From 5729e06c819184b7ba40869c1ad53e1a463040b2 Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Thu, 18 May 2023 10:55:10 -0400 Subject: [PATCH] maple_tree: fix static analyser cppcheck issue Patch series "Maple tree mas_{next,prev}_range() and cleanup", v4. This patchset contains a number of clean ups to the code to make it more usable (next/prev range), the addition of debug output formatting, the addition of printing the maple state information in the WARN_ON/BUG_ON code. There is also work done here to keep nodes active during iterations to reduce the necessity of re-walking the tree. Finally, there is a new interface added to move to the next or previous range in the tree, even if it is empty. The organisation of the patches is as follows: 0001-0004 - Small clean ups 0005-0018 - Additional debug options and WARN_ON/BUG_ON changes 0019 - Test module __init and __exit addition 0020-0021 - More functional clean ups 0022-0026 - Changes to keep nodes active 0027-0034 - Add new mas_{prev,next}_range() 0035 - Use new mas_{prev,next}_range() in mmap_region() This patch (of 35): Static analyser of the maple tree code noticed that the split variable is being used to dereference into an array prior to checking the variable itself. Fix this issue by changing the order of the statement to check the variable first. Link: https://lkml.kernel.org/r/20230518145544.1722059-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20230518145544.1722059-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Reported-by: David Binderman Reviewed-by: Peng Zhang Cc: Sergey Senozhatsky Cc: Vernon Yang Cc: Wei Yang Signed-off-by: Andrew Morton --- lib/maple_tree.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 35264f1936a3..0b375a63c153 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -1943,8 +1943,9 @@ static inline int mab_calc_split(struct ma_state *mas, * causes one node to be deficient. * NOTE: mt_min_slots is 1 based, b_end and split are zero. */ - while (((bn->pivot[split] - min) < slot_count - 1) && - (split < slot_count - 1) && (b_end - split > slot_min)) + while ((split < slot_count - 1) && + ((bn->pivot[split] - min) < slot_count - 1) && + (b_end - split > slot_min)) split++; }