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.
SYSLIB CHANGES:
- SEF framework now supports a new SEF Init request type from RS. 3 different
callbacks are available (init_fresh, init_lu, init_restart) to specify
initialization code when a service starts fresh, starts after a live update,
or restarts.
SYSTEM SERVICE CHANGES:
- Initialization code for system services is now enclosed in a callback SEF will
automatically call at init time. The return code of the callback will
tell RS whether the initialization completed successfully.
- Each init callback can access information passed by RS to initialize. As of
now, each system service has access to the public entries of RS's system process
table to gather all the information required to initialize. This design
eliminates many existing or potential races at boot time and provides a uniform
initialization interface to system services. The same interface will be reused
for the upcoming publish/subscribe model to handle dynamic
registration / deregistration of system services.
VM CHANGES:
- Uniform privilege management for all system services. Every service uses the
same call mask format. For boot services, VM copies the call mask from init
data. For dynamic services, VM still receives the call mask via rs_set_priv
call that will be soon replaced by the upcoming publish/subscribe model.
RS CHANGES:
- The system process table has been reorganized and split into private entries
and public entries. Only the latter ones are exposed to system services.
- VM call masks are now entirely configured in rs/table.c
- RS has now its own slot in the system process table. Only kernel tasks and
user processes not included in the boot image are now left out from the system
process table.
- RS implements the initialization protocol for system services.
- For services in the boot image, RS blocks till initialization is complete and
panics when failure is reported back. Services are initialized in their order of
appearance in the boot image priv table and RS blocks to implements synchronous
initialization for every system service having the flag SF_SYNCH_BOOT set.
- For services started dynamically, the initialization protocol is implemented
as though it were the first ping for the service. In this case, if the
system service fails to report back (or reports failure), RS brings the service
down rather than trying to restart it.
form. Subscriptions are regular expressions.
. different types are stored per key; currently u32 and/or string.
the same key can be referenced (publish, subscribe, check) as any type.
. notify()s are sent when subscriptions are triggered (publishing or
updating of matching keys); optionally, a subscribe flag sends
updates for all matching keys at subscription time, instead of only
after updates after subscribing
. all interfacing to ds is in /usr/src/lib/syslib/ds.c.
. subscribe is ds_subscribe
publish functions are ds_publish_<type>
retrieve functions are ds_retrieve_<type> (one-time retrieval of a value)
check functions are ds_check_<type> (check for updated key caller
subscribes to not yet checked for, or ESRCH for none)
. ramdisk driver updated with new ds interface
. added safecopies.c:
these are library functions to maintain grant tables in own address space
. sys_safecopy.c:
interfaces to kernel calls to perform safe copy functions in from or to
foreign process
. changes in i/o fields (type merged with request) reflected in
library functions (sys_out.c, sys_vinb.c, sys_vinl.c, sys_vinw.c,
sys_voutb.c, sys_voutl.c, sys_voutw.c)
. type merged with request in sys_sdevio, also now accepts offset which
is used when a grant is specified (the _DIO_SAFE subtype)
. system printf() function changed to send DIAGNOSTICS_S messages, which
specify a grant id instead of a direct address for the buffer to be
printed; tty and log can then safecopy the buffer
