For skcipher algorithms, the input, output HW S/G tables
look like this: [IV, src][dst, IV]
Now, we can have 2 conditions here:
- there is no IV;
- src and dst are equal (in-place encryption) and scattered
and the error is an "off-by-one" in the HW S/G table.

This issue was seen with KASAN:
BUG: KASAN: slab-out-of-bounds in skcipher_edesc_alloc+0x95c/0x1018

Read of size 4 at addr ffff000022a02958 by task cryptomgr_test/321

CPU: 2 PID: 321 Comm: cryptomgr_test Not tainted
5.6.0-rc1-00165-ge4ef8383-dirty #4
Hardware name: LS1046A RDB Board (DT)
Call trace:
 dump_backtrace+0x0/0x260
 show_stack+0x14/0x20
 dump_stack+0xe8/0x144
 print_address_description.isra.11+0x64/0x348
 __kasan_report+0x11c/0x230
 kasan_report+0xc/0x18
 __asan_load4+0x90/0xb0
 skcipher_edesc_alloc+0x95c/0x1018
 skcipher_encrypt+0x84/0x150
 crypto_skcipher_encrypt+0x50/0x68
 test_skcipher_vec_cfg+0x4d4/0xc10
 test_skcipher_vec+0x178/0x1d8
 alg_test_skcipher+0xec/0x230
 alg_test.part.44+0x114/0x4a0
 alg_test+0x1c/0x60
 cryptomgr_test+0x34/0x58
 kthread+0x1b8/0x1c0
 ret_from_fork+0x10/0x18

Allocated by task 321:
 save_stack+0x24/0xb0
 __kasan_kmalloc.isra.10+0xc4/0xe0
 kasan_kmalloc+0xc/0x18
 __kmalloc+0x178/0x2b8
 skcipher_edesc_alloc+0x21c/0x1018
 skcipher_encrypt+0x84/0x150
 crypto_skcipher_encrypt+0x50/0x68
 test_skcipher_vec_cfg+0x4d4/0xc10
 test_skcipher_vec+0x178/0x1d8
 alg_test_skcipher+0xec/0x230
 alg_test.part.44+0x114/0x4a0
 alg_test+0x1c/0x60
 cryptomgr_test+0x34/0x58
 kthread+0x1b8/0x1c0
 ret_from_fork+0x10/0x18

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff000022a02800
 which belongs to the cache dma-kmalloc-512 of size 512
The buggy address is located 344 bytes inside of
 512-byte region [ffff000022a02800, ffff000022a02a00)
The buggy address belongs to the page:
page:fffffe00006a8000 refcount:1 mapcount:0 mapping:ffff00093200c400
index:0x0 compound_mapcount: 0
flags: 0xffff00000010200(slab|head)
raw: 0ffff00000010200 dead000000000100 dead000000000122 ffff00093200c400
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000022a02800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff000022a02880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff000022a02900: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                    ^
 ffff000022a02980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff000022a02a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 334d37c9

 ("crypto: caam - update IV using HW support")
Cc: <stable@vger.kernel.org> # v5.3+
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Here's the KASAN report:
BUG: KASAN: use-after-free in rsa_pub_done+0x70/0xe8
Read of size 1 at addr ffff000023082014 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc1-00162-gfcb90d5 #60
Hardware name: LS1046A RDB Board (DT)
Call trace:
 dump_backtrace+0x0/0x260
 show_stack+0x14/0x20
 dump_stack+0xe8/0x144
 print_address_description.isra.11+0x64/0x348
 __kasan_report+0x11c/0x230
 kasan_report+0xc/0x18
 __asan_load1+0x5c/0x68
 rsa_pub_done+0x70/0xe8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370
 irq_exit+0x114/0x128
 __handle_domain_irq+0x80/0xe0
 gic_handle_irq+0x50/0xa0
 el1_irq+0xb8/0x180
 cpuidle_enter_state+0xa4/0x490
 cpuidle_enter+0x48/0x70
 call_cpuidle+0x44/0x70
 do_idle+0x304/0x338
 cpu_startup_entry+0x24/0x40
 rest_init+0xf8/0x10c
 arch_call_rest_init+0xc/0x14
 start_kernel+0x774/0x7b4

Allocated by task 263:
 save_stack+0x24/0xb0
 __kasan_kmalloc.isra.10+0xc4/0xe0
 kasan_kmalloc+0xc/0x18
 __kmalloc+0x178/0x2b8
 rsa_edesc_alloc+0x2cc/0xe10
 caam_rsa_enc+0x9c/0x5f0
 test_akcipher_one+0x78c/0x968
 alg_test_akcipher+0x78/0xf8
 alg_test.part.44+0x114/0x4a0
 alg_test+0x1c/0x60
 cryptomgr_test+0x34/0x58
 kthread+0x1b8/0x1c0
 ret_from_fork+0x10/0x18

