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  1. 23 12月, 2020 4 次提交
  3. 16 12月, 2020 1 次提交
  5. 12 12月, 2020 1 次提交
    • K
      kasan: fix object remaining in offline per-cpu quarantine · 6c82d45c
      由 Kuan-Ying Lee 提交于 
      We hit this issue in our internal test.  When enabling generic kasan, a
kfree()'d object is put into per-cpu quarantine first.  If the cpu goes
offline, object still remains in the per-cpu quarantine.  If we call
kmem_cache_destroy() now, slub will report "Objects remaining" error.

  =============================================================================
  BUG test_module_slab (Not tainted): Objects remaining in test_module_slab on __kmem_cache_shutdown()
  -----------------------------------------------------------------------------

  Disabling lock debugging due to kernel taint
  INFO: Slab 0x(____ptrval____) objects=34 used=1 fp=0x(____ptrval____) flags=0x2ffff00000010200
  CPU: 3 PID: 176 Comm: cat Tainted: G    B             5.10.0-rc1-00007-g4525c878-dirty #10
  Hardware name: linux,dummy-virt (DT)
  Call trace:
     dump_backtrace+0x0/0x2b0
     show_stack+0x18/0x68
     dump_stack+0xfc/0x168
     slab_err+0xac/0xd4
     __kmem_cache_shutdown+0x1e4/0x3c8
     kmem_cache_destroy+0x68/0x130
     test_version_show+0x84/0xf0
     module_attr_show+0x40/0x60
     sysfs_kf_seq_show+0x128/0x1c0
     kernfs_seq_show+0xa0/0xb8
     seq_read+0x1f0/0x7e8
     kernfs_fop_read+0x70/0x338
     vfs_read+0xe4/0x250
     ksys_read+0xc8/0x180
     __arm64_sys_read+0x44/0x58
     el0_svc_common.constprop.0+0xac/0x228
     do_el0_svc+0x38/0xa0
     el0_sync_handler+0x170/0x178
     el0_sync+0x174/0x180
  INFO: Object 0x(____ptrval____) @offset=15848
  INFO: Allocated in test_version_show+0x98/0xf0 age=8188 cpu=6 pid=172
     stack_trace_save+0x9c/0xd0
     set_track+0x64/0xf0
     alloc_debug_processing+0x104/0x1a0
     ___slab_alloc+0x628/0x648
     __slab_alloc.isra.0+0x2c/0x58
     kmem_cache_alloc+0x560/0x588
     test_version_show+0x98/0xf0
     module_attr_show+0x40/0x60
     sysfs_kf_seq_show+0x128/0x1c0
     kernfs_seq_show+0xa0/0xb8
     seq_read+0x1f0/0x7e8
     kernfs_fop_read+0x70/0x338
     vfs_read+0xe4/0x250
     ksys_read+0xc8/0x180
     __arm64_sys_read+0x44/0x58
     el0_svc_common.constprop.0+0xac/0x228
  kmem_cache_destroy test_module_slab: Slab cache still has objects

Register a cpu hotplug function to remove all objects in the offline
per-cpu quarantine when cpu is going offline.  Set a per-cpu variable to
indicate this cpu is offline.

[qiang.zhang@windriver.com: fix slab double free when cpu-hotplug]
  Link: https://lkml.kernel.org/r/20201204102206.20237-1-qiang.zhang@windriver.com

Link: https://lkml.kernel.org/r/1606895585-17382-2-git-send-email-Kuan-Ying.Lee@mediatek.comSigned-off-by: NKuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Signed-off-by: NZqiang <qiang.zhang@windriver.com>
Suggested-by: NDmitry Vyukov <dvyukov@google.com>
Reported-by: NGuangye Yang <guangye.yang@mediatek.com>
Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Qian Cai <qcai@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6c82d45c
  7. 14 10月, 2020 2 次提交
  9. 08 8月, 2020 3 次提交
  11. 07 7月, 2020 1 次提交
  13. 05 6月, 2020 1 次提交
    • M
      mm: remove __ARCH_HAS_5LEVEL_HACK and include/asm-generic/5level-fixup.h · f089dcc7
      由 Mike Rapoport 提交于 
      There are no architectures that use include/asm-generic/5level-fixup.h
therefore it can be removed along with __ARCH_HAS_5LEVEL_HACK define and
the code it surrounds
Signed-off-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: James Morse <james.morse@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200414153455.21744-15-rppt@kernel.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f089dcc7
  15. 03 6月, 2020 2 次提交
  17. 24 5月, 2020 1 次提交
  19. 15 5月, 2020 2 次提交
  21. 08 4月, 2020 2 次提交
  23. 03 4月, 2020 1 次提交
  25. 23 1月, 2020 1 次提交
  27. 31 12月, 2019 1 次提交
    • J
      x86/kasan: Print original address on #GP · 2f004eea
      由 Jann Horn 提交于 
      Make #GP exceptions caused by out-of-bounds KASAN shadow accesses easier
to understand by computing the address of the original access and
printing that. More details are in the comments in the patch.

