1. 29 12月, 2018 7 次提交
    • W
      mm/slub.c: record final state of slub action in deactivate_slab() · 88349a28
      Wei Yang 提交于
      If __cmpxchg_double_slab() fails and (l != m), current code records
      transition states of slub action.
      
      Update the action after __cmpxchg_double_slab() success to record the
      final state.
      
      [akpm@linux-foundation.org: more whitespace cleanup]
      Link: http://lkml.kernel.org/r/20181107013119.3816-1-richard.weiyang@gmail.comSigned-off-by: NWei Yang <richard.weiyang@gmail.com>
      Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
      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>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      88349a28
    • W
      mm/slub.c: page is always non-NULL in node_match() · 6159d0f5
      Wei Yang 提交于
      node_match() is a static function and is only invoked in slub.c.
      
      In all three places, `page' is ensured to be valid.
      
      Link: http://lkml.kernel.org/r/20181106150245.1668-1-richard.weiyang@gmail.comSigned-off-by: NWei Yang <richard.weiyang@gmail.com>
      Acked-by: NChristoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6159d0f5
    • W
      mm/slub.c: remove validation on cpu_slab in __flush_cpu_slab() · 1265ef2d
      Wei Yang 提交于
      cpu_slab is a per cpu variable which is allocated in all or none.  If a
      cpu_slab failed to be allocated, the slub is not usable.
      
      We could use cpu_slab without validation in __flush_cpu_slab().
      
      Link: http://lkml.kernel.org/r/20181103141218.22844-1-richard.weiyang@gmail.comSigned-off-by: NWei Yang <richard.weiyang@gmail.com>
      Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
      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>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1265ef2d
    • A
      kasan: preassign tags to objects with ctors or SLAB_TYPESAFE_BY_RCU · 4d176711
      Andrey Konovalov 提交于
      An object constructor can initialize pointers within this objects based on
      the address of the object.  Since the object address might be tagged, we
      need to assign a tag before calling constructor.
      
      The implemented approach is to assign tags to objects with constructors
      when a slab is allocated and call constructors once as usual.  The
      downside is that such object would always have the same tag when it is
      reallocated, so we won't catch use-after-frees on it.
      
      Also pressign tags for objects from SLAB_TYPESAFE_BY_RCU caches, since
      they can be validy accessed after having been freed.
      
      Link: http://lkml.kernel.org/r/f158a8a74a031d66f0a9398a5b0ed453c37ba09a.1544099024.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
      Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
      Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4d176711
    • A
      kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS · 2bd926b4
      Andrey Konovalov 提交于
      This commit splits the current CONFIG_KASAN config option into two:
      1. CONFIG_KASAN_GENERIC, that enables the generic KASAN mode (the one
         that exists now);
      2. CONFIG_KASAN_SW_TAGS, that enables the software tag-based KASAN mode.
      
      The name CONFIG_KASAN_SW_TAGS is chosen as in the future we will have
      another hardware tag-based KASAN mode, that will rely on hardware memory
      tagging support in arm64.
      
      With CONFIG_KASAN_SW_TAGS enabled, compiler options are changed to
      instrument kernel files with -fsantize=kernel-hwaddress (except the ones
      for which KASAN_SANITIZE := n is set).
      
      Both CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS support both
      CONFIG_KASAN_INLINE and CONFIG_KASAN_OUTLINE instrumentation modes.
      
      This commit also adds empty placeholder (for now) implementation of
      tag-based KASAN specific hooks inserted by the compiler and adjusts
      common hooks implementation.
      
      While this commit adds the CONFIG_KASAN_SW_TAGS config option, this option
      is not selectable, as it depends on HAVE_ARCH_KASAN_SW_TAGS, which we will
      enable once all the infrastracture code has been added.
      
      Link: http://lkml.kernel.org/r/b2550106eb8a68b10fefbabce820910b115aa853.1544099024.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
      Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
      Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2bd926b4
    • A
      kasan, slub: handle pointer tags in early_kmem_cache_node_alloc · 12b22386
      Andrey Konovalov 提交于
      The previous patch updated KASAN hooks signatures and their usage in SLAB
      and SLUB code, except for the early_kmem_cache_node_alloc function.  This
      patch handles that function separately, as it requires to reorder some of
      the initialization code to correctly propagate a tagged pointer in case a
      tag is assigned by kasan_kmalloc.
      
