git.samba.org - sfrench/cifs-2.6.git/log

Merge branch 'topic/secureboot' into next

Merge the secureboot support, as well as the IMA changes needed to
support it.

From Nayna's cover letter:
  In order to verify the OS kernel on PowerNV systems, secure boot
  requires X.509 certificates trusted by the platform. These are
  stored in secure variables controlled by OPAL, called OPAL secure
  variables. In order to enable users to manage the keys, the secure
  variables need to be exposed to userspace.

  OPAL provides the runtime services for the kernel to be able to
  access the secure variables. This patchset defines the kernel
  interface for the OPAL APIs. These APIs are used by the hooks, which
  load these variables to the keyring and expose them to the userspace
  for reading/writing.

  Overall, this patchset adds the following support:
    * expose secure variables to the kernel via OPAL Runtime API interface
    * expose secure variables to the userspace via kernel sysfs interface
    * load kernel verification and revocation keys to .platform and
      .blacklist keyring respectively.

  The secure variables can be read/written using simple linux
  utilities cat/hexdump.

  For example:
  Path to the secure variables is: /sys/firmware/secvar/vars

    Each secure variable is listed as directory.
    $ ls -l
    total 0
    drwxr-xr-x. 2 root root 0 Aug 20 21:20 db
    drwxr-xr-x. 2 root root 0 Aug 20 21:20 KEK
    drwxr-xr-x. 2 root root 0 Aug 20 21:20 PK

  The attributes of each of the secure variables are (for example: PK):
    $ ls -l
    total 0
    -r--r--r--. 1 root root  4096 Oct  1 15:10 data
    -r--r--r--. 1 root root 65536 Oct  1 15:10 size
    --w-------. 1 root root  4096 Oct  1 15:12 update

  The "data" is used to read the existing variable value using
  hexdump. The data is stored in ESL format. The "update" is used to
  write a new value using cat. The update is to be submitted as AUTH
  file.

powerpc: Load firmware trusted keys/hashes into kernel keyring

The keys used to verify the Host OS kernel are managed by firmware as
secure variables. This patch loads the verification keys into the
.platform keyring and revocation hashes into .blacklist keyring. This
enables verification and loading of the kernels signed by the boot
time keys which are trusted by firmware.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
[mpe: Search by compatible in load_powerpc_certs(), not using format]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573441836-3632-5-git-send-email-nayna@linux.ibm.com

x86/efi: move common keyring handler functions to new file

The handlers to add the keys to the .platform keyring and blacklisted
hashes to the .blacklist keyring is common for both the uefi and powerpc
mechanisms of loading the keys/hashes from the firmware.

This patch moves the common code from load_uefi.c to keyring_handler.c

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573441836-3632-4-git-send-email-nayna@linux.ibm.com

powerpc: expose secure variables to userspace via sysfs

PowerNV secure variables, which store the keys used for OS kernel
verification, are managed by the firmware. These secure variables need to
be accessed by the userspace for addition/deletion of the certificates.

This patch adds the sysfs interface to expose secure variables for PowerNV
secureboot. The users shall use this interface for manipulating
the keys stored in the secure variables.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573441836-3632-3-git-send-email-nayna@linux.ibm.com

powerpc/powernv: Add OPAL API interface to access secure variable

The X.509 certificates trusted by the platform and required to secure
boot the OS kernel are wrapped in secure variables, which are
controlled by OPAL.

This patch adds firmware/kernel interface to read and write OPAL
secure variables based on the unique key.

This support can be enabled using CONFIG_OPAL_SECVAR.

Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
[mpe: Make secvar_ops __ro_after_init, only build opal-secvar.c if PPC_SECURE_BOOT=y]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573441836-3632-2-git-send-email-nayna@linux.ibm.com

sysfs: Fixes __BIN_ATTR_WO() macro

This patch fixes the size and write parameter for the macro
__BIN_ATTR_WO().

Fixes: 7f905761e15a8 ("sysfs: add BIN_ATTR_WO() macro")
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1569973038-2710-1-git-send-email-nayna@linux.ibm.com

Merge branch 'topic/ima' into topic/secureboot

From Nayna's cover letter:
  The IMA subsystem supports custom, built-in, arch-specific policies
  to define the files to be measured and appraised. These policies are
  honored based on priority, where arch-specific policy is the highest
  and custom is the lowest.

  PowerNV systems use a Linux-based bootloader to kexec the OS. The
  bootloader kernel relies on IMA for signature verification of the OS
  kernel before doing the kexec. This patchset adds support for
  powerpc arch-specific IMA policies that are conditionally defined
  based on a system's secure boot and trusted boot states. The OS
  secure boot and trusted boot states are determined via device-tree
  properties.

  The verification needs to be performed only for binaries that are
  not blacklisted. The kernel currently only checks against the
  blacklist of keys. However, doing so results in blacklisting all the
  binaries that are signed by the same key. In order to prevent just
  one particular binary from being loaded, it must be checked against
  a blacklist of binary hashes. This patchset also adds support to IMA
  for checking against a hash blacklist for files. signed by appended
  signature.

powerpc/ima: Indicate kernel modules appended signatures are enforced

The arch specific kernel module policy rule requires kernel modules to
be signed, either as an IMA signature, stored as an xattr, or as an
appended signature. As a result, kernel modules appended signatures
could be enforced without "sig_enforce" being set or reflected in
/sys/module/module/parameters/sig_enforce. This patch sets
"sig_enforce".

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-10-git-send-email-zohar@linux.ibm.com

powerpc/ima: Update ima arch policy to check for blacklist

This patch updates the arch-specific policies for PowerNV system to
make sure that the binary hash is not blacklisted.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-9-git-send-email-zohar@linux.ibm.com

ima: Check against blacklisted hashes for files with modsig

Asymmetric private keys are used to sign multiple files. The kernel
currently supports checking against blacklisted keys. However, if the
public key is blacklisted, any file signed by the blacklisted key will
automatically fail signature verification. Blacklisting the public key
is not fine enough granularity, as we might want to only blacklist a
particular file.

This patch adds support for checking against the blacklisted hash of
the file, without the appended signature, based on the IMA policy. It
defines a new policy option "appraise_flag=check_blacklist".

In addition to the blacklisted binary hashes stored in the firmware
"dbx" variable, the Linux kernel may be configured to load blacklisted
binary hashes onto the .blacklist keyring as well. The following
example shows how to blacklist a specific kernel module hash.

  $ sha256sum kernel/kheaders.ko
  77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
  kernel/kheaders.ko

  $ grep BLACKLIST .config
  CONFIG_SYSTEM_BLACKLIST_KEYRING=y
  CONFIG_SYSTEM_BLACKLIST_HASH_LIST="blacklist-hash-list"

  $ cat certs/blacklist-hash-list
  "bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3"

Update the IMA custom measurement and appraisal policy
rules (/etc/ima-policy):

  measure func=MODULE_CHECK template=ima-modsig
  appraise func=MODULE_CHECK appraise_flag=check_blacklist
  appraise_type=imasig|modsig

After building, installing, and rebooting the kernel:

   545660333 ---lswrv      0     0   \_ blacklist:
  bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3

  measure func=MODULE_CHECK template=ima-modsig
  appraise func=MODULE_CHECK appraise_flag=check_blacklist
  appraise_type=imasig|modsig

  modprobe: ERROR: could not insert 'kheaders': Permission denied

  10 0c9834db5a0182c1fb0cdc5d3adcf11a11fd83dd ima-sig
  sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40
  2 /usr/lib/modules/5.4.0-rc3+/kernel/kernel/kheaders.ko

  10 82aad2bcc3fa8ed94762356b5c14838f3bcfa6a0 ima-modsig
  sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40
  2 /usr/lib/modules/5.4.0rc3+/kernel/kernel/kheaders.ko  sha256:77fa889b3
  5a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
  3082029a06092a864886f70d010702a082028b30820287020101310d300b0609608648
  016503040201300b06092a864886f70d01070131820264....

  10 25b72217cc1152b44b134ce2cd68f12dfb71acb3 ima-buf
  sha256:8b58427fedcf8f4b20bc8dc007f2e232bf7285d7b93a66476321f9c2a3aa132
  b blacklisted-hash
  77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
[zohar@linux.ibm.com: updated patch description]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-8-git-send-email-zohar@linux.ibm.com

certs: Add wrapper function to check blacklisted binary hash

The -EKEYREJECTED error returned by existing is_hash_blacklisted() is
misleading when called for checking against blacklisted hash of a
binary.

This patch adds a wrapper function is_binary_blacklisted() to return
-EPERM error if binary is blacklisted.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-7-git-send-email-zohar@linux.ibm.com

ima: Make process_buffer_measurement() generic

process_buffer_measurement() is limited to measuring the kexec boot
command line. This patch makes process_buffer_measurement() more
generic, allowing it to measure other types of buffer data (e.g.
blacklisted binary hashes or key hashes).

process_buffer_measurement() may be called directly from an IMA hook
or as an auxiliary measurement record. In both cases the buffer
measurement is based on policy. This patch modifies the function to
conditionally retrieve the policy defined PCR and template for the IMA
hook case.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
[zohar@linux.ibm.com: added comment in process_buffer_measurement()]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-6-git-send-email-zohar@linux.ibm.com

powerpc/ima: Define trusted boot policy

This patch defines an arch-specific trusted boot only policy and a
combined secure and trusted boot policy.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-5-git-send-email-zohar@linux.ibm.com

powerpc: Detect the trusted boot state of the system

While secure boot permits only properly verified signed kernels to be
booted, trusted boot calculates the file hash of the kernel image and
stores the measurement prior to boot, that can be subsequently
compared against good known values via attestation services.

This patch reads the trusted boot state of a PowerNV system. The state
is used to conditionally enable additional measurement rules in the
IMA arch-specific policies.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e9eeee6b-b9bf-1e41-2954-61dbd6fbfbcf@linux.ibm.com

powerpc/ima: Add support to initialize ima policy rules

PowerNV systems use a Linux-based bootloader, which rely on the IMA
subsystem to enforce different secure boot modes. Since the
verification policy may differ based on the secure boot mode of the
system, the policies must be defined at runtime.

This patch implements arch-specific support to define IMA policy rules
based on the runtime secure boot mode of the system.

This patch provides arch-specific IMA policies if PPC_SECURE_BOOT
config is enabled.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-3-git-send-email-zohar@linux.ibm.com

powerpc: Detect the secure boot mode of the system

This patch defines a function to detect the secure boot state of a
PowerNV system.

The PPC_SECURE_BOOT config represents the base enablement of secure
boot for powerpc.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
[mpe: Fold in change from Nayna to add "ibm,secureboot" to ids]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/46b003b9-3225-6bf7-9101-ed6580bb748c@linux.ibm.com

powerpc: Don't flush caches when adding memory

This operation takes a significant amount of time when hotplugging
large amounts of memory (~50 seconds with 890GB of persistent memory).