This turns an error like this:

  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault, probably for non-canonical address
      0xe017577ddf75b7dd: 0000 [#1] PREEMPT SMP KASAN PTI

into this:

  general protection fault, probably for non-canonical address
      0xe017577ddf75b7dd: 0000 [#1] PREEMPT SMP KASAN PTI
  KASAN: maybe wild-memory-access in range
      [0x00badbeefbadbee8-0x00badbeefbadbeef]

The hook is placed in architecture-independent code, but is currently
only wired up to the X86 exception handler because I'm not sufficiently
familiar with the address space layout and exception handling mechanisms
on other architectures.
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191218231150.12139-4-jannh@google.com
      2f004eea
  29. 18 12月, 2019 2 次提交
    • D
      kasan: use apply_to_existing_page_range() for releasing vmalloc shadow · e218f1ca
      由 Daniel Axtens 提交于 
      kasan_release_vmalloc uses apply_to_page_range to release vmalloc
shadow.  Unfortunately, apply_to_page_range can allocate memory to fill
in page table entries, which is not what we want.

Also, kasan_release_vmalloc is called under free_vmap_area_lock, so if
apply_to_page_range does allocate memory, we get a sleep in atomic bug:

	BUG: sleeping function called from invalid context at mm/page_alloc.c:4681
	in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 15087, name:

	Call Trace:
	 __dump_stack lib/dump_stack.c:77 [inline]
	 dump_stack+0x199/0x216 lib/dump_stack.c:118
	 ___might_sleep.cold.97+0x1f5/0x238 kernel/sched/core.c:6800
	 __might_sleep+0x95/0x190 kernel/sched/core.c:6753
	 prepare_alloc_pages mm/page_alloc.c:4681 [inline]
	 __alloc_pages_nodemask+0x3cd/0x890 mm/page_alloc.c:4730
	 alloc_pages_current+0x10c/0x210 mm/mempolicy.c:2211
	 alloc_pages include/linux/gfp.h:532 [inline]
	 __get_free_pages+0xc/0x40 mm/page_alloc.c:4786
	 __pte_alloc_one_kernel include/asm-generic/pgalloc.h:21 [inline]
	 pte_alloc_one_kernel include/asm-generic/pgalloc.h:33 [inline]
	 __pte_alloc_kernel+0x1d/0x200 mm/memory.c:459
	 apply_to_pte_range mm/memory.c:2031 [inline]
	 apply_to_pmd_range mm/memory.c:2068 [inline]
	 apply_to_pud_range mm/memory.c:2088 [inline]
	 apply_to_p4d_range mm/memory.c:2108 [inline]
	 apply_to_page_range+0x77d/0xa00 mm/memory.c:2133
	 kasan_release_vmalloc+0xa7/0xc0 mm/kasan/common.c:970
	 __purge_vmap_area_lazy+0xcbb/0x1f30 mm/vmalloc.c:1313
	 try_purge_vmap_area_lazy mm/vmalloc.c:1332 [inline]
	 free_vmap_area_noflush+0x2ca/0x390 mm/vmalloc.c:1368
	 free_unmap_vmap_area mm/vmalloc.c:1381 [inline]
	 remove_vm_area+0x1cc/0x230 mm/vmalloc.c:2209
	 vm_remove_mappings mm/vmalloc.c:2236 [inline]
	 __vunmap+0x223/0xa20 mm/vmalloc.c:2299
	 __vfree+0x3f/0xd0 mm/vmalloc.c:2356
	 __vmalloc_area_node mm/vmalloc.c:2507 [inline]
	 __vmalloc_node_range+0x5d5/0x810 mm/vmalloc.c:2547
	 __vmalloc_node mm/vmalloc.c:2607 [inline]
	 __vmalloc_node_flags mm/vmalloc.c:2621 [inline]
	 vzalloc+0x6f/0x80 mm/vmalloc.c:2666
	 alloc_one_pg_vec_page net/packet/af_packet.c:4233 [inline]
	 alloc_pg_vec net/packet/af_packet.c:4258 [inline]
	 packet_set_ring+0xbc0/0x1b50 net/packet/af_packet.c:4342
	 packet_setsockopt+0xed7/0x2d90 net/packet/af_packet.c:3695
	 __sys_setsockopt+0x29b/0x4d0 net/socket.c:2117
	 __do_sys_setsockopt net/socket.c:2133 [inline]
	 __se_sys_setsockopt net/socket.c:2130 [inline]
	 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2130
	 do_syscall_64+0xfa/0x780 arch/x86/entry/common.c:294
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Switch to using the apply_to_existing_page_range() helper instead, which
won't allocate memory.

