Commit Graph

461 Commits

Author SHA1 Message Date
Konstantin Belousov
f62651920d Add GNU hash support for rtld.
Based on dragonflybsd support for GNU hash by John Marino <draco marino st>
Reviewed by:	kan
Tested by:	bapt
MFC after:	2 weeks
2012-04-30 13:31:10 +00:00
Konstantin Belousov
34cb87ba95 Split the symlook_obj1 into a loop iterating over the ELF object symbol
hash elements, and a helper matched_symbol() which match the given hash
entry and request, performing needed type and version checks.

Based on dragonflybsd support for GNU hash by John Marino <draco marino st>
Reviewed by:	kan
Tested by:	bapt
MFC after:	2 weeks
2012-04-30 13:29:21 +00:00
Nathan Whitehorn
c606eab458 Fix a missed file in r234580: replace the now-obsolete powerpc_mb() with
regular mb().
2012-04-23 00:54:06 +00:00
Konstantin Belousov
fdfc035be6 Propagate the current state of rtld_bind_lock to dlopen_object() calls
through the filter loading call chain. This fixes attempts to
write-lock the already locked rtld_bind_lock when filter loading is
initiated by relocation of dlopening dso.

Reported and tested by:	Taku YAMAMOTO <taku tackymt homeip net>
MFC after:	1 week
2012-04-12 10:32:22 +00:00
Konstantin Belousov
3f4e35f752 Properly handle absent AT_CANARY aux entry.
Submitted by:	Andrey Zonov <andrey zonov org>
MFC after:	3 days
2012-04-05 18:47:54 +00:00
Alexander Kabaev
4aed2ce86e Remove extra blank line from revious commit.
Submitted by:	trema
2012-04-02 11:59:13 +00:00
Alexander Kabaev
7605b428c9 Do not try to adjust stacks if dlopen_object is called too early.
This is a follow-up to r233231, which fixed similar issue with
object initialization code.

Reviewed by:	kib
MFC after:	1 week (with 233231)
2012-04-02 11:50:14 +00:00
Konstantin Belousov
5b7a7b02b8 Fix ia64 build after r233655.
MFC after:	1 week
2012-03-29 17:50:01 +00:00
Konstantin Belousov
5ceeeba90c Import DragonFly BSD commit
From: Sascha Wildner <saw@online.de>
  Date: Fri, 2 Mar 2012 09:15:56 +0000 (+0100)
  Subject: rtld: Add a special case in do_dlsym() for TLS stored symbols.
  X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/1388aaafe730c85693936aaf9bc6d83fc2d981be?hp=bca4412595a8979ab9f1bf36068c806ce88a667a

  rtld: Add a special case in do_dlsym() for TLS stored symbols.

  Submitted-by: Markus Pfeiffer <markus.pfeiffer@morphism.de>

Discussed with:	kan
MFC after:	1 week
2012-03-29 10:32:34 +00:00
Konstantin Belousov
ff17bc61e2 Prevent rtld_verify_object_versions() from being called several times
for the same object. This can happen when object is a dependency of the
dlopen()ed dso. When called several times, we waste time due to unneeded
processing, and memory, because obj->vertab is allocated anew on each
iteration.

Reviewed by:	kan
MFC after:	2 weeks
2012-03-27 14:10:15 +00:00
Konstantin Belousov
2aa3a46729 Remove libssp_nonshared from the rtld linking set. The only use for the
library was definition for the weak alias of __stack_chk_fail.

No objections from:	kan
MFC after:	2 weeks
2012-03-24 19:14:44 +00:00
Konstantin Belousov
83dd177761 Provide short-circuit exit(3) implementation for rtld.
There is no atexit finalizers in rtld to call on rtld exiting (due to errors).

Submitted by:	bde
No objections from:	kan
MFC after:	2 weeks
2012-03-24 19:13:10 +00:00
Oleksandr Tymoshenko
bbc54af80e Before jumping to application's entry point set ra == pc in order
to let backtracing routine know to go no further.
2012-03-23 17:54:06 +00:00
Konstantin Belousov
e24348df7f Remove superfluous extern keywords.
MFC after:	   2 weeks
2012-03-23 12:13:31 +00:00
Konstantin Belousov
f7c419f22d Centralize the calculation of the top source directory. This
simplifies the build of rtld with partial checkout, allowing to
override only one place to reference other tree.

