libjava peeks into the dynamic linker's private Obj_Entry structures.
My recent changes introduced some new members near the front of
the structures, causing libjava to get the wrong fields. This commit
moves the new members toward the end of the structure so that the
layout of the portion that is relevant to JDK remains the same as
before.
I will work with the JDK porting team to see if we can come up with
a less fragile way for them to do what they need to do. I understand
the current approach was necessary in order to work around some
limitations of the dynamic linker. Maybe it's not necessary any
more.
PT_INTERP program header entry, to ensure that gdb always finds
the right dynamic linker.
Use obj->relocbase to simplify a few calculations where appropriate.
loaded separately by dlopen that have global symbols with identical
names. Viewing each dlopened object as a DAG which is linked by its
DT_NEEDED entries in the dynamic table, the search order is as
follows:
* If the referencing object was linked with -Bsymbolic, search it
internally.
* Search all dlopened DAGs containing the referencing object.
* Search all objects loaded at program start up.
* Search all objects which were dlopened() using the RTLD_GLOBAL
flag (which is now supported too).
The search terminates as soon as a strong definition is found.
Lacking that, the first weak definition is used.
These rules match those of Solaris, as best I could determine them
from its vague manual pages and the results of experiments I performed.
PR: misc/12438
violations in certain obscure cases involving failed dlopens. Many
thanks to Archie Cobbs for providing me with a good test case.
Eliminate a block that existed only to localize a declaration.
the dynamic linker didn't clean up properly. A subsequent dlopen()
of the same object would appear to succeed.
Another excellent fix from Max Khon.
PR: bin/12471
Submitted by: Max Khon <fjoe@iclub.nsu.ru>
discovered by Hidetoshi Shimokawa. Large programs need multiple
GOTs. The lazy binding stub in the PLT can be reached from any of
these GOTs, but the dynamic linker only has enough information to
fix up the first GOT entry. Thus calls through the other GOTs went
through the time-consuming lazy binding process on every call.
This fix rewrites the PLT entries themselves to bypass the lazy
binding.
Tested by Hidetoshi Shimokawa and Steve Price.
Reviewed by: Doug Rabson <dfr@freebsd.org>
o main returns int not void
o use return 0 at end of main when needed
o use braces to avoid potentially ambiguous else
o don't default to type int (and also remove a useless register
modifier).
Reviewed by: obrien and chuckr
function. It was an ill-considered feature. It didn't solve the
problem I wanted it to solve. And it added Yet Another Version
Number that would have to be maintained at every release point.
I'm nuking it now before anybody grows too fond of it.
_init() functions, initialize the global variables "__progname" and
"environ". This makes it possible for the _init() functions to call
things like getenv() and err().
the Makefile, and move it down into the architecture-specific
subdirectories.
Eliminate an asm() statement for the i386.
Make the dynamic linker work if it is built as an executable instead
of as a shared library. See i386/Makefile.inc to find out how to
do it. Note, this change is not enabled and it might never be
enabled. But it might be useful in the future. Building the
dynamic linker as an executable should make it start up faster,
because it won't have any relocations. But in practice I suspect
the difference is negligible.
MAXHOSTNAMELEN and call trimdomain() before implementing
the -u option.
This allows local hosts of a lan with a long domain name to
appear properly in utmp by base host name (w/o domain) rather
than by IP number.
friends are terminated and allow for a maximum
host name length of MAXHOSTNAMELEN - 1.
Put parenthesis around sizeof args.
Make some variables static.
Fix telnetd -u (broken by my last commit)
Prompted by: bde
lookup on the incoming IP, do a forward lookup on
the result and make sure that the IP is in the
resulting list. If it's not, put the IP number
in utmp/wtmp instead of the rogue name.
Stolen from: rlogind
Suggested by: sef
avoid crashing inside rtld (since it's easy) since everything else handles
it. Of course, if the target program checks argv[], it'll fall over.
