mdb_page_search_root Bus error #12
Description
GDB debug：
If the word can be found, then it won't bus error. If the word can't be found, it will Bus error.
- This is mdb_page_search_root:
/** Finish #mdb_page_search() / #mdb_page_search_lowest().
* The cursor is at the root page, set up the rest of it.
*/
static int
mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
{
MDB_page *mp = mc->mc_pg[mc->mc_top];
int rc;
DKBUF;
while (IS_BRANCH(mp)) {
MDB_node *node;
indx_t i;
DPRINTF(("branch page %"Yu" has %u keys", mp->mp_pgno, NUMKEYS(mp)));
/* Don't assert on branch pages in the FreeDB. We can get here
* while in the process of rebalancing a FreeDB branch page; we must
* let that proceed. ITS#8336
*/
mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);
DPRINTF(("found index 0 to page %"Yu, NODEPGNO(NODEPTR(mp, 0))));
if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
i = 0;
if (flags & MDB_PS_LAST) {
i = NUMKEYS(mp) - 1;
/* if already init'd, see if we're already in right place */
if (mc->mc_flags & C_INITIALIZED) {
if (mc->mc_ki[mc->mc_top] == i) {
mc->mc_top = mc->mc_snum++;
mp = mc->mc_pg[mc->mc_top];
goto ready;
}
}
}
} else {
int exact;
node = mdb_node_search(mc, key, &exact);
if (node == NULL)
i = NUMKEYS(mp) - 1;
else {
i = mc->mc_ki[mc->mc_top];
if (!exact) {
mdb_cassert(mc, i > 0);
i--;
}
}
DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
}
mdb_cassert(mc, i < NUMKEYS(mp));
node = NODEPTR(mp, i);
if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)
return rc;
mc->mc_ki[mc->mc_top] = i;
if ((rc = mdb_cursor_push(mc, mp)))
return rc;
ready:
if (flags & MDB_PS_MODIFY) {
if ((rc = mdb_page_touch(mc)) != 0)
return rc;
mp = mc->mc_pg[mc->mc_top];
}
}
if (!IS_LEAF(mp)) {
DPRINTF(("internal error, index points to a %02X page!?",
mp->mp_flags));
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
return MDB_CORRUPTED;
}
DPRINTF(("found leaf page %"Yu" for key [%s]", mp->mp_pgno,
key ? DKEY(key) : "null"));
mc->mc_flags |= C_INITIALIZED;
mc->mc_flags &= ~C_EOF;
return MDB_SUCCESS;
}