This was orignally in commit fb5924fddf9e
("powerpc/mm: Flush cache on memory hot(un)plug") to support memtrace,
but the flush on add is not needed as it is flushed on remove.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-7-alastair@au1.ibm.com

powerpc: Chunk calls to flush_dcache_range in arch_*_memory

When presented with large amounts of memory being hotplugged
(in my test case, ~890GB), the call to flush_dcache_range takes
a while (~50 seconds), triggering RCU stalls.

This patch breaks up the call into 1GB chunks, calling
cond_resched() inbetween to allow the scheduler to run.

Fixes: fb5924fddf9e ("powerpc/mm: Flush cache on memory hot(un)plug")
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-6-alastair@au1.ibm.com

powerpc: Convert flush_icache_range & friends to C

Similar to commit 22e9c88d486a
("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
this patch converts the following ASM symbols to C:
    flush_icache_range()
    __flush_dcache_icache()
    __flush_dcache_icache_phys()

This was done as we discovered a long-standing bug where the length of the
range was truncated due to using a 32 bit shift instead of a 64 bit one.

By converting these functions to C, it becomes easier to maintain.

flush_dcache_icache_phys() retains a critical assembler section as we must
ensure there are no memory accesses while the data MMU is disabled
(authored by Christophe Leroy). Since this has no external callers, it has
also been made static, allowing the compiler to inline it within
flush_dcache_icache_page().

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[mpe: Minor fixups, don't export __flush_dcache_icache()]
Link: https://lore.kernel.org/r/20191104023305.9581-5-alastair@au1.ibm.com

powerpc: define helpers to get L1 icache sizes

This patch adds helpers to retrieve icache sizes, and renames the existing
helpers to make it clear that they are for dcache.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-4-alastair@au1.ibm.com

powerpc: Allow 64bit VDSO __kernel_sync_dicache to work across ranges >4GB

When calling __kernel_sync_dicache with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.

This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-3-alastair@au1.ibm.com

powerpc: Allow flush_icache_range to work across ranges >4GB

When calling flush_icache_range with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.

This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-2-alastair@au1.ibm.com

powerpc: Support CMDLINE_EXTEND

Bring powerpc in line with other architectures that support extending or
overriding the bootloader provided command line.

The current behaviour is most like CMDLINE_FROM_BOOTLOADER where the
bootloader command line is preferred but the kernel config can provide a
fallback so CMDLINE_FROM_BOOTLOADER is the default. CMDLINE_EXTEND can
be used to append the CMDLINE from the kernel config to the one provided
by the bootloader.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190801225006.21952-1-chris.packham@alliedtelesis.co.nz

powerpc/64s: Always disable branch profiling for prom_init.o

Otherwise the build fails because prom_init is calling symbols it's
not allowed to, eg:

Error: External symbol 'ftrace_likely_update' referenced from prom_init.c
make[3]: *** [arch/powerpc/kernel/Makefile:197: arch/powerpc/kernel/prom_init_check] Error 1

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191106051129.7626-1-mpe@ellerman.id.au

macintosh: ans-lcd: make anslcd_logo static and __initconst

This variable has no reason to have external linkage, and since it is
only used in an __init function, it might as well be made __initconst
also.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20181102211707.10229-1-linux@rasmusvillemoes.dk

powerpc/security: Fix debugfs data leak on 32-bit

"powerpc_security_features" is "unsigned long", i.e. 32-bit or 64-bit,
depending on the platform (PPC_FSL_BOOK3E or PPC_BOOK3S_64). Hence
casting its address to "u64 *", and calling debugfs_create_x64() is
wrong, and leaks 32-bit of nearby data to userspace on 32-bit platforms.

While all currently defined SEC_FTR_* security feature flags fit in
32-bit, they all have "ULL" suffixes to make them 64-bit constants.
Hence fix the leak by changing the type of "powerpc_security_features"
(and the parameter types of its accessors) to "u64". This also allows
to drop the cast.

Fixes: 398af571128fe75f ("powerpc/security: Show powerpc_security_features in debugfs")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191021142309.28105-1-geert+renesas@glider.be

powerpc/book3s64/hash: Add cond_resched to avoid soft lockup warning

With large memory (8TB and more) hotplug, we can get soft lockup
warnings as below. These were caused by a long loop without any
explicit cond_resched which is a problem for !PREEMPT kernels.

Avoid this using cond_resched() while inserting hash page table
entries. We already do similar cond_resched() in __add_pages(), see
commit f64ac5e6e306 ("mm, memory_hotplug: add scheduling point to
__add_pages").

  rcu:     3-....: (24002 ticks this GP) idle=13e/1/0x4000000000000002 softirq=722/722 fqs=12001
   (t=24003 jiffies g=4285 q=2002)
  NMI backtrace for cpu 3
  CPU: 3 PID: 3870 Comm: ndctl Not tainted 5.3.0-197.18-default+ #2
  Call Trace:
    dump_stack+0xb0/0xf4 (unreliable)
    nmi_cpu_backtrace+0x124/0x130
    nmi_trigger_cpumask_backtrace+0x1ac/0x1f0
    arch_trigger_cpumask_backtrace+0x28/0x3c
    rcu_dump_cpu_stacks+0xf8/0x154
    rcu_sched_clock_irq+0x878/0xb40
    update_process_times+0x48/0x90
    tick_sched_handle.isra.16+0x4c/0x80
    tick_sched_timer+0x68/0xe0
    __hrtimer_run_queues+0x180/0x430
    hrtimer_interrupt+0x110/0x300
    timer_interrupt+0x108/0x2f0
    decrementer_common+0x114/0x120
  --- interrupt: 901 at arch_add_memory+0xc0/0x130
      LR = arch_add_memory+0x74/0x130
    memremap_pages+0x494/0x650
    devm_memremap_pages+0x3c/0xa0
    pmem_attach_disk+0x188/0x750
    nvdimm_bus_probe+0xac/0x2c0
    really_probe+0x148/0x570
    driver_probe_device+0x19c/0x1d0
    device_driver_attach+0xcc/0x100
    bind_store+0x134/0x1c0
    drv_attr_store+0x44/0x60
    sysfs_kf_write+0x64/0x90
    kernfs_fop_write+0x1a0/0x270
    __vfs_write+0x3c/0x70
    vfs_write+0xd0/0x260
    ksys_write+0xdc/0x130
    system_call+0x5c/0x68

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191001084656.31277-1-aneesh.kumar@linux.ibm.com

powerpc/mm/book3s64/radix: Flush the full mm even when need_flush_all is set

With the previous patch, we should now not be using need_flush_all for
powerpc. But then make sure we force a PID tlbie flush with RIC=2 if
we ever find need_flush_all set. Also don't reset it after a mmu
gather flush.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024075801.22434-3-aneesh.kumar@linux.ibm.com

powerpc/mm/book3s64/radix: Use freed_tables instead of need_flush_all

With commit 22a61c3c4f13 ("asm-generic/tlb: Track freeing of
page-table directories in struct mmu_gather") we now track whether we
freed page table in mmu_gather. Use that to decide whether to flush
Page Walk Cache.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024075801.22434-2-aneesh.kumar@linux.ibm.com

powerpc/mm/book3s64/radix: Remove unused code.

mm_tlb_flush_nested change was added in the mmu gather tlb flush to
handle the case of parallel pte invalidate happening with mmap_sem
held in read mode. This fix was done by commit
02390f66bd23 ("powerpc/64s/radix: Fix MADV_[FREE|DONTNEED] TLB flush
miss problem with THP") and the problem is explained in detail in
commit 99baac21e458 ("mm: fix MADV_[FREE|DONTNEED] TLB flush miss
problem")

This was later updated by commit 7a30df49f63a ("mm: mmu_gather: remove
__tlb_reset_range() for force flush") to do a full mm flush rather
than a range flush. By commit dd2283f2605e ("mm: mmap: zap pages with
read mmap_sem in munmap") we are also now allowing a page table free
in mmap_sem read mode which means we should do a PWC flush too. Our
current full mm flush imply a PWC flush.

With all the above change the mm_tlb_flush_nested(mm) branch in
radix__tlb_flush will never be taken because for the nested case we
would have taken the if (tlb->fullmm) branch. This patch removes the
unused code. Also, remove the gflush change in
__radix__flush_tlb_range that was added to handle the range tlb flush
code. We only check for THP there because hugetlb is flushed via a
different code path where page size is explicitly specified.

This is a partial revert of commit 02390f66bd23 ("powerpc/64s/radix:
Fix MADV_[FREE|DONTNEED] TLB flush miss problem with THP")

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024075801.22434-1-aneesh.kumar@linux.ibm.com

powerpc/security/book3s64: Report L1TF status in sysfs

Some PowerPC CPUs are vulnerable to L1TF to the same extent as to
Meltdown. It is also mitigated by flushing the L1D on privilege
transition.

Currently the sysfs gives a false negative on L1TF on CPUs that I
verified to be vulnerable, a Power9 Talos II Boston 004e 1202, PowerNV
T2P9D01.

Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[mpe: Just have cpu_show_l1tf() call cpu_show_meltdown() directly]
Link: https://lore.kernel.org/r/20191029190759.84821-1-asteinhauser@google.com

powerpc/pseries: safely roll back failed DLPAR cpu add

dlpar_online_cpu() attempts to online all threads of a core that has
been added to an LPAR. If onlining a non-primary thread
fails (e.g. due to an allocation failure), the core is left with at
least one thread online. dlpar_cpu_add() attempts to roll back the
whole operation, releasing the core back to the platform. However,
since some threads of the core being removed are still online, the
BUG_ON(cpu_online(cpu)) in pseries_remove_processor() strikes:

LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
CPU: 3 PID: 8587 Comm: drmgr Not tainted 5.3.0-rc2-00190-g9b123d1ea237-dirty #46
NIP:  c0000000000eeb2c LR: c0000000000eeac4 CTR: c0000000000ee9e0
REGS: c0000001f745b6c0 TRAP: 0700   Not tainted  (5.3.0-rc2-00190-g9b123d1ea237-dirty)
MSR:  800000010282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]>  CR: 44002448  XER: 00000000
CFAR: c00000000195d718 IRQMASK: 0
GPR00: c0000000000eeac4 c0000001f745b950 c0000000032f6200 0000000000000008
GPR04: 0000000000000008 c000000003349c78 0000000000000040 00000000000001ff
GPR08: 0000000000000008 0000000000000000 0000000000000001 0007ffffffffffff
GPR12: 0000000084002844 c00000001ecacb80 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000008
GPR24: c000000003349ee0 c00000000334a2e4 c0000000fca4d7a8 c000000001d20048
GPR28: 0000000000000001 ffffffffffffffff ffffffffffffffff c0000000fca4d7c4
NIP [c0000000000eeb2c] pseries_smp_notifier+0x14c/0x2e0
LR [c0000000000eeac4] pseries_smp_notifier+0xe4/0x2e0
Call Trace:
[c0000001f745b950] [c0000000000eeac4] pseries_smp_notifier+0xe4/0x2e0 (unreliable)
[c0000001f745ba10] [c0000000001ac774] notifier_call_chain+0xb4/0x190
[c0000001f745bab0] [c0000000001ad62c] blocking_notifier_call_chain+0x7c/0xb0
[c0000001f745baf0] [c00000000167bda0] of_detach_node+0xc0/0x110
[c0000001f745bb50] [c0000000000e7ae4] dlpar_detach_node+0x64/0xa0
[c0000001f745bb80] [c0000000000edefc] dlpar_cpu_add+0x31c/0x360
[c0000001f745bc10] [c0000000000ee980] dlpar_cpu_probe+0x50/0xb0
[c0000001f745bc50] [c00000000002cf70] arch_cpu_probe+0x40/0x70
[c0000001f745bc70] [c000000000ccd808] cpu_probe_store+0x48/0x80
[c0000001f745bcb0] [c000000000cbcef8] dev_attr_store+0x38/0x60
[c0000001f745bcd0] [c00000000059c980] sysfs_kf_write+0x70/0xb0
[c0000001f745bd10] [c00000000059afb8] kernfs_fop_write+0xf8/0x280
[c0000001f745bd60] [c0000000004b437c] __vfs_write+0x3c/0x70
[c0000001f745bd80] [c0000000004b8710] vfs_write+0xd0/0x220
[c0000001f745bdd0] [c0000000004b8acc] ksys_write+0x7c/0x140
[c0000001f745be20] [c00000000000bbd8] system_call+0x5c/0x68

