Commit Graph

850 Commits

Author SHA1 Message Date
Konstantin Belousov
e3741c01c6 r357895: fix typo in the relocation name for i386 IRELATIVE.
Reported by: antoine
Sponsored by:	The FreeBSD Foundation
MFC after:	6 days
2020-02-14 12:59:27 +00:00
Konstantin Belousov
c5ca0d1132 Handle non-plt IRELATIVE relocations, at least for x86.
lld 10.0 seems to generate this relocation for rdtsc_mb() ifunc in our libc.

Reported, reviewed, and tested by:	dim (amd64, previous version)
Discussed with:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D23652
2020-02-13 23:42:09 +00:00
Konstantin Belousov
c626c88e58 Fix indent.
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2020-02-12 12:23:46 +00:00
Konstantin Belousov
aef199e563 Use sigfastblock(2) in rtld.
This allows for rtld to not issue two sigprocmask(2) syscalls for each
symbol binding operation in single-threaded processes.  Rtld needs to
block signals as part of locking to ensure signal safety of the bind
process, because signal handlers might need to lazily resolve symbol
references.

As result, number of syscalls issued on startup by simple programs not
using libthr, is typically reduced 2x.  For instance, for hello world,
I see:
non-sigfastblock
# (truss ./hello > /dev/null) |& wc -l
      63
sigfastblock
# (truss ./hello > /dev/null) |& wc -l
      37

Tested by:	pho
Disscussed with:	cem, emaste, jilles
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D12773
2020-02-09 12:22:43 +00:00
Mateusz Guzik
da8e950a27 rtld: remove hand rolled memset and bzero
They were introduced to take care of ifunc, but right now no architecture
provides ifunc'ed variants. Since rtld uses memset extensively this results in
a pessmization. Should someone want to use ifunc here they should provide a
mandatory symbol (e.g., rtld_memset).

See the review for profiling data.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D23176
2020-01-15 01:30:32 +00:00
Konstantin Belousov
7e3300e505 rtld: clean up Makefile.
Move all MD statements into $MACHINE_ARCH/Makefile.inc.
Unconditionally apply version script to rtld, the interpreter is not
functional without it for long time.

Reviewed by:	brooks, emaste
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D23083
2020-01-11 09:18:58 +00:00
Konstantin Belousov
1021c8d705 Stop prepending prefix to the result of realpath(3).
The path is already absolute.

Noted and reviewed by:	rstone
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D23121
2020-01-11 09:08:02 +00:00
Konstantin Belousov
8707334301 rtld: Return error if $ORIGIN for a dlopen-ed library cannot be resolved ...
instead of killing the process.  The same behaviour of terminating
image activation if the $ORIGIN cannot be resolved for the main
object, is kept.

Reported by:	Greg V <greg@unrelenting.technology>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D23053
2020-01-09 10:05:45 +00:00
Konstantin Belousov
f160596397 Resolve relative argv0 for direct exec mode to absolute path for AT_EXECPATH.
We know the binary relative name and can reliably calculate cwd path.
Because realpath(3) was already linked into ld-elf.so.1, reuse it
there to resolve dots and dotdots making the path more canonical.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D23014
2020-01-09 10:00:24 +00:00
Konstantin Belousov
f26c30a5f3 rtld: fix after r356300
binpath local was changed from char array to a char pointer, update
strlcpy/strlcat uses.

Reported by:	Coverity through vangyzen
CID:	1412239 and 1412240
Reviewed by:	emaste, imp, vangyzen
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D23090
2020-01-08 17:37:20 +00:00
Ryan Stone
68faee11e8 rtld: Fix segfault in direct exec mode
When rtld is directly executed with arguments, it has to move the
program arguments, environment and elf aux data up a few slots to
remove its own arguments before the process being executed sees
them.  When copying the environment, rtld was incorrectly testing
whether the location about to be written to currently contained
NULL, when was supposed to check whether it had just copied the
NULL terminator of the environment string.  This had the result
that the ELF aux data was mostly treated as environment variables,
and rtld would quickly crash when it tried to access required
ELF aux data that it didn't think was present.

