Commit Graph

122 Commits

Author SHA1 Message Date
Christian S.J. Peron
d61e5aa4ed In the event a process is tainted (setuid/setgid binaries), un-set any
potentially dangerous environment variables all together. It should be
noted that the run-time linker will not honnor these environment variables
if the process is tainted currently. However, once a child of the tainted
process calls setuid(2), it's status as being tainted (as defined by
issetugid(2)) will be removed. This could be problematic because
subsequent activations of the run-time linker could honnor these
dangerous variables.

This is more of an anti foot-shot mechanism, there is nothing I am
aware of in base that does this, however there may be third party
utilities which do, and there is no real negative impact of clearing
these environment variables.

Discussed on:	secteam
Reviewed by:	cperciva
PR:		kern/109836
MFC after:	2 weeks
2007-05-17 18:00:27 +00:00
David Xu
25785f9165 Fix a TLS memory leak.
PR: threads/112297
MFC: 1 week
2007-05-05 08:44:59 +00:00
Alexander Kabaev
ac34654dd9 Catch up on rtld's special status. Since it does not appear on
main object list, its versioning information needs to be examined
separately.

This hopefully fixes problems that people running with SYMVER_ENABLED
are experiencing.
2007-04-07 23:17:00 +00:00
Alexander Kabaev
49f90ad282 Implement dl_iterate_phdr function.
Convert boolean flags in internal Obj_Entry structure into bitfields.
Properly check for loaded segment alignment in map_object.
2007-04-03 18:31:20 +00:00
John Baldwin
1f4b63f824 Add various utrace's for use with ktrace to the ELF runtime linker. To
activate the traces, set the LD_UTRACE (or LD_32_UTRACE) environment
variable.  This also includes code in kdump(8) to parse the traces.

Reviewed by:	kan, jdp
MFC after:	2 weeks
2007-01-09 17:50:05 +00:00
Jung-uk Kim
da7bf2bb26 Clean up white spaces and fix style(9). 2006-09-19 16:48:08 +00:00
Konstantin Belousov
5fd885b07b Fix the buggy rev. 1.117. dagmembers are only initialized for dlopen'ed
dso that are actually loading. If dso a.so depends on b.so, then dlsym
with handle from dlopen("b.so") will fail unconditionally.

Correct implementation shall use the Obj_Entry.needed list to walk
dependencies DAG.

Test provided by: jkim
Tested (prev. version) by:	jkim, Nicolas Blais <nb_root at videotron ca>, h.blanke at chello nl
Pointy hat to:	kib
Approved by:	kan (mentor)
2006-09-19 12:47:13 +00:00
Konstantin Belousov
d0cb0064fe When looking up the symbol by dlsym, look it not only in the object
given as dso handle, but also in the implicit dependencies of that dso.

Also, const-ify the read-only parameter objlist of symlook_list.

Reported by:	"Simon 'corecode' Schubert" <corecode at fs ei tum de>
Approved by:	kan (mentor)
X-MFC-After:	6.2
2006-09-08 14:59:54 +00:00
Marcel Moolenaar
3614156c7d Fix the variant I allocation for KSE: Allow a larger TCB and assume
that the documented TCB is at the tail of the extended TCB. In other
words, the base of the TCB has a negative offset from the TLS.
2006-09-01 06:13:16 +00:00
Xin LI
c93b8edf09 In symlook_obj(): fix _rtld_error output.
MFC After:	2 weeks
2006-08-04 13:37:54 +00:00
David Xu
c771787169 Er, forgot to clear tls space to zero for Variant II. 2006-03-28 06:14:22 +00:00
David Xu
c0d2338cdd Allocate space for thread pointer, this allows thread library to access
its pointer from begin, and simplifies _get_curthread() in libthr.
2006-03-28 06:09:24 +00:00
Alexander Kabaev
96ff9a2bf4 Make lookups for relocations from old unversioned binaries return
oldest versioned symbol available. Do not accept hidden symbols for
all other versions.

Use "<obj->path>: <error message>" for all error messages in new
functions to make them more consistent.
2005-12-24 15:37:30 +00:00
Alexander Kabaev
b80d39d0c0 Remove debugging statement that slipped into lone of the previous commits
unintentionally.
2005-12-23 15:30:53 +00:00
Alexander Kabaev
f6e5db226f Initialize object dagmembers list before checking version dependencies. 2005-12-22 16:42:38 +00:00
Alexander Kabaev
0eb88f2029 Implement ELF symbol versioning using GNU semantics. This code aims
to be compatible with symbol versioning support as implemented by
GNU libc and documented by http://people.redhat.com/~drepper/symbol-versioning
and LSB 3.0.