Move dlpar_offline_cpu() up in the file so that dlpar_online_cpu() can
use it to re-offline any threads that have been onlined when an error
is encountered.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: e666ae0b10aa ("powerpc/pseries: Update CPU hotplug error recovery")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191016183611.10867-3-nathanl@linux.ibm.com

powerpc/pseries: address checkpatch warnings in dlpar_offline_cpu

Remove some stray blank lines, convert a printk to pr_warn, and
address a line length violation.

One functional change: use WARN_ON instead of BUG_ON in case H_PROD of
a ceded thread yields an unexpected result from the platform. We can
expect this code path to get uninterruptibly stuck in __cpu_die() if
this happens, but that's more desirable than crashing.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: b6db63d1a7f0 ("pseries/pseries: Add code to online/offline CPUs of a DLPAR node")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191016183611.10867-2-nathanl@linux.ibm.com

selftests/powerpc: Skip tm-signal-sigreturn-nt if TM not available

On systems where TM (Transactional Memory) is disabled the
tm-signal-sigreturn-nt test causes a SIGILL:

  test: tm_signal_sigreturn_nt
  tags: git_version:7c202575ef63
  !! child died by signal 4
  failure: tm_signal_sigreturn_nt

We should skip the test if TM is not available.

Fixes: 34642d70ac7e ("selftests/powerpc: Add checks for transactional sigreturn")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104233524.24348-1-mpe@ellerman.id.au

Merge branch 'fixes' into next

Merge our fixes branch, primarily to bring in the powernv CPU hotplug
warning fix.

powerpc/tools: Don't quote $objdump in scripts

Some of our scripts are passed $objdump and then call it as
"$objdump". This doesn't work if it contains spaces because we're
using ccache, for example you get errors such as:

./arch/powerpc/tools/relocs_check.sh: line 48: ccache ppc64le-objdump: No such file or directory
./arch/powerpc/tools/unrel_branch_check.sh: line 26: ccache ppc64le-objdump: No such file or directory

Fix it by not quoting the string when we expand it, allowing the shell
to do the right thing for us.

Fixes: a71aa05e1416 ("powerpc: Convert relocs_check to a shell script using grep")
Fixes: 4ea80652dc75 ("powerpc/64s: Tool to flag direct branches from unrelocated interrupt vectors")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024004730.32135-1-mpe@ellerman.id.au

powerpc: Add build-time check of ptrace PT_xx defines

As part of the uapi we export a lot of PT_xx defines for each register
in struct pt_regs. These are expressed as an index from gpr[0], in
units of unsigned long.

Currently there's nothing tying the values of those defines to the
actual layout of the struct.

But we *don't* want to change the uapi defines to derive the PT_xx
values based on the layout of the struct, those values are ABI and
must never change.

Instead we want to do the reverse, make sure that the layout of the
struct never changes vs the PT_xx defines. So add build time checks of
that.

This probably seems paranoid, but at least once in the past someone
has sent a patch that would have broken the ABI if it hadn't been
spotted. Although it probably would have been detected via testing,
it's preferable to just quash any issues at the source.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191030111231.22720-1-mpe@ellerman.id.au

powerpc/ptrace: Add prototype for function pt_regs_check

`pt_regs_check` is a dummy function, its purpose is to break the build
if struct pt_regs and struct user_pt_regs don't match.

This function has no functionnal purpose, and will get eliminated at
link time or after init depending on CONFIG_LD_DEAD_CODE_DATA_ELIMINATION

This commit adds a prototype to fix warning at W=1:

arch/powerpc/kernel/ptrace.c:3339:13: error: no previous prototype for ‘pt_regs_check’ [-Werror=missing-prototypes]

Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20181208154624.6504-1-malat@debian.org

selftests/powerpc: Add a test of spectre_v2 mitigations

This test uses the PMU to count branch prediction hits/misses for a
known loop, and compare the result to the reported spectre v2
mitigation.

This gives us a way of sanity checking that the reported mitigation is
actually in effect.

Sample output for some cases, eg:

  Power9:
    sysfs reports: 'Vulnerable'
     PM_BR_PRED_CCACHE: result        368 running/enabled 5792777124
    PM_BR_MPRED_CCACHE: result        319 running/enabled 5792775546
     PM_BR_PRED_PCACHE: result 2147483281 running/enabled 5792773128
    PM_BR_MPRED_PCACHE: result  213604201 running/enabled 5792771640
    Miss percent 9 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

    sysfs reports: 'Mitigation: Indirect branch serialisation (kernel only)'
     PM_BR_PRED_CCACHE: result        895 running/enabled 5780320920
    PM_BR_MPRED_CCACHE: result        822 running/enabled 5780312414
     PM_BR_PRED_PCACHE: result 2147482754 running/enabled 5780308836
    PM_BR_MPRED_PCACHE: result  213639731 running/enabled 5780307912
    Miss percent 9 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

    sysfs reports: 'Mitigation: Indirect branch cache disabled'
     PM_BR_PRED_CCACHE: result 2147483649 running/enabled 20540186160
    PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 20540180056
     PM_BR_PRED_PCACHE: result          0 running/enabled 20540176090
    PM_BR_MPRED_PCACHE: result          0 running/enabled 20540174182
    Miss percent 100 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

  Power8:
    sysfs reports: 'Vulnerable'
     PM_BR_PRED_CCACHE: result 2147483649 running/enabled 3505888142
    PM_BR_MPRED_CCACHE: result          9 running/enabled 3505882788
    Miss percent 0 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

    sysfs reports: 'Mitigation: Indirect branch cache disabled'
     PM_BR_PRED_CCACHE: result 2147483649 running/enabled 16931421988
    PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 16931416478
    Miss percent 100 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.
    success: spectre_v2

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190520105520.22274-1-mpe@ellerman.id.au

powerpc/powernv: Fix CPU idle to be called with IRQs disabled

Commit e78a7614f3876 ("idle: Prevent late-arriving interrupts from
disrupting offline") changes arch_cpu_idle_dead to be called with
interrupts disabled, which triggers the WARN in pnv_smp_cpu_kill_self.

Fix this by fixing up irq_happened after hard disabling, rather than
requiring there are no pending interrupts, similarly to what was done
done until commit 2525db04d1cc5 ("powerpc/powernv: Simplify lazy IRQ
handling in CPU offline").

Fixes: e78a7614f3876 ("idle: Prevent late-arriving interrupts from disrupting offline")
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add unexpected_mask rather than checking for known bad values,
change the WARN_ON() to a WARN_ON_ONCE()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191022115814.22456-1-npiggin@gmail.com

selftests/powerpc: Fixup clobbers for TM tests

Some of our TM (Transactional Memory) tests, list "r1" (the stack
pointer) as a clobbered register.

GCC >= 9 doesn't accept this, and the build breaks:

  ptrace-tm-spd-tar.c: In function 'tm_spd_tar':
  ptrace-tm-spd-tar.c:31:2: error: listing the stack pointer register 'r1' in a clobber list is deprecated [-Werror=deprecated]
     31 |  asm __volatile__(
        |  ^~~
  ptrace-tm-spd-tar.c:31:2: note: the value of the stack pointer after an 'asm' statement must be the same as it was before the statement

We do have some fairly large inline asm blocks in these tests, and
some of them do change the value of r1. However they should all return
to C with the value in r1 restored, so I think it's legitimate to say
r1 is not clobbered.

As Segher points out, the r1 clobbers may have been added because of
the use of `or 1,1,1`, however that doesn't actually clobber r1.

Segher also points out that some of these tests do clobber LR, because
they call functions, and that is not listed in the clobbers, so add
that where appropriate.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191029095324.14669-1-mpe@ellerman.id.au

powerpc/prom_init: Undo relocation before entering secure mode

The ultravisor will do an integrity check of the kernel image but we
relocated it so the check will fail. Restore the original image by
relocating it back to the kernel virtual base address.

This works because during build vmlinux is linked with an expected
virtual runtime address of KERNELBASE.

Fixes: 6a9c930bd775 ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Michael Anderson <andmike@linux.ibm.com>
[mpe: Add IS_ENABLED() to fix the CONFIG_RELOCATABLE=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911163433.12822-1-bauerman@linux.ibm.com

powerpc/book3s64/hash: Use secondary hash for bolted mapping if the primary is full

With bolted hash page table entry, kernel currently only use primary hash group
when inserting the hash page table entry. In the rare case where kernel find all the
8 primary hash slot occupied by bolted entries, this can result in hash page
table insert failure for bolted entries. Avoid this by using the secondary hash
group.

This is different from what kernel does for the non-bolted mapping. With
non-bolted entries kernel will try secondary before removing an existing entry
from hash page table group. With bolted prefer primary hash group and hence
try to insert the page table entry by removing a slot from primary before trying
the secondary hash group.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024093542.29777-3-aneesh.kumar@linux.ibm.com

powerpc/pseries: Don't fail hash page table insert for bolted mapping

If the hypervisor returned H_PTEG_FULL for H_ENTER hcall, retry a hash page table
insert by removing a random entry from the group.

After some runtime, it is very well possible to find all the 8 hash page table
entry slot in the hpte group used for mapping. Don't fail a bolted entry insert
in that case. With Storage class memory a user can find this error easily since
a namespace enable/disable is equivalent to memory add/remove.

This results in failures as reported below:

$ ndctl create-namespace -r region1 -t pmem -m devdax -a 65536 -s 100M
libndctl: ndctl_dax_enable: dax1.3: failed to enable
Error: namespace1.2: failed to enable

failed to create namespace: No such device or address

In kernel log we find the details as below:

Unable to create mapping for hot added memory 0xc000042006000000..0xc00004200d000000: -1
dax_pmem: probe of dax1.3 failed with error -14

This indicates that we failed to create a bolted hash table entry for direct-map
address backing the namespace.

