Replace the a.out emulation of 'struct linker_set' with something
a little more flexible. <sys/linker_set.h> now provides macros for
accessing elements and completely hides the implementation.
The linker_set.h macros have been on the back burner in various
forms since 1998 and has ideas and code from Mike Smith (SET_FOREACH()),
John Polstra (ELF clue) and myself (cleaned up API and the conversion
of the rest of the kernel to use it).
The macros declare a strongly typed set. They return elements with the
type that you declare the set with, rather than a generic void *.
For ELF, we use the magic ld symbols (__start_<setname> and
__stop_<setname>). Thanks to Richard Henderson <rth@redhat.com> for the
trick about how to force ld to provide them for kld's.
For a.out, we use the old linker_set struct.
NOTE: the item lists are no longer null terminated. This is why
the code impact is high in certain areas.
The runtime linker has a new method to find the linker set
boundaries depending on which backend format is in use.
linker sets are still module/kld unfriendly and should never be used
for anything that may be modular one day.
Reviewed by: eivind
usb, all in usb.ko. uhub depends on usb. The bug was that the preload
processing only adds a module to the list once it's internal dependencies
are resolved... Since it was not "seeing" the internal usb module it
believed that uhub had a missing dependency.
after the acquisition of any advisory locks. This fix corrects a case
in which a process tries to open a file with a non-blocking exclusive
lock. Even if it fails to get the lock it would still truncate the
file even though its open failed. With this change, the truncation
is done only after the lock is successfully acquired.
Obtained from: BSD/OS
instead of requiring every caller of linker_load_file() to perform the
check itself. This avoids netgraph loading KLD's when securelevel > 0,
not to mention any future code that may call linker_load_file().
Reviewed by: dfr
version dependency system. This isn't quite finished, but it is at a
useful stage to do a functional checkpoint.
Highlights:
- version and dependency metadata is gathered via linker sets, so things
are handled the same for static kernels and code built to live in a kld.
- The dependencies are at module level (versus at file level).
- Dependencies determine kld symbol search order - this means that you
cannot link against symbols in another file unless you depend on it. This
is so that you cannot accidently unload the target out from underneath
the ones referencing it.
- It is flexible enough that we can put tags in #include files and macros
so that we can get decent hooks for enforcing recompiles on incompatable
ABI changes. eg: if we change struct proc, we could force a recompile
for all kld's that reference the proc struct.
- Tangled dependency references at boot time are sorted. Files are
relocated once all their dependencies are already relocated.
Caveats:
- Loader support is incomplete, but has been worked on seperately.
- Actual enforcement of the version number tags is not active yet - just
the module dependencies are live. The actual structure of versioning
hasn't been agreed on yet. (eg: major.minor, or whatever)
- There is some backwards compatability for old modules without metadata
but I'm not sure how good it is.
This is based on work originally done by Boris Popov (bp@freebsd.org),
but I'm not sure he'd recognize much of it now. Don't blame him. :-)
Also, ideas have been borrowed from Mike Smith.
* Report link errors to stdout with uprintf() so that the user can see
what went wrong (PR kern/9214).
* Add support code to allow module symbols to be loaded into GDB using
the debugger's "sharedlibrary" command.
I've made a seperate version (c_index() etc) that use const/const, but
I'm not sure it's worth it considering there is one file in the tree
that uses index on const strings (kern_linker.c) and it's easily adjusted
to scan the strings directly (and is perhaps more efficient that way).
are still converted to u_long by assignment of the uintptr_t, and
address calculations are still done using u_long. This is OK for
currently supported machines, but addresses should be represented
by vm_offset_t or uintptr_t in case pointers are longer than longs.
"Fixed" size of linker_path[]. MAXPATHLEN + 1 was 1 too large for
search paths with only one file path in them, but much too small
for search paths with several long file paths in them.
