[pypy-commit] pypy stmgc-c7: import stmgc/0492e398156b

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: stmgc-c7
Changeset: r70535:3b8d9d990e35
Date: 2014-04-09 13:06 +0200
http://bitbucket.org/pypy/pypy/changeset/3b8d9d990e35/

Log:	import stmgc/0492e398156b

diff --git a/rpython/translator/stm/src_stm/revision b/rpython/translator/stm/src_stm/revision
--- a/rpython/translator/stm/src_stm/revision
+++ b/rpython/translator/stm/src_stm/revision
@@ -1,1 +1,1 @@
-859b241ec058
+0492e398156b
diff --git a/rpython/translator/stm/src_stm/stm/setup.c b/rpython/translator/stm/src_stm/stm/setup.c
--- a/rpython/translator/stm/src_stm/stm/setup.c
+++ b/rpython/translator/stm/src_stm/stm/setup.c
@@ -10,7 +10,7 @@
                         PROT_READ | PROT_WRITE,
                         MAP_PAGES_FLAGS, -1, 0);
     if (result == MAP_FAILED)
-        stm_fatalerror("%s failed: %m\n", reason);
+        stm_fatalerror("%s failed: %m", reason);
 
     return result;
 }
@@ -132,17 +132,37 @@
     teardown_pages();
 }
 
+static void _shadowstack_trap_page(char *start, int prot)
+{
+    size_t bsize = STM_SHADOW_STACK_DEPTH * sizeof(struct stm_shadowentry_s);
+    char *end = start + bsize + 4095;
+    end -= (((uintptr_t)end) & 4095);
+    mprotect(end, 4096, prot);
+}
+
 static void _init_shadow_stack(stm_thread_local_t *tl)
 {
-    struct stm_shadowentry_s *s = (struct stm_shadowentry_s *)
-        malloc(STM_SHADOW_STACK_DEPTH * sizeof(struct stm_shadowentry_s));
-    assert(s);
+    size_t bsize = STM_SHADOW_STACK_DEPTH * sizeof(struct stm_shadowentry_s);
+    char *start = malloc(bsize + 8192);  /* for the trap page, plus rounding */
+    if (!start)
+        stm_fatalerror("can't allocate shadow stack");
+
+    /* set up a trap page: if the shadowstack overflows, it will
+       crash in a clean segfault */
+    _shadowstack_trap_page(start, PROT_NONE);
+
+    struct stm_shadowentry_s *s = (struct stm_shadowentry_s *)start;
     tl->shadowstack = s;
     tl->shadowstack_base = s;
 }
 
 static void _done_shadow_stack(stm_thread_local_t *tl)
 {
+    assert(tl->shadowstack >= tl->shadowstack_base);
+
+    char *start = (char *)tl->shadowstack_base;
+    _shadowstack_trap_page(start, PROT_READ | PROT_WRITE);
+
     free(tl->shadowstack_base);
     tl->shadowstack = NULL;
     tl->shadowstack_base = NULL;
diff --git a/rpython/translator/stm/src_stm/stm/weakref.c b/rpython/translator/stm/src_stm/stm/weakref.c
--- a/rpython/translator/stm/src_stm/stm/weakref.c
+++ b/rpython/translator/stm/src_stm/stm/weakref.c
@@ -35,7 +35,7 @@
     stm_char *point_to_loc = (stm_char*)WEAKREF_PTR(weakref, size);
 
     long i;
-    for (i = 1; i <= NB_SEGMENTS; i++) {
+    for (i = 0; i <= NB_SEGMENTS; i++) {
         char *base = get_segment_base(i);
         object_t ** ref_loc = (object_t **)REAL_ADDRESS(base, point_to_loc);
         *ref_loc = value;
@@ -58,11 +58,14 @@
                a young outside nursery object. */
             assert(_is_in_nursery(item));
             object_t *TLPREFIX *pforwarded_array = (object_t *TLPREFIX *)item;
+            ssize_t size = 16;
 
-            /* the following checks are done like in nursery.c: */
-            if (!(item->stm_flags & GCFLAG_HAS_SHADOW)
-                || (pforwarded_array[0] != GCWORD_MOVED)) {
-                /* weakref dies */
+            /* check if the weakref object was moved out of the nursery */
+            if (pforwarded_array[0] != GCWORD_MOVED) {
+                /* no: weakref dies */
+#ifndef NDEBUG
+                *WEAKREF_PTR(item, size) = (object_t *)-99;
+#endif
                 continue;
             }
 
@@ -70,15 +73,13 @@
 
             assert(!_is_young(item));
 
-            ssize_t size = 16;
             object_t *pointing_to = *WEAKREF_PTR(item, size);
             assert(pointing_to != NULL);
 
             if (_is_in_nursery(pointing_to)) {
                 object_t *TLPREFIX *pforwarded_array = (object_t *TLPREFIX *)pointing_to;
-                /* the following checks are done like in nursery.c: */
-                if (!(pointing_to->stm_flags & GCFLAG_HAS_SHADOW)
-                    || (pforwarded_array[0] != GCWORD_MOVED)) {
+                /* check if the target was moved out of the nursery */
+                if (pforwarded_array[0] != GCWORD_MOVED) {
                     /* pointing_to dies */
                     _set_weakref_in_all_segments(item, NULL);
                     continue;   /* no need to remember in old_weakrefs */
@@ -97,7 +98,9 @@
                     _set_weakref_in_all_segments(item, NULL);
                     continue;   /* no need to remember in old_weakrefs */
                 }
-                /* pointing_to was already old */
+                /* pointing_to is either a surviving young object outside
+                   the nursery, or it was already old; in both cases keeping
+                   the currently stored pointer is what we need */
             }
             LIST_APPEND(STM_PSEGMENT->old_weakrefs, item);
         }));
@@ -129,7 +132,7 @@
             stm_char *wr = (stm_char *)WEAKREF_PTR(weakref, size);
             char *real_wr = REAL_ADDRESS(pseg->pub.segment_base, wr);
             object_t *pointing_to = *(object_t **)real_wr;
-            assert(pointing_to != NULL);
+            assert((uintptr_t)pointing_to >= NURSERY_END);
             if (!mark_visited_test(pointing_to)) {
                 //assert(flag_page_private[(uintptr_t)weakref / 4096UL] != PRIVATE_PAGE);
                 _set_weakref_in_all_segments(weakref, NULL);