MDEV-26494 Fix buffer overflow of string lib on Arm64
In the hexlo function, the element type of the array hex_lo_digit is not
explicitly declared as signed char, causing elements with a value of -1
to be converted to 255 on Arm64. The problem occurs because "char" is
unsigned by default on Arm64 compiler, but signed on x86 compiler. This
problem can be seen in https://godbolt.org/z/rT775xshj
2728 if ((byte1= hexlo(byte1)) >= 0 &&
2729 (byte2= hexlo(byte2)) >= 0)
{
2731 int byte3= hexlo(s[3]);
…
}
At line 2729, when byte2 is 0, which indicates the end of the string s.
(1) On x86, hexlo(0) return -1 and line 2731 is skipped, as expected.
(2) On Arm64, hexlo(0) return 255 and line 2731 is executed, not as
expected, accessing s[3] after the null character of string s, thus
raising the "user-after-poison" error.
The problem was discovered when executing the main.mysqlcheck test.
fil_page_compress_low returns 0 for both innodb_compression_algorithm=0
and where there is compression errors. On the two callers to this
function, don't increment the compression errors if the algorithm was
none.
Reviewed by: Marko Mäkelä
ac15141...
by
Dmitry Shulga <email address hidden>
MDEV-32369: Memory leak when executing PS for query with IN subquery
The memory allocated for an instance of the class Item_direct_ref_to_item
was leaked on second execution of a query run as a prepared statement and
involving conversion of strings with different character sets.
The reason of leaking the memory was caused by the fact that a statement
arena could be already set by the moment the method
Type_std_attributes::agg_item_set_converter() is called.
MDEV-27523 main.delayed fails with wrong error code or timeout when executed after main.deadlock_ftwrl
don't forget to reset mdl_context.m_deadlock_overweight when
taking the THD out of the cache - the history of previous connections
should not affect the weight in deadlock victim selection
(small cleanup of the test to help the correct merge)