Submitted by:	bde
MFC after:	2 weeks
2012-03-23 12:10:12 +00:00
Konstantin Belousov
f7b343037f Implement xstrdup() using strlen()/xmalloc()/memcpy() already
presented in rtld, instead of pulling in libc strdup().

Submitted by:	   bde
MFC after:	   2 weeks
2012-03-23 12:04:44 +00:00
Konstantin Belousov
758ffbfa3b Use xmalloc() instead of malloc() in the places where malloc() calls
are assumed to not fail.

Make the xcalloc() calling conventions follow the calloc(3) calling
conventions and replace unchecked calls to calloc() with calls to
xcalloc().

Remove redundand declarations from xmalloc.c, which are already
present in rtld.h.

Reviewed by:	kan
Discussed with:	bde
MFC after:	2 weeks
2012-03-22 14:20:51 +00:00
Konstantin Belousov
ff6cd33319 Remove the fragments which are not needed on FreeBSD. The caltech
malloc hardly would ever be updated.

Reviewed by:  bde, kan
MFC after:    2 weeks
2012-03-22 14:11:10 +00:00
Konstantin Belousov
082f959ac8 Fix several problems with our ELF filters implementation.
Do not relocate twice an object which happens to be needed by loaded
binary (or dso) and some filtee opened due to symbol resolution when
relocating need objects.  Record the state of the relocation
processing in Obj_Entry and short-circuit relocate_objects() if
current object already processed.

Do not call constructors for filtees loaded during the early
relocation processing before image is initialized enough to run
user-provided code.  Filtees are loaded using dlopen_object(), which
normally performs relocation and initialization.  If filtee is
lazy-loaded during the relocation of dso needed by the main object,
dlopen_object() runs too earlier, when most runtime services are not
yet ready.

Postpone the constructors call to the time when main binary and
depended libraries constructors are run, passing the new flag
RTLD_LO_EARLY to dlopen_object().  Symbol lookups callers inform
symlook_* functions about early stage of initialization with
SYMLOOK_EARLY.  Pass flags through all functions participating in
object relocation.

Use the opportunity and fix flags argument to find_symdef() in
arch-specific reloc.c to use proper name SYMLOOK_IN_PLT instead of
true, which happen to have the same numeric value.

Reported and tested by:	theraven
Reviewed by:	kan
MFC after:	2 weeks
2012-03-20 13:20:49 +00:00
Konstantin Belousov
31f7a2032e Remove write-only variable.
MFC after:	3 days
2012-03-16 19:09:34 +00:00
Konstantin Belousov
6fea10fb9f Rtld on diet 3.
Stop using strerror(3) in rtld, which brings in msgcat and stdio.
Directly access sys_errlist array of errno messages with private
rtld_strerror() function.

Now,
$ size /libexec/ld-elf.so.1
   text    data     bss     dec     hex filename
  96983    2480    8744  108207   1a6af /libexec/ld-elf.so.1

Reviewed by:	dim, kan
MFC after:	2 weeks
2012-03-14 15:39:59 +00:00
Oleksandr Tymoshenko
0bf1897832 Use PTR_SUBU instead of subu (missed this one) 2012-03-12 20:59:18 +00:00
Oleksandr Tymoshenko
7730e5971e Use PTR_(ADD|SUB)U macrosses instead of hardcoded addu/subu
Spotted by: juli
2012-03-12 20:58:09 +00:00
Oleksandr Tymoshenko
33ddd0f61a - Although we pass first 4 arguments in registers, function callinf ABI requires
space to be reserved for them in stack. _rtld() prologue saves a1 and a2 in
   this space.

- Whitespace cleanup while I'm at it
2012-03-12 20:24:59 +00:00
Konstantin Belousov
68f1db20b3 Rtld on diet part 2:
Do not use stdio for libmap.conf read.  Directly map the file and
parse lines from the mappings.

Reviewed by:	kan
MFC after:	3 weeks
2012-03-12 12:16:08 +00:00
Konstantin Belousov
ef5cdcbd69 Rtld on diet part 1:
Provide rtld-private implementations of __stack_chk_guard,
__stack_chk_fail() and __chk_fail() symbols, to be used by functions
linked from libc_pic.a.  This avoids use of libc stack_protector.c,
which pulls in syslog(3) and stdio as dependency.