Differential Revision:	https://reviews.freebsd.org/D23008
Reviewed by:	kib
MFC after:	1 month
2020-01-07 16:03:11 +00:00
Konstantin Belousov
137aed91e7 Fix AT_EXECPATH for direct exec mode.
When activated in direct exec mode, kernel-provided AT_EXECPATH points
to the interpreter.  We need to recalculate auxv to point to the
string with the path to the executable which is actually executed.

The somewhat problematic case is when the executable path is relative
and either $PATH use is not enabled or it contains '/' so $PATH search
is not performed. In this case resulting AT_EXECPATH is relative, I
might fix this later.

Reported and reviewed by:	rstone
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D22894
2020-01-02 22:48:08 +00:00
Conrad Meyer
168bbfa737 rtld(1): Do booleans like C99
Reviewed by:	kib, rlibby
Differential Revision:	https://reviews.freebsd.org/D22964
2019-12-31 05:41:47 +00:00
Justin Hibbits
adea0d6368 Eliminate the last MI difference in AT_* definitions (for powerpc).
Summary:
As a transition aide, implement an alternative elfN_freebsd_fixup which
is called for old powerpc binaries.  Similarly, add a translation to rtld to
convert old values to new ones (as expected by a new rtld).

Translation of old<->new values  is incomplete, but sufficient to allow an
installworld of a new userspace from an old one when a new kernel is running.

Test Plan:
Someone needs to see how a new kernel/rtld/libc works with an old
binary.  If if works we can probalby ship this.  If not we probalby need
some more compat bits.

Submitted by:	brooks
Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D20799
2019-12-27 04:07:03 +00:00
Brandon Bergren
57462f8f81 [PowerPC] powerpc32 rtld IFUNC handling code
As PowerPC is moving to clang, we can finally start taking advantage of
IFUNC.

Implement the MD parts of IFUNC handling for rtld.

Currently, it is necessary to look for R_PPC_IRELATIVE in the PLT in
addition to RELA. This is an ABI violation, but LLD9 has some .iplt bugs
that require this as a workaround.

Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D22855
2019-12-24 16:13:15 +00:00
Brandon Bergren
41b4ec8ab0 [PowerPC] powerpc64 rtld IFUNC handling code
As PowerPC is moving to clang, we can finally start taking advantage of
IFUNC.

Implement the MD parts of IFUNC handling for rtld.

Currently, it is necessary to look for R_PPC_IRELATIVE in the PLT in
addition to RELA. This is an ABI violation, but LLD9 has some .iplt bugs
that require this as a workaround.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D22789
2019-12-24 16:07:35 +00:00
Konstantin Belousov
f5392eb672 rtld: make checks for mmap(2) failures compliant with documentation.
On error, mmap(2) returns MAP_FAILED.  There is no need to use its
definition or to cast.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-12-12 22:59:22 +00:00
Brandon Bergren
44c9aa49ea rtld: do not try to mmap a zero-sized PT_LOAD
When a PT_LOAD segment has a zero p_filesz, skip the data mmap, as mmapping
zero bytes from a file is an error.

A PT_LOAD with zero p_filesz is legal (but somewhat uncommon due to segment
merging in modern linkers, as it is more efficient to merge .data and .bss
by just extending p_memsz in the previous segment, assuming compatible
page protection.)

This was seen on ports/graphics/glew on a powerpc64 ELFv2 experimental
build.

Submitted by:	Alfredo Dal'Ava Junior <alfredo.junior@eldorado.org.br>
Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D22634
2019-12-12 17:40:32 +00:00
John Baldwin
15d0350503 Correct the offset of static TLS variables for Initial-Exec on RISC-V.
TP points to the start of the TLS block after the tcb, but
Obj_Entry.tlsoffset includes the tcb, so subtract the size of the tcb
to compute the offset relative to TP.

This is identical to the same fixes for powerpc in r339072 and r342671.

Reviewed by:	James Clarke
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D22661
2019-12-10 21:56:44 +00:00
Brandon Bergren
e58d379587 [PowerPC] Fix stack padding issue on ppc32.
Four bytes of padding are needed in the regular powerpc case to bring the
stack frame size up to a multiple of 16 bytes to meet ABI requirements.