Freed by task 0:
 save_stack+0x24/0xb0
 __kasan_slab_free+0x10c/0x188
 kasan_slab_free+0x10/0x18
 kfree+0x7c/0x298
 rsa_pub_done+0x68/0xe8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370

The buggy address belongs to the object at ffff000023082000
 which belongs to the cache dma-kmalloc-256 of size 256
The buggy address is located 20 bytes inside of
 256-byte region [ffff000023082000, ffff000023082100)
The buggy address belongs to the page:
page:fffffe00006c2080 refcount:1 mapcount:0 mapping:ffff00093200c200 index:0x0 compound_mapcount: 0
flags: 0xffff00000010200(slab|head)
raw: 0ffff00000010200 dead000000000100 dead000000000122 ffff00093200c200
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000023081f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000023081f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff000023082000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff000023082080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff000023082100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: bf537950

 ("crypto: caam - add crypto_engine support for RSA algorithms")
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Here's the KASAN report:
BUG: KASAN: use-after-free in ahash_done+0xdc/0x3b8
Read of size 1 at addr ffff00002303f010 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc1-00162-gfcb90d5 #59
Hardware name: LS1046A RDB Board (DT)
Call trace:
 dump_backtrace+0x0/0x260
 show_stack+0x14/0x20
 dump_stack+0xe8/0x144
 print_address_description.isra.11+0x64/0x348
 __kasan_report+0x11c/0x230
 kasan_report+0xc/0x18
 __asan_load1+0x5c/0x68
 ahash_done+0xdc/0x3b8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370
 irq_exit+0x114/0x128
 __handle_domain_irq+0x80/0xe0
 gic_handle_irq+0x50/0xa0
 el1_irq+0xb8/0x180
 cpuidle_enter_state+0xa4/0x490
 cpuidle_enter+0x48/0x70
 call_cpuidle+0x44/0x70
 do_idle+0x304/0x338
 cpu_startup_entry+0x24/0x40
 rest_init+0xf8/0x10c
 arch_call_rest_init+0xc/0x14
 start_kernel+0x774/0x7b4

Allocated by task 263:
 save_stack+0x24/0xb0
 __kasan_kmalloc.isra.10+0xc4/0xe0
 kasan_kmalloc+0xc/0x18
 __kmalloc+0x178/0x2b8
 ahash_edesc_alloc+0x58/0x1f8
 ahash_final_no_ctx+0x94/0x6e8
 ahash_final+0x24/0x30
 crypto_ahash_op+0x58/0xb0
 crypto_ahash_final+0x30/0x40
 do_ahash_op+0x2c/0xa0
 test_ahash_vec_cfg+0x894/0x9e0
 test_hash_vec_cfg+0x6c/0x88
 test_hash_vec+0xfc/0x1e0
 __alg_test_hash+0x1ac/0x368
 alg_test_hash+0xf8/0x1c8
 alg_test.part.44+0x114/0x4a0
 alg_test+0x1c/0x60
 cryptomgr_test+0x34/0x58
 kthread+0x1b8/0x1c0
 ret_from_fork+0x10/0x18

Freed by task 0:
 save_stack+0x24/0xb0
 __kasan_slab_free+0x10c/0x188
 kasan_slab_free+0x10/0x18
 kfree+0x7c/0x298
 ahash_done+0xd4/0x3b8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370

The buggy address belongs to the object at ffff00002303f000
 which belongs to the cache dma-kmalloc-128 of size 128
The buggy address is located 16 bytes inside of
 128-byte region [ffff00002303f000, ffff00002303f080)
The buggy address belongs to the page:
page:fffffe00006c0fc0 refcount:1 mapcount:0 mapping:ffff00093200c000 index:0x0
flags: 0xffff00000000200(slab)
raw: 0ffff00000000200 dead000000000100 dead000000000122 ffff00093200c000
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff00002303ef00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff00002303ef80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff00002303f000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff00002303f080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff00002303f100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 21b014f0