We also observe failures such that not all namespaces will be enabled with
ndctl enable-namespace all command.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024093542.29777-2-aneesh.kumar@linux.ibm.com

powerpc/pseries: Don't opencode HPTE_V_BOLTED

No functional change in this patch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024093542.29777-1-aneesh.kumar@linux.ibm.com

powerpc/pseries: Mark accumulate_stolen_time() as notrace

accumulate_stolen_time() is called prior to interrupt state being
reconciled, which can trip the warning in arch_local_irq_restore():

  WARNING: CPU: 5 PID: 1017 at arch/powerpc/kernel/irq.c:258 .arch_local_irq_restore+0x9c/0x130
  ...
  NIP .arch_local_irq_restore+0x9c/0x130
  LR  .rb_start_commit+0x38/0x80
  Call Trace:
    .ring_buffer_lock_reserve+0xe4/0x620
    .trace_function+0x44/0x210
    .function_trace_call+0x148/0x170
    .ftrace_ops_no_ops+0x180/0x1d0
    ftrace_call+0x4/0x8
    .accumulate_stolen_time+0x1c/0xb0
    decrementer_common+0x124/0x160

For now just mark it as notrace. We may change the ordering to call it
after interrupt state has been reconciled, but that is a larger
change.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024055932.27940-1-mpe@ellerman.id.au

powerpc/configs: Rename foo_basic_defconfig to foo_base.config

We have several "defconfigs" that are not actually full defconfigs
they are just a base set of options which are then merged with other
fragments to produce a working defconfig.

The most obvious example is corenet_basic_defconfig which only
contains one symbol CONFIG_CORENET_GENERIC=y. And in fact if you build
it as a "defconfig" that one symbol ends up undefined, because its
prerequisites are missing.

There is also mpc85xx_base_defconfig which doesn't actually enable
CONFIG_PPC_85xx.

To avoid confusion, rename these config fragments to "foo_base.config"
to make it clearer that they are not full defconfigs and are instaed
just fragments that are used to generate real defconfigs.

Reported-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190528081614.26096-1-mpe@ellerman.id.au

powerpc/configs: Add debug config fragment

Add a debug config fragment that we can use to put useful debug
options into.

It can be used like:
# make foo_defconfig
# make debug.config

Currently the only option included is to enable debugfs SCOM access.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Drop the special targets, just use the fragment directly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190801045855.5822-1-ajd@linux.ibm.com

powerpc/nvdimm: Update vmemmap_populated to check sub-section range

With commit: 7cc7867fb061 ("mm/devm_memremap_pages: enable sub-section remap")
pmem namespaces are remapped in 2M chunks. On architectures like ppc64 we
can map the memmap area using 16MB hugepage size and that can cover
a memory range of 16G.

While enabling new pmem namespaces, since memory is added in sub-section chunks,
before creating a new memmap mapping, kernel should check whether there is an
existing memmap mapping covering the new pmem namespace. Currently, this is
validated by checking whether the section covering the range is already
initialized or not. Considering there can be multiple namespaces in the same
section this can result in wrong validation. Update this to check for
sub-sections in the range. This is done by checking for all pfns in the range we
are mapping.

We could optimize this by checking only just one pfn in each sub-section. But
since this is not fast-path we keep this simple.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190917123851.22553-1-aneesh.kumar@linux.ibm.com

powerpc/xmon: Restrict when kernel is locked down

Xmon should be either fully or partially disabled depending on the
kernel lockdown state.

Put xmon into read-only mode for lockdown=integrity and prevent user
entry into xmon when lockdown=confidentiality. Xmon checks the lockdown
state on every attempted entry:

(1) during early xmon'ing

(2) when triggered via sysrq

(3) when toggled via debugfs

(4) when triggered via a previously enabled breakpoint

The following lockdown state transitions are handled:

(1) lockdown=none -> lockdown=integrity
     set xmon read-only mode

(2) lockdown=none -> lockdown=confidentiality
     clear all breakpoints, set xmon read-only mode,
     prevent user re-entry into xmon

(3) lockdown=integrity -> lockdown=confidentiality
     clear all breakpoints, set xmon read-only mode,
     prevent user re-entry into xmon

Suggested-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190907061124.1947-3-cmr@informatik.wtf

powerpc/xmon: Allow listing and clearing breakpoints in read-only mode

Read-only mode should not prevent listing and clearing any active
breakpoints.

Tested-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190907061124.1947-2-cmr@informatik.wtf

powerpc/powernv/eeh: Fix oops when probing cxl devices

Recent cleanup in the way EEH support is added to a device causes a
kernel oops when the cxl driver probes a device and creates virtual
devices discovered on the FPGA:

  BUG: Kernel NULL pointer dereference at 0x000000a0
  Faulting instruction address: 0xc000000000048070
  Oops: Kernel access of bad area, sig: 7 [#1]
  ...
  NIP eeh_add_device_late.part.9+0x50/0x1e0
  LR  eeh_add_device_late.part.9+0x3c/0x1e0
  Call Trace:
    _dev_info+0x5c/0x6c (unreliable)
    pnv_pcibios_bus_add_device+0x60/0xb0
    pcibios_bus_add_device+0x40/0x60
    pci_bus_add_device+0x30/0x100
    pci_bus_add_devices+0x64/0xd0
    cxl_pci_vphb_add+0xe0/0x130 [cxl]
    cxl_probe+0x504/0x5b0 [cxl]
    local_pci_probe+0x6c/0x110
    work_for_cpu_fn+0x38/0x60

The root cause is that those cxl virtual devices don't have a
representation in the device tree and therefore no associated pci_dn
structure. In eeh_add_device_late(), pdn is NULL, so edev is NULL and
we oops.

We never had explicit support for EEH for those virtual devices.
Instead, EEH events are reported to the (real) pci device and handled
by the cxl driver. Which can then forward to the virtual devices and
handle dependencies. The fact that we try adding EEH support for the
virtual devices is new and a side-effect of the recent cleanup.

This patch fixes it by skipping adding EEH support on powernv for
devices which don't have a pci_dn structure.

The cxl driver doesn't create virtual devices on pseries so this patch
doesn't fix it there intentionally.

Fixes: b905f8cdca77 ("powerpc/eeh: EEH for pSeries hot plug")
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191016162833.22509-1-fbarrat@linux.ibm.com

selftests/powerpc: Reduce sigfuz runtime to ~60s

The defaults for the sigfuz test is to run for 4000 iterations, but
that can take quite a while and the test harness may kill the test.
Reduce the number of iterations to 600, which gives a runtime of
roughly 1 minute on a Power8 system.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191013234643.3430-1-mpe@ellerman.id.au

powerpc/32s: fix allow/prevent_user_access() when crossing segment boundaries.

Make sure starting addr is aligned to segment boundary so that when
incrementing the segment, the starting address of the new segment is
below the end address. Otherwise the last segment might get missed.

Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/067a1b09f15f421d40797c2d04c22d4049a1cee8.1571071875.git.christophe.leroy@c-s.fr

Merge branch 'fixes' into next

Merge our fixes branch, to bring in the fixes for the KVM PCR bug and
the spufs crash.

powerpc/powernv: Add queue mechanism for early messages

When issuing a BMC soft poweroff during IPL, the poweroff can be lost
so the machine would not poweroff.

This is because opal messages can be received before the opal-power
code registered its notifiers.

Fix it by buffering messages. If we receive a message and do not yet
have a handler for that type, store the message and replay when a
handler for that type is registered.

Signed-off-by: Deb McLemore <debmc@linux.vnet.ibm.com>
[mpe: Single unlock path in opal_message_notifier_register(), tweak
comments/formatting and change log.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1526868278-4204-1-git-send-email-debmc@linux.vnet.ibm.com

powerpc/pkeys: remove unused pkey_allows_readwrite

pkey_allows_readwrite() was first introduced in the commit 5586cf61e108
("powerpc: introduce execute-only pkey"), but the usage was removed
entirely in the commit a4fcc877d4e1 ("powerpc/pkeys: Preallocate
execute-only key").

Found by the "-Wunused-function" compiler warning flag.

Fixes: a4fcc877d4e1 ("powerpc/pkeys: Preallocate execute-only key")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1568733750-14580-1-git-send-email-cai@lca.pw

powerpc/setup_64: fix -Wempty-body warnings

At the beginning of setup_64.c, it has,

  #ifdef DEBUG
  #define DBG(fmt...) udbg_printf(fmt)
  #else
  #define DBG(fmt...)
  #endif

where DBG() could be compiled away, and generate warnings,

  arch/powerpc/kernel/setup_64.c: In function 'initialize_cache_info':
  arch/powerpc/kernel/setup_64.c:579:49: warning: suggest braces around
  empty body in an 'if' statement [-Wempty-body]
      DBG("Argh, can't find dcache properties !\n");
                                                 ^
  arch/powerpc/kernel/setup_64.c:582:49: warning: suggest braces around
  empty body in an 'if' statement [-Wempty-body]
      DBG("Argh, can't find icache properties !\n");

Fix it by using the suggestions from Michael:

  "Neither of those sites should use DBG(), that's not really early
  boot code, they should just use pr_warn().

  And the other uses of DBG() in initialize_cache_info() should just
  be removed.

  In smp_release_cpus() the entry/exit DBG's should just be removed,
  and the spinning_secondaries line should just be pr_debug().

  That would just leave the two calls in early_setup(). If we taught
  udbg_printf() to return early when udbg_putc is NULL, then we could
  just call udbg_printf() unconditionally and get rid of the DBG macro
  entirely."

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Qian Cai <cai@lca.pw>
[mpe: Split udbg change out into previous patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1563215552-8166-1-git-send-email-cai@lca.pw

powerpc/udbg: Make it safe to call udbg_printf() always

Make udbg_printf() check if udbg_putc is set, and if not just return.
This makes it safe to call udbg_printf() anytime, even when a udbg
backend has not been registered, which means we can avoid some ifdefs
at call sites.

Signed-off-by: Qian Cai <cai@lca.pw>
[mpe: Split out of larger patch, write change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: make syntax for FADump config options in kernel/Makefile readable

arch/powerpc/kernel/fadump.c file needs to be compiled in if 'config
FA_DUMP' or 'config PRESERVE_FA_DUMP' is set. The current syntax
achieves that but looks a bit odd. Fix it for better readability.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/157063484064.11906.3586824898111397624.stgit@hbathini.in.ibm.com

powerpc/configs: add FADump awareness to skiroot_defconfig

FADump is supported on PowerNV platform. To fulfill this support, the
petitboot kernel must be FADump aware. Enable config PRESERVE_FA_DUMP
to make the petitboot kernel FADump aware.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/157062986936.23016.10146169203560084401.stgit@hbathini.in.ibm.com

spufs: fix a crash in spufs_create_root()

The spu_fs_context was not set in fc->fs_private, this caused a crash
when accessing ctx->mode in spufs_create_root().

