Don't bitshift by negative amounts.

Don't bitshift by negative amounts when encoding/decoding run sizes in
chunk header maps.  This affected systems with page sizes greater than 8
KiB.

Reported by Ingvar Hagelund <ingvar@redpill-linpro.com>.
This commit is contained in:
Jason Evans
2015-08-19 14:12:05 -07:00
parent 6e98caf8f0
commit 5ef33a9f2b
4 changed files with 50 additions and 13 deletions

View File

@@ -39,7 +39,7 @@ JEMALLOC_INLINE_C arena_chunk_map_misc_t *
arena_miscelm_key_create(size_t size)
{
return ((arena_chunk_map_misc_t *)((size << CHUNK_MAP_SIZE_SHIFT) |
return ((arena_chunk_map_misc_t *)(arena_mapbits_size_encode(size) |
CHUNK_MAP_KEY));
}
@@ -58,8 +58,7 @@ arena_miscelm_key_size_get(const arena_chunk_map_misc_t *miscelm)
assert(arena_miscelm_is_key(miscelm));
return (((uintptr_t)miscelm & CHUNK_MAP_SIZE_MASK) >>
CHUNK_MAP_SIZE_SHIFT);
return (arena_mapbits_size_decode((uintptr_t)miscelm));
}
JEMALLOC_INLINE_C size_t
@@ -73,7 +72,7 @@ arena_miscelm_size_get(arena_chunk_map_misc_t *miscelm)
chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(miscelm);
pageind = arena_miscelm_to_pageind(miscelm);
mapbits = arena_mapbits_get(chunk, pageind);
return ((mapbits & CHUNK_MAP_SIZE_MASK) >> CHUNK_MAP_SIZE_SHIFT);
return (arena_mapbits_size_decode(mapbits));
}
JEMALLOC_INLINE_C int