 ("crypto: caam - add crypto_engine support for HASH algorithms")
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Here's the KASAN report:
BUG: KASAN: use-after-free in aead_crypt_done+0x60/0xd8
Read of size 1 at addr ffff00002303f014 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc1-00162-gfcb90d5 #58
Hardware name: LS1046A RDB Board (DT)
Call trace:
 dump_backtrace+0x0/0x260
 show_stack+0x14/0x20
 dump_stack+0xe8/0x144
 print_address_description.isra.11+0x64/0x348
 __kasan_report+0x11c/0x230
 kasan_report+0xc/0x18
 __asan_load1+0x5c/0x68
 aead_crypt_done+0x60/0xd8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370
 irq_exit+0x114/0x128
 __handle_domain_irq+0x80/0xe0
 gic_handle_irq+0x50/0xa0
 el1_irq+0xb8/0x180
 _raw_spin_unlock_irq+0x2c/0x78
 finish_task_switch+0xa4/0x2f8
 __schedule+0x3a4/0x890
 schedule_idle+0x28/0x50
 do_idle+0x22c/0x338
 cpu_startup_entry+0x24/0x40
 rest_init+0xf8/0x10c
 arch_call_rest_init+0xc/0x14
 start_kernel+0x774/0x7b4

Allocated by task 263:
 save_stack+0x24/0xb0
 __kasan_kmalloc.isra.10+0xc4/0xe0
 kasan_kmalloc+0xc/0x18
 __kmalloc+0x178/0x2b8
 aead_edesc_alloc+0x1b4/0xbf0
 ipsec_gcm_encrypt+0xd4/0x140
 crypto_aead_encrypt+0x50/0x68
 test_aead_vec_cfg+0x498/0xec0
 test_aead_vec+0x110/0x200
 alg_test_aead+0xfc/0x680
 alg_test.part.44+0x114/0x4a0
 alg_test+0x1c/0x60
 cryptomgr_test+0x34/0x58
 kthread+0x1b8/0x1c0
 ret_from_fork+0x10/0x18

Freed by task 0:
 save_stack+0x24/0xb0
 __kasan_slab_free+0x10c/0x188
 kasan_slab_free+0x10/0x18
 kfree+0x7c/0x298
 aead_crypt_done+0x58/0xd8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370

The buggy address belongs to the object at ffff00002303f000
 which belongs to the cache dma-kmalloc-128 of size 128
The buggy address is located 20 bytes inside of
 128-byte region [ffff00002303f000, ffff00002303f080)
The buggy address belongs to the page:
page:fffffe00006c0fc0 refcount:1 mapcount:0 mapping:ffff00093200c000 index:0x0
flags: 0xffff00000000200(slab)
raw: 0ffff00000000200 dead000000000100 dead000000000122 ffff00093200c000
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff00002303ef00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff00002303ef80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff00002303f000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff00002303f080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff00002303f100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 1c240226

 ("crypto: caam - add crypto_engine support for AEAD algorithms")
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Here's the KASAN report:
BUG: KASAN: use-after-free in skcipher_crypt_done+0xe8/0x1a8
Read of size 1 at addr ffff00002304001c by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc1-00162-gfcb90d5 #57
Hardware name: LS1046A RDB Board (DT)
Call trace:
 dump_backtrace+0x0/0x260
 show_stack+0x14/0x20
 dump_stack+0xe8/0x144
 print_address_description.isra.11+0x64/0x348
 __kasan_report+0x11c/0x230
 kasan_report+0xc/0x18
 __asan_load1+0x5c/0x68
 skcipher_crypt_done+0xe8/0x1a8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370
 irq_exit+0x114/0x128
 __handle_domain_irq+0x80/0xe0
 gic_handle_irq+0x50/0xa0
 el1_irq+0xb8/0x180
 _raw_spin_unlock_irq+0x2c/0x78
 finish_task_switch+0xa4/0x2f8
 __schedule+0x3a4/0x890
 schedule_idle+0x28/0x50
 do_idle+0x22c/0x338
 cpu_startup_entry+0x24/0x40
 rest_init+0xf8/0x10c
 arch_call_rest_init+0xc/0x14
 start_kernel+0x774/0x7b4

Allocated by task 263:
 save_stack+0x24/0xb0
 __kasan_kmalloc.isra.10+0xc4/0xe0
 kasan_kmalloc+0xc/0x18
 __kmalloc+0x178/0x2b8
 skcipher_edesc_alloc+0x21c/0x1018
 skcipher_encrypt+0x84/0x150
 crypto_skcipher_encrypt+0x50/0x68
 test_skcipher_vec_cfg+0x4d4/0xc10
 test_skcipher_vec+0xf8/0x1d8
 alg_test_skcipher+0xec/0x230
 alg_test.part.44+0x114/0x4a0
 alg_test+0x1c/0x60
 cryptomgr_test+0x34/0x58
 kthread+0x1b8/0x1c0
 ret_from_fork+0x10/0x18

