When using nano malloc and the remaning heap space is not big enough to
fullfill the allocation, malloc will attempt to merge the last chunk in
the free list with a new allocation in order to create a bigger chunk.
This is successful, but the chunk still remains in the free_list, so
any later call to malloc can give out the same region without it first
being freed.
Possible sequence to verify:
void *p1 = malloc(3000);
void *p2 = malloc(4000);
void *p3 = malloc(5000);
void *p4 = malloc(6000);
void *p5 = malloc(7000);
free(p2);
free(p4);
void *p6 = malloc(35000);
free(p6);
void *p7 = malloc(42000);
void *p8 = malloc(32000);
Without the change, p7 and p8 points to the same address.
Requirement, after malloc(35000), there is less than 42000 bytes
available on the heap.
Contributed by STMicroelectronics
Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
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