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  1. 21 Nov, 2021 1 commit
  3. 20 Nov, 2021 20 commits
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 923dcc5e
      Linus Torvalds authored 
      Merge misc fixes from Andrew Morton:
 "15 patches.

  Subsystems affected by this patch series: ipc, hexagon, mm (swap,
  slab-generic, kmemleak, hugetlb, kasan, damon, and highmem), and proc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  proc/vmcore: fix clearing user buffer by properly using clear_user()
  kmap_local: don't assume kmap PTEs are linear arrays in memory
  mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
  mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
  kasan: test: silence intentional read overflow warnings
  hugetlb, userfaultfd: fix reservation restore on userfaultfd error
  hugetlb: fix hugetlb cgroup refcounting during mremap
  mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag
  hexagon: ignore vmlinux.lds
  hexagon: clean up timer-regs.h
  hexagon: export raw I/O routines for modules
  mm: emit the "free" trace report before freeing memory in kmem_cache_free()
  shm: extend forced shm destroy to support objects from several IPC nses
  ipc: WARN if trying to remove ipc object which is absent
  mm/swap.c:put_pages_list(): reinitialise the page list
      923dcc5e
    • Linus Torvalds's avatar
      Merge tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-block · 61564e7b
      Linus Torvalds authored 
      Pull block fixes from Jens Axboe:

 - Flip a cap check to avoid a selinux error (Alistair)

 - Fix for a regression this merge window where we can miss a queue ref
   put (me)

 - Un-mark pstore-blk as broken, as the condition that triggered that
   change has been rectified (Kees)

 - Queue quiesce and sync fixes (Ming)

 - FUA insertion fix (Ming)

 - blk-cgroup error path put fix (Yu)

* tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-block:
  blk-mq: don't insert FUA request with data into scheduler queue
  blk-cgroup: fix missing put device in error path from blkg_conf_pref()
  block: avoid to quiesce queue in elevator_init_mq
  Revert "mark pstore-blk as broken"
  blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()
  block: fix missing queue put in error path
  block: Check ADMIN before NICE for IOPRIO_CLASS_RT
      61564e7b
    • Linus Torvalds's avatar
      Merge tag 'pinctrl-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl · b100274c
      Linus Torvalds authored 
      Pull pin control fixes from Linus Walleij:
 "There is an ACPI stubs fix which is ACKed by the ACPI maintainer for
  merging through my tree.

  One item stand out and that is that I delete the <linux/sdb.h> header
  that is used by nothing. I deleted this subsystem (through the GPIO
  tree) a while back so I feel responsible for tidying up the floor.

  Other than that it is the usual mistakes, a bit noisy around build
  issue and Kconfig then driver fixes.

  Specifics:

   - Fix some stubs causing compile issues for ACPI.

   - Fix some wakeups on AMD IRQs shared between GPIO and SCI.

   - Fix a build warning in the Tegra driver.

   - Fix a Kconfig issue in the Qualcomm driver.

   - Add a missing include the RALink driver.

   - Return a valid type for the Apple pinctrl IRQs.

   - Implement some Qualcomm SDM845 dual-edge errata.

   - Remove the unused <linux/sdb.h> header. (The subsystem was once
     deleted by the pinctrl maintainer...)

   - Fix a duplicate initialized in the Tegra driver.

   - Fix register offsets for UFS and SDC in the Qualcomm SM8350 driver"

* tag 'pinctrl-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: qcom: sm8350: Correct UFS and SDC offsets
  pinctrl: tegra194: remove duplicate initializer again
  Remove unused header <linux/sdb.h>
  pinctrl: qcom: sdm845: Enable dual edge errata
  pinctrl: apple: Always return valid type in apple_gpio_irq_type
  pinctrl: ralink: include 'ralink_regs.h' in 'pinctrl-mt7620.c'
  pinctrl: qcom: fix unmet dependencies on GPIOLIB for GPIOLIB_IRQCHIP
  pinctrl: tegra: Return const pointer from tegra_pinctrl_get_group()
  pinctrl: amd: Fix wakeups when IRQ is shared with SCI
  ACPI: Add stubs for wakeup handler functions
      b100274c
    • Linus Torvalds's avatar
      Merge tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · 6b38e2fb
      Linus Torvalds authored 
      Pull s390 updates from Heiko Carstens:

 - Add missing Kconfig option for ftrace direct multi sample, so it can
   be compiled again, and also add s390 support for this sample.

