Modern software (including text editors, static analysis software,
and web-based code review interfaces) often requires source code files
to be interpretable via a consistent character encoding, with UTF-8 or
ASCII (a strict subset of UTF-8) as the default. Several of the MariaDB
source files contain bytes that are not valid in either the UTF-8 or
ASCII encodings, but instead represent strings encoded in the
ISO-8859-1/Latin-1 or ISO-8859-2/Latin-2 encodings.
These inconsistent encodings may prevent software from correctly
presenting or processing such files. Converting all source files to
valid UTF8 characters will ensure correct handling.
Comments written in Czech were replaced with lightly-corrected
translations from Google Translate. Additionally, comments describing
the proper handling of special characters were changed so that the
comments are now purely UTF8.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.
Co-authored-by: Andrew Hutchings <andrew@linuxjedi.co.uk>
collations
Fix by Alexey Botchkov
The 'value_len' is calculated wrong for the multibyte charsets. In the
read_strn() function we get the length of the string with the final ' " '
character. So have to subtract it's length from the value_len. And the
length of '1' isn't correct for the ucs2 charset (must be 2).
- Adding a new argument "flag" to MY_COLLATION_HANDLER::strnncollsp_nchars()
and a flag MY_STRNNCOLLSP_NCHARS_EMULATE_TRIMMED_TRAILING_SPACES.
The flag defines if strnncollsp_nchars() should emulate trailing spaces
which were possibly trimmed earlier (e.g. in InnoDB CHAR compression).
This is important for NOPAD collations.
For example, with this input:
- str1= 'a ' (Latin letter a followed by one space)
- str2= 'a ' (Latin letter a followed by two spaces)
- nchars= 3
if the flag is given, strnncollsp_nchars() will virtually restore
one trailing space to str1 up to nchars (3) characters and compare two
strings as equal:
- str1= 'a ' (one extra trailing space emulated)
- str2= 'a ' (as is)
If the flag is not given, strnncollsp_nchars() does not add trailing
virtual spaces, so in case of a NOPAD collation, str1 will be compared
as less than str2 because it is shorter.
- Field_string::cmp_prefix() now passes the new flag.
Field_varstring::cmp_prefix() and Field_blob::cmp_prefix() do
not pass the new flag.
- The branch in cmp_whole_field() in storage/innobase/rem/rem0cmp.cc
(which handles the CHAR data type) now also passed the new flag.
- Fixing UCA collations to respect the new flag.
Other collations are possibly also affected, however
I had no success in making an SQL script demonstrating the problem.
Other collations will be extended to respect this flags in a separate
patch later.
- Changing the meaning of the last parameter of Field::cmp_prefix()
from "number of bytes" (internal length)
to "number of characters" (user visible length).
The code calling cmp_prefix() from handler.cc was wrong.
After this change, the call in handler.cc became correct.
The code calling cmp_prefix() from key_rec_cmp() in key.cc
was adjusted according to this change.
- Old strnncollsp_nchar() related tests in unittest/strings/strings-t.c
now pass the new flag.
A few new tests also were added, without the flag.
Replace calls to `sprintf` and `strcpy` by the safer options `snprintf`
and `safe_strcpy` in the following directories:
- libmysqld
- mysys
- sql-common
- strings
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.
1. Adding a separate MY_COLLATION_HANDLER
my_collation_ucs2_general_mysql500_ci_handler
implementing a proper order for ucs2_general_mysql500_ci
The problem happened because ucs2_general_mysql500_ci
erroneously used my_collation_ucs2_general_ci_handler.
2. Cosmetic changes: Renaming:
- plane00_mysql500 to my_unicase_mysql500_page00
- my_unicase_pages_mysql500 to my_unicase_mysql500_pages
to use the same naming style with:
- my_unicase_default_page00
- my_unicase_defaul_pages
3. Moving code fragments from
- handler::check_collation_compatibility() in handler.cc
- upgrade_collation() in table.cc
into new methods in class Charset, to reuse the code easier.
Also fixes:
MDEV-27768 MDEV-25440: Assertion `(cs->state & 0x20000) == 0' failed in my_strnncollsp_nchars_generic_8bit
The "strnncollsp_nchars" virtual function pointer for tis620_thai_nopad_ci
was incorrectly initialized to a generic function
my_strnncollsp_nchars_generic_8bit(), which crashed on assert.
Implementing a tis620 specific function version.
Fixing a few problems relealed by UBSAN in type_float.test
- multiplication overflow in dtoa.c
- uninitialized Field::geom_type (and Field::srid as well)
- Wrong call-back function types used in combination with SHOW_FUNC.
Changes in the mysql_show_var_func data type definition were not
properly addressed all around the code by the following commits:
b4ff64568c18feb62fee0ee879ff8a
Adding a helper SHOW_FUNC_ENTRY() function and replacing
all mysql_show_var_func declarations using SHOW_FUNC
to SHOW_FUNC_ENTRY, to catch mysql_show_var_func in the future
at compilation time.
my_copy_fix_mb() passed MIN(src_length,dst_length) to
my_append_fix_badly_formed_tail(). It could break a multi-byte
character in the middle, which put the question mark to the
destination.
Fixing the code to pass the true src_length to
my_append_fix_badly_formed_tail().
strmake() puts one extra 0x00 byte at the end of the string.
The code in my_strnxfrm_tis620[_nopad] did not take this into
account, so in the reported scenario the 0x00 byte was put outside
of a stack variable, which made ASAN crash.
