Commit Graph

138 Commits

Author SHA1 Message Date
Alexander Kabaev
8b7f25d41d Add support for binaries with arbitrary number of PT_LOAD sections.
Reviewed by:	peter
2002-10-23 01:43:29 +00:00
Alexander Kabaev
b2ce513208 Change the symbol lookup order to search RTLD_GLOBAL objects
before referencing object's DAG. This makes it possible for
C++ exceptions to work across shared libraries and brings
us closer to the search order used by Solaris/Linux.

Reviewed by:	jdp
Approved by:	obrien
MFC after:	1 month
2002-10-19 23:03:35 +00:00
Maxim Sobolev
d1cf9ea2c4 Fix a problem with RTLD_TRACE flag to dlopen(3), which sometimes can return
even if there was no error occured (when trying to dlopen(3) object that
already linked into executable which does dlopen(3) call). This is more
proper fix for `ldd /usr/lib/libc.so' problem, because the new behaviour
conforms to documentation.

Remove workaround from ldd.c (rev.1.32).

PR:		35099
Submitted by:	Nathan Hawkins <utsl@quic.net>
MFC after:	1 week
2002-10-19 10:18:29 +00:00
David E. O'Brien
b2bced0aef Use the new freebsd output format from Binutils 2.13.1. 2002-10-12 02:30:53 +00:00
Ruslan Ermilov
2908cc64eb <machine/atomic.h> requires <sys/types.h>.
Reviewed by:	jake, mike
2002-10-09 20:20:43 +00:00
Thomas Moestl
a4823075e5 Return an error if a symbol is not found in reloc_jmpslots() instead of
crashing.
2002-09-14 12:14:24 +00:00
Marcel Moolenaar
708bc7c7b4 Fix a nasty memory corruption bug caused by having a bogus pointer
for the DT_IA64_PLT_RESERVE dynamic table entry. When a shared object
does not have any PLT relocations, the linker apparently doesn't find
it necessary to actually reserve the space for the BOR (Bind On
Reference) entries as pointed to by the DTE. As a result, relocatable
data in the PLT was overwritten, causing some unexpected control flow
with annoyingly predictable outcome: coredump.
To reproduce:
	% echo 'int main() { return 0; }' > foo.c
	% cc -o foo foo.c -lxpg4
2002-08-22 03:56:57 +00:00
Warner Losh
7b5564b2ee Include stddef.h for NULL definition, rather than rolling our own here.
Reviewed by: jdp
2002-08-21 19:03:26 +00:00
Marcel Moolenaar
ecfdc2e0cd Add support for the R_IA64_IPLTLSB relocation in non-PLT context.
This relocation creates a function descriptor at the specified
address and is commonly used for C++ to create virtual function
tables.
2002-08-20 00:24:33 +00:00
John Polstra
0df23e4bd5 Don't acquire the writer lock in rtld_exit when clearing the shared
objects' reference counts.  This function is called by the atexit
mechanism at program shutdown.  I don't think the locking is necessary
here.  It caused OpenOffice builds to hang more often than not.
Credit to Martin Blapp and Matt Dillon for helping to diagnose this
problem and for testing the fix.
2002-08-08 15:53:23 +00:00
Jake Burkholder
b1d6ef2ee9 Add END markers to asm functions so that debuggers can find their size. 2002-07-17 22:20:41 +00:00
John Polstra
e6f0183bff Remove the nanosleep calls from the spin loops in the locking code.
They provided little benefit (if any) and they caused some problems
in OpenOffice, at least in post-KSE -current and perhaps in other
environments too.  The nanosleep calls prevented the profiling timer
from advancing during the spinloops, thereby preventing the thread
scheduler from ever pre-empting the spinning thread.  Alexander
Kabaev diagnosed this problem, Martin Blapp helped with testing,
and Matt Dillon provided some helpful suggestions.

This is a short-term fix for a larger problem.  The use of spinlocking
isn't guaranteed to work in all cases.  For example, if the spinning
thread has higher priority than all other threads, it may never be
pre-empted, and the thread holding the lock may never progress far
enough to release the lock.  On the other hand, spinlocking is the
only locking that can work with an arbitrary unknown threads package.