 - Update Christian Borntraeger's email address.

 - Various fixes for memory layout setup. Besides other this makes it
   possible to load shared DCSS segments again.

 - Fix copy to user space of swapped kdump oldmem.

 - Remove -mstack-guard and -mstack-size compile options when building
   vdso binaries. This can happen when CONFIG_VMAP_STACK is disabled and
   results in broken vdso code which causes more or less random
   exceptions. Also remove the not needed -nostdlib option.

 - Fix memory leak on cpu hotplug and return code handling in kexec
   code.

 - Wire up futex_waitv system call.

 - Replace snprintf with sysfs_emit where appropriate.

* tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  ftrace/samples: add s390 support for ftrace direct multi sample
  ftrace/samples: add missing Kconfig option for ftrace direct multi sample
  MAINTAINERS: update email address of Christian Borntraeger
  s390/kexec: fix memory leak of ipl report buffer
  s390/kexec: fix return code handling
  s390/dump: fix copying to user-space of swapped kdump oldmem
  s390: wire up sys_futex_waitv system call
  s390/vdso: filter out -mstack-guard and -mstack-size
  s390/vdso: remove -nostdlib compiler flag
  s390: replace snprintf in show functions with sysfs_emit
  s390/boot: simplify and fix kernel memory layout setup
  s390/setup: re-arrange memblock setup
  s390/setup: avoid using memblock_enforce_memory_limit
  s390/setup: avoid reserving memory above identity mapping
      6b38e2fb
    • Linus Torvalds's avatar
      Merge tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6 · b38bfc74
      Linus Torvalds authored 
      Pull cifs fixes from Steve French:
 "Three small cifs/smb3 fixes: two to address minor coverity issues and
  one cleanup"

* tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: introduce cifs_ses_mark_for_reconnect() helper
  cifs: protect srv_count with cifs_tcp_ses_lock
  cifs: move debug print out of spinlock
      b38bfc74
    • David Hildenbrand's avatar
      proc/vmcore: fix clearing user buffer by properly using clear_user() · c1e63117
      David Hildenbrand authored 
      To clear a user buffer we cannot simply use memset, we have to use
clear_user().  With a virtio-mem device that registers a vmcore_cb and
has some logically unplugged memory inside an added Linux memory block,
I can easily trigger a BUG by copying the vmcore via "cp":

  systemd[1]: Starting Kdump Vmcore Save Service...
  kdump[420]: Kdump is using the default log level(3).
  kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[465]: saving vmcore-dmesg.txt complete
  kdump[467]: saving vmcore
  BUG: unable to handle page fault for address: 00007f2374e01000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867
  Oops: 0003 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014
  RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86
  Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81
  RSP: 0018:ffffc9000073be08 EFLAGS: 00010212
  RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000
  RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008
  RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50
  R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000
  R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8
  FS:  00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0
  Call Trace:
   read_vmcore+0x236/0x2c0
   proc_reg_read+0x55/0xa0
   vfs_read+0x95/0x190
   ksys_read+0x4f/0xc0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access
Prevention (SMAP)", which is used to detect wrong access from the kernel
to user buffers like this: SMAP triggers a permissions violation on
wrong access.  In the x86-64 variant of clear_user(), SMAP is properly
handled via clac()+stac().

To fix, properly use clear_user() when we're dealing with a user buffer.

Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com
Fixes: 997c136f ("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages")
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarBaoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c1e63117
    • Ard Biesheuvel's avatar
      kmap_local: don't assume kmap PTEs are linear arrays in memory · 825c43f5
      Ard Biesheuvel authored 
      The kmap_local conversion broke the ARM architecture, because the new
code assumes that all PTEs used for creating kmaps form a linear array
in memory, and uses array indexing to look up the kmap PTE belonging to
a certain kmap index.

On ARM, this cannot work, not only because the PTE pages may be
non-adjacent in memory, but also because ARM/!LPAE interleaves hardware
entries and extended entries (carrying software-only bits) in a way that
is not compatible with array indexing.

Fortunately, this only seems to affect configurations with more than 8
CPUs, due to the way the per-CPU kmap slots are organized in memory.

