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Fixing misuse of format header offset to decode tagging. see <https://info.ravenbrook.com/mail/2016/02/11/17-20-12/0/> point 5.

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 Change: 189134
 ServerID: perforce.ravenbrook.com
This commit is contained in:
Richard Brooksby 2016-02-11 21:32:41 +00:00
parent 31870a9b95
commit 27730a09d7
2 changed files with 33 additions and 43 deletions
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45
mps/code/tagtest.c
View file

@ -54,19 +54,14 @@ static mps_word_t make_cons(mps_ap_t ap, mps_word_t car, mps_word_t cdr)
static void fwd(mps_addr_t old, mps_addr_t new)
{
cons_t cons;
Insist(TAG(old) == tag_cons);
cons = UNTAGGED(old, cons);
cons_t cons = old;
cons->car = TAGGED(0, fwd);
cons->cdr = (mps_word_t)new;
}
static mps_addr_t isfwd(mps_addr_t addr)
{
cons_t cons;
if (TAG(addr) != tag_cons)
return NULL;
cons = UNTAGGED(addr, cons);
cons_t cons = addr;
if (TAG(cons->car) != tag_fwd)
return NULL;
return (mps_addr_t)cons->cdr;
@ -82,27 +77,24 @@ static void pad(mps_addr_t addr, size_t size)
}
}
static mps_res_t scan(mps_ss_t ss, mps_addr_t client_base,
mps_addr_t client_limit)
static mps_res_t scan(mps_ss_t ss, mps_addr_t base,
mps_addr_t limit)
{
mps_addr_t *base, *limit;
Insist(TAG(client_base) == tag_cons);
Insist(TAG(client_limit) == tag_cons);
base = (mps_addr_t *)UNTAGGED(client_base, cons);
limit = (mps_addr_t *)UNTAGGED(client_limit, cons);
MPS_SCAN_BEGIN(ss) {
while (base < limit) {
if (MPS_FIX1(ss, *base)) {
mps_addr_t addr = *base;
mps_word_t tag = TAG(addr);
if (tag == tag_cons) {
mps_res_t res = MPS_FIX2(ss, &addr);
mps_word_t *p = base;
while (p < (mps_word_t *)limit) {
mps_word_t word = *p;
mps_word_t tag = TAG(word);
if (tag == tag_cons) {
mps_addr_t ref = UNTAGGED(word, cons);
if (MPS_FIX1(ss, ref)) {
mps_res_t res = MPS_FIX2(ss, &ref);
if (res != MPS_RES_OK)
return res;
*base = addr;
*p = TAGGED(ref, cons);
}
}
++base;
++p;
}
} MPS_SCAN_END(ss);
return MPS_RES_OK;
@ -124,7 +116,7 @@ static void collect(mps_arena_t arena, size_t expected)
cdie(mps_message_get(&message, arena, mps_message_type_finalization()),
"message_get");
mps_message_finalization_ref(&objaddr, arena, message);
Insist(TAG(objaddr) == tag_cons);
Insist(TAG(objaddr) == 0);
mps_message_discard(arena, message);
++ finalized;
}
@ -148,8 +140,11 @@ static void alloc_recursively(mps_arena_t arena, mps_ap_t ap,
Insist(TAG(p) == tag_cons);
r = TAGGED(p, imm);
UNTAGGED(p, cons)->cdr = r;
addr = (mps_addr_t)p;
addr = (mps_addr_t)UNTAGGED(p, cons);
die(mps_finalize(arena, &addr), "finalize");
/* Avoid leaving a zero-tagged reference on the stack, as it will
prevent finalization when scanned with the default mode. */
addr = NULL;
if (count > 1) {
alloc_recursively(arena, ap, expected, count - 1);
} else {
@ -225,8 +220,6 @@ static void test(int mode, void *marker)
}
MPS_ARGS_BEGIN(args) {
MPS_ARGS_ADD(args, MPS_KEY_FMT_HEADER_SIZE, tag_cons);
MPS_ARGS_ADD(args, MPS_KEY_FMT_ALIGN, sizeof(cons_s));
MPS_ARGS_ADD(args, MPS_KEY_FMT_SCAN, scan);
MPS_ARGS_ADD(args, MPS_KEY_FMT_SKIP, skip);
MPS_ARGS_ADD(args, MPS_KEY_FMT_FWD, fwd);

31
mps/code/trace.c
View file

@ -1470,9 +1470,6 @@ ATTRIBUTE_NO_SANITIZE_ADDRESS
Res TraceScanAreaTagged(ScanState ss, Word *base, Word *limit, Word mask,
Word pattern)
{
Res res;
Word word, *p;
AVERT(ScanState, ss);
AVER(base != NULL);
AVER(limit != NULL);
@ -1481,20 +1478,20 @@ Res TraceScanAreaTagged(ScanState ss, Word *base, Word *limit, Word mask,
EVENT3(TraceScanAreaTagged, ss, base, limit);
TRACE_SCAN_BEGIN(ss) {
p = base;
loop:
if (p >= limit)
goto out;
word = *p++;
if ((word & mask) != pattern)
goto loop;
if (!TRACE_FIX1(ss, (Ref)word))
goto loop;
res = TRACE_FIX2(ss, (Ref *)(p-1));
if(res == ResOK)
goto loop;
return res;
out:
Word *p = base;
while (p < limit) {
Word word = *p;
if ((word & mask) == pattern) {
Ref ref = (Ref)(word ^ pattern);
if (TRACE_FIX1(ss, ref)) {
Res res = TRACE_FIX2(ss, &ref);
if(res != ResOK)
return res;
*p = (Word)ref | pattern;
}
}
++p;
}
AVER(p == limit);
} TRACE_SCAN_END(ss);