Reviewed by: jdp
damn useful thing for using with serial consoles in clusters etc or secure
console locations. Using a custom gettytab entry for console with
an entry like 'al=root' means that there is *always* a root login ready on
the console. This should replace hacks like those which go with conserver
etc. (This is a loaded gun, watch out for those feet!)
Submitted by: "Andrew J. Korty" <ajk@purdue.edu>
There's not much point in having uucpd behave differently than
login(1) for this, and now uucpd is compatible to the default chat
script of Taylor UUCP which sends a single \r at first.
While i was at it, added a few strategic ``errno = 0;''s, so at least
an `Undefined error 0' will be returned for things like a closed
connection while reading the login ID or password, as opposed to an
even more bogus thing like `No such file or directory'.
on rshd and rlogind. However, note that:
1: rshd used to drop a connection with -a if the hostname != ip address.
This is unneeded, because iruserok() does it's own checking.
It was also wrong if .rhosts had an explicit IP address in it,
connections would be dropped from that host solely because the DNS was
mismatched even though it was explicitly intended to work by IP address.
2: rlogind and rshd check the hostname mappings by default now because that
is what goes into the utmp/wtmp and logs. If the hostname != ip address,
then it uses the IP address for logging/utmp/wtmp purposes. There isn't
much point logging ficticious hostnames.
3: rshd -a is now accepted (but ignored) for compatability. If you really
want to make life miserable for people with bad reverse DNS, use tcpd in
paranoid mode (which is questionable anyway, given DNS ttl tweaking).
Removed getuid() root check so ntalkd can be run from a tty sandbox.
It isn't suid root anyway, who knows why the getuid() check was even
in there in the first place!
rtld would accept the first shared library it found with the right
major version number, even if the minor version number was too low.
If a different version of the shared library with an adequate minor
version number appeared later in the search path, it would not be
found.
Now the rtld searches all locations first looking for a library
with a minor version that is high enough. Only if such a library
is not found will it fall back to accepting a minor version number
that is too low. As before, a warning comes out in that case.
This solves some problems encountered when building an older world
on a -current system.
References from GDB to "printf" and various other functions would
find the versions in the dynamic linker itself, rather than the
versions in the program's libc. This fix moves the GDB link map
entry for the dynamic linker to the end of the search list, where
its symbols will be found only if they are not found anywhere else.
It was suggested by Doug Rabson, though I implemented it a little
differently.
I personally would prefer to leave the dynamic linker's entry out
of the GDB search list altogether. But Doug argues that it is
handy there for such things as setting breakpoints on dlopen().
So it stays for now, at least.
Note, if we ever integrate the dynamic linker with libc (which has
several important benefits to recommend it), this whole problem
goes away.
dynamic linker itself dynamically allocated. All of them are
supposed to be dynamically allocated, but we cheated before. It
made gdb unhappy under some circumstances.
least 2 version numbers. This fixes the bug where the dynamic
linker would try to load an ELF shared library if it found one.
Note, this change also fixes the same thing in "ld", because the
code is shared.
For "ld" there is still a problem with ".a" libraries, which cannot
be distinguished by name. I haven't decided what, if anything, to
do about that.
a different file than the a.out hints, namely, "/var/run/ld-elf.so.hints".
These hints consist only of the directory search path. There is
no hash table as in the a.out hints, because ELF doesn't have to
search for the file with the highest minor version number. (It
doesn't have minor version numbers at all.)
A single run of ldconfig updates either the a.out hints or the ELF
hints, but not both. The set of hints to process is selected in
the usual way, via /etc/objformat, or ${OBJFORMAT}, or the "-aout"
or "-elf" command line option. The rationale is that you probably
want to search different directories for ELF than for a.out.
"ldconfig -r" is faked up to produce output like we are used to,
except that for ELF there are no minor version numbers. This should
enable "ldconfig -r" to be used for checking LIB_DEPENDS in ports
even for ELF.