Fixes: d2e0981c3b9a ("vfs: Convert spufs to use the new mount API")
Signed-off-by: Emmanuel Nicolet <emmanuel.nicolet@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20191008141342.GA266797@gmail.com

powerpc/papr_scm: Fix an off-by-one check in papr_scm_meta_{get, set}

A validation check to prevent out of bounds read/write inside
functions papr_scm_meta_{get,set}() is off-by-one that prevent reads
and writes to the last byte of the label area.

This bug manifests as a failure to probe a dimm when libnvdimm is
unable to read the entire config-area as advertised by
ND_CMD_GET_CONFIG_SIZE. This usually happens when there are large
number of namespaces created in the region backed by the dimm and the
label-index spans max possible config-area. An error of the form below
usually reported in the kernel logs:

[ 255.293912] nvdimm: probe of nmem0 failed with error -22

The patch fixes these validation checks there by letting libnvdimm
access the entire config-area.

Fixes: 53e80bd042773('powerpc/nvdimm: Add support for multibyte read/write for metadata')
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190927062002.3169-1-vaibhav@linux.ibm.com

powerpc/kvm: Fix kvmppc_vcore->in_guest value in kvmhv_switch_to_host

kvmhv_switch_to_host() in arch/powerpc/kvm/book3s_hv_rmhandlers.S
needs to set kvmppc_vcore->in_guest to 0 to signal secondary CPUs to
continue. This happens after resetting the PCR. Before commit
13c7bb3c57dc ("powerpc/64s: Set reserved PCR bits"), r0 would always
be 0 before it was stored to kvmppc_vcore->in_guest. However because
of this change in the commit:

          /* Reset PCR */
          ld      r0, VCORE_PCR(r5)
  -       cmpdi   r0, 0
  +       LOAD_REG_IMMEDIATE(r6, PCR_MASK)
  +       cmpld   r0, r6
          beq     18f
  -       li      r0, 0
  -       mtspr   SPRN_PCR, r0
  +       mtspr   SPRN_PCR, r6
   18:
          /* Signal secondary CPUs to continue */
          stb     r0,VCORE_IN_GUEST(r5)

We are no longer comparing r0 against 0 and loading it with 0 if it
contains something else. Hence when we store r0 to
kvmppc_vcore->in_guest, it might not be 0. This means that secondary
CPUs will not be signalled to continue. Those CPUs get stuck and
errors like the following are logged:

    KVM: CPU 1 seems to be stuck
    KVM: CPU 2 seems to be stuck
    KVM: CPU 3 seems to be stuck
    KVM: CPU 4 seems to be stuck
    KVM: CPU 5 seems to be stuck
    KVM: CPU 6 seems to be stuck
    KVM: CPU 7 seems to be stuck

This can be reproduced with:
    $ for i in `seq 1 7` ; do chcpu -d $i ; done ;
    $ taskset -c 0 qemu-system-ppc64 -smp 8,threads=8 \
       -M pseries,accel=kvm,kvm-type=HV -m 1G -nographic -vga none \
       -kernel vmlinux -initrd initrd.cpio.xz

Fix by making sure r0 is 0 before storing it to
kvmppc_vcore->in_guest.

Fixes: 13c7bb3c57dc ("powerpc/64s: Set reserved PCR bits")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191004025317.19340-1-jniethe5@gmail.com

selftests/powerpc: Fix compile error on tlbie_test due to newer gcc

Newer versions of GCC (>= 9) demand that the size of the string to be
copied must be explicitly smaller than the size of the destination.
Thus, the NULL char has to be taken into account on strncpy.

This will avoid the following compiling error:

  tlbie_test.c: In function 'main':
  tlbie_test.c:639:4: error: 'strncpy' specified bound 100 equals destination size
      strncpy(logdir, optarg, LOGDIR_NAME_SIZE);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191003211010.9711-1-desnesn@linux.ibm.com

powerpc/pseries: Remove confusing warning message.

Since commit 1211ee61b4a8 ("powerpc/pseries: Read TLB Block Invalidate
Characteristics"), a warning message is displayed when booting a guest
on top of KVM:

lpar: arch/powerpc/platforms/pseries/lpar.c pseries_lpar_read_hblkrm_characteristics Error calling get-system-parameter (0xfffffffd)

This message is displayed because this hypervisor is not supporting
the H_BLOCK_REMOVE hcall and thus is not exposing the corresponding
feature.

Reading the TLB Block Invalidate Characteristics should not be done if
the feature is not exposed.

Fixes: 1211ee61b4a8 ("powerpc/pseries: Read TLB Block Invalidate Characteristics")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191001132928.72555-1-ldufour@linux.ibm.com

powerpc/64s/radix: Fix build failure with RADIX_MMU=n

After merging the powerpc tree, today's linux-next build (powerpc64
allnoconfig) failed like this:

arch/powerpc/mm/book3s64/pgtable.c:216:3:
error: implicit declaration of function 'radix__flush_all_lpid_guest'

radix__flush_all_lpid_guest() is only declared for
CONFIG_PPC_RADIX_MMU which is not set for this build.

Fix it by adding an empty version for the RADIX_MMU=n case, which
should never be called.

Fixes: 99161de3a283 ("powerpc/64s/radix: tidy up TLB flushing code")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[mpe: Munge change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190930101342.36c1afa0@canb.auug.org.au

Linux 5.4-rc2

elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings

In commit 4ed28639519c ("fs, elf: drop MAP_FIXED usage from elf_map") we
changed elf to use MAP_FIXED_NOREPLACE instead of MAP_FIXED for the
executable mappings.

Then, people reported that it broke some binaries that had overlapping
segments from the same file, and commit ad55eac74f20 ("elf: enforce
MAP_FIXED on overlaying elf segments") re-instated MAP_FIXED for some
overlaying elf segment cases.  But only some - despite the summary line
of that commit, it only did it when it also does a temporary brk vma for
one obvious overlapping case.

Now Russell King reports another overlapping case with old 32-bit x86
binaries, which doesn't trigger that limited case.  End result: we had
better just drop MAP_FIXED_NOREPLACE entirely, and go back to MAP_FIXED.

Yes, it's a sign of old binaries generated with old tool-chains, but we
do pride ourselves on not breaking existing setups.

This still leaves MAP_FIXED_NOREPLACE in place for the load_elf_interp()
and the old load_elf_library() use-cases, because nobody has reported
breakage for those. Yet.

Note that in all the cases seen so far, the overlapping elf sections
seem to be just re-mapping of the same executable with different section
attributes.  We could possibly introduce a new MAP_FIXED_NOFILECHANGE
flag or similar, which acts like NOREPLACE, but allows just remapping
the same executable file using different protection flags.

It's not clear that would make a huge difference to anything, but if
people really hate that "elf remaps over previous maps" behavior, maybe
at least a more limited form of remapping would alleviate some concerns.

Alternatively, we should take a look at our elf_map() logic to see if we
end up not mapping things properly the first time.

In the meantime, this is the minimal "don't do that then" patch while
people hopefully think about it more.

Reported-by: Russell King <linux@armlinux.org.uk>
Fixes: 4ed28639519c ("fs, elf: drop MAP_FIXED usage from elf_map")
Fixes: ad55eac74f20 ("elf: enforce MAP_FIXED on overlaying elf segments")
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'dma-mapping-5.4-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping regression fix from Christoph Hellwig:
"Revert an incorret hunk from a patch that caused problems on various
arm boards (Andrey Smirnov)"

* tag 'dma-mapping-5.4-1' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: fix false positive warnings in dma_common_free_remap()

Merge tag 'armsoc-fixes' of git://git./linux/kernel/git/soc/soc

Pull ARM SoC fixes from Olof Johansson:
"A few fixes this time around:

   - Fixup of some clock specifications for DRA7 (device-tree fix)

   - Removal of some dead/legacy CPU OPP/PM code for OMAP that throws
     warnings at boot

   - A few more minor fixups for OMAPs, most around display

   - Enable STM32 QSPI as =y since their rootfs sometimes comes from
     there

   - Switch CONFIG_REMOTEPROC to =y since it went from tristate to bool

   - Fix of thermal zone definition for ux500 (5.4 regression)"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  ARM: multi_v7_defconfig: Fix SPI_STM32_QSPI support
  ARM: dts: ux500: Fix up the CPU thermal zone
  arm64/ARM: configs: Change CONFIG_REMOTEPROC from m to y
  ARM: dts: am4372: Set memory bandwidth limit for DISPC
  ARM: OMAP2+: Fix warnings with broken omap2_set_init_voltage()
  ARM: OMAP2+: Add missing LCDC midlemode for am335x
  ARM: OMAP2+: Fix missing reset done flag for am3 and am43
  ARM: dts: Fix gpio0 flags for am335x-icev2
  ARM: omap2plus_defconfig: Enable more droid4 devices as loadable modules
  ARM: omap2plus_defconfig: Enable DRM_TI_TFP410
  DTS: ARM: gta04: introduce legacy spi-cs-high to make display work again
  ARM: dts: Fix wrong clocks for dra7 mcasp
  clk: ti: dra7: Fix mcasp8 clock bits

Merge tag 'kbuild-fixes-v5.4' of git://git./linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

- remove unneeded ar-option and KBUILD_ARFLAGS

- remove long-deprecated SUBDIRS

- fix modpost to suppress false-positive warnings for UML builds

- fix namespace.pl to handle relative paths to ${objtree}, ${srctree}

- make setlocalversion work for /bin/sh

- make header archive reproducible

- fix some Makefiles and documents

* tag 'kbuild-fixes-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kheaders: make headers archive reproducible
  kbuild: update compile-test header list for v5.4-rc2
  kbuild: two minor updates for Documentation/kbuild/modules.rst
  scripts/setlocalversion: clear local variable to make it work for sh
  namespace: fix namespace.pl script to support relative paths
  video/logo: do not generate unneeded logo C files
  video/logo: remove unneeded *.o pattern from clean-files
  integrity: remove pointless subdir-$(CONFIG_...)
  integrity: remove unneeded, broken attempt to add -fshort-wchar
  modpost: fix static EXPORT_SYMBOL warnings for UML build
  kbuild: correct formatting of header in kbuild module docs
  kbuild: remove SUBDIRS support
  kbuild: remove ar-option and KBUILD_ARFLAGS

Merge tag 'scsi-fixes' of git://git./linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
"Twelve patches mostly small but obvious fixes or cosmetic but small
  updates"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qla2xxx: Fix Nport ID display value
  scsi: qla2xxx: Fix N2N link up fail
  scsi: qla2xxx: Fix N2N link reset
  scsi: qla2xxx: Optimize NPIV tear down process
  scsi: qla2xxx: Fix stale mem access on driver unload
  scsi: qla2xxx: Fix unbound sleep in fcport delete path.
  scsi: qla2xxx: Silence fwdump template message
  scsi: hisi_sas: Make three functions static
  scsi: megaraid: disable device when probe failed after enabled device
  scsi: storvsc: setup 1:1 mapping between hardware queue and CPU queue
  scsi: qedf: Remove always false 'tmp_prio < 0' statement
  scsi: ufs: skip shutdown if hba is not powered
  scsi: bnx2fc: Handle scope bits when array returns BUSY or TSF

Merge branch 'readdir' (readdir speedup and sanity checking)

This makes getdents() and getdents64() do sanity checking on the
pathname that it gives to user space.  And to mitigate the performance
impact of that, it first cleans up the way it does the user copying, so
that the code avoids doing the SMAP/PAN updates between each part of the
dirent structure write.