Work around this by permitting an architecture to set a Kconfig symbol
that signifies that the kmap PTEs do not form a lineary array in memory,
and so the only way to locate the appropriate one is to walk the page
tables.

Link: https://lore.kernel.org/linux-arm-kernel/20211026131249.3731275-1-ardb@kernel.org/
Link: https://lkml.kernel.org/r/20211116094737.7391-1-ardb@kernel.org
Fixes: 2a15ba82 ("ARM: highmem: Switch to generic kmap atomic")
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Reported-by: default avatarQuanyang Wang <quanyang.wang@windriver.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Acked-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      825c43f5
    • SeongJae Park's avatar
      mm/damon/dbgfs: fix missed use of damon_dbgfs_lock · d78f3853
      SeongJae Park authored 
      DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and
dbgfs_dirs using damon_dbgfs_lock.  However, some of the code is
accessing the variables without the protection.  This fixes it by
protecting all such accesses.

Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org
Fixes: 75c1c2b5 ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d78f3853
    • SeongJae Park's avatar
      mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation · db7a347b
      SeongJae Park authored 
      Patch series "DAMON fixes".

This patch (of 2):

DAMON users can trigger below warning in '__alloc_pages()' by invoking
write() to some DAMON debugfs files with arbitrarily high count
argument, because DAMON debugfs interface allocates some buffers based
on the user-specified 'count'.

        if (unlikely(order >= MAX_ORDER)) {
                WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
                return NULL;
        }

Because the DAMON debugfs interface code checks failure of the
'kmalloc()', this commit simply suppresses the warnings by adding
'__GFP_NOWARN' flag.

Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org
Fixes: 4bc05954 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      db7a347b
    • Kees Cook's avatar
      kasan: test: silence intentional read overflow warnings · cab71f74
      Kees Cook authored 
      As done in commit d73dad4e ("kasan: test: bypass __alloc_size
checks") for __write_overflow warnings, also silence some more cases
that trip the __read_overflow warnings seen in 5.16-rc1[1]:

  In file included from include/linux/string.h:253,
                   from include/linux/bitmap.h:10,
                   from include/linux/cpumask.h:12,
                   from include/linux/mm_types_task.h:14,
                   from include/linux/mm_types.h:5,
                   from include/linux/page-flags.h:13,
                   from arch/arm64/include/asm/mte.h:14,
                   from arch/arm64/include/asm/pgtable.h:12,
                   from include/linux/pgtable.h:6,
                   from include/linux/kasan.h:29,
                   from lib/test_kasan.c:10:
  In function 'memcmp',
      inlined from 'kasan_memcmp' at lib/test_kasan.c:897:2:
  include/linux/fortify-string.h:263:25: error: call to '__read_overflow' declared with attribute error: detected read beyond size of object (1st parameter)
    263 |                         __read_overflow();
        |                         ^~~~~~~~~~~~~~~~~
  In function 'memchr',
      inlined from 'kasan_memchr' at lib/test_kasan.c:872:2:
  include/linux/fortify-string.h:277:17: error: call to '__read_overflow' declared with attribute error: detected read beyond size of object (1st parameter)
    277 |                 __read_overflow();
        |                 ^~~~~~~~~~~~~~~~~

[1] http://kisskb.ellerman.id.au/kisskb/buildresult/14660585/log/

Link: https://lkml.kernel.org/r/20211116004111.3171781-1-keescook@chromium.org
Fixes: d73dad4e ("kasan: test: bypass __alloc_size checks")
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarAndrey Konovalov <andreyknvl@gmail.com>
Acked-by: default avatarMarco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cab71f74
    • Mina Almasry's avatar
      hugetlb, userfaultfd: fix reservation restore on userfaultfd error · cc30042d
      Mina Almasry authored 
      Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we
bail out using "goto out_release_unlock;" in the cases where idx >=
size, or !huge_pte_none(), the code will detect that new_pagecache_page
== false, and so call restore_reserve_on_error().  In this case I see
restore_reserve_on_error() delete the reservation, and the following
call to remove_inode_hugepages() will increment h->resv_hugepages
causing a 100% reproducible leak.

We should treat the is_continue case similar to adding a page into the
pagecache and set new_pagecache_page to true, to indicate that there is
no reservation to restore on the error path, and we need not call
restore_reserve_on_error().  Rename new_pagecache_page to
page_in_pagecache to make that clear.

