mm_memalign: avoid two adjacent free nodes situation. #8339
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original code assumes the previous node in physical must be ALLOCED, but other thread may free the previous node between mm_malloc() and mm_lock(), and the original code didn't condsider this, which will cause two adjacent free nodes situation and this should not be happened. This commit will merge the previous node and node if the previous node is free to avoid the situation discribed above. Signed-off-by: wangbowen6 <wangbowen6@xiaomi.com>
acassis
reviewed
Jan 29, 2023
Comment on lines
+159
to
+160
| prev = (FAR struct mm_freenode_s *) | ||
| ((FAR char *)node - node->preceding); |
There was a problem hiding this comment.
I think if you out it in a single line it will be smaller than 78 chars
There was a problem hiding this comment.
I tried, it's 79 chars, checkpatch.sh report this:
wangbowen@ubuntu:~/project/community/nuttx_rpmsg_server/nuttx$ tools/checkpatch.sh -g HEAD~...HEAD
/home/wangbowen/project/community/nuttx_rpmsg_server/nuttx/mm/mm_heap/mm_memalign.c:159:78: error: Long line found
xiaoxiang781216
approved these changes
Jan 30, 2023
GUIDINGLI
approved these changes
Jan 30, 2023
|
@yamt @masayuki2009 Could you review this patch? |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
Original mm_memalign code assumes the previous node in physical must be ALLOCED, but other thread may free the previous node between mm_malloc() and mm_lock(), and the original code didn't condsider this, which will cause two adjacent free nodes situation and this should not be happened.
This commit will merge the previous node and node if the previous node is free to avoid the situation discribed above.
Impact
memalign
Testing
vela and sim mmtest