Fixes odd hangs I was encountering during testing.
2019-11-24 06:43:03 +00:00
Justin Hibbits
7511645efa rtld/powerpc: Fix _rtld_bind_start for powerpcspe
Summary:
We need to save off the full 64-bit register, not just the low 32 bits,
of all registers getting saved off in _rtld_bind_start.  Additionally,
we need to save off the other SPE registers (SPEFSCR and accumulator),
so that their program state is not affected by the PLT resolver.

Reviewed by:	bdragon
Differential Revision:	https://reviews.freebsd.org/D22520
2019-11-24 04:35:29 +00:00
Brooks Davis
051ed84f28 libcompat: Correct rtld MLINKS
Don't install duplicate ld-elf.so.1.1 and ld.so.1 links in rtld-elf32.
Do install lib-elf32.so.1.1 and ldd32.1 links.

Reported by:	madpilot
2019-11-12 22:31:59 +00:00
Brooks Davis
a4330302f2 libcompat: build 32-bit rtld and ldd as part of "everything"
Alter bsd.compat.mk to set MACHINE and MACHINE_ARCH when included
directly so MD paths in Makefiles work. In the process centralize
setting them in LIBCOMPATWMAKEENV.

Alter .PATH and CFLAGS settings in work when the Makefile is included.

While here only support LIB32 on supported platforms rather than always
enabling it and requiring users of MK_LIB32 to filter based
TARGET/MACHINE_ARCH.

The net effect of this change is to make Makefile.libcompat only build
compatability libraries.

Changes relative to r354449:

Correct detection of the compiler type when bsd.compat.mk is used
outside Makefile.libcompat.  Previously it always matched the clang
case.

Set LDFLAGS including the linker emulation for mips where -m32 seems to
be insufficent.

Reviewed by:	imp, kib (origional version in r354449)
Obtained from:	CheriBSD (conceptually)
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D22251
2019-11-07 22:58:10 +00:00
Brooks Davis
ccad77fe1e Revert r354449: libcompat: build 32-bit rtld and ldd as part of "everything"
Additional testing is required..
2019-11-07 19:22:51 +00:00
Brooks Davis
36712a9497 libcompat: build 32-bit rtld and ldd as part of "everything"
Alter bsd.compat.mk to set MACHINE and MACHINE_ARCH when included
directly so MD paths in Makefiles work. In the process centralize
setting them in LIBCOMPATWMAKEENV.

Alter .PATH and CFLAGS settings in work when the Makefile is included.

While here only support LIB32 on supported platforms rather than always
enabling it and requiring users of MK_LIB32 to filter based
TARGET/MACHINE_ARCH.

The net effect of this change is to make Makefile.libcompat only build
compatability libraries.

Reviewed by:	imp, kib
Obtained from:	CheriBSD (conceptually)
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D22251
2019-11-07 17:10:33 +00:00
Brandon Bergren
d020b3ebde Fix aux_info corruption in rtld direct execution mode.
After the aux vector is moved, it is necessary to re-digest aux_info so the
pointers are updated to the new locations.

This was causing thread creation to fail on powerpc64 when using direct
execution due to a nonsense value being read for aux_info[AT_STACKPROT].

Approved by: jhibbits (mentor)
Differential Revision: https://reviews.freebsd.org/D21656
2019-09-14 21:18:10 +00:00
Brooks Davis
389154096a Remove remnants of optimization for > pagesize allocations.
In the past, this allocator seems to have allocated things larger than
a page seperately. Much of this code was removed at some point (perhaps
along with sbrk() used) so remove the rest. Instead, keep allocating in
power-of-two bins up to FIRST_BUCKET_SIZE << (NBUCKETS - 1). If we want
something more efficent, we should use a fancier allocator.

While here, remove some vestages of sbrk() use. Most importantly, don't
try to page align the pagepool since it's always page aligned by mmap().

Reviewed by:	kib
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D21453
2019-09-02 08:03:29 +00:00
Brooks Davis
98ab79066d Remove some compatability with Seventh Edition UNIX realloc().
In Seventh Edition UNIX, the last pointer passed to free() was
guaranteed to not actually have been freed allowing memory to be
"compacted" via the following pattern:

free(foo);
foo = realloc(foo, newsize);

Further, Andrew Koenig reports in "C Traps and Pitfalls" that the
original realloc() implementation required this pattern.

