MariaDB server prints the stack information if a crash happens.
It traverses the stack frames in function `print_with_addr_resolve`.
For *EACH* frame, it tries to parse the file name and line number of the
frame using `addr2line`, or prints `backtrace_symbols_fd` if `addr2line`
fails.
1. Logic in `addr_resolve` function uses addr2line to get the file name
and line numbers. It has a timeout of 500ms to wait for the response
from addr2line. However, that's not enough on small instances
especially if the debug information is in a separate file or
compressed.
Increase the timeout to 5 seconds to support some edge cases, as
experiments showed addr2line may take 2-3 seconds on some frames.
2. While parsing a frame inside of a shared library using `addr2line`,
the file name and line numbers could be `??`, empty or `0` if the
debug info is not loaded.
It's easy to reproduce when glibc-debuginfo is not installed.
Instead of printing a meaningless frame like:
:0(__GI___poll)[0x1505e9197639]
...
??:0(__libc_start_main)[0x7ffff6c8913a]
We want to print the frame information using `backtrace_symbols_fd`,
with the shared library name and a hexadecimal offset.
Stacktrace example on a real instance with this commit:
/lib64/libc.so.6(__poll+0x49)[0x145cbf71a639]
...
/lib64/libc.so.6(__libc_start_main+0xea)[0x7f4d0034d13a]
`addr_resolve` has considered the case of meaningless combination of
file name and line number returned by `addr2line`. e.g. `??:?`
However, conditions like `:0` and `??:0` are not handled. So now the
function will rollback to `backtrace_symbols_fd` in above cases.
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.
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.
This patch also fixes some bugs detected by valgrind after this
patch:
- Not enough copy_func elements was allocated by Create_tmp_table() which
causes an memory overwrite in Create_tmp_table::add_fields()
I added an ASSERT() to be able to detect this also without valgrind.
The bug was that TMP_TABLE_PARAM::copy_fields was not correctly set
when calling create_tmp_table().
- Aria::empty_bits is not allocated if there is no varchar/char/blob
fields in the table. Fixed code to take this into account.
This cannot cause any issues as this is just a memory access
into other Aria memory and the content of the memory would not be used.
- Aria::last_key_buff was not allocated big enough. This may have caused
issues with rtrees and ma_extra(HA_EXTRA_REMEMBER_POS) as they
would use the same memory area.
- Aria and MyISAM didn't take extended key parts into account, which
caused problems when copying rec_per_key from engine to sql level.
- Mark asan builds with 'asan' in version strihng to detect these in
not_valgrind_build.inc.
This is needed to not have main.sp-no-valgrind fail with asan.
__gcov_flush was never an external symbol in the documentation.
It was removed in gcc-11. The correct function to use is __gcov_dump
which is defined in the gcov.h header.
The MDEV-25004 test innodb_fts.versioning is omitted because ever since
commit 685d958e38 InnoDB would not allow
writes to a database where the redo log file ib_logfile0 is missing.
Since 7c58e97 the PSI_memory_key was added to some routines in the
mysys/. This commit fixes synopses of functions that were updated with
the PSI_memory_key parameter.
When trying to output stacktrace, and addr2line is not installed, the
child process forked by start_addr2line_fork() will fail to do exec(),
and finish with exit(1).
There is a problem with exit() though - it runs exit handlers,
and for the forked copy of crashing process, it is a bad idea.
In 10.5+ code for example, exit handlers include
tpool::task_group static destructors, and it will hang infinitely
waiting for completion of the outstanding tasks.
The fix is to use _exit() instead, which skips the execution of exit
handlers
Fix build failure in comp_err, if git is configured with default,
platform-specific EOL.
The error happens because comp_err is not prepared to handle extraneous
CR characters from errmgs-utf8.txt. Use fopen in text mode to fix.
