
  Link: https://lkml.kernel.org/r/20211006181119.2851441-1-catalin.marinas@arm.com
  Link: https://lkml.kernel.org/r/YV6pejGzLy5ppEpt@arm.com

Link: https://lkml.kernel.org/r/20211006082209.417-1-lukas.bulwahn@gmail.com
Fixes: 6e7b64b9dd6d ("elfcore: fix building with clang")
Signed-off-by: Lukas Bulwahn 
Cc: Arnd Bergmann 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Catalin Marinas 
Cc: Barret Rhoden 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

sched: Always inline is_percpu_thread()

2021-10-17T08:08:34+00:00

[ Upstream commit 83d40a61046f73103b4e5d8f1310261487ff63b0 ]

  vmlinux.o: warning: objtool: check_preemption_disabled()+0x81: call to is_percpu_thread() leaves .noinstr.text section

Reported-by: Stephen Rothwell 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20210928084218.063371959@infradead.org
Signed-off-by: Sasha Levin

lib/timerqueue: Rely on rbtree semantics for next timer

2021-10-09T12:09:46+00:00

commit 511885d7061eda3eb1faf3f57dcc936ff75863f1 upstream.

Simplify the timerqueue code by using cached rbtrees and rely on the tree
leftmost node semantics to get the timer with earliest expiration time.
This is a drop in conversion, and therefore semantics remain untouched.

The runtime overhead of cached rbtrees is be pretty much the same as the
current head->next method, noting that when removing the leftmost node,
a common operation for the timerqueue, the rb_next(leftmost) is O(1) as
well, so the next timer will either be the right node or its parent.
Therefore no extra pointer chasing. Finally, the size of the struct
timerqueue_head remains the same.

Passes several hours of rcutorture.

Signed-off-by: Davidlohr Bueso 
Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20190724152323.bojciei3muvfxalm@linux-r8p5
Reference: CVE-2021-20317
Signed-off-by: Nobuhiro Iwamatsu (CIP) 
Signed-off-by: Greg Kroah-Hartman

libata: Add ATA_HORKAGE_NO_NCQ_ON_ATI for Samsung 860 and 870 SSD.

2021-10-09T12:09:46+00:00

commit 7a8526a5cd51cf5f070310c6c37dd7293334ac49 upstream.

Many users are reporting that the Samsung 860 and 870 SSD are having
various issues when combined with AMD/ATI (vendor ID 0x1002)  SATA
controllers and only completely disabling NCQ helps to avoid these
issues.

Always disabling NCQ for Samsung 860/870 SSDs regardless of the host
SATA adapter vendor will cause I/O performance degradation with well
behaved adapters. To limit the performance impact to ATI adapters,
introduce the ATA_HORKAGE_NO_NCQ_ON_ATI flag to force disable NCQ
only for these adapters.

Also, two libata.force parameters (noncqati and ncqati) are introduced
to disable and enable the NCQ for the system which equipped with ATI
SATA adapter and Samsung 860 and 870 SSDs. The user can determine NCQ
function to be enabled or disabled according to the demand.

After verifying the chipset from the user reports, the issue appears
on AMD/ATI SB7x0/SB8x0/SB9x0 SATA Controllers and does not appear on
recent AMD SATA adapters. The vendor ID of ATI should be 0x1002.
Therefore, ATA_HORKAGE_NO_NCQ_ON_AMD was modified to
ATA_HORKAGE_NO_NCQ_ON_ATI.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=201693
Signed-off-by: Kate Hsuan 
Reviewed-by: Hans de Goede 
Link: https://lore.kernel.org/r/20210903094411.58749-1-hpa@redhat.com
Reviewed-by: Martin K. Petersen 
Signed-off-by: Jens Axboe 
Cc: Krzysztof Olędzki 
Signed-off-by: Greg Kroah-Hartman

net: mdio: introduce a shutdown method to mdio device drivers

2021-10-09T12:09:45+00:00

[ Upstream commit cf9579976f724ad517cc15b7caadea728c7e245c ]

MDIO-attached devices might have interrupts and other things that might
need quiesced when we kexec into a new kernel. Things are even more
creepy when those interrupt lines are shared, and in that case it is
absolutely mandatory to disable all interrupt sources.

Moreover, MDIO devices might be DSA switches, and DSA needs its own
shutdown method to unlink from the DSA master, which is a new
requirement that appeared after commit 2f1e8ea726e9 ("net: dsa: link
interfaces with the DSA master to get rid of lockdep warnings").

So introduce a ->shutdown method in the MDIO device driver structure.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Andrew Lunn 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

cred: allow get_cred() and put_cred() to be given NULL.

2021-10-06T13:05:11+00:00

commit f06bc03339ad4c1baa964a5f0606247ac1c3c50b upstream.

It is common practice for helpers like this to silently,
accept a NULL pointer.
get_rpccred() and put_rpccred() used by NFS act this way
and using the same interface will ease the conversion
for NFS, and simplify the resulting code.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker 
Cc: Eric Dumazet 
Signed-off-by: Greg Kroah-Hartman

af_unix: fix races in sk_peer_pid and sk_peer_cred accesses

2021-10-06T13:05:09+00:00

[ Upstream commit 35306eb23814444bd4021f8a1c3047d3cb0c8b2b ]

Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations
are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred.

In order to fix this issue, this patch adds a new spinlock that needs
to be used whenever these fields are read or written.

Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently
reading sk->sk_peer_pid which makes no sense, as this field
is only possibly set by AF_UNIX sockets.
We will have to clean this in a separate patch.
This could be done by reverting b48596d1dc25 "Bluetooth: L2CAP: Add get_peer_pid callback"
or implementing what was truly expected.

Fixes: 109f6e39fa07 ("af_unix: Allow SO_PEERCRED to work across namespaces.")
Signed-off-by: Eric Dumazet 
Reported-by: Jann Horn 
Cc: Eric W. Biederman 
Cc: Luiz Augusto von Dentz 
Cc: Marcel Holtmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

compiler.h: Introduce absolute_pointer macro

2021-10-06T13:05:06+00:00

[ Upstream commit f6b5f1a56987de837f8e25cd560847106b8632a8 ]

absolute_pointer() disassociates a pointer from its originating symbol
type and context. Use it to prevent compiler warnings/errors such as

  drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
  arch/m68k/include/asm/string.h:72:25: error:
	'__builtin_memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread]

Such warnings may be reported by gcc 11.x for string and memory
operations on fixed addresses.

Suggested-by: Linus Torvalds 
Signed-off-by: Guenter Roeck 
Reviewed-by: Geert Uytterhoeven 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin