linux-toradex.git/mm, branch v4.15-rc8

kmemleak: allow to coexist with fault injection

2018-01-13T18:42:48+00:00

kmemleak does one slab allocation per user allocation.  So if slab fault
injection is enabled to any degree, kmemleak instantly fails to allocate
and turns itself off.  However, it's useful to use kmemleak with fault
injection to find leaks on error paths.  On the other hand, checking
kmemleak itself is not so useful because (1) it's a debugging tool and
(2) it has a very regular allocation pattern (basically a single
allocation site, so it either works or not).

Turn off fault injection for kmemleak allocations.

Link: http://lkml.kernel.org/r/20180109192243.19316-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov 
Cc: Catalin Marinas 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-01-07T01:13:21+00:00

Pull vfs fixes from Al Viro:

 - untangle sys_close() abuses in xt_bpf

 - deal with register_shrinker() failures in sget()

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'"
  sget(): handle failures of register_shrinker()
  mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.

mm/sparse.c: wrong allocation for mem_section

2018-01-05T00:45:09+00:00

In commit 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime
for CONFIG_SPARSEMEM_EXTREME=y") mem_section is allocated at runtime to
save memory.

It allocates the first dimension of array with sizeof(struct mem_section).

It costs extra memory, should be sizeof(struct mem_section *).

Fix it.

Link: http://lkml.kernel.org/r/1513932498-20350-1-git-send-email-bhe@redhat.com
Fixes: 83e3c48729 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y")
Signed-off-by: Baoquan He 
Tested-by: Dave Young 
Acked-by: Kirill A. Shutemov 
Cc: Kirill A. Shutemov 
Cc: Ingo Molnar 
Cc: Andy Lutomirski 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Atsushi Kumagai 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/zsmalloc.c: include fs.h

2018-01-05T00:45:09+00:00

`struct file_system_type' and alloc_anon_inode() function are defined in
fs.h, include it directly.

Link: http://lkml.kernel.org/r/20171219104219.3017-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky 
Cc: Minchan Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/debug.c: provide useful debugging information for VM_BUG

2018-01-05T00:45:09+00:00

With the recent addition of hashed kernel pointers, places which need to
produce useful debug output have to specify %px, not %p.  This patch
fixes all the VM debug to use %px.  This is appropriate because it's
debug output that the user should never be able to trigger, and kernel
developers need to see the actual pointers.

Link: http://lkml.kernel.org/r/20171219133236.GE13680@bombadil.infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Michal Hocko 
Cc: "Tobin C. Harding" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/mprotect: add a cond_resched() inside change_pmd_range()

2018-01-05T00:45:09+00:00

While testing on a large CPU system, detected the following RCU stall
many times over the span of the workload.  This problem is solved by
adding a cond_resched() in the change_pmd_range() function.

  INFO: rcu_sched detected stalls on CPUs/tasks:
   154-....: (670 ticks this GP) idle=022/140000000000000/0 softirq=2825/2825 fqs=612
   (detected by 955, t=6002 jiffies, g=4486, c=4485, q=90864)
  Sending NMI from CPU 955 to CPUs 154:
  NMI backtrace for cpu 154
  CPU: 154 PID: 147071 Comm: workload Not tainted 4.15.0-rc3+ #3
  NIP:  c0000000000b3f64 LR: c0000000000b33d4 CTR: 000000000000aa18
  REGS: 00000000a4b0fb44 TRAP: 0501   Not tainted  (4.15.0-rc3+)
  MSR:  8000000000009033   CR: 22422082  XER: 00000000
  CFAR: 00000000006cf8f0 SOFTE: 1
  GPR00: 0010000000000000 c00003ef9b1cb8c0 c0000000010cc600 0000000000000000
  GPR04: 8e0000018c32b200 40017b3858fd6e00 8e0000018c32b208 40017b3858fd6e00
  GPR08: 8e0000018c32b210 40017b3858fd6e00 8e0000018c32b218 40017b3858fd6e00
  GPR12: ffffffffffffffff c00000000fb25100
  NIP [c0000000000b3f64] plpar_hcall9+0x44/0x7c
  LR [c0000000000b33d4] pSeries_lpar_flush_hash_range+0x384/0x420
  Call Trace:
    flush_hash_range+0x48/0x100
    __flush_tlb_pending+0x44/0xd0
    hpte_need_flush+0x408/0x470
    change_protection_range+0xaac/0xf10
    change_prot_numa+0x30/0xb0
    task_numa_work+0x2d0/0x3e0
    task_work_run+0x130/0x190
    do_notify_resume+0x118/0x120
    ret_from_except_lite+0x70/0x74
  Instruction dump:
  60000000 f8810028 7ca42b78 7cc53378 7ce63b78 7d074378 7d284b78 7d495378
  e9410060 e9610068 e9810070 44000022 <7d806378> e9810028 f88c0000 f8ac0008

Link: http://lkml.kernel.org/r/20171214140551.5794-1-khandual@linux.vnet.ibm.com
Signed-off-by: Anshuman Khandual 
Suggested-by: Nicholas Piggin 
Acked-by: Michal Hocko 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: check pfn_valid first in zero_resv_unavail