      Link: http://lkml.kernel.org/r/fc8d0fdcf733a7a52e8d0daaa650f4736a57de8c.1544099024.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
      Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      12b22386
    • A
      kasan, mm: change hooks signatures · 0116523c
      Andrey Konovalov 提交于
      Patch series "kasan: add software tag-based mode for arm64", v13.
      
      This patchset adds a new software tag-based mode to KASAN [1].  (Initially
      this mode was called KHWASAN, but it got renamed, see the naming rationale
      at the end of this section).
      
      The plan is to implement HWASan [2] for the kernel with the incentive,
      that it's going to have comparable to KASAN performance, but in the same
      time consume much less memory, trading that off for somewhat imprecise bug
      detection and being supported only for arm64.
      
      The underlying ideas of the approach used by software tag-based KASAN are:
      
      1. By using the Top Byte Ignore (TBI) arm64 CPU feature, we can store
         pointer tags in the top byte of each kernel pointer.
      
      2. Using shadow memory, we can store memory tags for each chunk of kernel
         memory.
      
      3. On each memory allocation, we can generate a random tag, embed it into
         the returned pointer and set the memory tags that correspond to this
         chunk of memory to the same value.
      
      4. By using compiler instrumentation, before each memory access we can add
         a check that the pointer tag matches the tag of the memory that is being
         accessed.
      
      5. On a tag mismatch we report an error.
      
      With this patchset the existing KASAN mode gets renamed to generic KASAN,
      with the word "generic" meaning that the implementation can be supported
      by any architecture as it is purely software.
      
      The new mode this patchset adds is called software tag-based KASAN.  The
      word "tag-based" refers to the fact that this mode uses tags embedded into
      the top byte of kernel pointers and the TBI arm64 CPU feature that allows
      to dereference such pointers.  The word "software" here means that shadow
      memory manipulation and tag checking on pointer dereference is done in
      software.  As it is the only tag-based implementation right now, "software
      tag-based" KASAN is sometimes referred to as simply "tag-based" in this
      patchset.
      
      A potential expansion of this mode is a hardware tag-based mode, which
      would use hardware memory tagging support (announced by Arm [3]) instead
      of compiler instrumentation and manual shadow memory manipulation.
      
      Same as generic KASAN, software tag-based KASAN is strictly a debugging
      feature.
      
      [1] https://www.kernel.org/doc/html/latest/dev-tools/kasan.html
      
      [2] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html
      
      [3] https://community.arm.com/processors/b/blog/posts/arm-a-profile-architecture-2018-developments-armv85a
      
      ====== Rationale
      
      On mobile devices generic KASAN's memory usage is significant problem.
      One of the main reasons to have tag-based KASAN is to be able to perform a
      similar set of checks as the generic one does, but with lower memory
      requirements.
      
      Comment from Vishwath Mohan <vishwath@google.com>:
      
      I don't have data on-hand, but anecdotally both ASAN and KASAN have proven
      problematic to enable for environments that don't tolerate the increased
      memory pressure well.  This includes
      
      (a) Low-memory form factors - Wear, TV, Things, lower-tier phones like Go,
      (c) Connected components like Pixel's visual core [1].
      
      These are both places I'd love to have a low(er) memory footprint option at
      my disposal.
      
      Comment from Evgenii Stepanov <eugenis@google.com>:
      
      Looking at a live Android device under load, slab (according to
      /proc/meminfo) + kernel stack take 8-10% available RAM (~350MB).  KASAN's
      overhead of 2x - 3x on top of it is not insignificant.
      
      Not having this overhead enables near-production use - ex.  running
      KASAN/KHWASAN kernel on a personal, daily-use device to catch bugs that do
      not reproduce in test configuration.  These are the ones that often cost
      the most engineering time to track down.
      
      CPU overhead is bad, but generally tolerable.  RAM is critical, in our
      experience.  Once it gets low enough, OOM-killer makes your life
      miserable.
      
