for possible buffer overflow problems. Replaced most sprintf()'s
with snprintf(); for others cases, added terminating NUL bytes where
appropriate, replaced constants like "16" with sizeof(), etc.
These changes include several bug fixes, but most changes are for
maintainability's sake. Any instance where it wasn't "immediately
obvious" that a buffer overflow could not occur was made safer.
Reviewed by: Bruce Evans <bde@zeta.org.au>
Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: Mike Spengler <mks@networkcs.com>
- Use the system headers method for Elf32/Elf64 symbol compatability
- get rid of the UPRINTF debugging.
- check the ELF header for compatability much more completely
- optimize the section mapper. Use the same direct VM interfaces that
imgact_aout.c and kern_exec.c use.
- Check the return codes from the vm_* functions better. Some return
KERN_* results, not an errno.
- prefault the page tables to reduce startup faults on page tables like
a.out does.
- reset the segment protection to zero for each loop, otherwise each
segment could get progressively more privs. (eg: if the first was
read/write/execute, and the second was meant to be read/execute, the
bug would make the second r/w/x too. In practice this was not a
problem because executables are normally laid out with text first.)
- Don't impose arbitary limits. Use the limits on headers imposed by
the need to fit them into one page.
- Remove unused switch() cases now that the verbose debugging is gone.
I've been using an earlier version of this for a month or so.
This sped up ELF exec speed a bit for me but I found it hard to get
consistant benchmarks when I tested it last (a few weeks ago).
I'm still bothered by the page read out of order caused by the
transition from data to bss. This which requires either part filling the
transition page or clearing the remainder.
This is the bulk of the support for doing kld modules. Two linker_sets
were replaced by SYSINIT()'s. VFS's and exec handlers are self registered.
kld is now a superset of lkm. I have converted most of them, they will
follow as a seperate commit as samples.
This all still works as a static a.out kernel using LKM's.
1) The vnode pager wasn't properly tracking the file size due to
"size" being page rounded in some cases and not in others.
This sometimes resulted in corrupted files. First noticed by
Terry Lambert.
Fixed by changing the "size" pager_alloc parameter to be a 64bit
byte value (as opposed to a 32bit page index) and changing the
pagers and their callers to deal with this properly.
2) Fixed a bogus type cast in round_page() and trunc_page() that
caused some 64bit offsets and sizes to be scrambled. Removing
the cast required adding casts at a few dozen callers.
There may be problems with other bogus casts in close-by
macros. A quick check seemed to indicate that those were okay,
however.
Formerly, the heuristic involving the interpreter path took
precedence.
Also, print a better error message if the brand is missing or not
recognized. If there is no brand at all, give the user a hint that
"brandelf" needs to be run.
minus the NULL pointer dereference in rev. 1.33. Also simplify
things somewhat by eliminating one traversal of the VM map entries.
Finally, eliminate calls to vm_map_{un,}lock_read() which aren't
needed here. I originally took them from procfs_map.c, but here
we know we are dealing only with the map of the current process.
segments (except memory-mapped devices) in the ELF core file. This
is really nice. You get access to the data areas of all shared
libraries, and even to files that are mapped read-write.
In the future, it might be good to add a new resource limit in the
spirit of RLIMIT_CORE. It would specify the maximum sized writable
segment to include in core dumps. Segments larger than that would
be omitted. This would be useful for programs that map very large
files read/write but that still would like to get usable core dumps.
object format of the executable being dumped. This is the first
step toward producing ELF core dumps in the proper format. I will
commit the code to generate the ELF core dumps Real Soon Now. In
the meantime, ELF executables won't dump core at all. That is
probably no less useful than dumping a.out-style core dumps as they
have done until now.
Submitted by: Alex <garbanzo@hooked.net> (with very minor changes by me)
FreeBSD/alpha. The most significant item is to change the command
argument to ioctl functions from int to u_long. This change brings us
inline with various other BSD versions. Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.
The prototype FreeBSD/alpha machdep will follow in a couple of days
time.
Linux emulation. This make Allegro Common Lisp 4.3 work under
FreeBSD!
Submitted by: Fred Gilham <gilham@csl.sri.com>
Commented on by: bde, dg, msmith, tg
Hoping he got everything right: eivind
than rolling it's own. This means that it now uses the "safe"
exec_map_first_page() to get the ld.so headers rather than risking a panic
on a page fault failure (eg: NFS server goes down).
Since all the ELF tools go to a lot of trouble to make sure everything
lives in the first page for executables, this is a win. I have not seen
any ELF executable on any system where all the headers didn't fit in the
first page with lots of room to spare.
I have been running variations of this code for some time on my pure ELF
systems.
fork. (On my machine, fork is about 240usecs, vfork is 78usecs.)
Implement rfork(!RFPROC !RFMEM), which allows a thread to divorce its memory
from the other threads of a group.
Implement rfork(!RFPROC RFCFDG), which closes all file descriptors, eliminating
possible existing shares with other threads/processes.
Implement rfork(!RFPROC RFFDG), which divorces the file descriptors for a
thread from the rest of the group.
Fix the case where a thread does an exec. It is almost nonsense for a thread
to modify the other threads address space by an exec, so we
now automatically divorce the address space before modifying it.
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.
The system boots and can mount UFS filesystems.
Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
Mount_std mounts will not work until the getfsent
library routine is changed.
Reviewed by: various people
Submitted by: Jeffery Hsu <hsu@freebsd.org>
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
Compile and link a new kernel, that will give native ELF support, and
provide the hooks for other ELF interpreters as well.
To make native ELF binaries use John Polstras elf-kit-1.0.1..
For the time being also use his ld-elf.so.1 and put it in
/usr/libexec.
The Linux emulator has been enhanced to also run ELF binaries, it
is however in its very first incarnation.
Just get some Linux ELF libs (Slackware-3.0) and put them in the
prober place (/compat/linux/...).
I've ben able to run all the Slackware-3.0 binaries I've tried
so far.
(No it won't run quake yet :)
