Commit 2aea9387 authored by Monty's avatar Monty Committed by Oleksandr Byelkin

MDEV-31893 Valgrind reports issues in main.join_cache_notasan

This is also related to
MDEV-31348 Assertion `last_key_entry >= end_pos' failed in virtual bool
           JOIN_CACHE_HASHED::put_record()

Valgrind exposed a problem with the join_cache for hash joins:
=25636== Conditional jump or move depends on uninitialised value(s)
==25636== at 0xA8FF4E: JOIN_CACHE_HASHED::init_hash_table()
          (sql_join_cache.cc:2901)

The reason for this was that avg_record_length contained a random value
if one had used SET optimizer_switch='optimize_join_buffer_size=off'.

This causes either 'random size' memory to be allocated (up to
join_buffer_size) which can increase memory usage or, if avg_record_length
is less than the row size, memory overwrites in thd->mem_root, which is
bad.

Fixed by setting avg_record_length in JOIN_CACHE_HASHED::init()
before it's used.

There is no test case for MDEV-31893 as valgrind of join_cache_notasan
checks that.
I added a test case for MDEV-31348.
parent 0ede90dd
# include/no_valgrind_without_big.inc
#
# If we are running with Valgrind ($VALGRIND_TEST <> 0) than the resource
# consumption (storage space needed, runtime ...) will be extreme.
# Therefore we require that the option "--big-test" is also set.
#
if ($VALGRIND_TEST) {
if (!$BIG_TEST)
{
--skip Need "--big-test" when running with Valgrind
}
}
......@@ -6256,3 +6256,19 @@ length(concat(t1.f,t2.f))
DROP TABLE t;
set @@optimizer_switch=@org_optimizer_switch;
set @@join_buffer_size=@org_join_buffer_size;
#
# MDEV-31348 Assertion `last_key_entry >= end_pos' failed in
# virtual bool JOIN_CACHE_HASHED::put_record()
#
SET JOIN_buffer_size=1;
Warnings:
Warning 1292 Truncated incorrect join_buffer_size value: '1'
SET SESSION JOIN_cache_level=4;
SET SESSION optimizer_switch='optimize_JOIN_buffer_size=OFF';
SELECT * FROM information_schema.statistics JOIN information_schema.COLUMNS USING (table_name,column_name);
ERROR HY001: Could not create a join buffer. Please check and adjust the value of the variables 'JOIN_BUFFER_SIZE (128)' and 'JOIN_BUFFER_SPACE_LIMIT (2097152)'
SET JOIN_buffer_size=16384;
SELECT * FROM information_schema.statistics JOIN information_schema.COLUMNS USING (table_name,column_name);
#
# End of 10.4 tests
#
......@@ -4231,3 +4231,22 @@ SELECT length(concat(t1.f,t2.f)) FROM t t1, t t2;
DROP TABLE t;
set @@optimizer_switch=@org_optimizer_switch;
set @@join_buffer_size=@org_join_buffer_size;
--echo #
--echo # MDEV-31348 Assertion `last_key_entry >= end_pos' failed in
--echo # virtual bool JOIN_CACHE_HASHED::put_record()
--echo #
SET JOIN_buffer_size=1;
SET SESSION JOIN_cache_level=4;
SET SESSION optimizer_switch='optimize_JOIN_buffer_size=OFF';
--error ER_OUTOFMEMORY
SELECT * FROM information_schema.statistics JOIN information_schema.COLUMNS USING (table_name,column_name);
SET JOIN_buffer_size=16384;
--disable_result_log
SELECT * FROM information_schema.statistics JOIN information_schema.COLUMNS USING (table_name,column_name);
--enable_result_log
--echo #
--echo # End of 10.4 tests
--echo #
......@@ -2,7 +2,10 @@
# Tests that should be in join_cache but cannot be run with ASAN
--source include/have_64bit.inc
# Disable asan it asan builds crashes when trying to allocate too much memory
--source include/not_asan.inc
# Valgrind is useful here, but very slow as lots of memory is allocated
--source include/no_valgrind_without_big.inc
--source include/have_innodb.inc
--echo #
......
......@@ -800,6 +800,18 @@ size_t JOIN_CACHE::get_min_join_buffer_size()
}
size_t JOIN_CACHE::calc_avg_record_length()
{
size_t len= 0;
for (JOIN_TAB *tab= start_tab; tab != join_tab;
tab= next_linear_tab(join, tab, WITHOUT_BUSH_ROOTS))
{
len+= tab->get_used_fieldlength();
}
len+= get_record_max_affix_length();
return len;
}
/*
Get the maximum possible size of the cache join buffer
......@@ -822,9 +834,9 @@ size_t JOIN_CACHE::get_min_join_buffer_size()
'max_buff_size' in order to use it directly at the next
invocations of the function.
RETURN VALUE
The maximum possible size of the join buffer of this cache
The maximum possible size of the join buffer of this cache
avg_record_length is also updated if optimize_buff_size != 0
*/
size_t JOIN_CACHE::get_max_join_buffer_size(bool optimize_buff_size,
......@@ -839,19 +851,13 @@ size_t JOIN_CACHE::get_max_join_buffer_size(bool optimize_buff_size,
return max_buff_size= limit_sz;
size_t max_sz;
size_t len= 0;
size_t len;
double max_records, partial_join_cardinality=
(join_tab-1)->get_partial_join_cardinality();
/* Expected join buffer space used for one record */
size_t space_per_record;
for (JOIN_TAB *tab= start_tab; tab != join_tab;
tab= next_linear_tab(join, tab, WITHOUT_BUSH_ROOTS))
{
len+= tab->get_used_fieldlength();
}
len+= get_record_max_affix_length();
avg_record_length= len;
len= avg_record_length= calc_avg_record_length();
len+= get_max_key_addon_space_per_record() + avg_aux_buffer_incr;
space_per_record= len;
......@@ -2786,7 +2792,6 @@ bool JOIN_CACHE_BKAH::save_explain_data(EXPLAIN_BKA_TYPE *explain)
int JOIN_CACHE_HASHED::init(bool for_explain)
{
TABLE_REF *ref= &join_tab->ref;
DBUG_ENTER("JOIN_CACHE_HASHED::init");
hash_table= 0;
......@@ -2873,6 +2878,8 @@ int JOIN_CACHE_HASHED::init_hash_table()
hash_table= 0;
key_entries= 0;
avg_record_length= calc_avg_record_length();
/* Calculate the minimal possible value of size_of_key_ofs greater than 1 */
uint max_size_of_key_ofs= MY_MAX(2, get_size_of_rec_offset());
for (size_of_key_ofs= 2;
......
......@@ -130,6 +130,7 @@ class JOIN_CACHE :public Sql_alloc
case 4: int4store(ptr, (uint32) ofs); return;
}
}
size_t calc_avg_record_length();
/*
The maximum total length of the fields stored for a record in the cache.
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment