Re: bk commit into 5.1 tree (kaa:1.2436) BUG#5731

[Sergei Golubchik]

Hi!

On Jul 17, Alexey Kopytov wrote:
> ChangeSet@stripped, 2007-07-17 20:13:28+04:00, kaa@stripped +2 -0
>   This patch is a part of work on bug #5731 "key_buffer_size not properly restricted
> to 4GB".
>   
>   The patch limits read_buffer_size and read_rnd_buffer_size by 2 GB on all platforms
> for the following reasons:
>   
>   - I/O code in mysys, code in mf_iocache.c and in some storage
>   engines do not currently work with sizes > 2 GB for those buffers
>   - even if the above had been fixed, Windows POSIX read() and write()
>   calls are not 2GB-safe, so setting those buffer to sizes > 2GB would
>   not work correctly on 64-bit Windows.
> 
>   include/my_global.h@stripped, 2007-07-17 20:13:24+04:00, kaa@stripped +0 -3
>     Removed SSIZE_MAX because it's not neeeded anymore.
> 
>   sql/mysqld.cc@stripped, 2007-07-17 20:13:24+04:00, kaa@stripped +3 -3
>     Limit read_buffer_size and read_rnd_buffer_size by 2 GB on all platforms.
> 
> --- 1.619/sql/mysqld.cc	2007-02-14 16:51:46 +03:00
> +++ 1.620/sql/mysqld.cc	2007-07-17 20:13:24 +04:00
> @@ -6195,7 +6195,7 @@ The minimum value for this variable is 4
>     (gptr*) &global_system_variables.read_buff_size,
>     (gptr*) &max_system_variables.read_buff_size,0, GET_ULONG, REQUIRED_ARG,
> -   128*1024L, IO_SIZE*2+MALLOC_OVERHEAD, SSIZE_MAX, MALLOC_OVERHEAD, IO_SIZE,
> +   128*1024L, IO_SIZE*2+MALLOC_OVERHEAD, INT_MAX, MALLOC_OVERHEAD, IO_SIZE,

Wouldn't INT32_MAX be safer ?

>     0},
>    {"read_only", OPT_READONLY,

Regards / Mit vielen Grüssen,
Sergei

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