I implemented the ELF functionality in a new source file, with an
eye toward eliminating the a.out code entirely at some point in
the future.
shared object. Note, this searches _only_ that object, and not its
needed objects, in accordance with the documentation.
Also fix dlopen(NULL, ...) so that the executable's needed objects
are searched as well as the executable itself.
it to sit right...
The __error() hack gave out the wrong address. It returned the address of
errno in ld.so instead of the address of errno in the main program. Oops.
The hack is now correct, just in time to be obsoleted by elf.
or Elf64 based on the inclusion of the machine dependent header.
I've left the addition of the extra fields to handle the relocation
structures with addend for a separate commit after jdp has had a chance
to review what I've done. The current change is needed to compile
csu/alpha/crt1.c
alternative, I present .. ta! da! .. the __error() hack.
This patch to the a.out dynamic loader provides old a.out binaries
with __error() if they are linked with an older libc that lacks it,
but are also linked against a library that needs it.
There is a smaller, tricker hack that takes advantage of the fact
that ld.so has __error() too, courtesy of the new libc, but this
hack is the straightforward version.
Move a.out libraries to /usr/lib/aout to make space for ELF libs.
Make rtld usr /usr/lib/aout as default library path.
Make ldconfig reject /usr/lib as an a.out library path.
Fix various Makefiles for LIBDIR!=/usr/lib breakage.
This will after a make world & reboot give a system that no
longer uses /usr/lib/*, infact one could remove all the old
libraries there, they are not used anymore.
We are getting close to an ELF make world, but I'll let this
all settle for a week or two...
output for local users. FTP protocol RFC also says that 'ls' output is
not machine-readable. "always UTC" still possible with TZ= in ftpd
environment by price of having UTC in log files too.
Fix INTERNAL_LS to sense new /etc/localtime after chroot
any case.
It makes no difference for anon account (since chroot already makes it GMT),
but if you do mirror with special non-anon login, in old variant
your mirror will be wholy retransmitted twice in the year due to
time zone changes (/etc/localtime plays bad role here)
quite a few enhancements and bug fixes. There are still some known
deficiencies, but it should be adequate to get us started with ELF.
Submitted by: John Polstra <jdp@polstra.com>
MOUNT_LFS to "lfs" in one place. The merge was painful because it
conflicted with cosmetic FreeBSD changes. lfs_cleanerd still compiles
cleanly but has aproximately the same chance of working as before (0).
emacs a.out file, self-generated by emacs's "unexec" function in
"unexsunos4.c", is invalid. In particular, its "_end" symbol has
the wrong value. The dynamic linker was using the value of that
symbol to initialize its sbrk break level.
The workaround is to peek at the executable's a.out header in
memory, and calculate what "_end" should be based on the segment
sizes.
I will work out a fix for emacs and send it to the FSF. This
dynamic linker workaround is still worthwhile, if only to avoid
forcing all emacs users to build a new version.
Note: xemacs gives a bogus warning at startup, for related reasons.
The warning is harmless and can safely be ignored. I will send a
patch to the xemacs maintainers to get rid of it, and meanwhile
add a patch file to our port.
things so that it uses the same malloc as is used by the program
being executed. This has several advantages, the big one being
that you can now debug core dumps from dynamically linked programs
and get useful information out of them. Until now, that didn't
work. The internal malloc package placed the tables describing
the loaded shared libraries in a mapped region of high memory that
was not written to core files. Thus the debugger had no way of
determining what was loaded where in memory. Now that the dynamic
linker uses the application's malloc package (normally, but not
necessarily, the system malloc), its tables end up in the regular
heap area where they will be included in core dumps. The debugger
now works very well indeed, thank you very much.
Also ...
Bring the program a little closer to conformance with style(9).
There is still a long way to go.
Add minimal const correctness changes to get rid of compiler warnings
caused by the recent const changes in <dlfcn.h> and <link.h>.
Improve performance by eliminating redundant calculations of symbols'
hash values.
