Cleanup: Remove IF_VALGRIND

The purpose of the compress() wrapper my_compress_buffer() was twofold:
silence Valgrind warnings about uninitialized memory access before
zlib 1.2.4, and have PERFORMANCE_SCHEMA instrumentation of some zlib
related memory allocation. Because of PERFORMANCE_SCHEMA, we cannot
trivially replace my_compress_buffer() with compress().

az_open(): Remove a crc32() call. Any CRC of the empty string is 0.

Author: dr-m

include/my_valgrind.h

@@ -83,12 +83,6 @@
 # define MSAN_STAT_WORKAROUND(st) ((void) 0)
 #endif /* __has_feature(memory_sanitizer) */
 
-#ifdef HAVE_valgrind
-#define IF_VALGRIND(A,B) A
-#else
-#define IF_VALGRIND(A,B) B
-#endif
-
 #ifdef TRASH_FREED_MEMORY
 /*
   _TRASH_FILL() has to call MEM_MAKE_ADDRESSABLE() to cancel any effect of

mysql-test/valgrind.supp

@@ -1,5 +1,5 @@
 # Copyright (c) 2005, 2015, Oracle and/or its affiliates.
-# Copyright (c) 2008, 2019, MariaDB
+# Copyright (c) 2008, 2022, MariaDB
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Library General Public
@@ -100,137 +100,6 @@
    fun:_dl_start
 }
 
-#
-# Warnings in libz becasue it works with aligned memory(?)
-#
-
-{
-   libz tr_flush_block
-   Memcheck:Cond
-   fun:_tr_flush_block
-   fun:deflate_slow
-   fun:deflate
-   fun:do_flush
-   fun:gzclose
-}
-
-{
-   libz tr_flush_block2
-   Memcheck:Cond
-   fun:_tr_flush_block
-   fun:deflate_slow
-   fun:deflate
-   fun:compress2
-}
-
-{
-   libz longest_match
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:do_flush
-}
-
-{
-   libz longest_match called from btr_store_big_rec_extern_fields
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:btr_store_big_rec_extern_fields
-}
-
-{
-   libz longest_match called from page_zip_compress
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:page_zip_compress
-}
-
-{
-   libz longest_match2
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:compress2
-}
-
-{
-   libz longest_match 3
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:gzclose
-}
-
-{
-   libz longest_match 4 
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:gzflush
-}
-
-{
-   libz longest_match3
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:azflush
-}
-
-{
-   libz longest_match3
-   Memcheck:Cond
-   fun:longest_match
-   fun:deflate_slow
-   fun:deflate
-   fun:azclose
-}
-
-{
-   libz deflate
-   Memcheck:Cond
-   obj:*/libz.so.*
-   obj:*/libz.so.*
-   fun:deflate
-   fun:compress2
-}
-
-{
-   libz deflate2
-   Memcheck:Cond
-   obj:*/libz.so.*
-   obj:*/libz.so.*
-   fun:deflate
-   obj:*/libz.so.*
-   fun:gzflush
-}
-
-{
-   libz deflate3
-   Memcheck:Cond
-   obj:*/libz.so.*
-   obj:*/libz.so.*
-   fun:deflate
-   fun:do_flush
-}
-
-{
-   libz inflatereset2
-   Memcheck:Cond
-   fun:inflateReset2
-   fun:inflateInit2_
-   fun:uncompress
-}
-
 
 #
 # Warning from my_thread_init becasue mysqld dies before kill thread exists
@@ -705,39 +574,6 @@
    fun:buf_buddy_relocate
 }
 
-{
-   Bug 59874 Valgrind warning in InnoDB compression code
-   Memcheck:Cond
-   fun:*
-   fun:*
-   fun:deflate
-   fun:btr_store_big_rec_extern_fields_func
-   fun:row_ins_index_entry_low
-   fun:row_ins_index_entry
-   fun:row_ins_index_entry_step
-   fun:row_ins
-   fun:row_ins_step
-   fun:row_insert_for_mysql
-}
-
-{
-   In page0zip.c we have already checked that the memory is initialized before calling deflate()
-   Memcheck:Cond
-   fun:*
-   fun:*
-   fun:deflate
-   fun:page_zip_compress
-}
-
-{
-   In page0zip.c we have already checked that the memory is initialized before calling deflate()
-   Memcheck:Cond
-   fun:*
-   fun:*
-   fun:deflate
-   fun:page_zip_compress_deflate
-}
-
 {
    Bug 59875 Valgrind warning in buf0buddy.c
    Memcheck:Addr1

mysys/my_compress.c

@@ -1,4 +1,5 @@
 /* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2022, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -57,35 +58,11 @@ my_bool my_compress(uchar *packet, size_t *len, size_t *complen)
 }
 
 
-/*
-  Valgrind normally gives false alarms for zlib operations, in the form of
-  "conditional jump depends on uninitialised values" etc. The reason is
-  explained in the zlib FAQ (http://www.zlib.net/zlib_faq.html#faq36):
-
-    "That is intentional for performance reasons, and the output of deflate
-    is not affected."
-
-  Also discussed on a blog
-  (http://www.sirena.org.uk/log/2006/02/19/zlib-generating-valgrind-warnings/):
-
-    "...loop unrolling in the zlib library causes the mentioned
-    “Conditional jump or move depends on uninitialised value(s)”
-    warnings. These are safe since the results of the comparison are
-    subsequently ignored..."
-
-    "the results of the calculations are discarded by bounds checking done
-    after the loop exits"
-
-  Fix by initializing the memory allocated by zlib when running under Valgrind.
-
-  This fix is safe, since such memory is only used internally by zlib, so we
-  will not hide any bugs in mysql this way.
-*/
 void *my_az_allocator(void *dummy __attribute__((unused)), unsigned int items,
                       unsigned int size)
 {
   return my_malloc(key_memory_my_compress_alloc, (size_t)items*(size_t)size,
-                   IF_VALGRIND(MY_ZEROFILL, MYF(0)));
+                   MYF(0));
 }
 
 void my_az_free(void *dummy __attribute__((unused)), void *address)

sql/mysqld.cc

@@ -8706,12 +8706,16 @@ void set_server_version(char *buf, size_t size)
 {
   bool is_log= opt_log || global_system_variables.sql_log_slow || opt_bin_log;
   bool is_debug= IF_DBUG(!strstr(MYSQL_SERVER_SUFFIX_STR, "-debug"), 0);
-  bool is_valgrind= IF_VALGRIND(!strstr(MYSQL_SERVER_SUFFIX_STR, "-valgrind"), 0);
+  const char *is_valgrind=
+#ifdef HAVE_VALGRIND
+    !strstr(MYSQL_SERVER_SUFFIX_STR, "-valgrind") ? "-valgrind" :
+#endif
+    "";
   strxnmov(buf, size - 1,
            MYSQL_SERVER_VERSION,
            MYSQL_SERVER_SUFFIX_STR,
            IF_EMBEDDED("-embedded", ""),
-           is_valgrind ? "-valgrind" : "",
+           is_valgrind,
            is_debug ? "-debug" : "",
            is_log ? "-log" : "",
            NullS);

storage/archive/azio.c

@@ -71,7 +71,7 @@ int az_open (azio_stream *s, const char *path, int Flags, File fd)
   s->in = 0;
   s->out = 0;
   s->back = EOF;
-  s->crc = crc32(0L, Z_NULL, 0);
+  s->crc = 0;
   s->transparent = 0;
   s->mode = 'r';
   s->version = (unsigned char)az_magic[1]; /* this needs to be a define to version */