Also, do initialize rtld-private copy __stack_chk_guard, previously
libc-provided one was not initialized, since we do not call rtld
object _init() methods.

Reviewed by:	kan
MFC after:	3 weeks
2012-03-12 12:15:47 +00:00
Dimitry Andric
3c5b7c6fb9 Amend r232857, now dropping the casts entirely, as they were not
necessary at all.

Submitted by:	stefanf
2012-03-12 11:22:23 +00:00
Dimitry Andric
addfbd03b7 Fix the following warning/error with clang:
libexec/rtld-elf/rtld.c:1898:22: error: comparison between pointer and integer ('Elf_Addr *' (aka 'unsigned int *') and 'Elf_Addr' (aka 'unsigned int')) [-Werror]
    if (preinit_addr == (Elf_Addr)NULL)
        ~~~~~~~~~~~~ ^  ~~~~~~~~~~~~~~
libexec/rtld-elf/rtld.c:2039:16: error: comparison between pointer and integer ('Elf_Addr *' (aka 'unsigned int *') and 'Elf_Addr' (aka 'unsigned int')) [-Werror]
        if (init_addr != (Elf_Addr)NULL) {
            ~~~~~~~~~ ^  ~~~~~~~~~~~~~~

Reviewed by:	kib
2012-03-12 11:04:48 +00:00
Konstantin Belousov
5eab36f290 When iterating over the dso program headers, the object is not initialized
yet, and object segments are not yet mapped.  Only parse the notes that
appear in the first page of the dso (as it should be anyway), and use
the preloaded page content.

Reported and tested by:	stass
MFC after:	20 days
2012-03-12 10:36:03 +00:00
Konstantin Belousov
83aa9cc00c Add support for preinit, init and fini arrays. Some ABIs, in
particular on ARM, do require working init arrays.

Traditional FreeBSD crt1 calls _init and _fini of the binary, instead
of allowing runtime linker to arrange the calls.  This was probably
done to have the same crt code serve both statically and dynamically
linked binaries.  Since ABI mandates that first is called preinit
array functions, then init, and then init array functions, the init
have to be called from rtld now.

To provide binary compatibility to old FreeBSD crt1, which calls _init
itself, rtld only calls intializers and finalizers for main binary if
binary has a note indicating that new crt was used for linking.  Add
parsing of ELF notes to rtld, and cache p_osrel value since we parsed
it anyway.

The patch is inspired by init_array support for DragonflyBSD, written
by John Marino.

Reviewed by:	kan
Tested by:	andrew (arm, previous version), flo (sparc64, previous version)
MFC after:	3 weeks
2012-03-11 20:03:09 +00:00
Konstantin Belousov
6bfe9e8ccf Optimize tls_get_addr_common(). The change provides around 30% speedup
for TLS microbenchmark using global-dynamic TLS model on amd64 (which is
default for PIC dso objects).

Split the slow path into tls_get_addr_slow(), for which inlining is
disabled. This prevents the registers spill on tls_get_addr_common()
entry.

Provide static branch hint to the compiler, indicating that slow path
is not likely to be taken.

While there, do some minimal style adjustments.

Reported and tested by:	davidxu
MFC after:	1 week
2012-03-10 08:49:44 +00:00
Konstantin Belousov
5983b87199 Remove the use of toupper() from rtld_printf.c. Use of the libc function
relies on working TLS, which is particulary not true for LD_DEBUG uses.

MFC after:	1 week
2012-03-09 16:21:40 +00:00
Sergey Kandaurov
44976acae3 Cosmetic nit:
- rename isspace1() macro to the more appropriate rtld_isspace().

Discussed with:	kib
2012-03-06 09:34:30 +00:00
Oleksandr Tymoshenko
0a0f480835 - Switch to saving non-offseted pointer to TLS block in order too keep things simple 2012-03-06 03:27:08 +00:00
Konstantin Belousov
b36070f555 The libmap.conf initialization is performed before TLS is functional.
Since after r232498 the ctype macros require working access to
thread-local variables, rtld crashes when libmap.conf is present.

Use hand-made isspace1() macro which is enough to detect spaces in
libmap.conf.

Reported by:	alc, lme, many on current@
Tested by:	lme
Reviewed by:	dim, kan
MFC after:	1 week
2012-03-05 20:43:06 +00:00
Oleksandr Tymoshenko
dc3b6c3aa0 Add thread-local storage support for ARM to rtld-elf
Reviewed by:    cognet
Obtained from:  NetBSD
2012-02-14 00:16:34 +00:00
Konstantin Belousov
0eddfb0608 Add missed EOL when die() was converted to use rtld_fdputstr() instead
of errx().

