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WolfSSL is the WITH_SSL=bundled library since MDEV-18351. For the AMD64 architecture, the library includes some assembler code. That code is disabled in WITH_MSAN builds, because MemorySanitizer would consider any data that is computed by uninstrumented code to be uninitialized. With the following patch, we would have a massive amount of failures when following the steps outlined in MDEV-20377 to compile and run a WITH_MSAN executable:
diff --git a/extra/wolfssl/CMakeLists.txt b/extra/wolfssl/CMakeLists.txt
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index c99fb155dd6..f3b1c2af2c3 100644
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--- a/extra/wolfssl/CMakeLists.txt
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+++ b/extra/wolfssl/CMakeLists.txt
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@@ -17,16 +17,11 @@ ELSEIF(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64")
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IF(CMAKE_C_COMPILER_ID MATCHES GNU AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.9)
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MESSAGE_ONCE(NO_INTEL_ASSEMBLY "Disable Intel assembly for WolfSSL - compiler is too old")
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ELSE()
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- IF(WITH_MSAN)
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- MESSAGE_ONCE(MSAN_CANT_HANDLE_IT
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- "Disable Intel assembly for WolfSSL - MSAN can't handle it")
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- ELSE()
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- MY_CHECK_C_COMPILER_FLAG(-maes)
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- MY_CHECK_C_COMPILER_FLAG(-msse4)
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- MY_CHECK_C_COMPILER_FLAG(-mpclmul)
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- IF(have_C__maes AND have_C__msse4 AND have_C__mpclmul)
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- SET(WOLFSSL_INTELASM ON)
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- ENDIF()
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+ MY_CHECK_C_COMPILER_FLAG(-maes)
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+ MY_CHECK_C_COMPILER_FLAG(-msse4)
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+ MY_CHECK_C_COMPILER_FLAG(-mpclmul)
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+ IF(have_C__maes AND have_C__msse4 AND have_C__mpclmul)
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+ SET(WOLFSSL_INTELASM ON)
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ENDIF()
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MY_CHECK_C_COMPILER_FLAG(-mrdrnd)
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MY_CHECK_C_COMPILER_FLAG(-mrdseed)
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Here are two examples of failures:
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10.5 1bf9acceef252000618a137853638c612339024b
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2021-01-02 12:24:07 0 [Note] InnoDB: Encrypting redo log: 10485760 bytes; LSN=48382
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2021-01-02 12:24:07 0 [Note] InnoDB: Starting to delete and rewrite log file.
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2021-01-02 12:24:07 0 [Note] InnoDB: Setting log file ./ib_logfile101 size to 10485760 bytes
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Uninitialized bytes in __interceptor_pwrite64 at offset 500 inside [0x7fce3670e000, 512)
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==315544==WARNING: MemorySanitizer: use-of-uninitialized-value
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#0 0x5562f26baf94 in SyncFileIO::execute(IORequest const&) /mariadb/10.5m/storage/innobase/os/os0file.cc:742:13
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10.5 1bf9acceef252000618a137853638c612339024b
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Uninitialized bytes in __interceptor_pwrite64 at offset 16378 inside [0x728000040000, 16384)
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==315509==WARNING: MemorySanitizer: use-of-uninitialized-value
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Uninitialized bytes in __interceptor_pwrite64 at offset 16378 inside [0x728000044000, 16384)
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#0 0x5603a7d0112a in tpool::simulated_aio::simulated_aio_callback(void*) /mariadb/10.5m/tpool/aio_simulated.cc:148:16
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After applying an additional patch, we will get a little more information:
diff --git a/storage/innobase/os/os0file.cc b/storage/innobase/os/os0file.cc
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index ac362e50404..b1626285196 100644
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--- a/storage/innobase/os/os0file.cc
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+++ b/storage/innobase/os/os0file.cc
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@@ -3224,6 +3224,7 @@ os_file_pwrite(
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const bool monitor = MONITOR_IS_ON(MONITOR_OS_PENDING_WRITES);
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MONITOR_ATOMIC_INC_LOW(MONITOR_OS_PENDING_WRITES, monitor);
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+ MEM_CHECK_DEFINED(buf, n);
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ssize_t n_bytes = os_file_io(type, file, const_cast<byte*>(buf),
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n, offset, err);
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MONITOR_ATOMIC_DEC_LOW(MONITOR_OS_PENDING_WRITES, monitor);
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Uninitialized bytes in __msan_check_mem_is_initialized at offset 500 inside [0x7f731195e000, 512)
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==320701==WARNING: MemorySanitizer: use-of-uninitialized-value
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#0 0x556a7492c2bf in os_file_pwrite(IORequest const&, int, unsigned char const*, unsigned long, unsigned long, dberr_t*) /mariadb/10.5m/storage/innobase/os/os0file.cc:3227:2
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...
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Uninitialized value was stored to memory at
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#0 0x556a724ca909 in __msan_memcpy (/dev/shm/10.5msan/sql/mariadbd+0x716909)
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#1 0x556a74903869 in log_crypt(unsigned char*, unsigned long, unsigned long, log_crypt_t) /mariadb/10.5m/storage/innobase/log/log0crypt.cc:211:3
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Uninitialized value was stored to memory at
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#0 0x556a7427a056 in MyCTX_nopad::finish(unsigned char*, unsigned int*) /mariadb/10.5m/mysys_ssl/my_crypt.cc:158:15
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Uninitialized value was created by an allocation of 'mask' in the stack frame of function '_ZN11MyCTX_nopad6finishEPhPj'
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#0 0x556a74279960 in MyCTX_nopad::finish(unsigned char*, unsigned int*) /mariadb/10.5m/mysys_ssl/my_crypt.cc:133
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All uninstrumented assembler code is identified by the use of the macro XASM_LINK in the file wolfcrypt/src/aes.c of the submodule extra/wolfssl/wolfssl. WolfSSL pull request #3611 fixes that problem for me.
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