I have some ideas for a much better fix in the longer term.  It
would eliminate all locking inside the dynamic linker by making it
safe for symbol lookups and lazy binding to proceed in parallel
with a call to dlopen or dlclose.  This means that the only mutual
exclusion needed would be to prevent multiple simultaneous calls
to dlopen and/or dlclose.  That mutual exclusion could be put into
the native pthreads library.  Applications using foreign threads
packages would have to make their own arrangements to ensure that
they did not have multiple threads in dlopen and/or dlclose -- a
reasonable requirement in my opinion.

MFC after:	3 days
2002-07-06 20:25:56 +00:00
Philippe Charnier
3f162cb85d The .Nm utility 2002-07-06 19:19:48 +00:00
John Polstra
d1c02bccdc Update the asm statements to use the "+" modifier instead of
matching constraints where appropriate.  This makes the dynamic
linker buildable at -O0 again.

Thanks to Bruce Evans for identifying the cause of the build
problem.

MFC after:	1 week
2002-06-24 23:19:18 +00:00
Jake Burkholder
cf85da5c68 Add needed include of mman.h to fix sparc64 buildworld. 2002-06-24 05:23:46 +00:00
Matthew Dillon
b6801e6b54 The last bits of the alloca -> mmap fix. IA64 and SPARC64 (current only).
Untested (testing request went unanswered), but sparc64 is not expected to
cause problems.  IA64 is not expected to cause problems but the patch was
slightly more complex so the possibility exists.

Approved by:    jdp
2002-06-22 18:36:21 +00:00
Matthew Dillon
eebf98659e This is the same alloca() fix as was committed for i386. David O'Brien
tested the patch on -stable.

Reviewed by:	obrien
Approved by:	jdp
MFC after:	3 days
2002-06-18 05:42:33 +00:00
John Polstra
5f8aa32e1b Dillon's recent commits to the dynamic linker without running them
by me first have given me a good excuse to drop my MAINTAINERship.

MFC after:	1 week
2002-06-10 21:51:16 +00:00
Matthew Dillon
b08440e568 Correct a bug in the last commit. The whole point of creating a 'done:'
goto target was so the cache could be freed.  So free the cache after
done: rather then before done: (!)

Submitted by:	Gavin Atkinson <gavin@ury.york.ac.uk>
2002-06-10 21:15:50 +00:00
Matthew Dillon
b603db3019 In tracking down an installation seg fault with then openoffice port
Martin Blapp determined that the elf dynamic loader was at fault.  In
particular, the loader uses alloca() to allocate a symbol cache on the
stack.  Normally this would work just fine, but if the loader is called
from a threaded program and the object being loaded is fairly large the
alloca() can blow away the thread stack and effect other nearby thread
stacks as well.  My testing showed that the symbol cache can be as large
as 250KBytes during the openoffice port build and install sequence.  Martin
was able to work around the problem by disabling the symbol cache
(cache = NULL;).  However, this solution is not adequate for commit because
it can cause an enormous cpu burden for applications which do a lot of
dynamic loading (e.g. like konqueror).

The solution is to use anonymous mmap() to temporarily allocate space to
hold the symbol cache.  In testing I found that replacing the alloca()
with mmap() has no observable degredation in performance.

It should be noted that this bug does not necessarily cause an immediate
crash but can instead result in long term corruption and instability in
applications that load modules from threads.  The bug is almost certainly
responsible for some of the instabilities found in konqueror, for example,
and possibly netscape too.

Sleuthing work by: Martin Blapp <mb@imp.ch>
X-MFC after:	Before or after the 4.6 release depending on the release engineers
2002-06-10 18:52:31 +00:00
Marcel Moolenaar
5c8e25383a Include machine/ia64_cpu.h because we use ia64_mf().
Submitted by: ru
2002-05-21 00:04:08 +00:00
Marcel Moolenaar
2aba02382e Fix handling of weak references to undefined symbols on ia64:
o  Set st_shndx for sym_zero to SHN_UNDEF instead of SHN_ABS.
   This gives us something to reliably test against.
o  For weak references to undefined sysmbols (as indicated by
   having st_shndx equals SHN_UNDEF) in the context of OPDs,
   the address of the OPD is to be zero, not the address of
   the function it contains.
o  For weak references to undefined symbols in all other cases
   (only DIR64LSB at this time), the actual relocated value is
   to be zero, not the value prior to relocating.

