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fix mi_is_valid_pointer bit index search (related to issue #478)

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Daan 2021-10-27 10:35:16 -07:00
parent 54b65a556c
commit 1568dbb9e4
1 changed files with 15 additions and 5 deletions
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20
src/segment-cache.c
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@ -234,9 +234,11 @@ static size_t mi_segment_map_index_of(const mi_segment_t* segment, size_t* bitid
return MI_SEGMENT_MAP_WSIZE;
}
else {
uintptr_t segindex = ((uintptr_t)segment) / MI_SEGMENT_SIZE;
const uintptr_t segindex = ((uintptr_t)segment) / MI_SEGMENT_SIZE;
*bitidx = segindex % MI_INTPTR_BITS;
return (segindex / MI_INTPTR_BITS);
const size_t mapindex = segindex / MI_INTPTR_BITS;
mi_assert_internal(mapindex < MI_SEGMENT_MAP_WSIZE);
return mapindex;
}
}
@ -290,13 +292,21 @@ static mi_segment_t* _mi_segment_of(const void* p) {
loindex = index;
lobitidx = mi_bsr(lobits); // lobits != 0
}
else if (index == 0) {
return NULL;
}
else {
mi_assert_internal(index > 0);
uintptr_t lomask = mask;
loindex = index - 1;
while (loindex > 0 && (lomask = mi_atomic_load_relaxed(&mi_segment_map[loindex])) == 0) loindex--;
if (loindex==0) return NULL;
loindex = index;
do {
loindex--;
lomask = mi_atomic_load_relaxed(&mi_segment_map[loindex]);
} while (lomask != 0 && loindex > 0);
if (lomask == 0) return NULL;
lobitidx = mi_bsr(lomask); // lomask != 0
}
mi_assert_internal(loindex < MI_SEGMENT_MAP_WSIZE);
// take difference as the addresses could be larger than the MAX_ADDRESS space.
size_t diff = (((index - loindex) * (8*MI_INTPTR_SIZE)) + bitidx - lobitidx) * MI_SEGMENT_SIZE;
segment = (mi_segment_t*)((uint8_t*)segment - diff);