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SP: LargeAlloc return CBChunk & chase consequences

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Even if we opt not to bound these pointers internally (if they aren't headed out
to the user program or we later derive bounded pointers), they should still be
annotated as something other than CBArena, ensuring that we do not attempt to
use them for general amplification.
This commit is contained in:
Nathaniel Filardo
2021-04-01 13:20:17 +01:00
committed by Nathaniel Wesley Filardo
parent 54fec3821f
commit f7821e11eb
10 changed files with 175 additions and 126 deletions
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99
src/mem/alloc.h
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@@ -638,10 +638,10 @@ namespace snmalloc
};
SlabList small_classes[NUM_SMALL_CLASSES];
DLList<Mediumslab, CapPtrCBArena> medium_classes[NUM_MEDIUM_CLASSES];
DLList<Mediumslab, CapPtrCBChunk> medium_classes[NUM_MEDIUM_CLASSES];
DLList<Superslab> super_available;
DLList<Superslab> super_only_short_available;
DLList<Superslab, CapPtrCBChunk> super_available;
DLList<Superslab, CapPtrCBChunk> super_only_short_available;
RemoteCache remote;
@@ -901,7 +901,7 @@ namespace snmalloc
}
SNMALLOC_FAST_PATH void dealloc_not_large_local(
CapPtr<Superslab, CBArena> super,
CapPtr<Superslab, CBChunkD> super,
CapPtr<Remote, CBArena> p_auth_offseted,
sizeclass_t sizeclass)
{
@@ -963,28 +963,27 @@ namespace snmalloc
handle_message_queue_inner();
}
Superslab* get_superslab()
CapPtr<Superslab, CBChunk> get_superslab()
{
Superslab* super = super_available.get_head();
auto super = super_available.get_head();
if (super != nullptr)
return super;
super = large_allocator
.template alloc<NoZero>(0, SUPERSLAB_SIZE, SUPERSLAB_SIZE)
.template as_reinterpret<Superslab>()
.unsafe_capptr;
.template as_reinterpret<Superslab>();
if (super == nullptr)
return super;
super->init(public_state());
chunkmap().set_slab(CapPtr<Superslab, CBArena>(super));
chunkmap().set_slab(super);
super_available.insert(super);
return super;
}
void reposition_superslab(Superslab* super)
void reposition_superslab(CapPtr<Superslab, CBChunk> super)
{
switch (super->get_status())
{
@@ -1025,11 +1024,12 @@ namespace snmalloc
{
// Pull a short slab from the list of superslabs that have only the
// short slab available.
Superslab* super = super_only_short_available.pop();
CapPtr<Superslab, CBChunk> super = super_only_short_available.pop();
if (super != nullptr)
{
auto slab = Superslab::alloc_short_slab(super, sizeclass);
auto slab =
Superslab::alloc_short_slab(super.unsafe_capptr, sizeclass);
SNMALLOC_ASSERT(super->is_full());
return CapPtr<Slab, CBArena>(slab);
}
@@ -1039,17 +1039,17 @@ namespace snmalloc
if (super == nullptr)
return nullptr;
auto slab = Superslab::alloc_short_slab(super, sizeclass);
auto slab = Superslab::alloc_short_slab(super.unsafe_capptr, sizeclass);
reposition_superslab(super);
return CapPtr<Slab, CBArena>(slab);
}
Superslab* super = get_superslab();
auto super = get_superslab();
if (super == nullptr)
return nullptr;
auto slab = Superslab::alloc_slab(super, sizeclass);
auto slab = Superslab::alloc_slab(super.unsafe_capptr, sizeclass);
reposition_superslab(super);
return CapPtr<Slab, CBArena>(slab);
}
@@ -1233,7 +1233,7 @@ namespace snmalloc
}
SNMALLOC_FAST_PATH void small_dealloc_unchecked(
CapPtr<Superslab, CBArena> super,
CapPtr<Superslab, CBChunkD> super,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1246,7 +1246,7 @@ namespace snmalloc
}
SNMALLOC_FAST_PATH void small_dealloc_checked_chunkmap(
CapPtr<Superslab, CBArena> super,
CapPtr<Superslab, CBChunkD> super,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1260,8 +1260,8 @@ namespace snmalloc
}
SNMALLOC_FAST_PATH void small_dealloc_checked_sizeclass(
CapPtr<Superslab, CBArena> super,
CapPtr<Slab, CBArena> slab,
CapPtr<Superslab, CBChunkD> super,
CapPtr<Slab, CBChunkD> slab,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1274,8 +1274,8 @@ namespace snmalloc
}
SNMALLOC_FAST_PATH void small_dealloc_start(
CapPtr<Superslab, CBArena> super,
CapPtr<Slab, CBArena> slab,
CapPtr<Superslab, CBChunkD> super,
CapPtr<Slab, CBChunkD> slab,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1295,8 +1295,8 @@ namespace snmalloc
}
SNMALLOC_FAST_PATH void small_dealloc_offseted(
CapPtr<Superslab, CBArena> super,
CapPtr<Slab, CBArena> slab,
CapPtr<Superslab, CBChunkD> super,
CapPtr<Slab, CBChunkD> slab,