I really wanted to do this during the merge window, but didn't have
time.  The conversion of filldir to unsafe_put_user() is something I've
had around for years now in a private branch, but the extra pathname
checking finally made me clean it up to the point where it is mergable.

It's worth noting that the filename validity checking really should be a
bit smarter: it would be much better to delay the error reporting until
the end of the readdir, so that non-corrupted filenames are still
returned.  But that involves bigger changes, so let's see if anybody
actually hits the corrupt directory entry case before worrying about it
further.

* branch 'readdir':
  Make filldir[64]() verify the directory entry filename is valid
  Convert filldir[64]() from __put_user() to unsafe_put_user()

Make filldir[64]() verify the directory entry filename is valid

This has been discussed several times, and now filesystem people are
talking about doing it individually at the filesystem layer, so head
that off at the pass and just do it in getdents{64}().

This is partially based on a patch by Jann Horn, but checks for NUL
bytes as well, and somewhat simplified.

There's also commentary about how it might be better if invalid names
due to filesystem corruption don't cause an immediate failure, but only
an error at the end of the readdir(), so that people can still see the
filenames that are ok.

There's also been discussion about just how much POSIX strictly speaking
requires this since it's about filesystem corruption.  It's really more
"protect user space from bad behavior" as pointed out by Jann.  But
since Eric Biederman looked up the POSIX wording, here it is for context:

"From readdir:

   The readdir() function shall return a pointer to a structure
   representing the directory entry at the current position in the
   directory stream specified by the argument dirp, and position the
   directory stream at the next entry. It shall return a null pointer
   upon reaching the end of the directory stream. The structure dirent
   defined in the <dirent.h> header describes a directory entry.

  From definitions:

   3.129 Directory Entry (or Link)

   An object that associates a filename with a file. Several directory
   entries can associate names with the same file.

  ...

   3.169 Filename

   A name consisting of 1 to {NAME_MAX} bytes used to name a file. The
   characters composing the name may be selected from the set of all
   character values excluding the slash character and the null byte. The
   filenames dot and dot-dot have special meaning. A filename is
   sometimes referred to as a 'pathname component'."

Note that I didn't bother adding the checks to any legacy interfaces
that nobody uses.

Also note that if this ends up being noticeable as a performance
regression, we can fix that to do a much more optimized model that
checks for both NUL and '/' at the same time one word at a time.

We haven't really tended to optimize 'memchr()', and it only checks for
one pattern at a time anyway, and we really _should_ check for NUL too
(but see the comment about "soft errors" in the code about why it
currently only checks for '/')

See the CONFIG_DCACHE_WORD_ACCESS case of hash_name() for how the name
lookup code looks for pathname terminating characters in parallel.

Link: https://lore.kernel.org/lkml/20190118161440.220134-2-jannh@google.com/
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jann Horn <jannh@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Convert filldir[64]() from __put_user() to unsafe_put_user()

We really should avoid the "__{get,put}_user()" functions entirely,
because they can easily be mis-used and the original intent of being
used for simple direct user accesses no longer holds in a post-SMAP/PAN
world.

Manually optimizing away the user access range check makes no sense any
more, when the range check is generally much cheaper than the "enable
user accesses" code that the __{get,put}_user() functions still need.

So instead of __put_user(), use the unsafe_put_user() interface with
user_access_{begin,end}() that really does generate better code these
days, and which is generally a nicer interface.  Under some loads, the
multiple user writes that filldir() does are actually quite noticeable.

This also makes the dirent name copy use unsafe_put_user() with a couple
of macros.  We do not want to make function calls with SMAP/PAN
disabled, and the code this generates is quite good when the
architecture uses "asm goto" for unsafe_put_user() like x86 does.

Note that this doesn't bother with the legacy cases.  Nobody should use
them anyway, so performance doesn't really matter there.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge git://git./linux/kernel/git/netdev/net

Pull networking fixes from David Miller:

1) Fix ieeeu02154 atusb driver use-after-free, from Johan Hovold.

2) Need to validate TCA_CBQ_WRROPT netlink attributes, from Eric
    Dumazet.

3) txq null deref in mac80211, from Miaoqing Pan.

4) ionic driver needs to select NET_DEVLINK, from Arnd Bergmann.

5) Need to disable bh during nft_connlimit GC, from Pablo Neira Ayuso.

6) Avoid division by zero in taprio scheduler, from Vladimir Oltean.

7) Various xgmac fixes in stmmac driver from Jose Abreu.

8) Avoid 64-bit division in mlx5 leading to link errors on 32-bit from
    Michal Kubecek.

9) Fix bad VLAN check in rtl8366 DSA driver, from Linus Walleij.

10) Fix sleep while atomic in sja1105, from Vladimir Oltean.

11) Suspend/resume deadlock in stmmac, from Thierry Reding.

12) Various UDP GSO fixes from Josh Hunt.

13) Fix slab out of bounds access in tcp_zerocopy_receive(), from Eric
    Dumazet.

14) Fix OOPS in __ipv6_ifa_notify(), from David Ahern.

15) Memory leak in NFC's llcp_sock_bind, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits)
  selftests/net: add nettest to .gitignore
  net: qlogic: Fix memory leak in ql_alloc_large_buffers
  nfc: fix memory leak in llcp_sock_bind()
  sch_dsmark: fix potential NULL deref in dsmark_init()
  net: phy: at803x: use operating parameters from PHY-specific status
  net: phy: extract pause mode
  net: phy: extract link partner advertisement reading
  net: phy: fix write to mii-ctrl1000 register
  ipv6: Handle missing host route in __ipv6_ifa_notify
  net: phy: allow for reset line to be tied to a sleepy GPIO controller
  net: ipv4: avoid mixed n_redirects and rate_tokens usage
  r8152: Set macpassthru in reset_resume callback
  cxgb4:Fix out-of-bounds MSI-X info array access
  Revert "ipv6: Handle race in addrconf_dad_work"
  net: make sock_prot_memory_pressure() return "const char *"
  rxrpc: Fix rxrpc_recvmsg tracepoint
  qmi_wwan: add support for Cinterion CLS8 devices
  tcp: fix slab-out-of-bounds in tcp_zerocopy_receive()
  lib: textsearch: fix escapes in example code
  udp: only do GSO if # of segs > 1
  ...

Merge tag 's390-5.4-3' of git://git./linux/kernel/git/s390/linux

Pull s390 fixes from Vasily Gorbik:

- defconfig updates

- Fix build errors with CC_OPTIMIZE_FOR_SIZE due to usage of "i"
   constraint for function arguments. Two kvm changes acked-by Christian
   Borntraeger.

- Fix -Wunused-but-set-variable warnings in mm code.

- Avoid a constant misuse in qdio.

- Handle a case when cpumf is temporarily unavailable.

* tag 's390-5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  KVM: s390: mark __insn32_query() as __always_inline
  KVM: s390: fix __insn32_query() inline assembly
  s390: update defconfigs
  s390/pci: mark function(s) __always_inline
  s390/mm: mark function(s) __always_inline
  s390/jump_label: mark function(s) __always_inline
  s390/cpu_mf: mark function(s) __always_inline
  s390/atomic,bitops: mark function(s) __always_inline
  s390/mm: fix -Wunused-but-set-variable warnings
  s390: mark __cpacf_query() as __always_inline
  s390/qdio: clarify size of the QIB parm area
  s390/cpumf: Fix indentation in sampling device driver
  s390/cpumsf: Check for CPU Measurement sampling
  s390/cpumf: Use consistant debug print format

KVM: s390: mark __insn32_query() as __always_inline

__insn32_query() will not compile if the compiler decides to not
inline it, since it contains an inline assembly with an "i" constraint
with variable contents.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

KVM: s390: fix __insn32_query() inline assembly

The inline assembly constraints of __insn32_query() tell the compiler
that only the first byte of "query" is being written to. Intended was
probably that 32 bytes are written to.

Fix and simplify the code and just use a "memory" clobber.

Fixes: d668139718a9 ("KVM: s390: provide query function for instructions returning 32 byte")
Cc: stable@vger.kernel.org # v5.2+
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

dma-mapping: fix false positivse warnings in dma_common_free_remap()

Commit 5cf4537975bb ("dma-mapping: introduce a dma_common_find_pages
helper") changed invalid input check in dma_common_free_remap() from:

    if (!area || !area->flags != VM_DMA_COHERENT)

to

    if (!area || !area->flags != VM_DMA_COHERENT || !area->pages)

which seem to produce false positives for memory obtained via
dma_common_contiguous_remap()

This triggers the following warning message when doing "reboot" on ZII
VF610 Dev Board Rev B:

