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authorSverker Eriksson <[email protected]>2013-11-05 18:44:39 +0100
committerSverker Eriksson <[email protected]>2013-11-18 20:19:52 +0100
commitadcdcb2c7985ad6076a2bedebdfce08d14465b43 (patch)
treea394a03cab7e2e3f75f053dcce920b449dd8fb49 /erts/emulator/beam/external.c
parentbcb227d1f467439fa5f901233e8ad382e75373cb (diff)
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erts: Fix crash when binary_to_term throws badarg
after it has built off_heap data and then done at least one trap call. The undo mechanism in dec_term does not work if we build the magic binary after any other off_heap data.
Diffstat (limited to 'erts/emulator/beam/external.c')
-rw-r--r--erts/emulator/beam/external.c51
1 files changed, 27 insertions, 24 deletions
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index a73734d487..6a7d15cc88 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -1364,6 +1364,21 @@ static unsigned b2t_rand(void)
#endif
+static B2TContext* b2t_export_context(Process* p, B2TContext* src)
+{
+ Binary* context_b = erts_create_magic_binary(sizeof(B2TContext),
+ b2t_context_destructor);
+ B2TContext* ctx = ERTS_MAGIC_BIN_DATA(context_b);
+ Eterm* hp;
+ sys_memcpy(ctx, src, sizeof(B2TContext));
+ if (ctx->state >= B2TDecode && ctx->u.dc.next == &src->u.dc.res) {
+ ctx->u.dc.next = &ctx->u.dc.res;
+ }
+ hp = HAlloc(p, PROC_BIN_SIZE);
+ ctx->trap_bin = erts_mk_magic_binary_term(&hp, &MSO(p), context_b);
+ return ctx;
+}
+
static Eterm binary_to_term_int(Process* p, Uint32 flags, Eterm bin, Binary* context_b)
{
#ifdef EXTREME_B2T_TRAPPING
@@ -1373,16 +1388,18 @@ static Eterm binary_to_term_int(Process* p, Uint32 flags, Eterm bin, Binary* con
#endif
B2TContext c_buff;
B2TContext *ctx;
- Eterm* magic_space = NULL;
+ int is_first_call;
if (context_b == NULL) {
/* Setup enough to get started */
+ is_first_call = 1;
ctx = &c_buff;
ctx->state = B2TPrepare;
ctx->aligned_alloc = NULL;
ctx->flags = flags;
IF_DEBUG(ctx->trap_bin = THE_NON_VALUE;)
} else {
+ is_first_call = 0;
ctx = ERTS_MAGIC_BIN_DATA(context_b);
ASSERT(ctx->state != B2TPrepare);
}
@@ -1446,12 +1463,11 @@ static Eterm binary_to_term_int(Process* p, Uint32 flags, Eterm bin, Binary* con
break;
case B2TDecodeInit:
- if (context_b == NULL && ctx->b2ts.extsize > ctx->reds) {
+ if (ctx == &c_buff && ctx->b2ts.extsize > ctx->reds) {
/* dec_term will maybe trap, allocate space for magic bin
before result term to make it easy to trim with HRelease.
*/
- magic_space = HAlloc(p, PROC_BIN_SIZE);
- *magic_space = make_pos_bignum_header(PROC_BIN_SIZE-1);
+ ctx = b2t_export_context(p, &c_buff);
}
ctx->u.dc.ep = ctx->b2ts.extp;
ctx->u.dc.res = (Eterm) (UWord) NULL;
@@ -1476,7 +1492,7 @@ static Eterm binary_to_term_int(Process* p, Uint32 flags, Eterm bin, Binary* con
/*fall through*/
case B2TBadArg:
b2t_destroy_context(ctx);
- if (context_b) {
+ if (!is_first_call) {
erts_set_gc_state(p, 1);
}
BUMP_REDS(p, (initial_reds - ctx->reds) / B2T_BYTES_PER_REDUCTION);
@@ -1491,10 +1507,9 @@ static Eterm binary_to_term_int(Process* p, Uint32 flags, Eterm bin, Binary* con
}
HRelease(p, ctx->u.dc.hp_end, ctx->u.dc.hp);
- if (context_b) {
+ if (!is_first_call) {
erts_set_gc_state(p, 1);
}
-
BUMP_REDS(p, (initial_reds - ctx->reds) / B2T_BYTES_PER_REDUCTION);
return ctx->u.dc.res;
@@ -1503,27 +1518,15 @@ static Eterm binary_to_term_int(Process* p, Uint32 flags, Eterm bin, Binary* con
}
}while (ctx->reds > 0 || ctx->state >= B2TDone);
- if (context_b == NULL) {
+ if (ctx == &c_buff) {
ASSERT(ctx->trap_bin == THE_NON_VALUE);
-
- context_b = erts_create_magic_binary(sizeof(B2TContext),
- b2t_context_destructor);
- ctx = ERTS_MAGIC_BIN_DATA(context_b);
- sys_memcpy(ctx, &c_buff, sizeof(B2TContext));
- if (ctx->state >= B2TDecode && ctx->u.dc.next == &c_buff.u.dc.res) {
- ctx->u.dc.next = &ctx->u.dc.res;
- }
- if (!magic_space) {
- ASSERT(ctx->state < B2TDecode);
- magic_space = HAlloc(p, PROC_BIN_SIZE);
- }
- ctx->trap_bin = erts_mk_magic_binary_term(&magic_space, &MSO(p), context_b);
-
- erts_set_gc_state(p, 0);
+ ctx = b2t_export_context(p, &c_buff);
}
- ASSERT(context_b);
ASSERT(ctx->trap_bin != THE_NON_VALUE);
+ if (is_first_call) {
+ erts_set_gc_state(p, 0);
+ }
BUMP_ALL_REDS(p);
BIF_TRAP1(&binary_to_term_trap_export, p, ctx->trap_bin);
}