Freed by task 0:
 save_stack+0x24/0xb0
 __kasan_slab_free+0x10c/0x188
 kasan_slab_free+0x10/0x18
 kfree+0x7c/0x298
 skcipher_crypt_done+0xe0/0x1a8
 caam_jr_dequeue+0x390/0x608
 tasklet_action_common.isra.13+0x1ec/0x230
 tasklet_action+0x24/0x30
 efi_header_end+0x1a4/0x370

The buggy address belongs to the object at ffff000023040000
 which belongs to the cache dma-kmalloc-512 of size 512
The buggy address is located 28 bytes inside of
 512-byte region [ffff000023040000, ffff000023040200)
The buggy address belongs to the page:
page:fffffe00006c1000 refcount:1 mapcount:0 mapping:ffff00093200c400 index:0x0 compound_mapcount: 0
flags: 0xffff00000010200(slab|head)
raw: 0ffff00000010200 dead000000000100 dead000000000122 ffff00093200c400
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff00002303ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff00002303ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff000023040000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff000023040080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff000023040100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: ee38767f

 ("crypto: caam - support crypto_engine framework for SKCIPHER algorithms")
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

This sorts the actual field names too, potentially causing even more
chaos and confusion at merge time if you have edited the MAINTAINERS
file.  But the end result is a more consistent layout, and hopefully
it's a one-time pain minimized by doing this just before the -rc1
release.

This was entirely scripted:

  ./scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS --order

Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

They are all supposed to be sorted, but people who add new entries don't
always know the alphabet.  Plus sometimes the entry names get edited,
and people don't then re-order the entry.

Let's see how painful this will be for merging purposes (the MAINTAINERS
file is often edited in various different trees), but Joe claims there's
relatively few patches in -next that touch this, and doing it just
before -rc1 is likely the best time.  Fingers crossed.

This was scripted with

  /scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS

but then I also ended up manually upper-casing a few entry names that
stood out when looking at the end result.

Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
 "A set of three patches to fix the fallout of the newly added split
  lock detection feature.

  It addressed the case where a KVM guest triggers a split lock #AC and
  KVM reinjects it into the guest which is not prepared to handle it.

  Add proper sanity checks which prevent the unconditional injection
  into the guest and handles the #AC on the host side in the same way as
  user space detections are handled. Depending on the detection mode it
  either warns and disables detection for the task or kills the task if
  the mode is set to fatal"

* tag 'x86-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest
  KVM: x86: Emulate split-lock access as a write in emulator
  x86/split_lock: Provide handle_guest_split_lock()

Pull time(keeping) updates from Thomas Gleixner:

 - Fix the time_for_children symlink in /proc/$PID/ so it properly
   reflects that it part of the 'time' namespace

 - Add the missing userns limit for the allowed number of time
   namespaces, which was half defined but the actual array member was
   not added. This went unnoticed as the array has an exessive empty
   member at the end but introduced a user visible regression as the
   output was corrupted.

 - Prevent further silent ucount corruption by adding a BUILD_BUG_ON()
   to catch half updated data.

* tag 'timers-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ucount: Make sure ucounts in /proc/sys/user don't regress again
  time/namespace: Add max_time_namespaces ucount
  time/namespace: Fix time_for_children symlink

Pull scheduler fixes/updates from Thomas Gleixner:

 - Deduplicate the average computations in the scheduler core and the
   fair class code.

 - Fix a raise between runtime distribution and assignement which can
   cause exceeding the quota by up to 70%.

 - Prevent negative results in the imbalanace calculation

 - Remove a stale warning in the workqueue code which can be triggered
   since the call site was moved out of preempt disabled code. It's a
   false positive.

 - Deduplicate the print macros for procfs

 - Add the ucmap values to the SCHED_DEBUG procfs output for completness

* tag 'sched-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Add task uclamp values to SCHED_DEBUG procfs
  sched/debug: Factor out printing formats into common macros
  sched/debug: Remove redundant macro define
  sched/core: Remove unused rq::last_load_update_tick
  workqueue: Remove the warning in wq_worker_sleeping()
  sched/fair: Fix negative imbalance in imbalance calculation
  sched/fair: Fix race between runtime distribution and assignment
  sched/fair: Align rq->avg_idle and rq->avg_scan_cost

Pull perf fixes from Thomas Gleixner:
 "Three fixes/updates for perf:

   - Fix the perf event cgroup tracking which tries to track the cgroup
     even for disabled events.

