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.

1 files changed, 17 insertions, 0 deletions

diff --git a/erts/emulator/hipe/hipe_x86_gc.h b/erts/emulator/hipe/hipe_x86_gc.h
index c22b28c2d5..00fe03d8f9 100644
--- a/erts/emulator/hipe/hipe_x86_gc.h
+++ b/erts/emulator/hipe/hipe_x86_gc.h
@@ -81,6 +81,23 @@ nstack_walk_init_sdesc(const Process *p, struct nstack_walk_state *state)
 #endif
 }
 
+static inline const struct sdesc*
+nstack_walk_init_sdesc_ignore_trap(const Process *p,
+				   struct nstack_walk_state *state)
+{
+#ifdef SKIP_YOUNGEST_FRAME
+    unsigned long ra = p->hipe.nsp[0];
+    const struct sdesc *sdesc;
+    if (ra == (unsigned long)nbif_stack_trap_ra)
+	ra = (unsigned long)p->hipe.ngra;
+    sdesc = hipe_find_sdesc(ra);
+    state->sdesc0 = sdesc;
+    return sdesc;
+#else
+    return nstack_walk_init_sdesc(p, state);
+#endif
+}
+
 static inline void nstack_walk_update_trap(Process *p, const struct sdesc *sdesc0)
 {
 #ifdef SKIP_YOUNGEST_FRAME