Martin Beck 4ebac0fc86 MDEV-27088: Server crash on ARM (WMM architecture) due to missing barriers in lf-hash (10.5) ... MariaDB server crashes on ARM (weak memory model architecture) while concurrently executing l_find to load node->key and add_to_purgatory to store node->key = NULL. l_find then uses key (which is NULL), to pass it to a comparison function. The specific problem is the out-of-order execution that happens on a weak memory model architecture. Two essential reorderings are possible, which need to be prevented. a) As l_find has no barriers in place between the optimistic read of the key field lf_hash.cc#L117 and the verification of link lf_hash.cc#L124, the processor can reorder the load to happen after the while-loop. In that case, a concurrent thread executing add_to_purgatory on the same node can be scheduled to store NULL at the key field lf_alloc-pin.c#L253 before key is loaded in l_find. b) A node is marked as deleted by a CAS in l_delete lf_hash.cc#L247 and taken off the list with an upfollowing CAS lf_hash.cc#L252. Only if both CAS succeed, the key field is written to by add_to_purgatory. However, due to a missing barrier, the relaxed store of key lf_alloc-pin.c#L253 can be moved ahead of the two CAS operations, which makes the value of the local purgatory list stored by add_to_purgatory visible to all threads operating on the list. As the node is not marked as deleted yet, the same error occurs in l_find. This change three accesses to be atomic. * optimistic read of key in l_find lf_hash.cc#L117 * read of link for verification lf_hash.cc#L124 * write of key in add_to_purgatory lf_alloc-pin.c#L253 Reviewers: Sergei Vojtovich, Sergei Golubchik Fixes: MDEV-23510 / d30c1331a18d875e553f3fcf544997e4f33fb943		2021-11-30 15:16:16 +11:00
..
crc32	Fix building crc32_arm64 on NetBSD/aarch64	2021-07-22 16:41:59 +10:00
array.c
base64.c
ChangeLog
charset-def.c
charset.c
CMakeLists.txt	Merge 10.4 into 10.5	2021-10-21 15:26:25 +03:00
crc32ieee.cc
errors.c
file_logger.c
get_password.c
guess_malloc_library.c
hash.c
lf_alloc-pin.c	MDEV-27088: Server crash on ARM (WMM architecture) due to missing barriers in lf-hash (10.5)	2021-11-30 15:16:16 +11:00
lf_dynarray.c
lf_hash.cc	MDEV-27088: Server crash on ARM (WMM architecture) due to missing barriers in lf-hash (10.5)	2021-11-30 15:16:16 +11:00
list.c
ma_dyncol.c
mf_arr_appstr.c
mf_cache.c
mf_dirname.c
mf_fn_ext.c
mf_format.c
mf_getdate.c
mf_iocache.c
mf_iocache2.c
mf_keycache.c	MDEV-26533 MariaDB 10.5 crashes with key_buffer_size > 4Gb on Windows x64	2021-09-04 17:51:26 +02:00
mf_keycaches.c
mf_loadpath.c
mf_pack.c
mf_path.c
mf_qsort.c	fix clang build: check alignment the other way	2021-07-26 12:37:25 +03:00
mf_qsort2.c
mf_radix.c
mf_same.c
mf_sort.c
mf_soundex.c
mf_tempdir.c
mf_tempfile.c	MDEV-26601: mysys - O_TMPFILE ^ O_CREAT	2021-09-14 21:06:34 +10:00
mf_unixpath.c
mf_wcomp.c
mulalloc.c
my_access.c
my_addr_resolve.c
my_alarm.c
my_alloc.c
my_atomic_writes.c
my_basename.c
my_bit.c
my_bitmap.c
my_chmod.c
my_chsize.c
my_compare.c
my_compress.c
my_conio.c
my_context.c	Merge 10.2 into 10.3	2021-10-13 11:38:21 +03:00
my_copy.c
my_cpu.c
my_create.c
my_default.c
my_delete.c
my_div.c
my_dlerror.c
my_error.c
my_file.c
my_fopen.c
my_fstream.c
my_gethwaddr.c
my_getncpus.c
my_getopt.c
my_getpagesize.c
my_getsystime.c
my_getwd.c
my_init.c
my_largepage.c
my_lib.c
my_libwrap.c
my_likely.c
my_lock.c
my_lockmem.c
my_malloc.c
my_memmem.c
my_mess.c
my_minidump.cc	MDEV-11499 mysqltest, Windows : improve diagnostics if server fails to shutdown	2021-09-24 11:49:28 +02:00
my_mkdir.c
my_mmap.c
my_new.cc
my_once.c
my_open.c
my_port.c
my_pread.c
my_pthread.c
my_quick.c
my_rdtsc.c
my_read.c
my_redel.c
my_rename.c
my_rnd.c
my_safehash.c
my_safehash.h
my_seek.c
my_setuser.c
my_sleep.c
my_static.c
my_static.h
my_symlink.c
my_symlink2.c
my_sync.c
my_thr_init.c
my_uuid.c
my_win_popen.cc
my_wincond.c
my_winerr.c
my_winfile.c
my_winthread.c
my_wintoken.c
my_write.c
mysys_priv.h
psi_noop.c	Merge 10.4 into 10.5	2021-08-31 10:04:56 +03:00
ptr_cmp.c
queues.c
safemalloc.c	Merge 10.4 into 10.5	2021-10-28 08:48:36 +03:00
stacktrace.c
string.c
test_charset.c
test_dir.c
test_thr_mutex.c
test_xml.c
testhash.c
thr_alarm.c
thr_lock.c
thr_mutex.c
thr_rwlock.c
thr_timer.c
tree.c
typelib.c
waiting_threads.c
wqueue.c