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  1. 19 5月, 2018 3 次提交
    • R
      radix tree test suite: multi-order iteration race · fd8f58c4
      由 Ross Zwisler 提交于 
      Add a test which shows a race in the multi-order iteration code.  This
test reliably hits the race in under a second on my machine, and is the
result of a real bug report against kernel a production v4.15 based
kernel (4.15.6-300.fc27.x86_64).  With a real kernel this issue is hit
when using order 9 PMD DAX radix tree entries.

The race has to do with how we tear down multi-order sibling entries
when we are removing an item from the tree.  Remember that an order 2
entry looks like this:

  struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling]

where 'entry' is in some slot in the struct radix_tree_node, and the
three slots following 'entry' contain sibling pointers which point back
to 'entry.'

When we delete 'entry' from the tree, we call :

  radix_tree_delete()
    radix_tree_delete_item()
      __radix_tree_delete()
        replace_slot()

replace_slot() first removes the siblings in order from the first to the
last, then at then replaces 'entry' with NULL.  This means that for a
brief period of time we end up with one or more of the siblings removed,
so:

  struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling]

This causes an issue if you have a reader iterating over the slots in
the tree via radix_tree_for_each_slot() while only under
rcu_read_lock()/rcu_read_unlock() protection.  This is a common case in
mm/filemap.c.

The issue is that when __radix_tree_next_slot() => skip_siblings() tries
to skip over the sibling entries in the slots, it currently does so with
an exact match on the slot directly preceding our current slot.
Normally this works:

                                      V preceding slot
  struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling]
                                              ^ current slot

This lets you find the first sibling, and you skip them all in order.

But in the case where one of the siblings is NULL, that slot is skipped
and then our sibling detection is interrupted:

                                             V preceding slot
  struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling]
                                                    ^ current slot

This means that the sibling pointers aren't recognized since they point
all the way back to 'entry', so we think that they are normal internal
radix tree pointers.  This causes us to think we need to walk down to a
struct radix_tree_node starting at the address of 'entry'.

In a real running kernel this will crash the thread with a GP fault when
you try and dereference the slots in your broken node starting at
'entry'.

In the radix tree test suite this will be caught by the address
sanitizer:

  ==27063==ERROR: AddressSanitizer: heap-buffer-overflow on address
  0x60c0008ae400 at pc 0x00000040ce4f bp 0x7fa89b8fcad0 sp 0x7fa89b8fcac0
  READ of size 8 at 0x60c0008ae400 thread T3
      #0 0x40ce4e in __radix_tree_next_slot /home/rzwisler/project/linux/tools/testing/radix-tree/radix-tree.c:1660
      #1 0x4022cc in radix_tree_next_slot linux/../../../../include/linux/radix-tree.h:567
      #2 0x4022cc in iterator_func /home/rzwisler/project/linux/tools/testing/radix-tree/multiorder.c:655
      #3 0x7fa8a088d50a in start_thread (/lib64/libpthread.so.0+0x750a)
      #4 0x7fa8a03bd16e in clone (/lib64/libc.so.6+0xf516e)

Link: http://lkml.kernel.org/r/20180503192430.7582-5-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: CR, Sapthagirish <sapthagirish.cr@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fd8f58c4
    • R
      radix tree test suite: add item_delete_rcu() · 3e252fa7
      由 Ross Zwisler 提交于 
      Currently the lifetime of "struct item" entries in the radix tree are
not controlled by RCU, but are instead deleted inline as they are
removed from the tree.

In the following patches we add a test which has threads iterating over
items pulled from the tree and verifying them in an
rcu_read_lock()/rcu_read_unlock() section.  This means that though an
item has been removed from the tree it could still be being worked on by
other threads until the RCU grace period expires.  So, we need to
actually free the "struct item" structures at the end of the grace
period, just as we do with "struct radix_tree_node" items.

Link: http://lkml.kernel.org/r/20180503192430.7582-4-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: CR, Sapthagirish <sapthagirish.cr@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3e252fa7
    • R
      radix tree test suite: fix mapshift build target · 8d9fa88e
      由 Ross Zwisler 提交于 
      Commit c6ce3e2f ("radix tree test suite: Add config option for map
shift") introduced a phony makefile target called 'mapshift' that ends
up generating the file generated/map-shift.h.  This phony target was
then added as a dependency of the top level 'targets' build target,
which is what is run when you go to tools/testing/radix-tree and just
type 'make'.

Unfortunately, this phony target doesn't actually work as a dependency,
so you end up getting:

  $ make
  make: *** No rule to make target 'generated/map-shift.h', needed by 'main.o'.  Stop.
  make: *** Waiting for unfinished jobs....

Fix this by making the file generated/map-shift.h our real makefile
target, and add this a dependency of the top level build target.

Link: http://lkml.kernel.org/r/20180503192430.7582-2-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: CR, Sapthagirish <sapthagirish.cr@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8d9fa88e
  3. 11 5月, 2018 2 次提交
  5. 08 5月, 2018 1 次提交
  7. 02 5月, 2018 1 次提交
  9. 28 4月, 2018 2 次提交
    • M
      selftests: Fix lib.mk run_tests target shell script · a3355440
      由 Mathieu Desnoyers 提交于 
      Within run_tests target, the whole script needs to be executed within
the same shell and not as separate subshells, so the initial test_num
variable set to 0 is still present when executing "test_num=`echo
$$test_num+1 | bc`;".