      [1] https://www.blog.google/products/pixel/pixel-visual-core-image-processing-and-machine-learning-pixel-2/
      
      ====== Technical details
      
      Software tag-based KASAN mode is implemented in a very similar way to the
      generic one. This patchset essentially does the following:
      
      1. TCR_TBI1 is set to enable Top Byte Ignore.
      
      2. Shadow memory is used (with a different scale, 1:16, so each shadow
         byte corresponds to 16 bytes of kernel memory) to store memory tags.
      
      3. All slab objects are aligned to shadow scale, which is 16 bytes.
      
      4. All pointers returned from the slab allocator are tagged with a random
         tag and the corresponding shadow memory is poisoned with the same value.
      
      5. Compiler instrumentation is used to insert tag checks. Either by
         calling callbacks or by inlining them (CONFIG_KASAN_OUTLINE and
         CONFIG_KASAN_INLINE flags are reused).
      
      6. When a tag mismatch is detected in callback instrumentation mode
         KASAN simply prints a bug report. In case of inline instrumentation,
         clang inserts a brk instruction, and KASAN has it's own brk handler,
         which reports the bug.
      
      7. The memory in between slab objects is marked with a reserved tag, and
         acts as a redzone.
      
      8. When a slab object is freed it's marked with a reserved tag.
      
      Bug detection is imprecise for two reasons:
      
      1. We won't catch some small out-of-bounds accesses, that fall into the
         same shadow cell, as the last byte of a slab object.
      
      2. We only have 1 byte to store tags, which means we have a 1/256
         probability of a tag match for an incorrect access (actually even
         slightly less due to reserved tag values).
      
      Despite that there's a particular type of bugs that tag-based KASAN can
      detect compared to generic KASAN: use-after-free after the object has been
      allocated by someone else.
      
      ====== Testing
      
      Some kernel developers voiced a concern that changing the top byte of
      kernel pointers may lead to subtle bugs that are difficult to discover.
      To address this concern deliberate testing has been performed.
      
      It doesn't seem feasible to do some kind of static checking to find
      potential issues with pointer tagging, so a dynamic approach was taken.
      All pointer comparisons/subtractions have been instrumented in an LLVM
      compiler pass and a kernel module that would print a bug report whenever
      two pointers with different tags are being compared/subtracted (ignoring
      comparisons with NULL pointers and with pointers obtained by casting an
      error code to a pointer type) has been used.  Then the kernel has been
      booted in QEMU and on an Odroid C2 board and syzkaller has been run.
      
      This yielded the following results.
      
      The two places that look interesting are:
      
      is_vmalloc_addr in include/linux/mm.h
      is_kernel_rodata in mm/util.c
      
      Here we compare a pointer with some fixed untagged values to make sure
      that the pointer lies in a particular part of the kernel address space.
      Since tag-based KASAN doesn't add tags to pointers that belong to rodata
      or vmalloc regions, this should work as is.  To make sure debug checks to
      those two functions that check that the result doesn't change whether we
      operate on pointers with or without untagging has been added.
      
      A few other cases that don't look that interesting:
      
      Comparing pointers to achieve unique sorting order of pointee objects
      (e.g. sorting locks addresses before performing a double lock):
      
      tty_ldisc_lock_pair_timeout in drivers/tty/tty_ldisc.c
      pipe_double_lock in fs/pipe.c
      unix_state_double_lock in net/unix/af_unix.c
      lock_two_nondirectories in fs/inode.c
      mutex_lock_double in kernel/events/core.c
      
      ep_cmp_ffd in fs/eventpoll.c
      fsnotify_compare_groups fs/notify/mark.c
      
      Nothing needs to be done here, since the tags embedded into pointers
      don't change, so the sorting order would still be unique.
      
      Checks that a pointer belongs to some particular allocation:
      
      is_sibling_entry in lib/radix-tree.c
      object_is_on_stack in include/linux/sched/task_stack.h
      
      Nothing needs to be done here either, since two pointers can only belong
      to the same allocation if they have the same tag.
      
      Overall, since the kernel boots and works, there are no critical bugs.
      As for the rest, the traditional kernel testing way (use until fails) is
      the only one that looks feasible.
      