The C standard is clear that this is Undefined Behavior. Modern
allocators don't support it and no portable code could rely on it so
remove this support.

Note: the removed implementation contains an off-by-one error and if
an item isn't found on the freelist, then twice as much memory as the
largest possible allocation will be copied.

Reviewed by:	kib, imp
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D21296
2019-08-20 16:07:17 +00:00
Kyle Evans
12ba1c232d rtld-elf: fix build with xtoolchain-llvm90
strstr ends up using bcmp when compiled with llvm90; pull it in from libc
as well.

MFC after:	3 days
2019-08-15 17:35:24 +00:00
Leandro Lupori
1180fa861b [PPC64] Fix rtld direct exec mode
Instead of restoring the saved values of argc, argv and envp,
these must be loaded from the stack that _rtld() modifies.

This fixes rtld direct exec mode.
E.g.: /libexec/ld-elf.so.1 /bin/ls

Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D21131
2019-08-05 13:22:02 +00:00
Konstantin Belousov
4105901933 rtld-elf: Remove x86 elf_rtld.x linker scripts.
First, amd64 version of the script cannot work at least due to the
wrong architecture specification.  Second, kernel can activate shared
objects for long time, due to PIE support.

It seems the intent was to allow ld-elf.so.1 to be build and used as
an executable.  Since we have direct exec mode implemented for dso
ld-elf.so.1, the non-functional and commented out scripts can be
finally removed.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-08-04 21:43:34 +00:00
Alex Richardson
0cc62e2695 Fix build race when building rtld
I found this on one of the CheriBSD Jenkins builders. Using
beforelinking instead of ${PROG} should fix the dependency for the
DEBUG_FILES case.

Reviewed by:	brooks
2019-07-02 22:11:07 +00:00
Alex Richardson
10faac99fb Fix CROSS_TOOLCHAIN=amd64-gcc build after r349554
Apparently clang can remove the reference to __umoddi3 but GCC keeps it.

Reported by:	lwhsu
2019-06-30 17:03:14 +00:00
Alex Richardson
e1470c8f96 Fix my name in license header
Reported by:	trasz
2019-06-30 14:04:30 +00:00
Alex Richardson
b54a59f3ba Reduce size of rtld by 22% by pulling in less code from libc
Currently RTLD is linked against libc_nossp_pic which means that any libc
symbol used in rtld can pull in a lot of depedencies. This was causing
symbol such as __libc_interposing and all the pthread stubs to be included
in RTLD even though they are not required. It turns out most of these
dependencies can easily be avoided by providing overrides inside of rtld.

This change is motivated by CHERI, where we have an experimental ABI that
requires additional relocation processing to allow the use of function
pointers inside of rtld. Instead of adding this self-relocation code to
RTLD I attempted to remove most function pointers from RTLD and discovered
that most of them came from the libc dependencies instead of being actually
used inside rtld.

A nice side-effect of this change is that rtld is now 22% smaller on amd64.

   text	   data	    bss	    dec	    hex	filename
0x21eb6	  0xce0	  0xe60	 145910	  239f6	/home/alr48/ld-elf-x86.before.so.1
0x1a6ed	  0x728	  0xdd8	 113645	  1bbed	/home/alr48/ld-elf-x86.after.so.1

The number of R_X86_64_RELATIVE relocations that need to be processed on
startup has also gone down from 368 to 187 (almost 50% less).

Reviewed By:	kib
Differential Revision: https://reviews.freebsd.org/D20663
2019-06-30 11:49:58 +00:00
Alex Richardson
e69dc8626a Use rtld_putstr() instead of write() for the rtld msg() macro
This removes an unnecessary libc dependency from rtld.
See https://reviews.freebsd.org/D20663 for more details.
2019-06-26 15:43:26 +00:00
Justin Hibbits
f62da49b2f powerpc: Transition to Secure-PLT, like most other OSs
Summary:
PowerPC has two PLT models: BSS-PLT and Secure-PLT.  BSS-PLT uses runtime
code generation to generate the PLT stubs.  Secure-PLT was introduced with
GCC 4.1 and Binutils 2.17 (base has GCC 4.2.1 and Binutils 2.17), and is a
more secure PLT format, using a read-only linkage table, with the dynamic
linker populating a non-executable index table.