Link: https://lkml.kernel.org/r/20211117193825.378528-1-almasrymina@google.com
Fixes: c7b1850d ("hugetlb: don't pass page cache pages to restore_reserve_on_error")
Signed-off-by: default avatarMina Almasry <almasrymina@google.com>
Reported-by: default avatarJames Houghton <jthoughton@google.com>
Reviewed-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Cc: Wei Xu <weixugc@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cc30042d
    • Bui Quang Minh's avatar
      hugetlb: fix hugetlb cgroup refcounting during mremap · afe041c2
      Bui Quang Minh authored 
      When hugetlb_vm_op_open() is called during copy_vma(), we may take the
reference to resv_map->css.  Later, when clearing the reservation
pointer of old_vma after transferring it to new_vma, we forget to drop
the reference to resv_map->css.  This leads to a reference leak of css.

Fixes this by adding a check to drop reservation css reference in
clear_vma_resv_huge_pages()

Link: https://lkml.kernel.org/r/20211113154412.91134-1-minhquangbui99@gmail.com
Fixes: 550a7d60 ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: default avatarBui Quang Minh <minhquangbui99@gmail.com>
Reviewed-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: default avatarMina Almasry <almasrymina@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      afe041c2
    • Rustam Kovhaev's avatar
      mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag · 34dbc3aa
      Rustam Kovhaev authored 
      When kmemleak is enabled for SLOB, system does not boot and does not
print anything to the console.  At the very early stage in the boot
process we hit infinite recursion from kmemleak_init() and eventually
kernel crashes.

kmemleak_init() specifies SLAB_NOLEAKTRACE for KMEM_CACHE(), but
kmem_cache_create_usercopy() removes it because CACHE_CREATE_MASK is not
valid for SLOB.

Let's fix CACHE_CREATE_MASK and make kmemleak work with SLOB

Link: https://lkml.kernel.org/r/20211115020850.3154366-1-rkovhaev@gmail.com
Fixes: d8843922 ("slab: Ignore internal flags in cache creation")
Signed-off-by: default avatarRustam Kovhaev <rkovhaev@gmail.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarMuchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Glauber Costa <glommer@parallels.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      34dbc3aa
    • Nathan Chancellor's avatar
      hexagon: ignore vmlinux.lds · eaac2f89
      Nathan Chancellor authored 
      After building allmodconfig, there is an untracked vmlinux.lds file in
arch/hexagon/kernel:

    $ git ls-files . --exclude-standard --others
    arch/hexagon/kernel/vmlinux.lds

Ignore it as all other architectures have.

Link: https://lkml.kernel.org/r/20211115174250.1994179-4-nathan@kernel.orgSigned-off-by: default avatarNathan Chancellor <nathan@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      eaac2f89
    • Nathan Chancellor's avatar
      hexagon: clean up timer-regs.h · 51f2ec59
      Nathan Chancellor authored 
      When building allmodconfig, there is a warning about TIMER_ENABLE being
redefined:

  drivers/clocksource/timer-oxnas-rps.c:39:9: error: 'TIMER_ENABLE' macro redefined [-Werror,-Wmacro-redefined]
  #define TIMER_ENABLE            BIT(7)
          ^
  arch/hexagon/include/asm/timer-regs.h:13:9: note: previous definition is here
  #define TIMER_ENABLE            0
           ^
  1 error generated.

The values in this header are only used in one file each, if they are
used at all.  Remove the header and sink all of the constants into their
respective files.

TCX0_CLK_RATE is only used in arch/hexagon/include/asm/timex.h

TIMER_ENABLE, RTOS_TIMER_INT, RTOS_TIMER_REGS_ADDR are only used in
arch/hexagon/kernel/time.c.

SLEEP_CLK_RATE and TIMER_CLR_ON_MATCH have both been unused since the
file's introduction in commit 71e4a47f ("Hexagon: Add time and timer
functions").

TIMER_ENABLE is redefined as BIT(0) so the shift is moved into the
definition, rather than its use.

Link: https://lkml.kernel.org/r/20211115174250.1994179-3-nathan@kernel.orgSigned-off-by: default avatarNathan Chancellor <nathan@kernel.org>
Acked-by: default avatarBrian Cain <bcain@codeaurora.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      51f2ec59
    • Nathan Chancellor's avatar
      hexagon: export raw I/O routines for modules · ffb92ce8
      Nathan Chancellor authored 
      Patch series "Fixes for ARCH=hexagon allmodconfig", v2.