2018-01-05T00:45:09+00:00

With latest kernel I get below bug while testing kdump:

  BUG: unable to handle kernel paging request at ffffea00034b1040
  IP: zero_resv_unavail+0xbd/0x126
  PGD 37b98067 P4D 37b98067 PUD 37b97067 PMD 0
  Oops: 0002 [#1] SMP
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 4.15.0-rc1+ #316
  Hardware name: LENOVO 20ARS1BJ02/20ARS1BJ02, BIOS GJET92WW (2.42 ) 03/03/2017
  task: ffffffff81a0e4c0 task.stack: ffffffff81a00000
  RIP: 0010:zero_resv_unavail+0xbd/0x126
  RSP: 0000:ffffffff81a03d88 EFLAGS: 00010006
  RAX: 0000000000000000 RBX: ffffea00034b1040 RCX: 0000000000000010
  RDX: 0000000000000000 RSI: 0000000000000092 RDI: ffffea00034b1040
  RBP: 00000000000d2c41 R08: 00000000000000c0 R09: 0000000000000a0d
  R10: 0000000000000002 R11: 0000000000007f01 R12: ffffffff81a03d90
  R13: ffffea0000000000 R14: 0000000000000063 R15: 0000000000000062
  FS:  0000000000000000(0000) GS:ffffffff81c73000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffea00034b1040 CR3: 0000000037609000 CR4: 00000000000606b0
  Call Trace:
   ? free_area_init_nodes+0x640/0x664
   ? zone_sizes_init+0x58/0x72
   ? setup_arch+0xb50/0xc6c
   ? start_kernel+0x64/0x43d
   ? secondary_startup_64+0xa5/0xb0
  Code: c1 e8 0c 48 39 d8 76 27 48 89 de 48 c1 e3 06 48 c7 c7 7a 87 79 81 e8 b0 c0 3e ff 4c 01 eb b9 10 00 00 00 31 c0 48 89 df 49 ff c6  ab eb bc 6a 00 49 c7 c0 f0 93 d1 81 31 d2 83 ce ff 41 54 49
  RIP: zero_resv_unavail+0xbd/0x126 RSP: ffffffff81a03d88
  CR2: ffffea00034b1040
  ---[ end trace f5ba9e8f73c7ee26 ]---

This is introduced by commit a4a3ede2132a ("mm: zero reserved and
unavailable struct pages").

The reason is some efi reserved boot ranges is not reported in E820 ram.
In my case it is a bgrt buffer:

  efi: mem00: [Boot Data          |RUN|  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x00000000d2c41000-0x00000000d2c85fff] (0MB)

Use "add_efi_memmap" can workaround the problem with another fix:

  http://lkml.kernel.org/r/20171130052327.GA3500@dhcp-128-65.nay.redhat.com

In zero_resv_unavail it would be better to check pfn_valid first before
zero the page struct.  This fixes the problem and potential other
similar problems.  Also as Pavel Tatashin suggested checks pfn_valid at
the beginning of the section.

The range is backed by real memory.  The memory range is efi "Boot
Service Data", that means after ExitBootServices() these ranges can be
used as system ram.  But some of them need to be reserved, for example
the bgrt image address in an acpi table, if the image memory is freed
then kexec reboot will fail because kexec inherit same acpi table to
initialize the driver.

Link: http://lkml.kernel.org/r/20171201095048.GA3084@dhcp-128-65.nay.redhat.com
Fixes: a4a3ede2132a ("mm: zero reserved and unavailable struct pages")
Signed-off-by: Dave Young 
Cc: Michal Hocko 
Cc: Pavel Tatashin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2017-12-21T19:13:37+00:00

Pull block fixes from Jens Axboe:
 "It's been a few weeks, so here's a small collection of fixes that
  should go into the current series.

  This contains:

   - NVMe pull request from Christoph, with a few important fixes.

   - kyber hang fix from Omar.

   - A blk-throttl fix from Shaohua, fixing a case where we double
     charge a bio.

   - Two call_single_data alignment fixes from me, fixing up some
     unfortunate changes that went into 4.14 without being properly
     reviewed on the block side (since nobody was CC'ed on the
     patch...).

   - A bounce buffer fix in two parts, one from me and one from Ming.

   - Revert bdi debug error handling patch. It's causing boot issues for
     some folks, and a week down the line, we're still no closer to a
     fix. Revert this patch for now until it's figured out, then we can
     retry for 4.16"

* 'for-linus' of git://git.kernel.dk/linux-block:
  Revert "bdi: add error handle for bdi_debug_register"
  null_blk: unalign call_single_data
  block: unalign call_single_data in struct request
  block-throttle: avoid double charge
  block: fix blk_rq_append_bio
  block: don't let passthrough IO go into .make_request_fn()
  nvme: setup streams after initializing namespace head
  nvme: check hw sectors before setting chunk sectors
  nvme: call blk_integrity_unregister after queue is cleaned up
  nvme-fc: remove double put reference if admin connect fails
  nvme: set discard_alignment to zero
  kyber: fix another domain token wait queue hang

Revert "bdi: add error handle for bdi_debug_register"

2017-12-21T17:01:30+00:00

This reverts commit a0747a859ef6d3cc5b6cd50eb694499b78dd0025.

