From c045d1dcea0b2582b38ee5476b090097182c7144 Mon Sep 17 00:00:00 2001 From: Satya B Date: Tue, 7 Apr 2009 16:54:32 +0530 Subject: [PATCH] Fix for Bug #43973 - backup_myisam.test fails on 6.0-bugteam The test started failing following the push for BUG#41541. Some of the algorithms access bytes beyond the input data and this can affect up to one byte less than "word size" which is BITS_SAVED / 8. Fixed by adding (BITS_SAVED / 8) -1 bytes to buffer size (i.e. Memory Segment #2) to avoid accessing un-allocated data. --- myisam/mi_packrec.c | 36 +++++++++------------------------- mysql-test/r/myisampack.result | 22 +++++++++++++++++++++ mysql-test/t/myisampack.test | 25 +++++++++++++++++++++++ 3 files changed, 56 insertions(+), 27 deletions(-) diff --git a/myisam/mi_packrec.c b/myisam/mi_packrec.c index df9a4d18a6c..68911d7f129 100644 --- a/myisam/mi_packrec.c +++ b/myisam/mi_packrec.c @@ -208,10 +208,17 @@ my_bool _mi_read_pack_info(MI_INFO *info, pbool fix_keys) This segment will be reallocated after construction of the tables. */ length=(uint) (elements*2+trees*(1 << myisam_quick_table_bits)); + /* + To keep some algorithms simpler, we accept that they access + bytes beyond the end of the input data. This can affect up to + one byte less than the "word size" size used in this file, + which is BITS_SAVED / 8. To avoid accessing non-allocated + data, we add (BITS_SAVED / 8) - 1 bytes to the buffer size. + */ if (!(share->decode_tables=(uint16*) my_malloc((length + OFFSET_TABLE_SIZE) * sizeof(uint16) + - (uint) (share->pack.header_length - sizeof(header)), - MYF(MY_WME | MY_ZEROFILL)))) + (uint) (share->pack.header_length - sizeof(header) + + (BITS_SAVED / 8) - 1), MYF(MY_WME | MY_ZEROFILL)))) goto err1; tmp_buff=share->decode_tables+length; disk_cache=(byte*) (tmp_buff+OFFSET_TABLE_SIZE); @@ -1430,31 +1437,6 @@ static void fill_buffer(MI_BIT_BUFF *bit_buff) bit_buff->current_byte=0; return; } - else - { - uint len= 0; - uint i= 0; - /* - Check if the remaining buffer/record to read is less than the word size. - If so read byte by byte - - Note: if this branch becomes a bottleneck it can be removed, assuming - that the second memory segment allocates 7 extra bytes (see - _mi_read_pack_info()). - */ - len= bit_buff->end - bit_buff->pos; - if (len < (BITS_SAVED / 8)) - { - bit_buff->current_byte= 0; - for (i=0 ; i < len ; i++) - { - bit_buff->current_byte+= (((uint) ((uchar) bit_buff->pos[len - i - 1])) - << (8 * i)); - } - bit_buff->pos= bit_buff->end; - return; - } - } #if BITS_SAVED == 64 bit_buff->current_byte= ((((uint) ((uchar) bit_buff->pos[7]))) + diff --git a/mysql-test/r/myisampack.result b/mysql-test/r/myisampack.result index b4b200549a5..736a550e32b 100644 --- a/mysql-test/r/myisampack.result +++ b/mysql-test/r/myisampack.result @@ -38,3 +38,25 @@ SELECT COUNT(*) FROM t1; COUNT(*) 1024 DROP TABLE t1; +# +# Bug #43973 - backup_myisam.test fails on 6.0-bugteam +# +CREATE DATABASE mysql_db1; +CREATE TABLE mysql_db1.t1 (c1 VARCHAR(5), c2 int); +CREATE INDEX i1 ON mysql_db1.t1 (c1, c2); +INSERT INTO mysql_db1.t1 VALUES ('A',1); +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +FLUSH TABLE mysql_db1.t1; +# Compress the table using MYISAMPACK tool +# Run MYISAMCHK tool on the compressed table +SELECT COUNT(*) FROM mysql_db1.t1 WHERE c2 < 5; +COUNT(*) +128 +DROP TABLE mysql_db1.t1; +DROP DATABASE mysql_db1; diff --git a/mysql-test/t/myisampack.test b/mysql-test/t/myisampack.test index ace7afce88a..ce27071bcf8 100644 --- a/mysql-test/t/myisampack.test +++ b/mysql-test/t/myisampack.test @@ -50,3 +50,28 @@ FLUSH TABLE t1; --exec $MYISAMPACK $MYSQLTEST_VARDIR/master-data/test/t1 SELECT COUNT(*) FROM t1; DROP TABLE t1; + +--echo # +--echo # Bug #43973 - backup_myisam.test fails on 6.0-bugteam +--echo # +CREATE DATABASE mysql_db1; +CREATE TABLE mysql_db1.t1 (c1 VARCHAR(5), c2 int); +CREATE INDEX i1 ON mysql_db1.t1 (c1, c2); +INSERT INTO mysql_db1.t1 VALUES ('A',1); +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +INSERT INTO mysql_db1.t1 SELECT * FROM mysql_db1.t1; +FLUSH TABLE mysql_db1.t1; +# +--echo # Compress the table using MYISAMPACK tool +--exec $MYISAMPACK -s $MYSQLTEST_VARDIR/master-data/mysql_db1/t1 +--echo # Run MYISAMCHK tool on the compressed table +--exec $MYISAMCHK -srq $MYSQLTEST_VARDIR/master-data/mysql_db1/t1 +SELECT COUNT(*) FROM mysql_db1.t1 WHERE c2 < 5; +# +DROP TABLE mysql_db1.t1; +DROP DATABASE mysql_db1;