Implement dlvsym() function to allow lookups for a specific version of
a given symbol.
2005-12-18 19:43:33 +00:00
Marcel Moolenaar
757686b115 Make our ELF64 type definitions match standards. In particular this
means:
o  Remove Elf64_Quarter,
o  Redefine Elf64_Half to be 16-bit,
o  Redefine Elf64_Word to be 32-bit,
o  Add Elf64_Xword and Elf64_Sxword for 64-bit entities,
o  Use Elf_Size in MI code to abstract the difference between
   Elf32_Word and Elf64_Word.
o  Add Elf_Ssize as the signed counterpart of Elf_Size.

MFC after: 2 weeks
2005-12-18 04:52:37 +00:00
John Baldwin
4d5fe96d68 Fix a bug in dlinfo(RTLD_DI_SERINFOSIZE) requests. For each search path
we included the length of the path in the returned size but not the length
of the associated Dl_serpath structure.  Without this fix, programs
attempting to allocate a structure to hold the search path information
would allocate too small of a buffer and rtld would overrun the buffer
while filling it via a subsequent RTLD_DI_SERINFO request.

Submitted by:	"William K. Josephson" wkj at morphisms dot net
Reviewed by:	jdp
MFC after:	2 weeks
2005-11-11 19:57:41 +00:00
Doug Rabson
3709906a1d When allocating TLS and DTV, make sure that any unused slots in the DTV
are initialised to zero. When freeing TLS, don't attempt to free DTV
slots which were not used.

Pointed out by: Joerg Sonnenberger
X-MFC-After: After the branch, probably
2005-03-30 08:28:26 +00:00
Colin Percival
8fe7df9b68 If "dangerous" environment variables (LD_PRELOAD, LD_LIBMAP,
LD_LIBMAP_DISABLE, LD_LIBRARY_PATH) are used, then make sure the
libraries being loaded aren't on a noexec-mounted filesystem.

This is a compromise position: I'm assuming that nobody will be silly
enough to set the noexec mount flag on part of the default library
path, in order to avoid adding extra overhead into the common case
(where those environment variables aren't used).

Discussed with:	csjp, secteam
MFC after:	1 week
2005-03-24 10:12:29 +00:00
David Xu
c5fa3778bb Add locking code for tls routines. 2005-03-20 23:28:25 +00:00
Doug Rabson
ddab7ee80a Attempt to free any static TLS space used by a shared library when it
is unloaded. This allows applications which load and unload libraries
like libGL.so.1 several times to work properly.

MFC after: 2 days
2005-02-27 12:55:40 +00:00
Matthew N. Dodd
5b08cb0449 Description from Dan:
Another handy libmap patch.  Lets you do stuff like this:

	LD_LIBMAP="libpthread.so.1=libthr.so.1" mythreadedapp

	If you already have a program-specific override in libmap.conf, note
	that you must use a program-specific override in LD_LIBMAP:

	LD_LIBMAP="[mythreadedapp],libpthread.so.1=libthr.so.1" mythreadedapp

PR:		bin/74471
Submitted by:	Dan Nelson <dnelson AT allantgroup.com>
MFC after:	2 weeks
2005-02-04 02:46:41 +00:00
Suleiman Souhlal
5bbd22ee8d Do the TLS offset allocations before relocations, as otherwise there
can be overlap in the TLS offsets, if the relocations are done in a
certain order.

Approved by:	dfr, grehan (mentor)
2004-11-02 09:42:21 +00:00
Olivier Houchard
9ac88d19dc Add stubs for TLS.
Arbitraly choose the 2nd variant until I figure out which one I should use.
2004-09-23 23:04:52 +00:00
Doug Rabson
fca32c746e Add stubs for powerpc TLS.
Submitted by: ssouhlal
2004-08-04 19:12:14 +00:00
Doug Rabson
017246d02f Add support for Thread Local Storage. 2004-08-03 08:51:00 +00:00
Thomas Moestl
d05bb9a2a6 Fix the problem that surfaced with the new binutils import on sparc64
(and that is for now being worked around by a binutils patch).

The rtld code tested &_DYNAMIC against 0 to see whether rtld itself
was built as PIC or not. While the sparc64 MD code did not rely
on the preset value of the GOT slot for _DYNAMIC any more due
to previous binutils changes, it still used to not be 0, so
that this check did work. The new binutils do however initialize
this slot with 0. As a consequence, rtld would not properly initialize
itself and crash.
Fix that by introducing a new macro, RTLD_IS_DYNAMIC, to take the role
of this test. For sparc64, it is implemented using the rtld_dynamic()
code that was already there. If an architecture does not provide its
own implementation, we default to the old check.

While being there, mark _DYNAMIC as a weak symbol in the sparc64
rtld_start.S. This is needed in the LDSCRIPT case, which is however
not currently supported for want of an actual ldscript.

