Hi !
(First, I'm sorry for my bad english. Second, I'm a kernel newbie, and
I'm not familiar with mmap)
It seem that mmap had a bad behavior since some pre test5 patch.
The above program show this.
On 2.2.17-pre13, output is "1 2", and on test5-pre5/6, output is "1 1".
BTW, for example, INN stop working correctly.
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#include <stdlib.h>
#include <fcntl.h>
#include <sys/mman.h>
static int fd ;
char* ptr ;
void create_file()
{
char pattern = 1 ;
int n ;
fd = open( "test-mmap" , O_CREAT | O_WRONLY | O_TRUNC , 0664 ) ;
if ( fd < 0 )
exit( 1 ) ;
for ( n = 0 ; n < 100 ; ++ n )
write( fd , &pattern , 1 ) ;
close( fd ) ;
}
void init()
{
fd = open( "test-mmap" , O_RDWR ) ;
if ( fd < 1 )
exit( 1 ) ;
ptr = mmap( 0 , 100 , PROT_READ | PROT_WRITE , MAP_SHARED , fd , 0 ) ;
if ( ptr == MAP_FAILED )
exit( 1 ) ;
}
void cleanup()
{
munmap( ptr , 100 ) ;
close( fd ) ;
}
int main()
{
create_file() ;
init() ;
printf( "%d\n" , (int)ptr[ 2 ] ) ;
ptr[ 2 ] = 2 ;
cleanup() ;
init() ;
printf( "%d (should be 2 !?)\n" , (int)ptr[ 2 ] ) ;
cleanup() ;
printf( ".\n" ) ;
return 0 ;
}
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