   - Add Ice Lake server support for uncore events

   - Disable pagefaults when retrieving the physical address in the
     sampling code"

* tag 'perf-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Disable page faults when getting phys address
  perf/x86/intel/uncore: Add Ice Lake server uncore support
  perf/cgroup: Correct indirection in perf_less_group_idx()
  perf/core: Fix event cgroup tracking

Pull locking fixes from Thomas Gleixner:
 "Three small fixes/updates for the locking core code:

   - Plug a task struct reference leak in the percpu rswem
     implementation.

   - Document the refcount interaction with PID_MAX_LIMIT

   - Improve the 'invalid wait context' data dump in lockdep so it
     contains all information which is required to decode the problem"

* tag 'locking-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Improve 'invalid wait context' splat
  locking/refcount: Document interaction with PID_MAX_LIMIT
  locking/percpu-rwsem: Fix a task_struct refcount

Pull cifs fixes from Steve French:
 "Ten cifs/smb fixes:

   - five RDMA (smbdirect) related fixes

   - add experimental support for swap over SMB3 mounts

   - also a fix which improves performance of signed connections"

* tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: enable swap on SMB3 mounts
  smb3: change noisy error message to FYI
  smb3: smbdirect support can be configured by default
  cifs: smbd: Do not schedule work to send immediate packet on every receive
  cifs: smbd: Properly process errors on ib_post_send
  cifs: Allocate crypto structures on the fly for calculating signatures of incoming packets
  cifs: smbd: Update receive credits before sending and deal with credits roll back on failure before sending
  cifs: smbd: Check send queue size before posting a send
  cifs: smbd: Merge code to track pending packets
  cifs: ignore cached share root handle closing errors

Pull NFS client bugfix from Trond Myklebust:
 "Fix an RCU read lock leakage in pnfs_alloc_ds_commits_list()"

* tag 'nfs-for-5.7-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  pNFS: Fix RCU lock leakage

Pull nios2 updates from Ley Foon Tan:

 - Remove nios2-dev@lists.rocketboards.org from MAINTAINERS

 - remove 'resetvalue' property

 - rename 'altr,gpio-bank-width' -> 'altr,ngpio'

 - enable the common clk subsystem on Nios2

* tag 'nios2-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  MAINTAINERS: Remove nios2-dev@lists.rocketboards.org
  arch: nios2: remove 'resetvalue' property
  arch: nios2: rename 'altr,gpio-bank-width' -> 'altr,ngpio'
  arch: nios2: Enable the common clk subsystem on Nios2

Pull dma-mapping fixes from Christoph Hellwig:

 - fix an integer truncation in dma_direct_get_required_mask
   (Kishon Vijay Abraham)

 - fix the display of dma mapping types (Grygorii Strashko)

* tag 'dma-mapping-5.7-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-debug: fix displaying of dma allocation type
  dma-direct: fix data truncation in dma_direct_get_required_mask()

Pull more Kbuild updates from Masahiro Yamada:

 - raise minimum supported binutils version to 2.23

 - remove old CONFIG_AS_* macros that we know binutils >= 2.23 supports

 - move remaining CONFIG_AS_* tests to Kconfig from Makefile

 - enable -Wtautological-compare warnings to catch more issues

 - do not support GCC plugins for GCC <= 4.7

 - fix various breakages of 'make xconfig'

 - include the linker version used for linking the kernel into
   LINUX_COMPILER, which is used for the banner, and also exposed to
   /proc/version

 - link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y, which
   allows us to remove the lib-ksyms.o workaround, and to solve the last
   known issue of the LLVM linker

 - add dummy tools in scripts/dummy-tools/ to enable all compiler tests
   in Kconfig, which will be useful for distro maintainers

 - support the single switch, LLVM=1 to use Clang and all LLVM utilities
   instead of GCC and Binutils.

 - support LLVM_IAS=1 to enable the integrated assembler, which is still
   experimental

* tag 'kbuild-v5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (36 commits)
  kbuild: fix comment about missing include guard detection
  kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
  kbuild: replace AS=clang with LLVM_IAS=1
  kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig
  kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y
  MIPS: fw: arc: add __weak to prom_meminit and prom_free_prom_memory
  kbuild: remove -I$(srctree)/tools/include from scripts/Makefile
  kbuild: do not pass $(KBUILD_CFLAGS) to scripts/mkcompile_h
  Documentation/llvm: fix the name of llvm-size
  kbuild: mkcompile_h: Include $LD version in /proc/version
  kconfig: qconf: Fix a few alignment issues
  kconfig: qconf: remove some old bogus TODOs
  kconfig: qconf: fix support for the split view mode
  kconfig: qconf: fix the content of the main widget
  kconfig: qconf: Change title for the item window
  kconfig: qconf: clean deprecated warnings
  gcc-plugins: drop support for GCC <= 4.7
  kbuild: Enable -Wtautological-compare
  x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2
  crypto: x86 - clean up poly1305-x86_64-cryptogams.S by 'make clean'
  ...