It breaks some booting for some users, and more than a week
into this, there's still no good fix. Revert this commit
for now until a solution has been found.

Reported-by: Laura Abbott 
Reported-by: Bruno Wolff III 
Signed-off-by: Jens Axboe

mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.

2017-12-18T20:03:09+00:00

Syzbot caught an oops at unregister_shrinker() because combination of
commit 1d3d4437eae1bb29 ("vmscan: per-node deferred work") and fault
injection made register_shrinker() fail and the caller of
register_shrinker() did not check for failure.

----------
[  554.881422] FAULT_INJECTION: forcing a failure.
[  554.881422] name failslab, interval 1, probability 0, space 0, times 0
[  554.881438] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
[  554.881443] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  554.881445] Call Trace:
[  554.881459]  dump_stack+0x194/0x257
[  554.881474]  ? arch_local_irq_restore+0x53/0x53
[  554.881486]  ? find_held_lock+0x35/0x1d0
[  554.881507]  should_fail+0x8c0/0xa40
[  554.881522]  ? fault_create_debugfs_attr+0x1f0/0x1f0
[  554.881537]  ? check_noncircular+0x20/0x20
[  554.881546]  ? find_next_zero_bit+0x2c/0x40
[  554.881560]  ? ida_get_new_above+0x421/0x9d0
[  554.881577]  ? find_held_lock+0x35/0x1d0
[  554.881594]  ? __lock_is_held+0xb6/0x140
[  554.881628]  ? check_same_owner+0x320/0x320
[  554.881634]  ? lock_downgrade+0x990/0x990
[  554.881649]  ? find_held_lock+0x35/0x1d0
[  554.881672]  should_failslab+0xec/0x120
[  554.881684]  __kmalloc+0x63/0x760
[  554.881692]  ? lock_downgrade+0x990/0x990
[  554.881712]  ? register_shrinker+0x10e/0x2d0
[  554.881721]  ? trace_event_raw_event_module_request+0x320/0x320
[  554.881737]  register_shrinker+0x10e/0x2d0
[  554.881747]  ? prepare_kswapd_sleep+0x1f0/0x1f0
[  554.881755]  ? _down_write_nest_lock+0x120/0x120
[  554.881765]  ? memcpy+0x45/0x50
[  554.881785]  sget_userns+0xbcd/0xe20
(...snipped...)
[  554.898693] kasan: CONFIG_KASAN_INLINE enabled
[  554.898724] kasan: GPF could be caused by NULL-ptr deref or user memory access
[  554.898732] general protection fault: 0000 [#1] SMP KASAN
[  554.898737] Dumping ftrace buffer:
[  554.898741]    (ftrace buffer empty)
[  554.898743] Modules linked in:
[  554.898752] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
[  554.898755] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  554.898760] task: ffff8801d1dbe5c0 task.stack: ffff8801c9e38000
[  554.898772] RIP: 0010:__list_del_entry_valid+0x7e/0x150
[  554.898775] RSP: 0018:ffff8801c9e3f108 EFLAGS: 00010246
[  554.898780] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  554.898784] RDX: 0000000000000000 RSI: ffff8801c53c6f98 RDI: ffff8801c53c6fa0
[  554.898788] RBP: ffff8801c9e3f120 R08: 1ffff100393c7d55 R09: 0000000000000004
[  554.898791] R10: ffff8801c9e3ef70 R11: 0000000000000000 R12: 0000000000000000
[  554.898795] R13: dffffc0000000000 R14: 1ffff100393c7e45 R15: ffff8801c53c6f98
[  554.898800] FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
[  554.898804] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[  554.898807] CR2: 00000000dbc23000 CR3: 00000001c7269000 CR4: 00000000001406e0
[  554.898813] DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
[  554.898816] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
[  554.898818] Call Trace:
[  554.898828]  unregister_shrinker+0x79/0x300
[  554.898837]  ? perf_trace_mm_vmscan_writepage+0x750/0x750
[  554.898844]  ? down_write+0x87/0x120
[  554.898851]  ? deactivate_super+0x139/0x1b0
[  554.898857]  ? down_read+0x150/0x150
[  554.898864]  ? check_same_owner+0x320/0x320
[  554.898875]  deactivate_locked_super+0x64/0xd0
[  554.898883]  deactivate_super+0x141/0x1b0
----------

Since allowing register_shrinker() callers to call unregister_shrinker()
when register_shrinker() failed can simplify error recovery path, this
patch makes unregister_shrinker() no-op when register_shrinker() failed.
Also, reset shrinker->nr_deferred in case unregister_shrinker() was
by error called twice.

Signed-off-by: Tetsuo Handa 
Signed-off-by: Aliaksei Karaliou 
Reported-by: syzbot 
Cc: Glauber Costa 
Cc: Al Viro 
Signed-off-by: Al Viro