Demonstration of the issue (make run_tests):

TAP version 13
(standard_in) 1: syntax error
selftests: basic_test
========================================
ok 1.. selftests: basic_test [PASS]
(standard_in) 1: syntax error
selftests: basic_percpu_ops_test
========================================
ok 1.. selftests: basic_percpu_ops_test [PASS]
(standard_in) 1: syntax error
selftests: param_test
========================================
ok 1.. selftests: param_test [PASS]

With fix applied:

TAP version 13
selftests: basic_test
========================================
ok 1..1 selftests: basic_test [PASS]
selftests: basic_percpu_ops_test
========================================
ok 1..2 selftests: basic_percpu_ops_test [PASS]
selftests: param_test
========================================
ok 1..3 selftests: param_test [PASS]
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 1f87c7c1 ("selftests: lib.mk: change RUN_TESTS to print messages in TAP13 format")
CC: Shuah Khan <shuahkh@osg.samsung.com>
CC: linux-kselftest@vger.kernel.org
Signed-off-by: NShuah Khan (Samsung OSG) <shuah@kernel.org>
      a3355440
    • A
      selftests: net: add in_netns.sh TEST_GEN_PROGS_EXTENDED · 9faedd64
      由 Anders Roxell 提交于 
      Script in_netns.sh is a utility function and not its own test so it
shouldn't be part of the TEST_PROGS. The in_netns.sh get used by
run_afpackettests.
To install in_netns.sh without being added to the main run_kselftest.sh
script use the TEST_GEN_PROGS_EXTENDED variable.

Fixes: 5ff9c1a3 ("selftests: net: add in_netns.sh to TEST_PROGS")
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9faedd64
  11. 27 4月, 2018 1 次提交
    • A
      x86/entry/64/compat: Preserve r8-r11 in int $0x80 · 8bb2610b
      由 Andy Lutomirski 提交于 
      32-bit user code that uses int $80 doesn't care about r8-r11.  There is,
however, some 64-bit user code that intentionally uses int $0x80 to invoke
32-bit system calls.  From what I've seen, basically all such code assumes
that r8-r15 are all preserved, but the kernel clobbers r8-r11.  Since I
doubt that there's any code that depends on int $0x80 zeroing r8-r11,
change the kernel to preserve them.

I suspect that very little user code is broken by the old clobber, since
r8-r11 are only rarely allocated by gcc, and they're clobbered by function
calls, so they only way we'd see a problem is if the same function that
invokes int $0x80 also spills something important to one of these
registers.

The current behavior seems to date back to the historical commit
"[PATCH] x86-64 merge for 2.6.4".  Before that, all regs were
preserved.  I can't find any explanation of why this change was made.

Update the test_syscall_vdso_32 testcase as well to verify the new
behavior, and it strengthens the test to make sure that the kernel doesn't
accidentally permute r8..r15.
Suggested-by: NDenys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/d4c4d9985fbe64f8c9e19291886453914b48caee.1523975710.git.luto@kernel.org
      8bb2610b
  13. 25 4月, 2018 3 次提交
  15. 23 4月, 2018 2 次提交
  17. 19 4月, 2018 1 次提交
    • Y
      tools/bpf: fix test_sock and test_sock_addr.sh failure · 0a0a7e00
      由 Yonghong Song 提交于 
      The bpf selftests test_sock and test_sock_addr.sh failed
in my test machine. The failure looks like:
    $ ./test_sock
    Test case: bind4 load with invalid access: src_ip6 .. [PASS]
    Test case: bind4 load with invalid access: mark .. [PASS]
    Test case: bind6 load with invalid access: src_ip4 .. [PASS]
    Test case: sock_create load with invalid access: src_port .. [PASS]
    Test case: sock_create load w/o expected_attach_type (compat mode) .. [FAIL]
    Test case: sock_create load w/ expected_attach_type .. [FAIL]
    Test case: attach type mismatch bind4 vs bind6 .. [FAIL]
    ...
    Summary: 4 PASSED, 12 FAILED
    $ ./test_sock_addr.sh
    Wait for testing IPv4/IPv6 to become available .....
    ERROR: Timeout waiting for test IP to become available.

In test_sock, bpf program loads failed due to hitting memlock limits.
In test_sock_addr.sh, my test machine is a ipv6 only test box and using
"ping" without specifying address family for an ipv6 address does not work.

This patch fixed the issue by including header bpf_rlimit.h in test_sock.c
and test_sock_addr.c, and specifying address family for ping command.

Cc: Andrey Ignatov <rdna@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Acked-by: NAndrey Ignatov <rdna@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      0a0a7e00
  19. 18 4月, 2018 1 次提交
    • M
      selftests/filesystems: Don't run dnotify_test by default · 8bf24e83
      由 Michael Ellerman 提交于 
      In commit ce290a19 ("selftests: add devpts selftests"), the
filesystems directory was added to the top-level selftests Makefile.

That had the effect of causing the existing dnotify_test in the
filesystems directory to now be run as part of the default selftests
test-run. Unfortunately dnotify_test is actually an infinite loop.

Fix it by moving dnotify_test to TEST_GEN_PROGS_EXTENDED, which says
that it's a generated file (ie. built) but should not be run as part
of the default test suite run (it's an "extended" test).

While we're here cleanup a few other things, devpts_pts should be in
TEST_GEN_PROGS to indicate that it's built, and with the above two
changes we no longer need a custom all or clean rule.

Fixes: ce290a19 ("selftests: add devpts selftests")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NChristian brauner <christian.brauner@ubuntu.com>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
      8bf24e83
  21. 16 4月, 2018 5 次提交
  23. 13 4月, 2018 3 次提交
  25. 12 4月, 2018 7 次提交
  27. 11 4月, 2018 2 次提交
  29. 10 4月, 2018 1 次提交
  31. 08 4月, 2018 5 次提交