Roughly speaking, weak references to undefined symbols are no-ops.

Tested on: i386, ia64
2002-04-27 05:32:51 +00:00
Marcel Moolenaar
c7e3bd1ce6 Now that local symbols aren't looked up with the symbol hash table,
binding works for local symbols. Remove the workaround...
2002-04-27 02:53:31 +00:00
Marcel Moolenaar
9d4f27148f Don't do symbol lookups for local symbols. The symbol index in the
relocation identifies the symbol to which we need to bind. This
solves a problem seen on ia64 where the symbol hash table does not
contain local symbols and thus resulted in unresolved symbols.

Tested on: alpha, i386, ia64
2002-04-27 02:48:29 +00:00
Peter Wemm
968253905e Fix a relocation bug in the ia64 ld.so. Weak function pointers in shared
objects were not being correctly set to zero.  Instead, the function
descriptor pointer was set to the load address of the .so object.  This
caused gcc generated binaries to segfault on exit when crtbegin.asm's
_fini code tested the __cxa_finalize() function pointer for zero.

This is a bit of a hack because of a problem nearby workaround for
find_symdef and its quirks (failures) for local symbols.  This still
needs to be fixed.
2002-04-07 04:16:35 +00:00
Jake Burkholder
2da08e795e Minor changes to make this work on sparc64.
Approved by:	jdp
Tested on:	alpha, i386, sparc64
2002-04-02 02:19:02 +00:00
Jake Burkholder
e4c9dc6770 rtld support for sparc64.
Largely obtained from:	netbsd
Submitted by:	jake, tmm
2002-03-13 02:40:39 +00:00
Dag-Erling Smørgrav
e211585c77 When searching an object that was opened with RTLD_GLOBAL, search its DAG too.
PR:		bin/25059
Approved by:	jdp
MFC after:	3 weeks
2002-02-27 23:44:50 +00:00
Peter Wemm
939bc65715 ld-elf.so.1 assumed a few too many things about the ordering of sections
produced by ld(8) (ie: that _DYNAMIC immediately follows the _GOT).
The new binutils import changed that, and the intial GOT relocation
broke.  Use a custom linker script to provide a real end-of-GOT symbol.

Update ld.so to deal with the new (faster) PLT format that gcc-3.1 and
binutils can produce.

This is probably incomplete, but appears to be working again.

Obtained from:  NetBSD
(And a fix to a silly mistake that I made by:  gallatin)
2002-02-18 02:24:10 +00:00
David E. O'Brien
2024994319 Add support such that if LD_TRACE_LOADED_OBJECTS_ALL is defined to a
non-empty string in the environment; we indicate which objects caused
each object to be loaded.

PR:		30908
Submitted-by:	Mike Meyer <mwm@mired.org>
2002-02-17 07:04:32 +00:00
Maxim Sobolev
c6de4ce791 Allow ldd(1) be used on shared libraries in addition to executables. 2002-02-04 10:33:48 +00:00
Kris Kennaway
8f23d50652 Mark a function as __printflike()
MFC after:	1 week
2002-02-04 01:41:35 +00:00
John Polstra
a7dcaa3441 Change the library search order so that LD_LIBRARY_PATH overrides
all others.

PR:		bin/28191
MFC after:	2 weeks
2002-01-25 16:35:43 +00:00
David Malone
98d1592458 Change brk's prototype from char *brk(const char *) to int brk(const void *)
and sbrk's prototype from char *sbrk(int) to void *sbrk(intptr_t).

This makes us more consistant with NetBSD and standards which include
these functions. Bruce pointed out that ptrdiff_t would probably
have been better than intptr_t, but this doesn't match other
implimentations.

Also remove local declarations of sbrk and unnecessary casting.