This series fixes some issues noticed with ARCH=hexagon allmodconfig.

This patch (of 3):

When building ARCH=hexagon allmodconfig, the following errors occur:

  ERROR: modpost: "__raw_readsl" [drivers/i3c/master/svc-i3c-master.ko] undefined!
  ERROR: modpost: "__raw_writesl" [drivers/i3c/master/dw-i3c-master.ko] undefined!
  ERROR: modpost: "__raw_readsl" [drivers/i3c/master/dw-i3c-master.ko] undefined!
  ERROR: modpost: "__raw_writesl" [drivers/i3c/master/i3c-master-cdns.ko] undefined!
  ERROR: modpost: "__raw_readsl" [drivers/i3c/master/i3c-master-cdns.ko] undefined!

Export these symbols so that modules can use them without any errors.

Link: https://lkml.kernel.org/r/20211115174250.1994179-1-nathan@kernel.org
Link: https://lkml.kernel.org/r/20211115174250.1994179-2-nathan@kernel.org
Fixes: 013bf24c ("Hexagon: Provide basic implementation and/or stubs for I/O routines.")
Signed-off-by: default avatarNathan Chancellor <nathan@kernel.org>
Acked-by: default avatarBrian Cain <bcain@codeaurora.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ffb92ce8
    • Yunfeng Ye's avatar
      mm: emit the "free" trace report before freeing memory in kmem_cache_free() · 9a543f00
      Yunfeng Ye authored 
      After the memory is freed, it can be immediately allocated by other
CPUs, before the "free" trace report has been emitted.  This causes
inaccurate traces.

For example, if the following sequence of events occurs:

    CPU 0                 CPU 1

  (1) alloc xxxxxx
  (2) free  xxxxxx
                         (3) alloc xxxxxx
                         (4) free  xxxxxx

Then they will be inaccurately reported via tracing, so that they appear
to have happened in this order:

    CPU 0                 CPU 1

  (1) alloc xxxxxx
                         (2) alloc xxxxxx
  (3) free  xxxxxx
                         (4) free  xxxxxx

This makes it look like CPU 1 somehow managed to allocate memory that
CPU 0 still had allocated for itself.

In order to avoid this, emit the "free xxxxxx" tracing report just
before the actual call to free the memory, instead of just after it.

Link: https://lkml.kernel.org/r/374eb75d-7404-8721-4e1e-65b0e5b17279@huawei.comSigned-off-by: default avatarYunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9a543f00
    • Alexander Mikhalitsyn's avatar
      shm: extend forced shm destroy to support objects from several IPC nses · 85b6d246
      Alexander Mikhalitsyn authored 
      Currently, the exit_shm() function not designed to work properly when
task->sysvshm.shm_clist holds shm objects from different IPC namespaces.

This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it
leads to use-after-free (reproducer exists).

This is an attempt to fix the problem by extending exit_shm mechanism to
handle shm's destroy from several IPC ns'es.

To achieve that we do several things:

1. add a namespace (non-refcounted) pointer to the struct shmid_kernel

2. during new shm object creation (newseg()/shmget syscall) we
   initialize this pointer by current task IPC ns

3. exit_shm() fully reworked such that it traverses over all shp's in
   task->sysvshm.shm_clist and gets IPC namespace not from current task
   as it was before but from shp's object itself, then call
   shm_destroy(shp, ns).

Note: We need to be really careful here, because as it was said before
(1), our pointer to IPC ns non-refcnt'ed.  To be on the safe side we
using special helper get_ipc_ns_not_zero() which allows to get IPC ns
refcounter only if IPC ns not in the "state of destruction".

Q/A

Q: Why can we access shp->ns memory using non-refcounted pointer?
A: Because shp object lifetime is always shorther than IPC namespace
   lifetime, so, if we get shp object from the task->sysvshm.shm_clist
   while holding task_lock(task) nobody can steal our namespace.

Q: Does this patch change semantics of unshare/setns/clone syscalls?
A: No. It's just fixes non-covered case when process may leave IPC
   namespace without getting task->sysvshm.shm_clist list cleaned up.

Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife.com
Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com
Fixes: ab602f79 ("shm: make exit_shm work proportional to task activity")
Co-developed-by: default avatarManfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarManfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarAlexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      85b6d246
    • Alexander Mikhalitsyn's avatar
      ipc: WARN if trying to remove ipc object which is absent · 126e8bee
      Alexander Mikhalitsyn authored 
      Patch series "shm: shm_rmid_forced feature fixes".

Some time ago I met kernel crash after CRIU restore procedure,
fortunately, it was CRIU restore, so, I had dump files and could do
restore many times and crash reproduced easily.  After some
investigation I've constructed the minimal reproducer.  It was found
that it's use-after-free and it happens only if sysctl
kernel.shm_rmid_forced = 1.

The key of the problem is that the exit_shm() function not handles shp's
object destroy when task->sysvshm.shm_clist contains items from
different IPC namespaces.  In most cases this list will contain only
items from one IPC namespace.

How can this list contain object from different namespaces? The
exit_shm() function is designed to clean up this list always when
process leaves IPC namespace.  But we made a mistake a long time ago and
did not add a exit_shm() call into the setns() syscall procedures.

The first idea was just to add this call to setns() syscall but it
obviously changes semantics of setns() syscall and that's
userspace-visible change.  So, I gave up on this idea.

The first real attempt to address the issue was just to omit forced
destroy if we meet shp object not from current task IPC namespace [1].
But that was not the best idea because task->sysvshm.shm_clist was
protected by rwsem which belongs to current task IPC namespace.  It
means that list corruption may occur.

Second approach is just extend exit_shm() to properly handle shp's from
different IPC namespaces [2].  This is really non-trivial thing, I've
put a lot of effort into that but not believed that it's possible to
make it fully safe, clean and clear.

Thanks to the efforts of Manfred Spraul working an elegant solution was
designed.  Thanks a lot, Manfred!

Eric also suggested the way to address the issue in ("[RFC][PATCH] shm:
In shm_exit destroy all created and never attached segments") Eric's
idea was to maintain a list of shm_clists one per IPC namespace, use
lock-less lists.  But there is some extra memory consumption-related
concerns.

An alternative solution which was suggested by me was implemented in
("shm: reset shm_clist on setns but omit forced shm destroy").  The idea
is pretty simple, we add exit_shm() syscall to setns() but DO NOT
destroy shm segments even if sysctl kernel.shm_rmid_forced = 1, we just
clean up the task->sysvshm.shm_clist list.

This chages semantics of setns() syscall a little bit but in comparision
to the "naive" solution when we just add exit_shm() without any special
exclusions this looks like a safer option.

[1] https://lkml.org/lkml/2021/7/6/1108
[2] https://lkml.org/lkml/2021/7/14/736

This patch (of 2):

Let's produce a warning if we trying to remove non-existing IPC object
from IPC namespace kht/idr structures.

This allows us to catch possible bugs when the ipc_rmid() function was
called with inconsistent struct ipc_ids*, struct kern_ipc_perm*
arguments.

Link: https://lkml.kernel.org/r/20211027224348.611025-1-alexander.mikhalitsyn@virtuozzo.com
Link: https://lkml.kernel.org/r/20211027224348.611025-2-alexander.mikhalitsyn@virtuozzo.comCo-developed-by: default avatarManfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarManfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarAlexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      126e8bee
    • Matthew Wilcox's avatar
      mm/swap.c:put_pages_list(): reinitialise the page list · 3cd018b4
      Matthew Wilcox authored 
      While free_unref_page_list() puts pages onto the CPU local LRU list, it
does not remove them from the list they were passed in on.  That makes
the list_head appear to be non-empty, and would lead to various
corruption problems if we didn't have an assertion that the list was
empty.

Reinitialise the list after calling free_unref_page_list() to avoid this
problem.

Link: https://lkml.kernel.org/r/YYp40A2lNrxaZji8@casper.infradead.org
Fixes: 988c69f1 ("mm: optimise put_pages_list()")
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarSteve French <stfrench@microsoft.com>
Reported-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Tested-by: default avatarSteve French <stfrench@microsoft.com>
Tested-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyeoncheol Lee <hyc.lee@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3cd018b4
  5. 19 Nov, 2021 19 commits
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