in _ma_unique_hash, skip_trailing_space, my_hash_sort_mb_nopad_bin and my_strnncollsp_utf8mb4_bin
UBSAN detected the nullptr-with-offset in a few places
when handling empty blobs.
Fix:
- Adding DBUG_ASSERT(source_string) into all hash_sort() implementations
to catch this problem in non-UBSAN debug builds.
- Fixing mi_unique_hash(), mi_unique_comp(),
_ma_unique_hash(), _ma_unique_comp() to replace NULL pointer to
an empty string ponter..
Note, we should also add DBUG_ASSERT(source_string != NULL) into
all implementations of strnncoll*(). But I'm afraid the patch
is going to be too long and too dangerous for 10.5.
Also fixes:
MDEV-32190 Index corruption with unique key and nopad collation (without DESC or HASH keys)
MDEV-28328 Assertion failures in btr0cur.cc upon INSERT or in row0sel.cc afterwards
The code in strings/strcoll.inl when comparing an empty string
to a string like 0x0001050001 did not take into account
that the leftmost weight in the latter can be zero, while
there are some more weights can follow the zero weight.
Rewriting the code to treat the shorter string as smaller than
a longer string.
Rewriting loops in check_rules() and init_weight_level()
in the way to avoid UBSAN nullptr-with-offset error.
No MTR test are needed - the reported failures disappeared
from "mtr" output when running an UBSAN compiled build.
With UBSAN builds the function my_string_repertoire_8bit() failed on
"runtime error: applying zero offset to null pointer" when
NULL wad passed as the str parameter.
Fix:
test str for NULL, and return MY_REPERTOIRE_ASCII if str is NULL.
MTR:
This problem made MTR tests
- main.xa_sync
- innodb.xa_debug
- main.xa
fail with the nullptr-with-offset UNSAN error.
After this commit these tests do not fail anymore.
This commit does not need any new MTR tests.
The functions MY_CHARSET_HANDLER::caseup() and MY_CHARSET_HANDLER::casedn()
in their virtual imlementations do "const char *end= src + srclen"
in the very beginning. Therefore src cannot be NULL to avoid
"UBSAN: SUMMARY: UndefinedBehaviorSanitizer: nullptr-with-offset".
Adding DBUG_ASSERT(src != NULL) into all virtual implementations,
to catch this problem in regular Debug builds (without UBSAN).
Fixing Master_info_index::get_master_info() to check connection_name->str.
If it is NULL then passing empty_clex_str into IdentBufferCasedn
instead of *connection_name.
The problem was that get_collation_number_internal() loops over all
collations for finding a collation based on name. For looking up
utf8mb4_0900_ aliases it used 22633 character strings comparisons at
startup.
Fixed by adding the MariaDB internal collation number in the "0900" alias
lookup array. This is fine as collation numbers never changes.
Discussed-with: serg@mariadb.com
This is done by mapping most of the existing MySQL unicode 0900 collations
to MariadB 1400 unicode collations. The assumption is that 1400 is a super
set of 0900 for all practical purposes.
I also added a new function 'compare_collations()' and changed most code
to use this instead of comparing character sets directly.
This enables one to seamlessly mix-and-match the corresponding 0900 and
1400 sets. Field comparision and alter table treats the character sets
as identical.
All MySQL 8.0 0900 collations are supported except:
- utf8mb4_ja_0900_as_cs
- utf8mb4_ja_0900_as_cs_ks
- utf8mb4_ru_0900_as_cs
- utf8mb4_zh_0900_as_cs
These do not have corresponding entries in the MariadB 01400 collations.
Other things:
- Added COMMENT colum to information_schema.collations. For utf8mb4_0900
colletions it contains the corresponding alias collation.
strerror_s on Linux will, for unknown error codes, display
'Unknown error <codenum>' and our tests are written with this assumption.
However, on macOS, sterror_s returns 'Unknown error: <codenum>' in the
same case, which breaks tests. Make my_strerror consistent across the
platforms by removing the ':' when present.
The code in my_strtoll10_mb2 and my_strtoll10_utf32
could hit undefinite behavior by negation of LONGLONG_MIN.
Fixing to avoid this.
Also, fixing my_strtoll10() in the same style.
The previous reduction produced a redundant warning on
CAST(_latin1'-9223372036854775808' AS SIGNED)
The code in my_strntoull_8bit() and my_strntoull_mb2_or_mb4()
could hit undefinite behavior by negating of LONGLONG_MIN.
Fixing the code to avoid this.
This patch fixes two problems:
- The code inside my_strtod_int() in strings/dtoa.c could test the byte
behind the end of the string when processing the mantissa.
Rewriting the code to avoid this.
- The code in test_if_number() in sql/sql_analyse.cc called my_atof()
which is unsafe and makes the called my_strtod_int() look behind
the end of the string if the input string is not 0-terminated.
Fixing test_if_number() to use my_strtod() instead, passing the correct
end pointer.
nullptr+0 is an UB (undefined behavior).
- Fixing my_string_metadata_get_mb() to handle {nullptr,0} without UB.
- Fixing THD::copy_with_error() to disallow {nullptr,0} by DBUG_ASSERT().
- Fixing parse_client_handshake_packet() to call THD::copy_with_error()
with an empty string {"",0} instead of NULL string {nullptr,0}.
- Fixing the code in get_interval_value() to use Longlong_hybrid_null.
This allows to handle correctly:
- Signed and unsigned arguments
(the old code assumed the argument to be signed)
- Avoid undefined negation behavior the corner case with LONGLONG_MIN
This fixes the UBSAN warning:
negation of -9223372036854775808 cannot be represented
in type 'long long int';
- Fixing the code in get_interval_value() to avoid overflow in
the INTERVAL_QUARTER and INTERVAL_WEEK branches.
This fixes the UBSAN warning:
signed integer overflow: -9223372036854775808 * 7 cannot be represented
in type 'long long int'
- Fixing the INTERVAL_WEEK branch in date_add_interval() to handle
huge numbers correctly. Before the change, huge positive numeber
were treated as their negative complements.
Note, some other branches still can be affected by this problem
and should also be fixed eventually.
Fixing the condition to raise an overflow in the ulonglong
representation of the number is greater or equal to 0x8000000000000000ULL.
Before this change the condition did not catch -9223372036854775808
(the smallest possible signed negative longlong number).
The problem was introduced by MDEV-30879.
The function my_strntoll_8bit() was correctly changed by MDEV-30879.
The function my_strntoll_mb2_or_mb4() was not.
Applying the missing change to my_strntoll_mb2_or_mb4().