WARNING: CPU: 0 PID: 1 at kernel/dma/remap.c:112 dma_common_free_remap+0x88/0x8c
trying to free invalid coherent area: 9ef82980
Modules linked in:
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.3.0-rc6-next-20190820 #119
Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
Backtrace:
[<8010d1ec>] (dump_backtrace) from [<8010d588>] (show_stack+0x20/0x24)
r7:8015ed78 r6:00000009 r5:00000000 r4:9f4d9b14
[<8010d568>] (show_stack) from [<8077e3f0>] (dump_stack+0x24/0x28)
[<8077e3cc>] (dump_stack) from [<801197a0>] (__warn.part.3+0xcc/0xe4)
[<801196d4>] (__warn.part.3) from [<80119830>] (warn_slowpath_fmt+0x78/0x94)
r6:00000070 r5:808e540c r4:81c03048
[<801197bc>] (warn_slowpath_fmt) from [<8015ed78>] (dma_common_free_remap+0x88/0x8c)
r3:9ef82980 r2:808e53e0
r7:00001000 r6:a0b1e000 r5:a0b1e000 r4:00001000
[<8015ecf0>] (dma_common_free_remap) from [<8010fa9c>] (remap_allocator_free+0x60/0x68)
r5:81c03048 r4:9f4d9b78
[<8010fa3c>] (remap_allocator_free) from [<801100d0>] (__arm_dma_free.constprop.3+0xf8/0x148)
r5:81c03048 r4:9ef82900
[<8010ffd8>] (__arm_dma_free.constprop.3) from [<80110144>] (arm_dma_free+0x24/0x2c)
r5:9f563410 r4:80110120
[<80110120>] (arm_dma_free) from [<8015d80c>] (dma_free_attrs+0xa0/0xdc)
[<8015d76c>] (dma_free_attrs) from [<8020f3e4>] (dma_pool_destroy+0xc0/0x154)
r8:9efa8860 r7:808f02f0 r6:808f02d0 r5:9ef82880 r4:9ef82780
[<8020f324>] (dma_pool_destroy) from [<805525d0>] (ehci_mem_cleanup+0x6c/0x150)
r7:9f563410 r6:9efa8810 r5:00000000 r4:9efd0148
[<80552564>] (ehci_mem_cleanup) from [<80558e0c>] (ehci_stop+0xac/0xc0)
r5:9efd0148 r4:9efd0000
[<80558d60>] (ehci_stop) from [<8053c4bc>] (usb_remove_hcd+0xf4/0x1b0)
r7:9f563410 r6:9efd0074 r5:81c03048 r4:9efd0000
[<8053c3c8>] (usb_remove_hcd) from [<8056361c>] (host_stop+0x48/0xb8)
r7:9f563410 r6:9efd0000 r5:9f5f4040 r4:9f5f5040
[<805635d4>] (host_stop) from [<80563d0c>] (ci_hdrc_host_destroy+0x34/0x38)
r7:9f563410 r6:9f5f5040 r5:9efa8800 r4:9f5f4040
[<80563cd8>] (ci_hdrc_host_destroy) from [<8055ef18>] (ci_hdrc_remove+0x50/0x10c)
[<8055eec8>] (ci_hdrc_remove) from [<804a2ed8>] (platform_drv_remove+0x34/0x4c)
r7:9f563410 r6:81c4f99c r5:9efa8810 r4:9efa8810
[<804a2ea4>] (platform_drv_remove) from [<804a18a8>] (device_release_driver_internal+0xec/0x19c)
r5:00000000 r4:9efa8810
[<804a17bc>] (device_release_driver_internal) from [<804a1978>] (device_release_driver+0x20/0x24)
r7:9f563410 r6:81c41ed0 r5:9efa8810 r4:9f4a1dac
[<804a1958>] (device_release_driver) from [<804a01b8>] (bus_remove_device+0xdc/0x108)
[<804a00dc>] (bus_remove_device) from [<8049c204>] (device_del+0x150/0x36c)
r7:9f563410 r6:81c03048 r5:9efa8854 r4:9efa8810
[<8049c0b4>] (device_del) from [<804a3368>] (platform_device_del.part.2+0x20/0x84)
r10:9f563414 r9:809177e0 r8:81cb07dc r7:81c78320 r6:9f563454 r5:9efa8800
r4:9efa8800
[<804a3348>] (platform_device_del.part.2) from [<804a3420>] (platform_device_unregister+0x28/0x34)
r5:9f563400 r4:9efa8800
[<804a33f8>] (platform_device_unregister) from [<8055dce0>] (ci_hdrc_remove_device+0x1c/0x30)
r5:9f563400 r4:00000001
[<8055dcc4>] (ci_hdrc_remove_device) from [<805652ac>] (ci_hdrc_imx_remove+0x38/0x118)
r7:81c78320 r6:9f563454 r5:9f563410 r4:9f541010
[<8056538c>] (ci_hdrc_imx_shutdown) from [<804a2970>] (platform_drv_shutdown+0x2c/0x30)
[<804a2944>] (platform_drv_shutdown) from [<8049e4fc>] (device_shutdown+0x158/0x1f0)
[<8049e3a4>] (device_shutdown) from [<8013ac80>] (kernel_restart_prepare+0x44/0x48)
r10:00000058 r9:9f4d8000 r8:fee1dead r7:379ce700 r6:81c0b280 r5:81c03048
r4:00000000
[<8013ac3c>] (kernel_restart_prepare) from [<8013ad14>] (kernel_restart+0x1c/0x60)
[<8013acf8>] (kernel_restart) from [<8013af84>] (__do_sys_reboot+0xe0/0x1d8)
r5:81c03048 r4:00000000
[<8013aea4>] (__do_sys_reboot) from [<8013b0ec>] (sys_reboot+0x18/0x1c)
r8:80101204 r7:00000058 r6:00000000 r5:00000000 r4:00000000
[<8013b0d4>] (sys_reboot) from [<80101000>] (ret_fast_syscall+0x0/0x54)
Exception stack(0x9f4d9fa8 to 0x9f4d9ff0)
9fa0:                   00000000 00000000 fee1dead 28121969 01234567 379ce700
9fc0: 00000000 00000000 00000000 00000058 00000000 00000000 00000000 00016d04
9fe0: 00028e0c 7ec87c64 000135ec 76c1f410

Restore original invalid input check in dma_common_free_remap() to
avoid this problem.

Fixes: 5cf4537975bb ("dma-mapping: introduce a dma_common_find_pages helper")
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
[hch: just revert the offending hunk instead of creating a new helper]
Signed-off-by: Christoph Hellwig <hch@lst.de>

kheaders: make headers archive reproducible

In commit 43d8ce9d65a5 ("Provide in-kernel headers to make
extending kernel easier") a new mechanism was introduced, for kernels
>=5.2, which embeds the kernel headers in the kernel image or a module
and exposes them in procfs for use by userland tools.

The archive containing the header files has nondeterminism caused by
header files metadata. This patch normalizes the metadata and utilizes
KBUILD_BUILD_TIMESTAMP if provided and otherwise falls back to the
default behaviour.

In commit f7b101d33046 ("kheaders: Move from proc to sysfs") it was
modified to use sysfs and the script for generation of the archive was
renamed to what is being patched.

Signed-off-by: Dmitry Goldin <dgoldin+lkml@protonmail.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

kbuild: update compile-test header list for v5.4-rc2

Commit 6dc280ebeed2 ("coda: remove uapi/linux/coda_psdev.h") removed
a header in question. Some more build errors were fixed. Add more
headers into the test coverage.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

kbuild: two minor updates for Documentation/kbuild/modules.rst

Capitalize the first word in the sentence.

Use obj-m instead of obj-y. obj-y still works, but we have no built-in
objects in external module builds. So, obj-m is better IMHO.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/setlocalversion: clear local variable to make it work for sh

Geert Uytterhoeven reports a strange side-effect of commit 858805b336be
("kbuild: add $(BASH) to run scripts with bash-extension"), which
inserts the contents of a localversion file in the build directory twice.

[Steps to Reproduce]
  $ echo bar > localversion
  $ mkdir build
  $ cd build/
  $ echo foo > localversion
  $ make -s -f ../Makefile defconfig include/config/kernel.release
  $ cat include/config/kernel.release
  5.4.0-rc1foofoobar

This comes down to the behavior change of local variables.

The 'man sh' on my Ubuntu machine, where sh is an alias to dash,
explains as follows:
  When a variable is made local, it inherits the initial value and
  exported and readonly flags from the variable with the same name
  in the surrounding scope, if there is one. Otherwise, the variable
  is initially unset.

[Test Code]

  foo ()
  {
          local res
          echo "res: $res"
  }

  res=1
  foo

[Result]

  $ sh test.sh
  res: 1
  $ bash test.sh
  res:

So, scripts/setlocalversion correctly works only for bash in spite of
its hashbang being #!/bin/sh. Nobody had noticed it before because
CONFIG_SHELL was previously set to bash almost all the time.

Now that CONFIG_SHELL is set to sh, we must write portable and correct
code. I gave the Fixes tag to the commit that uncovered the issue.

Clear the variable 'res' in collect_files() to make it work for sh
(and it also works on distributions where sh is an alias to bash).

Fixes: 858805b336be ("kbuild: add $(BASH) to run scripts with bash-extension")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

namespace: fix namespace.pl script to support relative paths

The namespace.pl script does not work properly if objtree is not set to
an absolute path. The do_nm function is run from within the find
function, which changes directories.

Because of this, appending objtree, $File::Find::dir, and $source, will
return a path which is not valid from the current directory.

This used to work when objtree was set to an absolute path when using
"make namespacecheck". It appears to have not worked when calling
./scripts/namespace.pl directly.

This behavior was changed in 7e1c04779efd ("kbuild: Use relative path
for $(objtree)", 2014-05-14)

Rather than fixing the Makefile to set objtree to an absolute path, just
fix namespace.pl to work when srctree and objtree are relative. Also fix
the script to use an absolute path for these by default.

Use the File::Spec module for this purpose. It's been part of perl
5 since 5.005.

The curdir() function is used to get the current directory when the
objtree and srctree aren't set in the environment.

rel2abs() is used to convert possibly relative objtree and srctree
environment variables to absolute paths.

Finally, the catfile() function is used instead of string appending
paths together, since this is more robust when joining paths together.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

video/logo: do not generate unneeded logo C files

Currently, all the logo C files are generated irrespective of the
CONFIG options. Adding them to extra-y is wrong. What we need to do
here is to add them to 'targets' so that if_changed works properly.

Files listed in 'targets' are cleaned, so clean-files is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

video/logo: remove unneeded *.o pattern from clean-files

The pattern *.o is cleaned up globally by the top Makefile.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

integrity: remove pointless subdir-$(CONFIG_...)

The ima/ and evm/ sub-directories contain built-in objects, so
obj-$(CONFIG_...) is the correct way to descend into them.

subdir-$(CONFIG_...) is redundant.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

integrity: remove unneeded, broken attempt to add -fshort-wchar

I guess commit 15ea0e1e3e18 ("efi: Import certificates from UEFI Secure
Boot") attempted to add -fshort-wchar for building load_uefi.o, but it
has never worked as intended.

load_uefi.o is created in the platform_certs/ sub-directory. If you
really want to add -fshort-wchar, the correct code is:

$(obj)/platform_certs/load_uefi.o: KBUILD_CFLAGS += -fshort-wchar

But, you do not need to fix it.

Commit 8c97023cf051 ("Kbuild: use -fshort-wchar globally") had already
added -fshort-wchar globally. This code was unneeded in the first place.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

selftests/net: add nettest to .gitignore

nettest is missing from gitignore.

Fixes: acda655fefae ("selftests: Add nettest")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qlogic: Fix memory leak in ql_alloc_large_buffers

In ql_alloc_large_buffers, a new skb is allocated via netdev_alloc_skb.
This skb should be released if pci_dma_mapping_error fails.

Fixes: 0f8ab89e825f ("qla3xxx: Check return code from pci_map_single() in ql_release_to_lrg_buf_free_list(), ql_populate_free_queue(), ql_alloc_large_buffers(), and ql3xxx_send()")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfc: fix memory leak in llcp_sock_bind()

sysbot reported a memory leak after a bind() has failed.

While we are at it, abort the operation if kmemdup() has failed.