[akpm@linux-foundation.org: s/apply_to_existing_pages/apply_to_existing_page_range/]
Link: http://lkml.kernel.org/r/20191205140407.1874-2-dja@axtens.net
Fixes: 3c5c3cfb ("kasan: support backing vmalloc space with real shadow memory")
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e218f1ca
    • A
      kasan: fix crashes on access to memory mapped by vm_map_ram() · d98c9e83
      由 Andrey Ryabinin 提交于 
      With CONFIG_KASAN_VMALLOC=y any use of memory obtained via vm_map_ram()
will crash because there is no shadow backing that memory.

Instead of sprinkling additional kasan_populate_vmalloc() calls all over
the vmalloc code, move it into alloc_vmap_area(). This will fix
vm_map_ram() and simplify the code a bit.

[aryabinin@virtuozzo.com: v2]
  Link: http://lkml.kernel.org/r/20191205095942.1761-1-aryabinin@virtuozzo.comLink: http://lkml.kernel.org/r/20191204204534.32202-1-aryabinin@virtuozzo.com
Fixes: 3c5c3cfb ("kasan: support backing vmalloc space with real shadow memory")
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NUladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Alexander Potapenko <glider@google.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d98c9e83
  31. 05 12月, 2019 1 次提交
  33. 02 12月, 2019 1 次提交
    • D
      kasan: support backing vmalloc space with real shadow memory · 3c5c3cfb
      由 Daniel Axtens 提交于 
      Patch series "kasan: support backing vmalloc space with real shadow
memory", v11.

Currently, vmalloc space is backed by the early shadow page.  This means
that kasan is incompatible with VMAP_STACK.

This series provides a mechanism to back vmalloc space with real,
dynamically allocated memory.  I have only wired up x86, because that's
the only currently supported arch I can work with easily, but it's very
easy to wire up other architectures, and it appears that there is some
work-in-progress code to do this on arm64 and s390.

This has been discussed before in the context of VMAP_STACK:
 - https://bugzilla.kernel.org/show_bug.cgi?id=202009
 - https://lkml.org/lkml/2018/7/22/198
 - https://lkml.org/lkml/2019/7/19/822

In terms of implementation details:

Most mappings in vmalloc space are small, requiring less than a full
page of shadow space.  Allocating a full shadow page per mapping would
therefore be wasteful.  Furthermore, to ensure that different mappings
use different shadow pages, mappings would have to be aligned to
KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE.

Instead, share backing space across multiple mappings.  Allocate a
backing page when a mapping in vmalloc space uses a particular page of
the shadow region.  This page can be shared by other vmalloc mappings
later on.

We hook in to the vmap infrastructure to lazily clean up unused shadow
memory.

Testing with test_vmalloc.sh on an x86 VM with 2 vCPUs shows that:

 - Turning on KASAN, inline instrumentation, without vmalloc, introuduces
   a 4.1x-4.2x slowdown in vmalloc operations.

 - Turning this on introduces the following slowdowns over KASAN:
     * ~1.76x slower single-threaded (test_vmalloc.sh performance)
     * ~2.18x slower when both cpus are performing operations
       simultaneously (test_vmalloc.sh sequential_test_order=1)

This is unfortunate but given that this is a debug feature only, not the
end of the world.  The benchmarks are also a stress-test for the vmalloc
subsystem: they're not indicative of an overall 2x slowdown!

This patch (of 4):

Hook into vmalloc and vmap, and dynamically allocate real shadow memory
to back the mappings.

Most mappings in vmalloc space are small, requiring less than a full
page of shadow space.  Allocating a full shadow page per mapping would
therefore be wasteful.  Furthermore, to ensure that different mappings
use different shadow pages, mappings would have to be aligned to
KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE.

Instead, share backing space across multiple mappings.  Allocate a
backing page when a mapping in vmalloc space uses a particular page of
the shadow region.  This page can be shared by other vmalloc mappings
later on.

We hook in to the vmap infrastructure to lazily clean up unused shadow
memory.

To avoid the difficulties around swapping mappings around, this code
expects that the part of the shadow region that covers the vmalloc space
will not be covered by the early shadow page, but will be left unmapped.
This will require changes in arch-specific code.

This allows KASAN with VMAP_STACK, and may be helpful for architectures
that do not have a separate module space (e.g.  powerpc64, which I am
currently working on).  It also allows relaxing the module alignment
back to PAGE_SIZE.

Testing with test_vmalloc.sh on an x86 VM with 2 vCPUs shows that:

 - Turning on KASAN, inline instrumentation, without vmalloc, introuduces
   a 4.1x-4.2x slowdown in vmalloc operations.

