xCAT/xNBA
2
0
Fork 0
mirror of https://github.com/xcat2/xNBA.git synced 2024-12-15 07:41:45 +00:00
Code Issues Projects Releases Wiki Activity

Allow re-entrancy and provide a global counter of the number of

Browse Source 
interrupts hooked.
This commit is contained in:
Michael Brown 2006-05-13 11:44:11 +00:00
parent d822b3d4cd
commit 63499e9cfd
1 changed files with 20 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/arch/i386/interface/pcbios/biosint.c
View File

@ -7,6 +7,17 @@
*
*/
/**
* Hooked interrupt count
*
* At exit, after unhooking all possible interrupts, this counter
* should be examined. If it is non-zero, it means that we failed to
* unhook at least one interrupt vector, and so must not free up the
* memory we are using. (Note that this also implies that we should
* re-hook INT 15 in order to hide ourselves from the memory map).
*/
int hooked_bios_interrupts = 0;
/**
* Hook INT vector
*
@ -26,9 +37,15 @@ void hook_bios_interrupt ( unsigned int interrupt, unsigned int handler,
.offset = handler,
};
if ( ( chain_vector->segment != 0 ) ||
( chain_vector->offset != 0 ) ) {
/* Already hooked; do nothing */
return;
}
copy_from_real ( chain_vector, 0, ( interrupt * 4 ),
sizeof ( *chain_vector ) );
copy_to_real ( 0, ( interrupt * 4 ), &vector, sizeof ( vector ) );
hooked_bios_interrupts++;
}
/**
@ -53,5 +70,8 @@ int unhook_bios_interrupt ( unsigned int interrupt, unsigned int handler,
return -EBUSY;
copy_to_real ( 0, ( interrupt * 4 ), chain_vector,
sizeof ( *chain_vector ) );
chain_vector->segment = 0;
chain_vector->offset = 0;
hooked_bios_interrupts--;
return 0;
}