I do not longer work for credativ Germany.

Please, use my private email address instead.

This is for the case when people want to CC me on
patches sent from my old business email address.

Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Another brown paper bag moment. pnfs_alloc_ds_commits_list() is leaking
the RCU lock.

Fixes: a9901899

 ("pNFS: Add infrastructure for cleaning up per-layout commit structures")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Two types of #AC can be generated in Intel CPUs:
 1. legacy alignment check #AC
 2. split lock #AC

Reflect #AC back into the guest if the guest has legacy alignment checks
enabled or if split lock detection is disabled.

If the #AC is not a legacy one and split lock detection is enabled, then
invoke handle_guest_split_lock() which will either warn and disable split
lock detection for this task or force SIGBUS on it.

[ tglx: Switch it to handle_guest_split_lock() and rename the misnamed
  helper function. ]

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.176308876@linutronix.de

Emulate split-lock accesses as writes if split lock detection is on
to avoid #AC during emulation, which will result in a panic(). This
should never occur for a well-behaved guest, but a malicious guest can
manipulate the TLB to trigger emulation of a locked instruction[1].

More discussion can be found at [2][3].

[1] https://lkml.kernel.org/r/8c5b11c9-58df-38e7-a514-dc12d687b198@redhat.com
[2] https://lkml.kernel.org/r/20200131200134.GD18946@linux.intel.com
[3] https://lkml.kernel.org/r/20200227001117.GX9940@linux.intel.com

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.084300242@linutronix.de

Without at least minimal handling for split lock detection induced #AC,
VMX will just run into the same problem as the VMWare hypervisor, which
was reported by Kenneth.

It will inject the #AC blindly into the guest whether the guest is
prepared or not.

Provide a function for guest mode which acts depending on the host
SLD mode. If mode == sld_warn, treat it like user space, i.e. emit a
warning, disable SLD and mark the task accordingly. Otherwise force
SIGBUS.

 [ bp: Add a !CPU_SUP_INTEL stub for handle_guest_split_lock(). ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115516.978037132@linutronix.de
Link: https://lkml.kernel.org/r/20200402123258.895628824@linutronix.de

The keyword here is 'twice' to explain the trick.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Merge yet more updates from Andrew Morton:

 - Almost all of the rest of MM (memcg, slab-generic, slab, pagealloc,
   gup, hugetlb, pagemap, memremap)

 - Various other things (hfs, ocfs2, kmod, misc, seqfile)

* akpm: (34 commits)
  ipc/util.c: sysvipc_find_ipc() should increase position index
  kernel/gcov/fs.c: gcov_seq_next() should increase position index
  fs/seq_file.c: seq_read(): add info message about buggy .next functions
  drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings
  change email address for Pali Rohár
  selftests: kmod: test disabling module autoloading
  selftests: kmod: fix handling test numbers above 9
  docs: admin-guide: document the kernel.modprobe sysctl
  fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()
  kmod: make request_module() return an error when autoloading is disabled
  mm/memremap: set caching mode for PCI P2PDMA memory to WC
  mm/memory_hotplug: add pgprot_t to mhp_params
  powerpc/mm: thread pgprot_t through create_section_mapping()
  x86/mm: introduce __set_memory_prot()
  x86/mm: thread pgprot_t through init_memory_mapping()
  mm/memory_hotplug: rename mhp_restrictions to mhp_params
  mm/memory_hotplug: drop the flags field from struct mhp_restrictions
  mm/special: create generic fallbacks for pte_special() and pte_mkspecial()
  mm/vma: introduce VM_ACCESS_FLAGS
  mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS
  ...

Pull Documentation fixes from Jonathan Corbet:
 "A handful of late-arriving fixes for the documentation tree"

* tag 'docs-5.7-2' of git://git.lwn.net/linux:
  Documentation: android: binderfs: add 'stats' mount option
  Documentation: driver-api/usb/writing_usb_driver.rst Updates documentation links
  docs: driver-api: address duplicate label warning
  Documentation: sysrq: fix RST formatting
  docs: kernel-parameters.txt: Fix broken references
  docs: kernel-parameters.txt: Remove nompx
  docs: filesystems: fix typo in qnx6.rst

Pull orangefs updates from Mike Marshall:
 "A fix and two cleanups.

  Fix:

   - Christoph Hellwig noticed that some logic I added to
     orangefs_file_read_iter introduced a race condition, so he sent a
     reversion patch. I had to modify his patch since reverting at this
     point broke Orangefs.