PR:		32296
Tested by:	Harti Brandt <brandt@fokus.gmd.de>
MFC after:	1 month
2002-01-24 12:11:31 +00:00
Ruslan Ermilov
bcf2b1b312 mdoc(7) police: tidy up. 2002-01-10 17:49:57 +00:00
Peter Wemm
14a55adf36 Update rtld for the "new" ia64 ABI. In the old toolchain, the
DT_INIT and DT_FINI tags pointed to fptr records.  In 2.11.2, it points
to the actuall address of the function.  On IA64 you cannot just take
an address of a function, store it in a function pointer variable and
call it.. the function pointers point to a fptr data block that has the
target gp and address in it.  This is absolutely necessary for using
the in-tree binutils toolchain, but (unfortunately) will not work with
old shared libraries.  Save your old ld-elf.so.1 if you want to use
old ones still.  Do not mix-and-match.

This is a no-op change for i386 and alpha.

Reviewed by:	dfr
2001-10-29 10:10:10 +00:00
Peter Wemm
d4cf88ddc4 Fix a dependency violation (branch after alloc) 2001-10-29 10:05:32 +00:00
Doug Rabson
b5393d9f78 Add ia64 support. Various adjustments were made to existing targets to
cope with a few interface changes required by the ia64. In particular,
function pointers on ia64 need special treatment in rtld.
2001-10-15 18:48:42 +00:00
Doug Rabson
97571220e2 The support for accelerating find_symdef() with a cache was broken. This
fixes the problem and improves startup times for large applications such
as KDE2 considerably.

Reviewed by:	jdp
MFC after:	1 week
2001-10-10 07:15:01 +00:00
Ruslan Ermilov
c4d9468ea0 mdoc(7) police:
Avoid using parenthesis enclosure macros (.Pq and .Po/.Pc) with plain text.
Not only this slows down the mdoc(7) processing significantly, but it also
has an undesired (in this case) effect of disabling hyphenation within the
entire enclosed block.
2001-08-07 15:48:51 +00:00
Sheldon Hearn
e1b4d8d074 Use STD{ERR,IN,OUT}_FILENO instead of their numeric values. The
definitions are more readable, and it's possible that they're
more portable to pathalogical platforms.

Submitted by:   David Hill <david@phobia.ms>
2001-07-26 11:02:39 +00:00
Ruslan Ermilov
0efe23d669 mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 10:49:54 +00:00
Dima Dorfman
70d51341bf mdoc(7) police: remove extraneous .Pp before and/or after .Sh. 2001-07-09 09:54:33 +00:00
Ruslan Ermilov
5521ff5a4d mdoc(7) police: sort SEE ALSO xrefs (sort -b -f +2 -3 +1 -2). 2001-07-06 16:46:48 +00:00
Ruslan Ermilov
4cf39050cc Use new backup feature of install(1). 2001-05-28 16:58:35 +00:00
John Polstra
c15e7faad5 Performance improvements for the ELF dynamic linker. These
particularly help programs which load many shared libraries with
a lot of relocations.  Large C++ programs such as are found in KDE
are a prime example.

While relocating a shared object, maintain a vector of symbols
which have already been looked up, directly indexed by symbol
number.  Typically, symbols which are referenced by a relocation
entry are referenced by many of them.  This is the same optimization
I made to the a.out dynamic linker in 1995 (rtld.c revision 1.30).

Also, compare the first character of a sought-after symbol with its
symbol table entry before calling strcmp().

On a PII/400 these changes reduce the start-up time of a typical
KDE program from 833 msec (elapsed) to 370 msec.

MFC after:	5 days
2001-05-05 23:21:05 +00:00
David E. O'Brien
5e6220d9d0 * include/elf.h has been repo copied to include/elf-hints.h, and it no
longer includes machine/elf.h.
* consumers of elf.h now use the minimalist elf header possible.

This change is motivated by Binutils 2.11.0 and too much clashing over
our base elf headers and the Binutils elf headers.
2001-05-02 23:56:21 +00:00
Ruslan Ermilov
e5b5c66bca - Backout botched attempt to intoduce MANSECT feature.
- MAN[1-9] -> MAN.
2001-03-26 14:22:12 +00:00
Ruslan Ermilov
896eb7d10c Prepare for mdoc(7)NG. 2001-01-16 09:15:57 +00:00
John Polstra
27e2c03506 Fix a bug in which a program called dlclose from a destructor and
got an assert failure in the dynamic linker.
2001-01-05 04:36:17 +00:00