minix/lib/syslib/sys_safemap.c
Cristiano Giuffrida c5b309ff07 Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu)
Main changes:
- COW optimization for safecopy.
- safemap, a grant-based interface for sharing memory regions between processes.
- Integration with safemap and complete rework of DS, supporting new data types
  natively (labels, memory ranges, memory mapped ranges).
- For further information:
  http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants

Additional changes not included in the original Wu's branch:
- Fixed unhandled case in VM when using COW optimization for safecopy in case
  of a block that has already been shared as SMAP.
- Better interface and naming scheme for sys_saferevmap and ds_retrieve_map
  calls.
- Better input checking in syslib: check for page alignment when creating
  memory mapping grants.
- DS notifies subscribers when an entry is deleted.
- Documented the behavior of indirect grants in case of memory mapping.
- Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked
  and extended.
- Minor fixes and general cleanup.
- TO-DO: Grant ids should be generated and managed the way endpoints are to make
sure grant slots are never misreused.
2010-01-14 15:24:16 +00:00

72 lines
2.1 KiB
C

#include "syslib.h"
#include <minix/safecopies.h>
/*===========================================================================*
* sys_safemap *
*===========================================================================*/
PUBLIC int sys_safemap(endpoint_t grantor, cp_grant_id_t grant,
vir_bytes grant_offset, vir_bytes my_address,
size_t bytes, int my_seg, int writable)
{
/* Map a block of data for which the other process has previously
* granted permission.
*/
message copy_mess;
copy_mess.SMAP_EP = grantor;
copy_mess.SMAP_GID = grant;
copy_mess.SMAP_OFFSET = grant_offset;
copy_mess.SMAP_SEG = (void*) my_seg;
copy_mess.SMAP_ADDRESS = my_address;
copy_mess.SMAP_BYTES = bytes;
copy_mess.SMAP_FLAG = writable;
return(_taskcall(SYSTASK, SYS_SAFEMAP, &copy_mess));
}
/*===========================================================================*
* sys_saferevmap_gid *
*===========================================================================*/
PUBLIC int sys_saferevmap_gid(cp_grant_id_t grant)
{
/* Grantor revokes safemap by grant id. */
message copy_mess;
copy_mess.SMAP_FLAG = 1;
copy_mess.SMAP_GID = grant;
return(_taskcall(SYSTASK, SYS_SAFEREVMAP, &copy_mess));
}
/*===========================================================================*
* sys_saferevmap_addr *
*===========================================================================*/
PUBLIC int sys_saferevmap_addr(vir_bytes addr)
{
/* Grantor revokes safemap by address. */
message copy_mess;
copy_mess.SMAP_FLAG = 0;
copy_mess.SMAP_GID = addr;
return(_taskcall(SYSTASK, SYS_SAFEREVMAP, &copy_mess));
}
/*===========================================================================*
* sys_safeunmap *
*===========================================================================*/
PUBLIC int sys_safeunmap(int my_seg, vir_bytes my_address)
{
/* Requestor unmaps safemap. */
message copy_mess;
copy_mess.SMAP_SEG = (void*) my_seg;
copy_mess.SMAP_ADDRESS = my_address;
return(_taskcall(SYSTASK, SYS_SAFEUNMAP, &copy_mess));
}