Reported by:	amdmi3
PR:	bin/165075
MFC after:	3 days
2012-02-13 11:15:29 +00:00
Oleksandr Tymoshenko
b098345b9e Add handlers for TLS-related relocation entries 2012-02-11 00:54:57 +00:00
Oleksandr Tymoshenko
9b4f251484 Remove debug output 2012-02-10 19:58:04 +00:00
Oleksandr Tymoshenko
20c390af63 Switch MIPS TLS implementation to Variant I 2012-02-10 06:42:50 +00:00
Oleksandr Tymoshenko
cf9c1f8158 Fix debug output for MIPS part of rtld 2012-02-10 03:30:57 +00:00
Konstantin Belousov
6d7610d75a Add support for GNU RELRO.
Submitted by:	John Marino <draco marino st>
MFC after:	2 weeks
2012-01-30 19:52:17 +00:00
Ed Schouten
581f58e7a3 Remove unneeded dtv variable.
It is only assigned and not used at all. The object files stay identical
when the variables are removed.

Approved by:	kib
2012-01-17 21:55:20 +00:00
Ulrich Spörlein
1acf0dba17 Spelling fixes for libexec/ 2012-01-07 16:09:54 +00:00
Konstantin Belousov
5d8aec9c02 Implement fdlopen(3), an rtld interface to load shared object by file
descriptor.

Requested and tested by:	des (previous version)
Reviewed by:  des, kan (previous version)
MFC after:    2 weeks
2012-01-07 10:33:01 +00:00
Konstantin Belousov
68266d5aba Postpone the resolution of IRELATIVE relocations and IFUNC-targeted
relocations until tls is initialized and stacks permissions correctly
set. This allows the ifunc to call malloc(3) and some other heavy
services.

Add debug banner.

MFC after:	3 days
2012-01-04 17:17:11 +00:00
Nathan Whitehorn
4b51c69976 Additional icache paranoia: non-PLT relocations can modify the text segment.
It is then important to make sure the icache is synchronized again to
prevent (rare) random seg faults and illegal instructions.

MFC after:	3 days
2011-12-17 16:20:27 +00:00
Nathan Whitehorn
17bbcc52d1 Fix RTLD on PowerPC after r228435. Changing the order of init_pltgot()
caused the icache to be invalidated at the wrong time, resulting in
an icache full of nonsense in the PLT section.
2011-12-17 15:31:00 +00:00
Konstantin Belousov
5734c46c68 _rtld_bind() read-locks the bind lock, and possible plt resolution
from the dispatcher would also acquire bind lock in read mode, which
is the supported operation. plt is explicitely designed to allow safe
multithreaded updates, so the shared lock do not cause problems.

The error in r228435 is that it allows read lock acquisition after the
write lock for the bind block.  If we dlopened the shared object that
contains IRELATIVE or jump slot which target is STT_GNU_IFUNC, then
possible recursive plt resolve from the dispatcher would cause it.

Postpone the resolution for irelative/ifunc right before initializers
are called, and drop bind lock around calls to dispatcher.  Use
initlist to iterate over the objects instead of the ->next, due to
drop of the bind lock in iteration.

For i386/reloc.c:reloc_iresolve(), fix calculation of the dispatch
function address for dso, by taking into account possible non-zero
relocbase.

MFC after:	3 weeks
2011-12-14 16:47:53 +00:00
Konstantin Belousov
6be4b69715 Add support for STT_GNU_IFUNC and R_MACHINE_IRELATIVE GNU extensions to
rtld on 386 and amd64. This adds runtime bits neccessary for the use
of the dispatch functions from the dynamically-linked executables and
shared libraries.

To allow use of external references from the dispatch function, resolution
of the R_MACHINE_IRESOLVE relocations in PLT is postponed until GOT entries
for PLT are prepared, and normal resolution of the GOT entries is finished.
Similar to how it is done by GNU, IRELATIVE relocations are resolved in
advance, instead of normal lazy handling for PLT.

Move the init_pltgot() call before the relocations for the object are
processed.

MFC after:	3 weeks
2011-12-12 11:03:14 +00:00