This is the libc, rtld, and kernel support only.  The toolchain and build
parts will be updated separately.

Reviewed By: nwhitehorn, bdragon, pfg
Differential Revision: https://reviews.freebsd.org/D20598
MFC after:	1 month
2019-06-25 00:40:44 +00:00
Konstantin Belousov
3cac4083ef rtld_malloc.c: cleanup morepages().
Use roundup2() and rounddown2() instead of inlining them.
Get rid of the fd local variable, use literal -1 for the mmap argument.
Use MAP_FAILED as mmap(2) failure indicator.
After that, apply some style.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-05-16 13:13:33 +00:00
Konstantin Belousov
37f0b7f1d7 Remove more dead definitions from rtld_malloc.c after r347019.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-05-16 13:07:26 +00:00
Konstantin Belousov
78022527bb Switch to use shared vnode locks for text files during image activation.
kern_execve() locks text vnode exclusive to be able to set and clear
VV_TEXT flag. VV_TEXT is mutually exclusive with the v_writecount > 0
condition.

The change removes VV_TEXT, replacing it with the condition
v_writecount <= -1, and puts v_writecount under the vnode interlock.
Each text reference decrements v_writecount.  To clear the text
reference when the segment is unmapped, it is recorded in the
vm_map_entry backed by the text file as MAP_ENTRY_VN_TEXT flag, and
v_writecount is incremented on the map entry removal

The operations like VOP_ADD_WRITECOUNT() and VOP_SET_TEXT() check that
v_writecount does not contradict the desired change.  vn_writecheck()
is now racy and its use was eliminated everywhere except access.
Atomic check for writeability and increment of v_writecount is
performed by the VOP.  vn_truncate() now increments v_writecount
around VOP_SETATTR() call, lack of which is arguably a bug on its own.

nullfs bypasses v_writecount to the lower vnode always, so nullfs
vnode has its own v_writecount correct, and lower vnode gets all
references, since object->handle is always lower vnode.

On the text vnode' vm object dealloc, the v_writecount value is reset
to zero, and deadfs vop_unset_text short-circuit the operation.
Reclamation of lowervp always reclaims all nullfs vnodes referencing
lowervp first, so no stray references are left.

Reviewed by:	markj, trasz
Tested by:	mjg, pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D19923
2019-05-05 11:20:43 +00:00
Konstantin Belousov
5cac2021fe Cleanup for rtld_malloc.c.
- Remove dead and most likely rotten MALLOC_DEBUG, MSTAT, and RCHECK options.
- Remove unused headers.
- Remove one case of undefined behavior where left shift could overflow.
  It is impossible on practice for rtld and libthr consumer.

PR:	237577
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-05-02 15:03:16 +00:00
Konstantin Belousov
760e34772c Fix order of destructors between main binary and libraries.
Since inits for the main binary are run from rtld (for some time), the
rtld_exit atexit(3) handler, which is passed from rtld to the program
entry and installed by csu, is installed after any atexit(3) handlers
installed by main binary constructors.  This means that rtld_exit() is
fired before main binary handlers.

Typical C++ static constructors are executed from init (either binary
or libs) but use atexit(3) to ensure that destructors are called in
the right order, independent of the linking order.  Also, C++
libraries finalizers call __cxa_finalize(3) to flush library'
atexit(3) entries.  Since atexit(3) entry is cleared after being run,
this would be mostly innocent, except that, atexit(rtld_exit) done
after main binary constructors, makes destructors from libraries
executed before destructors for main.

Fix by reordering atexit(rtld_exit) before inits for main binary, same
as it happened when inits were called by csu.  Do it using new private
libc symbol with pre-defined ABI.