CapPtr<FreeObject, CBArena> p,
sizeclass_t sizeclass)
{
@@ -1306,8 +1306,8 @@ namespace snmalloc
}
SNMALLOC_FAST_PATH void small_dealloc_offseted_inner(
CapPtr<Superslab, CBArena> super,
CapPtr<Slab, CBArena> slab,
CapPtr<Superslab, CBChunkD> super,
CapPtr<Slab, CBChunkD> slab,
CapPtr<FreeObject, CBArena> p,
sizeclass_t sizeclass)
{
@@ -1318,8 +1318,8 @@ namespace snmalloc
}
SNMALLOC_SLOW_PATH void small_dealloc_offseted_slow(
CapPtr<Superslab, CBArena> super,
CapPtr<Slab, CBArena> slab,
CapPtr<Superslab, CBChunkD> super,
CapPtr<Slab, CBChunkD> slab,
CapPtr<FreeObject, CBArena> p,
sizeclass_t sizeclass)
{
@@ -1333,6 +1333,8 @@ namespace snmalloc
if (a == Superslab::NoStatusChange)
return;
auto super_slab = capptr_chunk_from_chunkd(super, SUPERSLAB_SIZE);
switch (super->get_status())
{
case Superslab::Full:
@@ -1345,29 +1347,29 @@ namespace snmalloc
{
if (was_full)
{
super_available.insert(super.unsafe_capptr);
super_available.insert(super_slab);
}
else
{
super_only_short_available.remove(super.unsafe_capptr);
super_available.insert(super.unsafe_capptr);
super_only_short_available.remove(super_slab);
super_available.insert(super_slab);
}
break;
}
case Superslab::OnlyShortSlabAvailable:
{
super_only_short_available.insert(super.unsafe_capptr);
super_only_short_available.insert(super_slab);
break;
}
case Superslab::Empty:
{
super_available.remove(super.unsafe_capptr);
super_available.remove(super_slab);
chunkmap().clear_slab(super);
chunkmap().clear_slab(super_slab);
large_allocator.dealloc(
super.template as_reinterpret<Largeslab>(), 0);
super_slab.template as_reinterpret<Largeslab>(), 0);
stats().superslab_push();
break;
}
@@ -1381,7 +1383,7 @@ namespace snmalloc
sizeclass_t medium_class = sizeclass - NUM_SMALL_CLASSES;
auto sc = &medium_classes[medium_class];
auto slab = sc->get_head();
CapPtr<Mediumslab, CBChunk> slab = sc->get_head();
CapPtr<void, CBAllocE> p;
if (slab != nullptr)
@@ -1437,7 +1439,7 @@ namespace snmalloc
SNMALLOC_FAST_PATH
void medium_dealloc_unchecked(
CapPtr<Mediumslab, CBArena> slab,
CapPtr<Mediumslab, CBChunkD> slab,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1451,7 +1453,7 @@ namespace snmalloc
SNMALLOC_FAST_PATH
void medium_dealloc_checked_chunkmap(
CapPtr<Mediumslab, CBArena> slab,
CapPtr<Mediumslab, CBChunkD> slab,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1465,7 +1467,7 @@ namespace snmalloc
SNMALLOC_FAST_PATH
void medium_dealloc_checked_sizeclass(
CapPtr<Mediumslab, CBArena> slab,
CapPtr<Mediumslab, CBChunkD> slab,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1480,7 +1482,7 @@ namespace snmalloc
SNMALLOC_FAST_PATH
void medium_dealloc_start(
CapPtr<Mediumslab, CBArena> slab,
CapPtr<Mediumslab, CBChunkD> slab,
CapPtr<void, CBArena> p_auth,
CapPtr<void, CBAllocE> p_ret,
sizeclass_t sizeclass)
@@ -1498,31 +1500,34 @@ namespace snmalloc
SNMALLOC_FAST_PATH
void medium_dealloc_local(
CapPtr<Mediumslab, CBArena> slab,
CapPtr<Mediumslab, CBChunkD> slab,
CapPtr<void, CBArena> p,
sizeclass_t sizeclass)
{
stats().sizeclass_dealloc(sizeclass);
bool was_full = Mediumslab::dealloc(slab, p);
auto slab_bounded = capptr_chunk_from_chunkd(slab, SUPERSLAB_SIZE);
if (Mediumslab::empty(slab))
{
if (!was_full)
{
sizeclass_t medium_class = sizeclass - NUM_SMALL_CLASSES;
auto sc = &medium_classes[medium_class];
sc->remove(slab);
sc->remove(slab_bounded);
}
chunkmap().clear_slab(slab);
large_allocator.dealloc(slab.template as_reinterpret<Largeslab>(), 0);
chunkmap().clear_slab(slab_bounded);
large_allocator.dealloc(
slab_bounded.template as_reinterpret<Largeslab>(), 0);
stats().superslab_push();
}
else if (was_full)
{
sizeclass_t medium_class = sizeclass - NUM_SMALL_CLASSES;
auto sc = &medium_classes[medium_class];
sc->insert(slab);
sc->insert(slab_bounded);
}
}
@@ -1549,7 +1554,7 @@ namespace snmalloc
if (large_class == 0)
size = rsize;
auto p =
CapPtr<Largeslab, CBChunk> p =
large_allocator.template alloc<zero_mem>(large_class, rsize, size);
if (likely(p != nullptr))
{
@@ -1615,13 +1620,13 @@ namespace snmalloc
}
size_t large_class = chunkmap_slab_kind - SUPERSLAB_BITS;
auto slab = Aal::capptr_bound<Largeslab, CBChunk>(p_auth, size);
chunkmap().clear_large_size(p_auth, size);
chunkmap().clear_large_size(slab, size);
stats().large_dealloc(large_class);
// Initialise in order to set the correct SlabKind.
auto slab = p_auth.template as_static<Largeslab>();
slab->init();
large_allocator.dealloc(slab, large_class);
}