      Another point here is that tag-based KASAN is available under a separate
      config option that needs to be deliberately enabled. Even though it might
      be used in a "near-production" environment to find bugs that are not found
      during fuzzing or running tests, it is still a debug tool.
      
      ====== Benchmarks
      
      The following numbers were collected on Odroid C2 board. Both generic and
      tag-based KASAN were used in inline instrumentation mode.
      
      Boot time [1]:
      * ~1.7 sec for clean kernel
      * ~5.0 sec for generic KASAN
      * ~5.0 sec for tag-based KASAN
      
      Network performance [2]:
      * 8.33 Gbits/sec for clean kernel
      * 3.17 Gbits/sec for generic KASAN
      * 2.85 Gbits/sec for tag-based KASAN
      
      Slab memory usage after boot [3]:
      * ~40 kb for clean kernel
      * ~105 kb (~260% overhead) for generic KASAN
      * ~47 kb (~20% overhead) for tag-based KASAN
      
      KASAN memory overhead consists of three main parts:
      1. Increased slab memory usage due to redzones.
      2. Shadow memory (the whole reserved once during boot).
      3. Quaratine (grows gradually until some preset limit; the more the limit,
         the more the chance to detect a use-after-free).
      
      Comparing tag-based vs generic KASAN for each of these points:
      1. 20% vs 260% overhead.
      2. 1/16th vs 1/8th of physical memory.
      3. Tag-based KASAN doesn't require quarantine.
      
      [1] Time before the ext4 driver is initialized.
      [2] Measured as `iperf -s & iperf -c 127.0.0.1 -t 30`.
      [3] Measured as `cat /proc/meminfo | grep Slab`.
      
      ====== Some notes
      
      A few notes:
      
      1. The patchset can be found here:
         https://github.com/xairy/kasan-prototype/tree/khwasan
      
      2. Building requires a recent Clang version (7.0.0 or later).
      
      3. Stack instrumentation is not supported yet and will be added later.
      
      This patch (of 25):
      
      Tag-based KASAN changes the value of the top byte of pointers returned
      from the kernel allocation functions (such as kmalloc).  This patch
      updates KASAN hooks signatures and their usage in SLAB and SLUB code to
      reflect that.
      
      Link: http://lkml.kernel.org/r/aec2b5e3973781ff8a6bb6760f8543643202c451.1544099024.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
      Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
      Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0116523c
  2. 27 10月, 2018 3 次提交
    • V
      mm, slab: combine kmalloc_caches and kmalloc_dma_caches · cc252eae
      Vlastimil Babka 提交于
      Patch series "kmalloc-reclaimable caches", v4.
      
      As discussed at LSF/MM [1] here's a patchset that introduces
      kmalloc-reclaimable caches (more details in the second patch) and uses
      them for dcache external names.  That allows us to repurpose the
      NR_INDIRECTLY_RECLAIMABLE_BYTES counter later in the series.
      
      With patch 3/6, dcache external names are allocated from kmalloc-rcl-*
      caches, eliminating the need for manual accounting.  More importantly, it
      also ensures the reclaimable kmalloc allocations are grouped in pages
      separate from the regular kmalloc allocations.  The need for proper
      accounting of dcache external names has shown it's easy for misbehaving
      process to allocate lots of them, causing premature OOMs.  Without the
      added grouping, it's likely that a similar workload can interleave the
      dcache external names allocations with regular kmalloc allocations (note:
      I haven't searched myself for an example of such regular kmalloc
      allocation, but I would be very surprised if there wasn't some).  A
      pathological case would be e.g.  one 64byte regular allocations with 63
      external dcache names in a page (64x64=4096), which means the page is not
      freed even after reclaiming after all dcache names, and the process can
      thus "steal" the whole page with single 64byte allocation.
      
      If other kmalloc users similar to dcache external names become identified,
      they can also benefit from the new functionality simply by adding
      __GFP_RECLAIMABLE to the kmalloc calls.
      
      Side benefits of the patchset (that could be also merged separately)
      include removed branch for detecting __GFP_DMA kmalloc(), and shortening
      kmalloc cache names in /proc/slabinfo output.  The latter is potentially
      an ABI break in case there are tools parsing the names and expecting the
      values to be in bytes.
      
