linux-stable.git/lib/test_maple_tree.c, branch v6.5.7

maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states

2023-10-10T20:02:55+00:00

commit a8091f039c1ebf5cb0d5261e3613f18eb2a5d8b7 upstream.

When updating the maple tree iterator to avoid rewalks, an issue was
introduced when shifting beyond the limits.  This can be seen by trying to
go to the previous address of 0, which would set the maple node to
MAS_NONE and keep the range as the last entry.

Subsequent calls to mas_find() would then search upwards from mas->last
and skip the value at mas->index/mas->last.  This showed up as a bug in
mprotect which skips the actual VMA at the current range after attempting
to go to the previous VMA from 0.

Since MAS_NONE may already be set when searching for a value that isn't
contained within a node, changing the handling of MAS_NONE in mas_find()
would make the code more complicated and error prone.  Furthermore, there
was no way to tell which limit was hit, and thus which action to take
(next or the entry at the current range).

This solution is to add two states to track what happened with the
previous iterator action.  This allows for the expected behaviour of the
next command to return the correct item (either the item at the range
requested, or the next/previous).

Tests are also added and updated accordingly.

Link: https://lkml.kernel.org/r/20230921181236.509072-3-Liam.Howlett@oracle.com
Link: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b
Link: https://lore.kernel.org/linux-mm/20230921181236.509072-1-Liam.Howlett@oracle.com/
Fixes: 39193685d585 ("maple_tree: try harder to keep active node with mas_prev()")
Signed-off-by: Liam R. Howlett 
Reported-by: Pedro Falcato 
Closes: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b
Closes: https://bugs.archlinux.org/task/79656
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

maple_tree: fix 32 bit mas_next testing

2023-07-17T19:53:22+00:00

The test setup of mas_next is dependent on node entry size to create a 2
level tree, but the tests did not account for this in the expected value
when shifting beyond the scope of the tree.

Fix this by setting up the test to succeed depending on the node entries
which is dependent on the 32/64 bit setup.

Link: https://lkml.kernel.org/r/20230712173916.168805-1-Liam.Howlett@oracle.com
Fixes: 120b116208a0 ("maple_tree: reorganize testing to restore module testing")
Signed-off-by: Liam R. Howlett 
Reported-by: Geert Uytterhoeven 
  Closes: https://lore.kernel.org/linux-mm/CAMuHMdV4T53fOw7VPoBgPR7fP6RYqf=CBhD_y_vOg53zZX_DnA@mail.gmail.com/
Tested-by: Geert Uytterhoeven 
Cc: 
Signed-off-by: Andrew Morton

maple_tree: update testing code for mas_{next,prev,walk}

2023-06-09T23:25:35+00:00

Now that the functions have changed the limits, update the testing of the
maple tree to test these new settings.

Link: https://lkml.kernel.org/r/20230518145544.1722059-34-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: David Binderman 
Cc: Peng Zhang 
Cc: Sergey Senozhatsky 
Cc: Vernon Yang 
Cc: Wei Yang 
Signed-off-by: Andrew Morton

maple_tree: fix testing mas_empty_area()

2023-06-09T23:25:33+00:00

Empty area will return -EINVAL if the search window is smaller than the
requested size.  Fix the test case to check for this error code.

Link: https://lkml.kernel.org/r/20230518145544.1722059-27-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: David Binderman 
Cc: Peng Zhang 
Cc: Sergey Senozhatsky 
Cc: Vernon Yang 
Cc: Wei Yang 
Signed-off-by: Andrew Morton

maple_tree: revise limit checks in mas_empty_area{_rev}()

2023-06-09T23:25:33+00:00

Since the maple tree is inclusive in range, ensure that a range of 1 (min
= max) works for searching for a gap in either direction, and make sure
the size is at least 1 but not larger than the delta between min and max.

This commit also updates the testing.  Unfortunately there isn't a way to
safely update the tests and code without a test failure.

Link: https://lkml.kernel.org/r/20230518145544.1722059-26-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Suggested-by: Peng Zhang 
Cc: David Binderman 
Cc: Sergey Senozhatsky 
Cc: Vernon Yang 
Cc: Wei Yang 
Signed-off-by: Andrew Morton

maple_tree: add init and exit to test module

2023-06-09T23:25:31+00:00

The test functions are not needed after the module is removed, so mark
them as such.  Add __exit to the module removal function.  Some other
variables have been marked as const static as well.

Link: https://lkml.kernel.org/r/20230518145544.1722059-20-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Suggested-by: Andrew Morton 
Cc: David Binderman 
Cc: Peng Zhang 
Cc: Sergey Senozhatsky 
Cc: Vernon Yang 
Cc: Wei Yang 
Signed-off-by: Andrew Morton

maple_tree: make test code work without debug enabled

2023-06-09T23:25:31+00:00

The test code is less useful without debug, but can still do general
validations.  Define mt_dump(), mas_dump() and mas_wr_dump() as a noop if
debug is not enabled and document it in the test module information that
more information can be obtained with another kernel config option.

MT_BUG_ON() will report a failures without tree dumps, and the output will
be less useful.

Link: https://lkml.kernel.org/r/20230518145544.1722059-17-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: David Binderman 
Cc: Peng Zhang 
Cc: Sergey Senozhatsky 
Cc: Vernon Yang 
Cc: Wei Yang 
Signed-off-by: Andrew Morton

maple_tree: add format option to mt_dump()

2023-06-09T23:25:28+00:00

Allow different formatting strings to be used when dumping the tree. 
Currently supports hex and decimal.

Link: https://lkml.kernel.org/r/20230518145544.1722059-6-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Cc: David Binderman 
Cc: Peng Zhang 
Cc: Sergey Senozhatsky 
Cc: Vernon Yang 
Cc: Wei Yang 
Signed-off-by: Andrew Morton

test_maple_tree: add more testing for mas_empty_area()

2023-03-24T00:18:32+00:00

Test robust filling of an entire area of the tree, then test one beyond. 
This is to test the walking back up the tree at the end of nodes and error
condition.  Test inspired by the reproducer code provided by Snild Dolkow.

The last test in the function tests for the case of a corrupted maple
state caused by the incorrect limits set during mas_skip_node().  There
needs to be a gap in the second last child and last child, but the search
must rule out the second last child's gap.  This would avoid correcting
the maple state to the correct max limit and return an error.

Link: https://lkml.kernel.org/r/20230307180247.2220303-3-Liam.Howlett@oracle.com
Cc: Snild Dolkow 
Link: https://lore.kernel.org/linux-mm/cb8dc31a-fef2-1d09-f133-e9f7b9f9e77a@sony.com/
Fixes: e15e06a83923 ("lib/test_maple_tree: add testing for maple tree")
Signed-off-by: Liam R. Howlett 
Cc: Peng Zhang 
Cc: 
Signed-off-by: Andrew Morton

test_maple_tree: test modifications while iterating

2023-02-10T00:51:31+00:00

Add a testcase to ensure the iterator detects bad states on modifications
and does what the user expects

Link: https://lkml.kernel.org/r/20230120162650.984577-5-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Signed-off-by: Andrew Morton