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authorMagnus Lång <[email protected]>2016-05-23 15:41:31 +0200
committerMagnus Lång <[email protected]>2016-07-06 16:08:20 +0200
commitf0131c58c42a286c8b3f611b47106393a37197b6 (patch)
treecaefc37baef32b065e69f23cc363a83ff70dcd12 /erts/emulator/beam
parent3b409021a70427bb2fe3834707edf822b6afce2d (diff)
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check_process_code: Sweep HiPE stack for literals
Because check_process_code neglected checking the HiPE stack for references to the literal area, such references would survive the purge and subsequent deletion of a module and its literal area. These dangling references would then cause incorrect behaviour or even hard crashes of the VM. By simply adding a scan of the HiPE stack to check_process_code and erts_garbage_collect_literals, this problem is fixed. In order to support full stack walks without deleting the graylimit trap, a new stack walking interface function, nstack_walk_init_sdesc_ignore_trap() was introduced.
Diffstat (limited to 'erts/emulator/beam')
-rw-r--r--erts/emulator/beam/beam_bif_load.c8
-rw-r--r--erts/emulator/beam/erl_gc.c104
2 files changed, 61 insertions, 51 deletions
diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index 15e878ba65..92815b2bcd 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -37,6 +37,10 @@
#include "erl_bits.h"
#include "erl_thr_progress.h"
+#ifdef HIPE
+# include "hipe_stack.h"
+#endif
+
static void set_default_trace_pattern(Eterm module);
static Eterm check_process_code(Process* rp, Module* modp, Uint flags, int *redsp, int fcalls);
static void delete_code(Module* modp);
@@ -916,6 +920,10 @@ check_process_code(Process* rp, Module* modp, Uint flags, int *redsp, int fcalls
}
if (any_heap_ref_ptrs(rp->stop, rp->hend, literals, lit_bsize))
goto try_literal_gc;
+#ifdef HIPE
+ if (nstack_any_heap_ref_ptrs(rp, literals, lit_bsize))
+ goto try_literal_gc;
+#endif
if (any_heap_refs(rp->heap, rp->htop, literals, lit_bsize))
goto try_literal_gc;
if (any_heap_refs(rp->old_heap, rp->old_htop, literals, lit_bsize))
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index d0d74bbf44..29646719d0 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -882,6 +882,58 @@ erts_garbage_collect_hibernate(Process* p)
}
+/*
+ * HiPE native code stack scanning procedures:
+ * - fullsweep_nstack()
+ * - gensweep_nstack()
+ * - offset_nstack()
+ * - sweep_literals_nstack()
+ */
+#if defined(HIPE)
+
+#define GENSWEEP_NSTACK(p,old_htop,n_htop) \
+ do { \
+ Eterm *tmp_old_htop = old_htop; \
+ Eterm *tmp_n_htop = n_htop; \
+ gensweep_nstack((p), &tmp_old_htop, &tmp_n_htop); \
+ old_htop = tmp_old_htop; \
+ n_htop = tmp_n_htop; \
+ } while(0)
+
+/*
+ * offset_nstack() can ignore the descriptor-based traversal the other
+ * nstack procedures use and simply call offset_heap_ptr() instead.
+ * This relies on two facts:
+ * 1. The only live non-Erlang terms on an nstack are return addresses,
+ * and they will be skipped thanks to the low/high range check.
+ * 2. Dead values, even if mistaken for pointers into the low/high area,
+ * can be offset safely since they won't be dereferenced.
+ *
+ * XXX: WARNING: If HiPE starts storing other non-Erlang values on the
+ * nstack, such as floats, then this will have to be changed.
+ */
+static ERTS_INLINE void offset_nstack(Process* p, Sint offs,
+ char* area, Uint area_size)
+{
+ if (p->hipe.nstack) {
+ ASSERT(p->hipe.nsp && p->hipe.nstend);
+ offset_heap_ptr(hipe_nstack_start(p), hipe_nstack_used(p),
+ offs, area, area_size);
+ }
+ else {
+ ASSERT(!p->hipe.nsp && !p->hipe.nstend);
+ }
+}
+
+#else /* !HIPE */
+
+#define fullsweep_nstack(p,n_htop) (n_htop)
+#define GENSWEEP_NSTACK(p,old_htop,n_htop) do{}while(0)
+#define offset_nstack(p,offs,area,area_size) do{}while(0)
+#define sweep_literals_nstack(p,old_htop,area,area_size) (old_htop)
+
+#endif /* HIPE */
+
void
erts_garbage_collect_literals(Process* p, Eterm* literals,
Uint byte_lit_size,
@@ -944,7 +996,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
area_size = byte_lit_size;
n = setup_rootset(p, p->arg_reg, p->arity, &rootset);
roots = rootset.roots;
- old_htop = p->old_htop;
+ old_htop = sweep_literals_nstack(p, p->old_htop, area, area_size);
while (n--) {
Eterm* g_ptr = roots->v;
Uint g_sz = roots->sz;
@@ -1211,56 +1263,6 @@ minor_collection(Process* p, ErlHeapFragment *live_hf_end,
return -1;
}
-/*
- * HiPE native code stack scanning procedures:
- * - fullsweep_nstack()
- * - gensweep_nstack()
- * - offset_nstack()
- */
-#if defined(HIPE)
-
-#define GENSWEEP_NSTACK(p,old_htop,n_htop) \
- do { \
- Eterm *tmp_old_htop = old_htop; \
- Eterm *tmp_n_htop = n_htop; \
- gensweep_nstack((p), &tmp_old_htop, &tmp_n_htop); \
- old_htop = tmp_old_htop; \
- n_htop = tmp_n_htop; \
- } while(0)
-
-/*
- * offset_nstack() can ignore the descriptor-based traversal the other
- * nstack procedures use and simply call offset_heap_ptr() instead.
- * This relies on two facts:
- * 1. The only live non-Erlang terms on an nstack are return addresses,
- * and they will be skipped thanks to the low/high range check.
- * 2. Dead values, even if mistaken for pointers into the low/high area,
- * can be offset safely since they won't be dereferenced.
- *
- * XXX: WARNING: If HiPE starts storing other non-Erlang values on the
- * nstack, such as floats, then this will have to be changed.
- */
-static ERTS_INLINE void offset_nstack(Process* p, Sint offs,
- char* area, Uint area_size)
-{
- if (p->hipe.nstack) {
- ASSERT(p->hipe.nsp && p->hipe.nstend);
- offset_heap_ptr(hipe_nstack_start(p), hipe_nstack_used(p),
- offs, area, area_size);
- }
- else {
- ASSERT(!p->hipe.nsp && !p->hipe.nstend);
- }
-}
-
-#else /* !HIPE */
-
-#define fullsweep_nstack(p,n_htop) (n_htop)
-#define GENSWEEP_NSTACK(p,old_htop,n_htop) do{}while(0)
-#define offset_nstack(p,offs,area,area_size) do{}while(0)
-
-#endif /* HIPE */
-
static void
do_minor(Process *p, ErlHeapFragment *live_hf_end,
char *mature, Uint mature_size,