 - Turning this on introduces the following slowdowns over KASAN:
     * ~1.76x slower single-threaded (test_vmalloc.sh performance)
     * ~2.18x slower when both cpus are performing operations
       simultaneously (test_vmalloc.sh sequential_test_order=3D1)

This is unfortunate but given that this is a debug feature only, not the
end of the world.

The full benchmark results are:

Performance

                              No KASAN      KASAN original x baseline  KASAN vmalloc x baseline    x KASAN

fix_size_alloc_test             662004            11404956      17.23       19144610      28.92       1.68
full_fit_alloc_test             710950            12029752      16.92       13184651      18.55       1.10
long_busy_list_alloc_test      9431875            43990172       4.66       82970178       8.80       1.89
random_size_alloc_test         5033626            23061762       4.58       47158834       9.37       2.04
fix_align_alloc_test           1252514            15276910      12.20       31266116      24.96       2.05
random_size_align_alloc_te     1648501            14578321       8.84       25560052      15.51       1.75
align_shift_alloc_test             147                 830       5.65           5692      38.72       6.86
pcpu_alloc_test                  80732              125520       1.55         140864       1.74       1.12
Total Cycles              119240774314        763211341128       6.40  1390338696894      11.66       1.82

Sequential, 2 cpus

                              No KASAN      KASAN original x baseline  KASAN vmalloc x baseline    x KASAN

fix_size_alloc_test            1423150            14276550      10.03       27733022      19.49       1.94
full_fit_alloc_test            1754219            14722640       8.39       15030786       8.57       1.02
long_busy_list_alloc_test     11451858            52154973       4.55      107016027       9.34       2.05
random_size_alloc_test         5989020            26735276       4.46       68885923      11.50       2.58
fix_align_alloc_test           2050976            20166900       9.83       50491675      24.62       2.50
random_size_align_alloc_te     2858229            17971700       6.29       38730225      13.55       2.16
align_shift_alloc_test             405                6428      15.87          26253      64.82       4.08
pcpu_alloc_test                 127183              151464       1.19         216263       1.70       1.43
Total Cycles               54181269392        308723699764       5.70   650772566394      12.01       2.11
fix_size_alloc_test            1420404            14289308      10.06       27790035      19.56       1.94
full_fit_alloc_test            1736145            14806234       8.53       15274301       8.80       1.03
long_busy_list_alloc_test     11404638            52270785       4.58      107550254       9.43       2.06
random_size_alloc_test         6017006            26650625       4.43       68696127      11.42       2.58
fix_align_alloc_test           2045504            20280985       9.91       50414862      24.65       2.49
random_size_align_alloc_te     2845338            17931018       6.30       38510276      13.53       2.15
align_shift_alloc_test             472                3760       7.97           9656      20.46       2.57
pcpu_alloc_test                 118643              132732       1.12         146504       1.23       1.10
Total Cycles               54040011688        309102805492       5.72   651325675652      12.05       2.11

[dja@axtens.net: fixups]
  Link: http://lkml.kernel.org/r/20191120052719.7201-1-dja@axtens.net
Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D202009
Link: http://lkml.kernel.org/r/20191031093909.9228-2-dja@axtens.net
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [shadow rework]
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Co-developed-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NVasily Gorbik <gor@linux.ibm.com>
Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3c5c3cfb
  35. 25 9月, 2019 3 次提交
  37. 25 8月, 2019 1 次提交
  39. 13 7月, 2019 3 次提交
  41. 02 6月, 2019 1 次提交
  43. 29 4月, 2019 1 次提交
    • T
      mm/kasan: Simplify stacktrace handling · 880e049c
      由 Thomas Gleixner 提交于 
      Replace the indirection through struct stack_trace by using the storage
array based interfaces.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Acked-by: NDmitry Vyukov <dvyukov@google.com>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094801.963261479@linutronix.de
      880e049c
  45. 15 4月, 2019 1 次提交
  47. 09 4月, 2019 1 次提交
  49. 03 4月, 2019 1 次提交
    • P
      x86/uaccess, kasan: Fix KASAN vs SMAP · 57b78a62
      由 Peter Zijlstra 提交于 
      KASAN inserts extra code for every LOAD/STORE emitted by te compiler.
Much of this code is simple and safe to run with AC=1, however the
kasan_report() function, called on error, is most certainly not safe
to call with AC=1.

Therefore wrap kasan_report() in user_access_{save,restore}; which for
x86 SMAP, saves/restores EFLAGS and clears AC before calling the real
function.

Also ensure all the functions are without __fentry__ hook. The
function tracer is also not safe.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      57b78a62
  51. 30 3月, 2019 1 次提交