This problem is already fixed in in MySQL:
commit 19bd66fe43c41f0bde5f36bc6b455a46693069fb
Author: bin.x.su@oracle.com <>
Date: Fri Apr 4 11:35:27 2014 +0800
But the fix does not seem to be correct, as it breaks when finds a zero byte
in the source string.
Using memcpy() instead of strmake().
- Unlike strmake(), memcpy() it does not write beyond the destination
size passed.
- Unlike the MySQL fix, memcpy() does not break on the first 0x00 byte found
in the source string.
The easiest way to compile and test the server with UBSAN is to run:
./BUILD/compile-pentium64-ubsan
and then run mysql-test-run.
After this commit, one should be able to run this without any UBSAN
warnings. There is still a few compiler warnings that should be fixed
at some point, but these do not expose any real bugs.
The 'special' cases where we disable, suppress or circumvent UBSAN are:
- ref10 source (as here we intentionally do some shifts that UBSAN
complains about.
- x86 version of optimized int#korr() methods. UBSAN do not like unaligned
memory access of integers. Fixed by using byte_order_generic.h when
compiling with UBSAN
- We use smaller thread stack with ASAN and UBSAN, which forced me to
disable a few tests that prints the thread stack size.
- Verifying class types does not work for shared libraries. I added
suppression in mysql-test-run.pl for this case.
- Added '#ifdef WITH_UBSAN' when using integer arithmetic where it is
safe to have overflows (two cases, in item_func.cc).
Things fixed:
- Don't left shift signed values
(byte_order_generic.h, mysqltest.c, item_sum.cc and many more)
- Don't assign not non existing values to enum variables.
- Ensure that bool and enum values are properly initialized in
constructors. This was needed as UBSAN checks that these types has
correct values when one copies an object.
(gcalc_tools.h, ha_partition.cc, item_sum.cc, partition_element.h ...)
- Ensure we do not called handler functions on unallocated objects or
deleted objects.
(events.cc, sql_acl.cc).
- Fixed bugs in Item_sp::Item_sp() where we did not call constructor
on Query_arena object.
- Fixed several cast of objects to an incompatible class!
(Item.cc, Item_buff.cc, item_timefunc.cc, opt_subselect.cc, sql_acl.cc,
sql_select.cc ...)
- Ensure we do not do integer arithmetic that causes over or underflows.
This includes also ++ and -- of integers.
(Item_func.cc, Item_strfunc.cc, item_timefunc.cc, sql_base.cc ...)
- Added JSON_VALUE_UNITIALIZED to json_value_types and ensure that
value_type is initialized to this instead of to -1, which is not a valid
enum value for json_value_types.
- Ensure we do not call memcpy() when second argument could be null.
- Fixed that Item_func_str::make_empty_result() creates an empty string
instead of a null string (safer as it ensures we do not do arithmetic
on null strings).
Other things:
- Changed struct st_position to an OBJECT and added an initialization
function to it to ensure that we do not copy or use uninitialized
members. The change to a class was also motived that we used "struct
st_position" and POSITION randomly trough the code which was
confusing.
- Notably big rewrite in sql_acl.cc to avoid using deleted objects.
- Changed in sql_partition to use '^' instead of '-'. This is safe as
the operator is either 0 or 0x8000000000000000ULL.
- Added check for select_nr < INT_MAX in JOIN::build_explain() to
avoid bug when get_select() could return NULL.
- Reordered elements in POSITION for better alignment.
- Changed sql_test.cc::print_plan() to use pointers instead of objects.
- Fixed bug in find_set() where could could execute '1 << -1'.
- Added variable have_sanitizer, used by mtr. (This variable was before
only in 10.5 and up). It can now have one of two values:
ASAN or UBSAN.
- Moved ~Archive_share() from ha_archive.cc to ha_archive.h and marked
it virtual. This was an effort to get UBSAN to work with loaded storage
engines. I kept the change as the new place is better.
- Added in CONNECT engine COLBLK::SetName(), to get around a wrong cast
in tabutil.cpp.
- Added HAVE_REPLICATION around usage of rgi_slave, to get embedded
server to compile with UBSAN. (Patch from Marko).
- Added #ifdef for powerpc64 to avoid a bug in old gcc versions related
to integer arithmetic.
Changes that should not be needed but had to be done to suppress warnings
from UBSAN:
- Added static_cast<<uint16_t>> around shift to get rid of a LOT of
compiler warnings when using UBSAN.
- Had to change some '/' of 2 base integers to shift to get rid of
some compile time warnings.
Reviewed by:
- Json changes: Alexey Botchkov
- Charset changes in ctype-uca.c: Alexander Barkov
- InnoDB changes & Embedded server: Marko Mäkelä
- sql_acl.cc changes: Vicențiu Ciorbaru
- build_explain() changes: Sergey Petrunia
This follows up commit
commit 94a520ddbe and
commit 7c5519c12d.
After these changes, the default test suites on a
cmake -DWITH_UBSAN=ON build no longer fail due to passing
null pointers as parameters that are declared to never be null,
but plenty of other runtime errors remain.
The characters parsed are always ascii characters, hence one byte. This
means that the code did not have "incorrect" logic because the boolean
condition, if true, would also evaluate to the value of 1.
The condition however is semantically wrong, assuming a length is equal
to the condition outcome. Change paranthesis to make it also read
according to the intent.
Passing a null pointer to a nonnull argument is not only undefined
behaviour, but it also grants the compiler the permission to optimize
away further checks whether the pointer is null. GCC -O2 at least
starting with version 8 may do that, potentially causing SIGSEGV.