      This is how /proc/slabinfo looks like after booting in virtme:
      
      ...
      kmalloc-rcl-4M         0      0 4194304    1 1024 : tunables    1    1    0 : slabdata      0      0      0
      ...
      kmalloc-rcl-96         7     32    128   32    1 : tunables  120   60    8 : slabdata      1      1      0
      kmalloc-rcl-64        25    128     64   64    1 : tunables  120   60    8 : slabdata      2      2      0
      kmalloc-rcl-32         0      0     32  124    1 : tunables  120   60    8 : slabdata      0      0      0
      kmalloc-4M             0      0 4194304    1 1024 : tunables    1    1    0 : slabdata      0      0      0
      kmalloc-2M             0      0 2097152    1  512 : tunables    1    1    0 : slabdata      0      0      0
      kmalloc-1M             0      0 1048576    1  256 : tunables    1    1    0 : slabdata      0      0      0
      ...
      
      /proc/vmstat with renamed nr_indirectly_reclaimable_bytes counter:
      
      ...
      nr_slab_reclaimable 2817
      nr_slab_unreclaimable 1781
      ...
      nr_kernel_misc_reclaimable 0
      ...
      
      /proc/meminfo with new KReclaimable counter:
      
      ...
      Shmem:               564 kB
      KReclaimable:      11260 kB
      Slab:              18368 kB
      SReclaimable:      11260 kB
      SUnreclaim:         7108 kB
      KernelStack:        1248 kB
      ...
      
      This patch (of 6):
      
      The kmalloc caches currently mainain separate (optional) array
      kmalloc_dma_caches for __GFP_DMA allocations.  There are tests for
      __GFP_DMA in the allocation hotpaths.  We can avoid the branches by
      combining kmalloc_caches and kmalloc_dma_caches into a single
      two-dimensional array where the outer dimension is cache "type".  This
      will also allow to add kmalloc-reclaimable caches as a third type.
      
      Link: http://lkml.kernel.org/r/20180731090649.16028-2-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
      Acked-by: NMel Gorman <mgorman@techsingularity.net>
      Acked-by: NChristoph Lameter <cl@linux.com>
      Acked-by: NRoman Gushchin <guro@fb.com>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Laura Abbott <labbott@redhat.com>
      Cc: Sumit Semwal <sumit.semwal@linaro.org>
      Cc: Vijayanand Jitta <vjitta@codeaurora.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cc252eae
    • A
      slub: extend slub debug to handle multiple slabs · c5fd3ca0
      Aaron Tomlin 提交于
      Extend the slub_debug syntax to "slub_debug=<flags>[,<slub>]*", where
      <slub> may contain an asterisk at the end.  For example, the following
      would poison all kmalloc slabs:
      
      	slub_debug=P,kmalloc*
      
      and the following would apply the default flags to all kmalloc and all
      block IO slabs:
      
      	slub_debug=,bio*,kmalloc*
      
      Please note that a similar patch was posted by Iliyan Malchev some time
      ago but was never merged:
      
      	https://marc.info/?l=linux-mm&m=131283905330474&w=2
      
      Link: http://lkml.kernel.org/r/20180928111139.27962-1-atomlin@redhat.comSigned-off-by: NAaron Tomlin <atomlin@redhat.com>
      Acked-by: NChristoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Iliyan Malchev <malchev@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c5fd3ca0
    • A
      mm/slub.c: switch to bitmap_zalloc() · 0684e652
      Andy Shevchenko 提交于
      Switch to bitmap_zalloc() to show clearly what we are allocating.  Besides
      that it returns pointer of bitmap type instead of opaque void *.
      
      Link: http://lkml.kernel.org/r/20180830104301.61649-1-andriy.shevchenko@linux.intel.comSigned-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
      Acked-by: NChristoph Lameter <cl@linux.com>
      Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
      Tested-by: NDavid Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0684e652
  3. 30 8月, 2018 1 次提交
  4. 18 8月, 2018 1 次提交
  5. 29 6月, 2018 1 次提交
    • M
      slub: fix failure when we delete and create a slab cache · d50d82fa
      Mikulas Patocka 提交于
      In kernel 4.17 I removed some code from dm-bufio that did slab cache
      merging (commit 21bb1327: "dm bufio: remove code that merges slab
      caches") - both slab and slub support merging caches with identical
      attributes, so dm-bufio now just calls kmem_cache_create and relies on
      implicit merging.
      