SYSINIT_KT() etc (which is a static, compile-time procedure), use a
NetBSD-style kthread_create() interface. kproc_start is still available
as a SYSINIT() hook. This allowed simplification of chunks of the
sysinit code in the process. This kthread_create() is our old kproc_start
internals, with the SYSINIT_KT fork hooks grafted in and tweaked to work
the same as the NetBSD one.
One thing I'd like to do shortly is get rid of nfsiod as a user initiated
process. It makes sense for the nfs client code to create them on the
fly as needed up to a user settable limit. This means that nfsiod
doesn't need to be in /sbin and is always "available". This is a fair bit
easier to do outside of the SYSINIT_KT() framework.
the caller can easily find the child proc struct. fork(), rfork() etc
syscalls set p->p_retval[] themselves. Simplify the SYSINIT_KT() code
and other kernel thread creators to not need to use pfind() to find the
child based on the pid. While here, partly tidy up some of the fork1()
code for RF_SIGSHARE etc.
particularly annoying hack, namely having the linker bash the moduledata
to set the container pointer, preventing it being const. In the process,
a stack of warnings were fixed and will probably allow a revisit of the
const C_SYSINIT() changes. This explicitly registers modules in files or
preload areas with the module system first, and let them initialize via
SYSINIT/DECLARE_MODULE later in their SI_ORDER_xxx order. The kludge of
finding the containing file is no longer needed since the registration
of modules onto the modules list is done in the context of initializing
the linker file.
- %fs register is added to trapframe and saved/restored upon kernel entry/exit.
- Per-cpu pages are no longer mapped at the same virtual address.
- Each cpu now has a separate gdt selector table. A new segment selector
is added to point to per-cpu pages, per-cpu global variables are now
accessed through this new selector (%fs). The selectors in gdt table are
rearranged for cache line optimization.
- fask_vfork is now on as default for both UP and SMP.
- Some aio code cleanup.
Reviewed by: Alan Cox <alc@cs.rice.edu>
John Dyson <dyson@iquest.net>
Julian Elischer <julian@whistel.com>
Bruce Evans <bde@zeta.org.au>
David Greenman <dg@root.com>
1:
s/suser/suser_xxx/
2:
Add new function: suser(struct proc *), prototyped in <sys/proc.h>.
3:
s/suser_xxx(\([a-zA-Z0-9_]*\)->p_ucred, \&\1->p_acflag)/suser(\1)/
The remaining suser_xxx() calls will be scrutinized and dealt with
later.
There may be some unneeded #include <sys/cred.h>, but they are left
as an exercise for Bruce.
More changes to the suser() API will come along with the "jail" code.
unregister them after sysuninits when unloading.
* Add code to vfs_register() to set the oid number of vfs sysctls to
the type number of the filesystem.
Reviewed by: bde
being loaded twice. It used rindex() to strip the pathname but failed
to account for the fact that rindex() will return a pointer to the '/',
not the first character of the filename.
Submitted by: Nick Hibma <hibma@skylink.it>
This makes it possible to change the sysctl tree at runtime.
* Change KLD to find and register any sysctl nodes contained in the loaded
file and to unregister them when the file is unloaded.
Reviewed by: Archie Cobbs <archie@whistle.com>,
Peter Wemm <peter@netplex.com.au> (well they looked at it anyway)
patch. lf can't be dereferenced after the unload attempt, in case it
was freed. Instead, decrement first and back it out if the unload failed.
This should be relatively immune to races caused by the user since the
userref count will be zero for the duration of the actual unloading and
will stop further kldunload attempts.
Submitted by: Ustimenko Semen <semen@iclub.nsu.ru>
suggestions from Greg Lehey some time ago. In the face of multiple
potential file formats, try and give a more sensible error than just
ENOEXEC.
XXX a good case can be made that the loading process is wrong - the linker
should locate the file first (using the search paths etc), then run the
loaders to see if they recognize it. While the present system allows for
the possibility of different search paths for different formats, we do not
use it and it just makes things more complicated than they need to be.