Reported. tested, and reviewed by:	kan
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-04-15 13:03:09 +00:00
Konstantin Belousov
e3e21edb19 ld-elf.so: make LD_DEBUG always functional.
This causes some increase of the dynamic linker size, but benefits of
avoiding compiling private copy or the linker when debugging is
required. definitely worth it.

The dbg() calls can be compiled out by defining LD_NO_DEBUG symbol.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-04-14 18:04:53 +00:00
Konstantin Belousov
5d00c5a657 Fix initial exec TLS mode for dynamically loaded shared objects.
If dso uses initial exec TLS mode, rtld tries to allocate TLS in
static space. If there is no space left, the dlopen(3) fails. If space
if allocated, initial content from PT_TLS segment is distributed to
all threads' pcbs, which was missed and caused un-initialized TLS
segment for such dso after dlopen(3).

The mode is auto-detected either due to the relocation used, or if the
DF_STATIC_TLS dynamic flag is set.  In the later case, the TLS segment
is tried to allocate earlier, which increases chance of the dlopen(3)
to succeed.  LLD was recently fixed to properly emit the flag, ld.bdf
did it always.

Initial test by:	dumbbell
Tested by:	emaste (amd64), ian (arm)
Tested by:	Gerald Aryeetey <aryeeteygerald_rogers.com> (arm64)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D19072
2019-03-29 17:52:57 +00:00
Ed Maste
650f4477a5 rtld: attempt to fix reloc_non_plt TLS allocation on MIPS
allocate_tls_offset returns true on success.  The same issue existed
on arm and was fixed in r345693.

PR:		236880
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
2019-03-29 15:07:00 +00:00
Ed Maste
dc412d2d4b rtld: attempt to fix reloc_nonplt_object TLS allocation
allocate_tls_offset returns true on success.  This still needs more
testing and review, but this change is consistent with other archs.

PR:		236880
Reported by:	Andrew Gierth <andrew@tao11.riddles.org.uk>
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2019-03-29 14:35:23 +00:00
Ed Maste
09b47fc1c2 revert r341429 "disable BIND_NOW in libc, libthr, and rtld"
r345620 by kib@ fixed the rtld issue that caused a crash at startup
during resolution of libc's ifuncs with BIND_NOW.

PR:		233333
Sponsored by:	The FreeBSD Foundation
2019-03-28 02:12:32 +00:00
Konstantin Belousov
ad484b8c53 rtld: disable relro enforcement for irelative relocation processing.
This fixes yet another breakage for relro + bind now.

Reported by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2019-03-27 22:35:28 +00:00
Ed Maste
bcf99d2d99 Add WITH_PIE knob to build Position Independent Executables
Building binaries as PIE allows the executable itself to be loaded at a
random address when ASLR is enabled (not just its shared libraries).

With this change PIE objects have a .pieo extension and INTERNALLIB
libraries libXXX_pie.a.

MK_PIE is disabled for some kerberos5 tools, Clang, and Subversion, as
they explicitly reference .a libraries in their Makefiles.  These can
be addressed on an individual basis later.  MK_PIE is also disabled for
rtld-elf because it is already position-independent using bespoke
Makefile rules.

Currently only dynamically linked binaries will be built as PIE.

Discussed with:	dim
Reviewed by:	kib
MFC after:	1 month
Relnotes:	Yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D18423
2019-02-15 22:22:38 +00:00
Eric van Gyzen
ac818ca644 rtld: pacify -Wmaybe-uninitialized from gcc6
Sponsored by:	Dell EMC Isilon
2019-02-01 23:16:59 +00:00
Konstantin Belousov
d49ca25de6 Rename rtld-elf/malloc.c to rtld-elf/rtld_malloc.c.
Then malloc.c file name is too generic to use it for libthr.a.

Sponsored by:	The FreeBSD Foundation
MFC after:	13 days
2019-01-30 16:28:27 +00:00
Konstantin Belousov
7a6d40b22c Add header file missed in r343564.
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D18988
2019-01-29 22:45:24 +00:00
Konstantin Belousov
1a3b2ebf95 Adjust posix symbols from rtld-elf/malloc.c with the __crt_ prefix.
This allows to reuse the allocator in other environments that get
malloc(3) and related functions from libc or interposer.

MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D18988
2019-01-29 22:40:42 +00:00
Konstantin Belousov
8b40aab156 Remove now redundand ifunc relocation code which should have been
removed as part of r341441.

This call to reloc_non_plt() may crash if ifunc resolvers use the
needed libraries symbols since the pass over the needed libs
relocation is not yet done.  The change in r341441 ensures the right
relocation order otherwise.

Submitted by:	theraven
MFC after:	1 week
Discussed in:	https://reviews.freebsd.org/D17529
2019-01-27 00:37:52 +00:00
Dag-Erling Smørgrav
c9cf7cb85b Revert r343093 until I can address the issues raised by kib@. 2019-01-17 16:50:50 +00:00
Dag-Erling Smørgrav
9b35e90238 Implement dlopenat(3).
MFC after:	3 weeks
2019-01-16 12:12:40 +00:00
Justin Hibbits
b6abe132d4 Fix rtld-elf compilation warning for powerpc64 ELFv2 ABI
Summary: reloc_jmpslot function parameter 'defobj' is not used when using ELFv2
ABI

Submitted by:	alfredo.junior_eldorado.org.br
Reviewed By: kib, git_bdragon.rtk0.net, emaste, jhibbits
Differential Revision: https://reviews.freebsd.org/D18808
2019-01-13 02:33:20 +00:00
Justin Hibbits
45a18a1fe3 rtld-elf: Fix powerpc64 TLS handling, matching powerpc's fix
We need to subtract the TLS_TCB_SIZE to get to the real data pointer, since
r13 points to the end of the TCB structure.  Prior to this, devel/protobuf-c
port broke with recent update to devel/protobuf, which exposed this issue.

Submitted by:	andreast
Reported by:	Piotr Kubaj
MFC after:	1 week
2019-01-01 20:12:58 +00:00
Michal Meloun
4849c3a570 Improve R_AARCH64_TLSDESC relocation.
The original code did not support dynamically loaded libraries and used
suboptimal access to TLS variables.
New implementation removes lazy resolving of TLS relocation - due to flaw
in TLSDESC design is impossible to switch resolver function at runtime
without expensive locking.

Due to this, 3 specialized resolvers are implemented:
 - load time resolver for TLS relocation from libraries loaded with main
   executable (thus with known TLS offset).
 - resolver for undefined thread weak symbols.
 - slower lazy resolver for dynamically loaded libraries with fast path for
   already resolved symbols.

PR:		228892, 232149, 233204, 232311
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D18417
2018-12-15 10:38:07 +00:00
Michal Meloun
63003c4bcb Implement R_AARCH64_TLS_DTPMOD64 and A_AARCH64_TLS_DTPREL64 relocations.
Although these are slightly obsolete in favor of R_AARCH64_TLSDESC,
gcc -mtls-dialect=trad still use them.

Please note that definition of TLS_DTPMOD64 and TLS_DTPREL64 are incorrectly
exchanged in GNU binutils. TLS_DTPREL64 should be encoded to 1028 (as is
defined in ARM ELF ABI) but binutils encode it to 1029. And vice versa,
TLS_DTPMOD64 should be encoded to 1029 but binutils encode it to 1028.

While I'm in, add also R_AARCH64_NONE. It can be produced as result of linker
relaxation.

MFC after:	1 week
2018-12-08 14:58:17 +00:00
Michal Meloun
419333b944 Tidy up arm64 reloc_jmpslots() implementation.
- don't relocate jump slots multiple times (if LD_BIND_NOW is defined).
- process only R_AARCH64_JUMP_SLOT here, other relocation types are handled
  by reloc_plt().

MFC after:	1 week
2018-12-05 10:30:53 +00:00
Michal Meloun
22e9ff95aa Implement arm64 version of __tls_get_addr().
MFC after:	1 week
2018-12-05 10:23:38 +00:00
Michal Meloun
e8c479fddc Fix style(9).
Not a functional change.