      This uncovered a bug in the slub subsystem - if we delete a cache and
      immediatelly create another cache with the same attributes, it fails
      because of duplicate filename in /sys/kernel/slab/.  The slub subsystem
      offloads freeing the cache to a workqueue - and if we create the new
      cache before the workqueue runs, it complains because of duplicate
      filename in sysfs.
      
      This patch fixes the bug by moving the call of kobject_del from
      sysfs_slab_remove_workfn to shutdown_cache.  kobject_del must be called
      while we hold slab_mutex - so that the sysfs entry is deleted before a
      cache with the same attributes could be created.
      
      Running device-mapper-test-suite with:
      
        dmtest run --suite thin-provisioning -n /commit_failure_causes_fallback/
      
      triggered:
      
        Buffer I/O error on dev dm-0, logical block 1572848, async page read
        device-mapper: thin: 253:1: metadata operation 'dm_pool_alloc_data_block' failed: error = -5
        device-mapper: thin: 253:1: aborting current metadata transaction
        sysfs: cannot create duplicate filename '/kernel/slab/:a-0000144'
        CPU: 2 PID: 1037 Comm: kworker/u48:1 Not tainted 4.17.0.snitm+ #25
        Hardware name: Supermicro SYS-1029P-WTR/X11DDW-L, BIOS 2.0a 12/06/2017
        Workqueue: dm-thin do_worker [dm_thin_pool]
        Call Trace:
         dump_stack+0x5a/0x73
         sysfs_warn_dup+0x58/0x70
         sysfs_create_dir_ns+0x77/0x80
         kobject_add_internal+0xba/0x2e0
         kobject_init_and_add+0x70/0xb0
         sysfs_slab_add+0xb1/0x250
         __kmem_cache_create+0x116/0x150
         create_cache+0xd9/0x1f0
         kmem_cache_create_usercopy+0x1c1/0x250
         kmem_cache_create+0x18/0x20
         dm_bufio_client_create+0x1ae/0x410 [dm_bufio]
         dm_block_manager_create+0x5e/0x90 [dm_persistent_data]
         __create_persistent_data_objects+0x38/0x940 [dm_thin_pool]
         dm_pool_abort_metadata+0x64/0x90 [dm_thin_pool]
         metadata_operation_failed+0x59/0x100 [dm_thin_pool]
         alloc_data_block.isra.53+0x86/0x180 [dm_thin_pool]
         process_cell+0x2a3/0x550 [dm_thin_pool]
         do_worker+0x28d/0x8f0 [dm_thin_pool]
         process_one_work+0x171/0x370
         worker_thread+0x49/0x3f0
         kthread+0xf8/0x130
         ret_from_fork+0x35/0x40
        kobject_add_internal failed for :a-0000144 with -EEXIST, don't try to register things with the same name in the same directory.
        kmem_cache_create(dm_bufio_buffer-16) failed with error -17
      
      Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1806151817130.6333@file01.intranet.prod.int.rdu2.redhat.comSigned-off-by: NMikulas Patocka <mpatocka@redhat.com>
      Reported-by: NMike Snitzer <snitzer@redhat.com>
      Tested-by: NMike Snitzer <snitzer@redhat.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: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d50d82fa
  6. 13 6月, 2018 2 次提交
    • K
      treewide: kzalloc() -> kcalloc() · 6396bb22
      Kees Cook 提交于
      The kzalloc() function has a 2-factor argument form, kcalloc(). This
      patch replaces cases of:
      
              kzalloc(a * b, gfp)
      
      with:
              kcalloc(a * b, gfp)
      
      as well as handling cases of:
      
              kzalloc(a * b * c, gfp)
      
      with:
      
              kzalloc(array3_size(a, b, c), gfp)
      
      as it's slightly less ugly than:
      
              kzalloc_array(array_size(a, b), c, gfp)
      
      This does, however, attempt to ignore constant size factors like:
      
              kzalloc(4 * 1024, gfp)
      
      though any constants defined via macros get caught up in the conversion.
      