BUG: memory leak
unreferenced object 0xffff888105d83ec0 (size 32):
  comm "syz-executor067", pid 7207, jiffies 4294956228 (age 19.430s)
  hex dump (first 32 bytes):
    00 69 6c 65 20 72 65 61 64 00 6e 65 74 3a 5b 34  .ile read.net:[4
    30 32 36 35 33 33 30 39 37 5d 00 00 00 00 00 00  026533097]......
  backtrace:
    [<0000000036bac473>] kmemleak_alloc_recursive /./include/linux/kmemleak.h:43 [inline]
    [<0000000036bac473>] slab_post_alloc_hook /mm/slab.h:522 [inline]
    [<0000000036bac473>] slab_alloc /mm/slab.c:3319 [inline]
    [<0000000036bac473>] __do_kmalloc /mm/slab.c:3653 [inline]
    [<0000000036bac473>] __kmalloc_track_caller+0x169/0x2d0 /mm/slab.c:3670
    [<000000000cd39d07>] kmemdup+0x27/0x60 /mm/util.c:120
    [<000000008e57e5fc>] kmemdup /./include/linux/string.h:432 [inline]
    [<000000008e57e5fc>] llcp_sock_bind+0x1b3/0x230 /net/nfc/llcp_sock.c:107
    [<000000009cb0b5d3>] __sys_bind+0x11c/0x140 /net/socket.c:1647
    [<00000000492c3bbc>] __do_sys_bind /net/socket.c:1658 [inline]
    [<00000000492c3bbc>] __se_sys_bind /net/socket.c:1656 [inline]
    [<00000000492c3bbc>] __x64_sys_bind+0x1e/0x30 /net/socket.c:1656
    [<0000000008704b2a>] do_syscall_64+0x76/0x1a0 /arch/x86/entry/common.c:296
    [<000000009f4c57a4>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 30cc4587659e ("NFC: Move LLCP code to the NFC top level diirectory")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sch_dsmark: fix potential NULL deref in dsmark_init()

Make sure TCA_DSMARK_INDICES was provided by the user.

syzbot reported :

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8799 Comm: syz-executor235 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:nla_get_u16 include/net/netlink.h:1501 [inline]
RIP: 0010:dsmark_init net/sched/sch_dsmark.c:364 [inline]
RIP: 0010:dsmark_init+0x193/0x640 net/sched/sch_dsmark.c:339
Code: 85 db 58 0f 88 7d 03 00 00 e8 e9 1a ac fb 48 8b 9d 70 ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 04 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 ca
RSP: 0018:ffff88809426f3b8 EFLAGS: 00010247
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff85c6eb09
RDX: 0000000000000000 RSI: ffffffff85c6eb17 RDI: 0000000000000004
RBP: ffff88809426f4b0 R08: ffff88808c4085c0 R09: ffffed1015d26159
R10: ffffed1015d26158 R11: ffff8880ae930ac7 R12: ffff8880a7e96940
R13: dffffc0000000000 R14: ffff88809426f8c0 R15: 0000000000000000
FS: 0000000001292880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 000000008ca1b000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
qdisc_create+0x4ee/0x1210 net/sched/sch_api.c:1237
tc_modify_qdisc+0x524/0x1c50 net/sched/sch_api.c:1653
rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5223
netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5241
netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:657
___sys_sendmsg+0x803/0x920 net/socket.c:2311
__sys_sendmsg+0x105/0x1d0 net/socket.c:2356
__do_sys_sendmsg net/socket.c:2365 [inline]
__se_sys_sendmsg net/socket.c:2363 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440369

Fixes: 758cc43c6d73 ("[PKT_SCHED]: Fix dsmark to apply changes consistent")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge branch 'Fix-regression-with-AR8035-speed-downgrade'

Russell King says:

====================
Fix regression with AR8035 speed downgrade

The following series attempts to address an issue spotted by tinywrkb
with the AR8035 on the Cubox-i2 in a situation where the PHY downgrades
the negotiated link.

This is version 2, not much has changed other than rebasing on the
current net tree.  Changes have happend to patch 2 due to conflicts,
so I dropped Andrew's reviewed-by.  Minor context changes to patch 4
which I don't consider important enough to warrant dropping the
reviewed-by.

Before commit 5502b218e001 ("net: phy: use phy_resolve_aneg_linkmode in
genphy_read_status"), we would read not only the link partner's
advertisement, but also our own advertisement from the PHY registers,
and use both to derive the PHYs current link mode.  This works when the
AR8035 downgrades the speed, because it appears that the AR8035 clears
link mode bits in the advertisement registers as part of the downgrade.

Commentary: what is not yet known is whether the AR8035 restores the
            advertisement register when the link goes down to the
    previous state.

However, since the above referenced commit, we no longer use the PHYs
advertisement registers, instead converting the link partner's
advertisement to the ethtool link mode array, and combine that with
phylib's cached version of our advertisement - which is not updated on
speed downgrade.

This results in phylib disagreeing with the actual operating mode of
the PHY.

Commentary: I wonder how many more PHY drivers are broken by this
    commit, but have yet to be discovered.

The obvious way to address this would be to disable the downgrade
feature, and indeed this does fix the problem in tinywrkb's case - his
link partner instead downgrades the speed by reducing its
advertisement, resulting in phylib correctly evaluating a slower speed.

However, it has a serious drawback - the gigabit control register (MII
register 9) appears to become read only.  It seems the only way to
update the register is to re-enable the downgrade feature, reset the
PHY, changing register 9, disable the downgrade feature, and reset the
PHY again.

This series attempts to address the problem using a different approach,
similar to the approach taken with Marvell PHYs.  The AR8031, AR8033
and AR8035 have a PHY-Specific Status register which reports the
actual operating mode of the PHY - both speed and duplex.  This
register correctly reports the operating mode irrespective of whether
autoneg is enabled or not.  We use this register to fill in phylib's
speed and duplex parameters.

In detail:

Patch 1 fixes a bug where writing to register 9 does not update
phylib's advertisement mask in the same way that writing register 4
does; this looks like an omission from when gigabit PHY support came
into being.

Patch 2 seperates the generic phylib code which reads the link partners
advertisement from the PHY, so that we can re-use this in the Atheros
PHY driver.

Patch 3 seperates the generic phylib pause mode; phylib provides no
help for MAC drivers to ascertain the negotiated pause mode, it merely
copies the link partner's pause mode bits into its own variables.

Commentary: Both the aforementioned Atheros PHYs and Marvell PHYs
            provide the resolved pause modes in terms of whether
    we should transmit pause frames, or whether we should
    allow reception of pause frames.  Surely the resolution
    of this should be in phylib?

Patch 4 provides the Atheros PHY driver with a private "read_status"
implementation that fills in phylib's speed and duplex settings
depending on the PHY-Specific status register.  This ensures that
phylib and the MAC driver match the operating mode that the PHY has
decided to use.  Since the register also gives us MDIX status, we
can trivially fill that status in as well.

Note that, although the bits mentioned in this patch for this register
match those in th Marvell PHY driver, and it is located at the same
address, the meaning of other register bits varies between the PHYs.
Therefore, I do not feel that it would be appropriate to make this some
kind of generic function.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: at803x: use operating parameters from PHY-specific status

Read the PHY-specific status register for the current operating mode
(speed and duplex) of the PHY. This register reflects the actual
mode that the PHY has resolved depending on either the advertisements
of autoneg is enabled, or the forced mode if autoneg is disabled.

This ensures that phylib's software state always tracks the hardware
state.

It seems both AR8033 (which uses the AR8031 ID) and AR8035 support
this status register. AR8030 is not known at the present time.

This patch depends on "net: phy: extract pause mode" and "net: phy:
extract link partner advertisement reading".

Reported-by: tinywrkb <tinywrkb@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: tinywrkb <tinywrkb@gmail.com>
Fixes: 5502b218e001 ("net: phy: use phy_resolve_aneg_linkmode in genphy_read_status")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: extract pause mode

Extract the update of phylib's software pause mode state from
genphy_read_status(), so that we can re-use this functionality with
PHYs that have alternative ways to read the negotiation results.

Tested-by: tinywrkb <tinywrkb@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: extract link partner advertisement reading

Move reading the link partner advertisement out of genphy_read_status()
into its own separate function. This will allow re-use of this code by
PHY drivers that are able to read the resolved status from the PHY.

Tested-by: tinywrkb <tinywrkb@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: fix write to mii-ctrl1000 register

When userspace writes to the MII_ADVERTISE register, we update phylib's
advertising mask and trigger a renegotiation. However, writing to the
MII_CTRL1000 register, which contains the gigabit advertisement, does
neither. This can lead to phylib's copy of the advertisement becoming
de-synced with the values in the PHY register set, which can result in
incorrect negotiation resolution.

Fixes: 5502b218e001 ("net: phy: use phy_resolve_aneg_linkmode in genphy_read_status")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: Handle missing host route in __ipv6_ifa_notify

Rajendra reported a kernel panic when a link was taken down:

    [ 6870.263084] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
    [ 6870.271856] IP: [<ffffffff8efc5764>] __ipv6_ifa_notify+0x154/0x290

    <snip>

    [ 6870.570501] Call Trace:
    [ 6870.573238] [<ffffffff8efc58c6>] ? ipv6_ifa_notify+0x26/0x40
    [ 6870.579665] [<ffffffff8efc98ec>] ? addrconf_dad_completed+0x4c/0x2c0
    [ 6870.586869] [<ffffffff8efe70c6>] ? ipv6_dev_mc_inc+0x196/0x260
    [ 6870.593491] [<ffffffff8efc9c6a>] ? addrconf_dad_work+0x10a/0x430
    [ 6870.600305] [<ffffffff8f01ade4>] ? __switch_to_asm+0x34/0x70
    [ 6870.606732] [<ffffffff8ea93a7a>] ? process_one_work+0x18a/0x430
    [ 6870.613449] [<ffffffff8ea93d6d>] ? worker_thread+0x4d/0x490
    [ 6870.619778] [<ffffffff8ea93d20>] ? process_one_work+0x430/0x430
    [ 6870.626495] [<ffffffff8ea99dd9>] ? kthread+0xd9/0xf0
    [ 6870.632145] [<ffffffff8f01ade4>] ? __switch_to_asm+0x34/0x70
    [ 6870.638573] [<ffffffff8ea99d00>] ? kthread_park+0x60/0x60
    [ 6870.644707] [<ffffffff8f01ae77>] ? ret_from_fork+0x57/0x70
    [ 6870.650936] Code: 31 c0 31 d2 41 b9 20 00 08 02 b9 09 00 00 0

addrconf_dad_work is kicked to be scheduled when a device is brought
up. There is a race between addrcond_dad_work getting scheduled and
taking the rtnl lock and a process taking the link down (under rtnl).
The latter removes the host route from the inet6_addr as part of
addrconf_ifdown which is run for NETDEV_DOWN. The former attempts
to use the host route in __ipv6_ifa_notify. If the down event removes
the host route due to the race to the rtnl, then the BUG listed above
occurs.

Since the DAD sequence can not be aborted, add a check for the missing
host route in __ipv6_ifa_notify. The only way this should happen is due
to the previously mentioned race. The host route is created when the
address is added to an interface; it is only removed on a down event
where the address is kept. Add a warning if the host route is missing
AND the device is up; this is a situation that should never happen.

Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional")
Reported-by: Rajendra Dendukuri <rajendra.dendukuri@broadcom.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>