Sanity checked with md5 on alpha, amd64, i386 and ia64.
2004-06-18 02:01:37 +00:00
Oliver Eikemeier
0a16eb8341 give out a little more information in case of a missing dependency
PR:		56549
Submitted by:	edwin
Reviewed by:	joerg, ru
Approved by:	joerg
MFC after:	2 weeks
2004-05-28 00:05:28 +00:00
Doug Rabson
f88e6caca2 If we change obj_rtld.path after initialising __progname, make sure we
change __progname to point at the new storage otherwise it ends up
pointing at freed memory which leads to confusing garbled error messages.
2004-03-29 18:37:37 +00:00
Peter Wemm
c905e45dc0 Add initial support for compiling a special 32 bit version of
ld-elf.so.1 on 64 bit systems.  Most of this involves using alternate
paths, environment variables and diagnostic messages.

The build glue is seperate.
2004-03-21 01:21:26 +00:00
Mark Murray
16fc3635f7 Make NULL a (void*)0 whereever possible, and fix the warnings(-Werror)
that this provokes. "Wherever possible" means "In the kernel OR NOT
C++" (implying C).

There are places where (void *) pointers are not valid, such as for
function pointers, but in the special case of (void *)0, agreement
settles on it being OK.

Most of the fixes were NULL where an integer zero was needed; many
of the fixes were NULL where ascii <nul> ('\0') was needed, and a
few were just "other".

Tested on: i386 sparc64
2004-03-05 08:10:19 +00:00
Alexander Kabaev
2627f3570d Do not depend on existence of _end symbol in obj_from_addr, use
obj->mapbase and obj->mapsize instead.

Prompted by: 	OpenOffice debugging session at last BSDCon.
2004-02-25 17:06:16 +00:00
Doug Rabson
ae59481b1a Initialise some uninitialised variables.
Thanks to: valgrind
2003-12-31 15:10:41 +00:00
Anton Berezin
4893027ac4 Sync comment with code's reality.
MFC after:	1 week
2003-11-14 12:56:56 +00:00
Matthew N. Dodd
5515f48ce3 Retire the WITH_LIBMAP compile knob; libmap is now a standard feature. 2003-09-13 21:50:36 +00:00
Matthew N. Dodd
4402996dea Change libmap.c:lm_init() to return a status value; 0 for success
(libmap available) and 1 for failure.  Assign this return to the
global 'libmap_disable' variable in rtld.c.

This totally prevents any libmap functions from being called after
lm_init() if no config file is present.
2003-09-13 21:43:08 +00:00
Gordon Tetlow
df7c0368c1 As long threatened, stage 2 of making a dynamically-linked root a reality.
Install rtld into /libexec.
2003-08-17 08:06:00 +00:00
Gordon Tetlow
7b73593acd Prepend /lib to the builtin library search path in rtld. 2003-08-17 07:55:17 +00:00
Matthew N. Dodd
c5d061c17a Provide a mechanism for dumping relocation information.
Setting the LD_DUMP_REL_PRE or LD_DUMP_REL_POST environment variables
cause rtld-elf to output a table of all relocations.

This is useful for debugging.
2003-06-19 03:55:38 +00:00
Matthew N. Dodd
5952de4b1b Avoid a NULL pointer dereference. 2003-06-18 16:17:13 +00:00
Matthew N. Dodd
da9f245470 - Add support for DT_FLAGS.
- Define various things from the most recent ELF spec.
2003-06-18 03:34:29 +00:00
Matthew N. Dodd
c930fec7a2 - use issetugid()
- be paranoid about honoring LD_LIBMAP_DISABLE.

Suggested by:	 rwatson
2003-05-31 15:24:29 +00:00
Matthew N. Dodd
4df60d1cac Use the environment variable LD_LIBMAP_DISABLE to disable
libmap.conf(5) functionality.
2003-05-31 14:45:11 +00:00
Alexander Kabaev
6d5d786f80 Allow threading libraries to register their own locking
implementation in case default one provided by rtld is
not suitable.

Consolidate various identical MD lock implementation into
a single file using appropriate machine/atomic.h.

Approved by:	re (scottl)
2003-05-29 22:58:26 +00:00
Alexander Kabaev
3ddc66d863 Rethink the way we count module references. Simply following
DT_NEEDED links is not flexible enough for cases where dynamically
loaded modules form a dependency cycle.

This should fix an infinite recursion problem encountered by Yahoo.

Approved by:	re (jhb)
2003-05-08 01:31:36 +00:00
David E. O'Brien
78af18bd24 Fix signed/unsigned comparison warnings. 2003-05-04 00:56:00 +00:00
Matthew N. Dodd
29ade36225 Dynamic object dependency mapping: libmap.
This is an optional feature, disabled by default.

This will be useful to people testing the various POSIX threading
libraries under -CURRENT but can easily serve other needs.
2003-04-07 16:21:26 +00:00
Alexander Kabaev
fa4a502e77 Do not remove object from the lists at the unref_dag() stage.
Introduce a new unlink_object() function and call it in
unload_object() instead. Removing the object in unref_dag() is
too early, rtld calls _fini() function after that and shared
objects might fail resolve their own symbols.
2003-02-17 20:58:27 +00:00
Alexander Kabaev
2542b742f1 Fix a typo in rtld_dirname. 2003-02-13 22:47:41 +00:00