diff options
| author | Peng Zhang <zhangpeng.00@bytedance.com> | 2023-05-05 22:58:29 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-24 17:32:51 +0100 |
| commit | 254ee530286aeb6d6de93d05b2247153df590af1 (patch) | |
| tree | 67cf407fe7680d616c6eacd50fa4a051362196f5 /lib | |
| parent | 6c4172d44cf971ed1f79d833eaafd8fef1b55cbd (diff) | |
| download | linux-254ee530286aeb6d6de93d05b2247153df590af1.tar.gz | |
maple_tree: make maple state reusable after mas_empty_area()
commit 0257d9908d38c0b1669af4bb1bc4dbca1f273fe6 upstream.
Make mas->min and mas->max point to a node range instead of a leaf entry
range. This allows mas to still be usable after mas_empty_area() returns.
Users would get unexpected results from other operations on the maple
state after calling the affected function.
For example, x86 MAP_32BIT mmap() acts as if there is no suitable gap when
there should be one.
Link: https://lkml.kernel.org/r/20230505145829.74574-1-zhangpeng.00@bytedance.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reported-by: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Reported-by: Tad <support@spotco.us>
Reported-by: Michael Keyes <mgkeyes@vigovproductions.net>
Link: https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.camel@intel.com/
Link: https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.camel@spotco.us/
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/maple_tree.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 9fe25ce9937b..b72268848ade 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -5338,15 +5338,9 @@ int mas_empty_area(struct ma_state *mas, unsigned long min, mt = mte_node_type(mas->node); pivots = ma_pivots(mas_mn(mas), mt); - if (offset) - mas->min = pivots[offset - 1] + 1; - - if (offset < mt_pivots[mt]) - mas->max = pivots[offset]; - - if (mas->index < mas->min) - mas->index = mas->min; - + min = mas_safe_min(mas, pivots, offset); + if (mas->index < min) + mas->index = min; mas->last = mas->index + size - 1; return 0; } |