      Any factors with a sizeof() of "unsigned char", "char", and "u8" were
      dropped, since they're redundant.
      
      The Coccinelle script used for this was:
      
      // Fix redundant parens around sizeof().
      @@
      type TYPE;
      expression THING, E;
      @@
      
      (
        kzalloc(
      -	(sizeof(TYPE)) * E
      +	sizeof(TYPE) * E
        , ...)
      |
        kzalloc(
      -	(sizeof(THING)) * E
      +	sizeof(THING) * E
        , ...)
      )
      
      // Drop single-byte sizes and redundant parens.
      @@
      expression COUNT;
      typedef u8;
      typedef __u8;
      @@
      
      (
        kzalloc(
      -	sizeof(u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(__u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(char) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(unsigned char) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(u8) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(__u8) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(char) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(unsigned char) * COUNT
      +	COUNT
        , ...)
      )
      
      // 2-factor product with sizeof(type/expression) and identifier or constant.
      @@
      type TYPE;
      expression THING;
      identifier COUNT_ID;
      constant COUNT_CONST;
      @@
      
      (
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (COUNT_ID)
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * COUNT_ID
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * COUNT_CONST
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (COUNT_ID)
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * COUNT_ID
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * COUNT_CONST
      +	COUNT_CONST, sizeof(THING)
        , ...)
      )
      
      // 2-factor product, only identifiers.
      @@
      identifier SIZE, COUNT;
      @@
      
      - kzalloc
      + kcalloc
        (
      -	SIZE * COUNT
      +	COUNT, SIZE
        , ...)
      
      // 3-factor product with 1 sizeof(type) or sizeof(expression), with
      // redundant parens removed.
      @@
      expression THING;
      identifier STRIDE, COUNT;
      type TYPE;
      @@
      
      (
        kzalloc(
      -	sizeof(TYPE) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      )
      
      // 3-factor product with 2 sizeof(variable), with redundant parens removed.
      @@
      expression THING1, THING2;
      identifier COUNT;
      type TYPE1, TYPE2;
      @@
      
      (
        kzalloc(
      -	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kzalloc(
      -	sizeof(THING1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(THING1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      )
      
      // 3-factor product, only identifiers, with redundant parens removed.
      @@
      identifier STRIDE, SIZE, COUNT;
      @@
      
      (
        kzalloc(
      -	(COUNT) * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      )
      
      // Any remaining multi-factor products, first at least 3-factor products,
      // when they're not all constants...
      @@
      expression E1, E2, E3;
      constant C1, C2, C3;
      @@
      
      (
        kzalloc(C1 * C2 * C3, ...)
      |
        kzalloc(
      -	(E1) * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	(E1) * (E2) * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	(E1) * (E2) * (E3)
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	E1 * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      )
      
      // And then all remaining 2 factors products when they're not all constants,
      // keeping sizeof() as the second factor argument.
      @@
      expression THING, E1, E2;
      type TYPE;
      constant C1, C2, C3;
      @@
      
      (
        kzalloc(sizeof(THING) * C2, ...)
      |
        kzalloc(sizeof(TYPE) * C2, ...)
      |
        kzalloc(C1 * C2 * C3, ...)
      |
        kzalloc(C1 * C2, ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (E2)
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * E2
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (E2)
      +	E2, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * E2
      +	E2, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	(E1) * E2
      +	E1, E2
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	(E1) * (E2)
      +	E1, E2
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	E1 * E2
      +	E1, E2
        , ...)
      )
      Signed-off-by: NKees Cook <keescook@chromium.org>
      6396bb22
    • K
      treewide: kmalloc() -> kmalloc_array() · 6da2ec56
      Kees Cook 提交于
      The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
      patch replaces cases of:
      
              kmalloc(a * b, gfp)
      
      with:
              kmalloc_array(a * b, gfp)
      
      as well as handling cases of:
      
              kmalloc(a * b * c, gfp)
      
      with:
      
              kmalloc(array3_size(a, b, c), gfp)
      
      as it's slightly less ugly than:
      
              kmalloc_array(array_size(a, b), c, gfp)
      
      This does, however, attempt to ignore constant size factors like:
      
              kmalloc(4 * 1024, gfp)
      
      though any constants defined via macros get caught up in the conversion.
      