  Cleanups:

   - Christoph Hellwig noticed that we were doing some unnecessary work
     in orangefs_flush, so he sent in a patch that removed the un-needed
     code.

   - Al Viro told me he had trouble building Orangefs. Orangefs should
     be easy to build, even for Al :-).

     I looked back at the test server build notes in orangefs.txt, just
     in case that's where the trouble really is, and found a couple of
     typos and made a couple of clarifications"

* tag 'for-linus-5.7-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: clarify build steps for test server in orangefs.txt
  orangefs: don't mess with I_DIRTY_TIMES in orangefs_flush
  orangefs: get rid of knob code...

Pull xtensa updates from Max Filippov:

 - replace setup_irq() by request_irq()

 - cosmetic fixes in xtensa Kconfig and boot/Makefile

* tag 'xtensa-20200410' of git://github.com/jcmvbkbc/linux-xtensa:
  arch/xtensa: fix grammar in Kconfig help text
  xtensa: remove meaningless export ccflags-y
  xtensa: replace setup_irq() by request_irq()

Pull more xen updates from Juergen Gross:

 - two cleanups

 - fix a boot regression introduced in this merge window

 - fix wrong use of memory allocation flags

* tag 'for-linus-5.7-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: fix booting 32-bit pv guest
  x86/xen: make xen_pvmmu_arch_setup() static
  xen/blkfront: fix memory allocation flags in blkfront_setup_indirect()
  xen: Use evtchn_type_t as a type for event channels

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <longman@redhat.com>
Link: http://lkml.kernel.org/r/f65c6ee7-bd00-f910-2f8a-37cc67e4ff88@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "seq_file .next functions should increase position index".

In Aug 2018 NeilBrown noticed commit 1f4aace6

 ("fs/seq_file.c:
simplify seq_file iteration code and interface")

"Some ->next functions do not increment *pos when they return NULL...
Note that such ->next functions are buggy and should be fixed.  A simple
demonstration is dd if=/proc/swaps bs=1000 skip=1 Choose any block size
larger than the size of /proc/swaps.  This will always show the whole
last line of /proc/swaps"

Described problem is still actual.  If you make lseek into middle of
last output line following read will output end of last line and whole
last line once again.

  $ dd if=/proc/swaps bs=1  # usual output
  Filename				Type		Size	Used	Priority
  /dev/dm-0                             partition	4194812	97536	-2
  104+0 records in
  104+0 records out
  104 bytes copied

  $ dd if=/proc/swaps bs=40 skip=1    # last line was generated twice
  dd: /proc/swaps: cannot skip to specified offset
  v/dm-0                                partition	4194812	97536	-2
  /dev/dm-0                             partition	4194812	97536	-2
  3+1 records in
  3+1 records out
  131 bytes copied

There are lot of other affected files, I've found 30+ including
/proc/net/ip_tables_matches and /proc/sysvipc/*

I've sent patches into maillists of affected subsystems already, this
patch-set fixes the problem in files related to pstore, tracing, gcov,
sysvipc and other subsystems processed via linux-kernel@ mailing list
directly

https://bugzilla.kernel.org/show_bug.cgi?id=206283

This patch (of 4):

Add debug code to seq_read() to detect missed or out-of-tree incorrect
.next seq_file functions.

[akpm@linux-foundation.org: s/pr_info/pr_info_ratelimited/, per Qian Cai]
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: NeilBrown <neilb@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Waiman Long <longman@redhat.com>
Link: http://lkml.kernel.org/r/244674e5-760c-86bd-d08a-047042881748@virtuozzo.com
Link: http://lkml.kernel.org/r/7c24087c-e280-e580-5b0c-0cdaeb14cd18@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Remove dev_err() messages after platform_get_irq*() failures.
platform_get_irq() already prints an error.

Generated by: scripts/coccinelle/api/platform_get_irq.cocci

Fixes: 6c41ac96

 ("dmaengine: tegra-apb: Support COMPILE_TEST")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2002271133450.2973@hadrien
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

For security reasons I stopped using gmail account and kernel address is
now up-to-date alias to my personal address.

People periodically send me emails to address which they found in source
code of drivers, so this change reflects state where people can contact
me.

[ Added .mailmap entry as per Joe Perches  - Linus ]
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200307104237.8199-1-pali@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Test that request_module() fails with -ENOENT when
/proc/sys/kernel/modprobe contains (a) a nonexistent path, and (b) an
empty path.

Case (b) is a regression test for the patch "kmod: make request_module()
return an error when autoloading is disabled".