      Any factors with a sizeof() of "unsigned char", "char", and "u8" were
      dropped, since they're redundant.
      
      The tools/ directory was manually excluded, since it has its own
      implementation of kmalloc().
      
      The Coccinelle script used for this was:
      
      // Fix redundant parens around sizeof().
      @@
      type TYPE;
      expression THING, E;
      @@
      
      (
        kmalloc(
      -	(sizeof(TYPE)) * E
      +	sizeof(TYPE) * E
        , ...)
      |
        kmalloc(
      -	(sizeof(THING)) * E
      +	sizeof(THING) * E
        , ...)
      )
      
      // Drop single-byte sizes and redundant parens.
      @@
      expression COUNT;
      typedef u8;
      typedef __u8;
      @@
      
      (
        kmalloc(
      -	sizeof(u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(__u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(char) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(unsigned char) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(u8) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(__u8) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(char) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(unsigned char) * COUNT
      +	COUNT
        , ...)
      )
      
      // 2-factor product with sizeof(type/expression) and identifier or constant.
      @@
      type TYPE;
      expression THING;
      identifier COUNT_ID;
      constant COUNT_CONST;
      @@
      
      (
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (COUNT_ID)
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * COUNT_ID
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * COUNT_CONST
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (COUNT_ID)
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * COUNT_ID
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * COUNT_CONST
      +	COUNT_CONST, sizeof(THING)
        , ...)
      )
      
      // 2-factor product, only identifiers.
      @@
      identifier SIZE, COUNT;
      @@
      
      - kmalloc
      + kmalloc_array
        (
      -	SIZE * COUNT
      +	COUNT, SIZE
        , ...)
      
      // 3-factor product with 1 sizeof(type) or sizeof(expression), with
      // redundant parens removed.
      @@
      expression THING;
      identifier STRIDE, COUNT;
      type TYPE;
      @@
      
      (
        kmalloc(
      -	sizeof(TYPE) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      )
      
      // 3-factor product with 2 sizeof(variable), with redundant parens removed.
      @@
      expression THING1, THING2;
      identifier COUNT;
      type TYPE1, TYPE2;
      @@
      
      (
        kmalloc(
      -	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kmalloc(
      -	sizeof(THING1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(THING1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      )
      
      // 3-factor product, only identifiers, with redundant parens removed.
      @@
      identifier STRIDE, SIZE, COUNT;
      @@
      
      (
        kmalloc(
      -	(COUNT) * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      )
      
      // Any remaining multi-factor products, first at least 3-factor products,
      // when they're not all constants...
      @@
      expression E1, E2, E3;
      constant C1, C2, C3;
      @@
      
      (
        kmalloc(C1 * C2 * C3, ...)
      |
        kmalloc(
      -	(E1) * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	(E1) * (E2) * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	(E1) * (E2) * (E3)
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	E1 * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      )
      
      // And then all remaining 2 factors products when they're not all constants,
      // keeping sizeof() as the second factor argument.
      @@
      expression THING, E1, E2;
      type TYPE;
      constant C1, C2, C3;
      @@
      
      (
        kmalloc(sizeof(THING) * C2, ...)
      |
        kmalloc(sizeof(TYPE) * C2, ...)
      |
        kmalloc(C1 * C2 * C3, ...)
      |
        kmalloc(C1 * C2, ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (E2)
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * E2
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (E2)
      +	E2, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * E2
      +	E2, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	(E1) * E2
      +	E1, E2
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	(E1) * (E2)
      +	E1, E2
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	E1 * E2
      +	E1, E2
        , ...)
      )
      Signed-off-by: NKees Cook <keescook@chromium.org>
      6da2ec56
  7. 08 6月, 2018 9 次提交
  8. 12 4月, 2018 1 次提交
  9. 06 4月, 2018 15 次提交
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