Tested with 'kmod.sh -t 0010 && kmod.sh -t 0011', and also simply with
'kmod.sh' to run all kmod tests.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: NeilBrown <neilb@suse.com>
Link: http://lkml.kernel.org/r/20200312202552.241885-5-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

get_test_count() and get_test_enabled() were broken for test numbers
above 9 due to awk interpreting a field specification like '$0010' as
octal rather than decimal.  Fix it by stripping the leading zeroes.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: NeilBrown <neilb@suse.com>
Link: http://lkml.kernel.org/r/20200318230515.171692-5-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Document the kernel.modprobe sysctl in the same place that all the other
kernel.* sysctls are documented.  Make sure to mention how to use this
sysctl to completely disable module autoloading, and how this sysctl
relates to CONFIG_STATIC_USERMODEHELPER.

[ebiggers@google.com: v5]
  Link: http://lkml.kernel.org/r/20200318230515.171692-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: NeilBrown <neilb@suse.com>
Link: http://lkml.kernel.org/r/20200312202552.241885-4-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After request_module(), nothing is stopping the module from being
unloaded until someone takes a reference to it via try_get_module().

The WARN_ONCE() in get_fs_type() is thus user-reachable, via userspace
running 'rmmod' concurrently.

Since WARN_ONCE() is for kernel bugs only, not for user-reachable
situations, downgrade this warning to pr_warn_once().

Keep it printed once only, since the intent of this warning is to detect
a bug in modprobe at boot time.  Printing the warning more than once
wouldn't really provide any useful extra information.

Fixes: 41124db8

 ("fs: warn in case userspace lied about modprobe return")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jessica Yu <jeyu@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: NeilBrown <neilb@suse.com>
Cc: <stable@vger.kernel.org>		[4.13+]
Link: http://lkml.kernel.org/r/20200312202552.241885-3-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "module autoloading fixes and cleanups", v5.

This series fixes a bug where request_module() was reporting success to
kernel code when module autoloading had been completely disabled via
'echo > /proc/sys/kernel/modprobe'.

It also addresses the issues raised on the original thread
(https://lkml.kernel.org/lkml/20200310223731.126894-1-ebiggers@kernel.org/T/#u)
bydocumenting the modprobe sysctl, adding a self-test for the empty path
case, and downgrading a user-reachable WARN_ONCE().

This patch (of 4):

It's long been possible to disable kernel module autoloading completely
(while still allowing manual module insertion) by setting
/proc/sys/kernel/modprobe to the empty string.

This can be preferable to setting it to a nonexistent file since it
avoids the overhead of an attempted execve(), avoids potential
deadlocks, and avoids the call to security_kernel_module_request() and
thus on SELinux-based systems eliminates the need to write SELinux rules
to dontaudit module_request.

However, when module autoloading is disabled in this way,
request_module() returns 0.  This is broken because callers expect 0 to
mean that the module was successfully loaded.

Apparently this was never noticed because this method of disabling
module autoloading isn't used much, and also most callers don't use the
return value of request_module() since it's always necessary to check
whether the module registered its functionality or not anyway.

But improperly returning 0 can indeed confuse a few callers, for example
get_fs_type() in fs/filesystems.c where it causes a WARNING to be hit:

	if (!fs && (request_module("fs-%.*s", len, name) == 0)) {
		fs = __get_fs_type(name, len);
		WARN_ONCE(!fs, "request_module fs-%.*s succeeded, but still no fs?\n", len, name);
	}

This is easily reproduced with:

	echo > /proc/sys/kernel/modprobe
	mount -t NONEXISTENT none /

It causes:

	request_module fs-NONEXISTENT succeeded, but still no fs?
	WARNING: CPU: 1 PID: 1106 at fs/filesystems.c:275 get_fs_type+0xd6/0xf0
	[...]

This should actually use pr_warn_once() rather than WARN_ONCE(), since
it's also user-reachable if userspace immediately unloads the module.
Regardless, request_module() should correctly return an error when it
fails.  So let's make it return -ENOENT, which matches the error when
the modprobe binary doesn't exist.

I've also sent patches to document and test this case.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Ben Hutchings <benh@debian.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200310223731.126894-1-ebiggers@kernel.org
Link: http://lkml.kernel.org/r/20200312202552.241885-1-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PCI BAR IO memory should never be mapped as WB, however prior to this
the PAT bits were set WB and it was typically overridden by MTRR
registers set by the firmware.

Set PCI P2PDMA memory to be UC as this is what it currently, typically,
ends up being mapped as on x86 after the MTRR registers override the
cache setting.

Future use-cases may need to generalize this by adding flags to select
the caching type, as some P2PDMA cases may not want UC.  However, those
use-cases are not upstream yet and this can be changed when they arrive.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-8-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>