MFC after:	1 week
2018-12-05 10:22:14 +00:00
Konstantin Belousov
4903c73faf Some fixes for LD_BIND_NOW + ifuncs.
- Do not perform ifunc relocations together with other PLT relocations
  in PLT.  Instead, do it during an additional pass over the init
  list, so that ifuncs are resolved in the order of dso
  dependencies. This allows the ifuncs resolvers to call into depended
  libs.  Init list now includes all objects instead of only objects
  with init/fini callables.
- Disable relro protection around bind_now ifunc relocations.

I considered calling ifunc resolvers of dso after initializers of all
dependencies are processed, and decided that this is wrong/should not
be supported. The order now is normal relocations for all
objects->ifunc resolution in init order->initializers, where each step
does complete pass over all loaded objects before moving to the next
step.

Reported, tested and reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D18400
2018-12-03 20:03:43 +00:00
Konstantin Belousov
5962a71ecf Provide naive but self-contained implementations of memset(3) and
bzero(3) for rtld.

This again reduces rtld dependency on libc, and in future, avoid ifunc
relocations when the functions are converted to ifuncs in libc.

Reported by:	mjg
Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D18400
2018-12-03 19:55:55 +00:00
Ed Maste
0e450664ad disable BIND_NOW in libc, libthr, and rtld
An issue remains with BIND_NOW and processes using threads.  For now,
restore libc's BIND_NOW disable, and also disable BIND_NOW in rtld and
libthr.

A patch is in review (D18400) that likely fixes this issue, but just
disable BIND_NOW pending further testing after it is committed.

PR:		233333
Sponsored by:	The FreeBSD Foundation
2018-12-03 15:59:46 +00:00
Konstantin Belousov
e8927aa6c6 rtld: parse FreeBSD Feature Control note on the object load.
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2018-11-23 22:37:35 +00:00
Conrad Meyer
c15faaac95 Revert r340843 - addressed independently in r340842! 2018-11-23 18:27:16 +00:00
Conrad Meyer
66a87f8cfd rtld: Silence a false positive GCC 6.4.0 warning
The function reloc_non_plt has complicated variable lifetimes that GCC 6.4.0
(the version currently used by amd64-xtoolchain-gcc) misunderstands and
produces an erroneous warning about.  Silence it to allow the -Werror build
to proceed.

Reviewed by:	emaste
2018-11-23 18:23:29 +00:00
Konstantin Belousov
bac111cc74 Silence gcc warnings.
Reported by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2018-11-23 18:15:23 +00:00
Konstantin Belousov
abfc3b2fef rtld: when immediate bind mode is requested, process irelocs in PLT
immediately after other PLT relocs.

Otherwise, if the object has relro page, we write to readonly page,
and we would need to use mprotect(2) two more times to fix it.  Note
that resolve_object_ifunc() does nothing when called second time, so
there is no need to avoid existing call.

Reported and tested by:	emaste
PR:	233333
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2018-11-20 14:52:43 +00:00
Alex Richardson
57fe7128b7 Handle the DT_MIPS_RLD_MAP_REL dynamic tag in RTLD
This dynamic tag contains the location of the .rld_map section relative to
the location of the dynamic tag. For PIE MIPS binaries DT_MIPS_RLD_MAP can
not be used since it contains an absolute address. Without this change
GDB can not find the function program counters in other libraries and once
I apply this change I can successfully run info sharedlibraries again.

Reviewed By:	kib
Differential Revision: https://reviews.freebsd.org/D17867
2018-11-07 15:04:41 +00:00
Ed Maste
eda66948fe rtld: move relro enforcement after ifunc processing
Previously the combination of relro (implicit), -z now and ifunc use
resulted in a segfault when applying ifuncs after relro (test binary
here just calls amd64_get_fsbase()):

| % env LD_DEBUG=1 libexec/rtld-elf/obj/ld-elf.so.1 a.out
| ...
| enforcing main obj relro
| ...
| resolving ifuncs
| reloc_jmpslot: *0x203198 = 0x189368ea4570
| zsh: bus error (core dumped)  LD_DEBUG=1 obj/ld-elf.so.1 ~/a.out

Reported by:	Shawn Webb
Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
2018-11-04 19:21:12 +00:00
Konstantin Belousov
561991144e Remove Obj_Entry textsize member.
It is unused after r340102, and more important, I do not see how to
define textsize in both practically useful and correct way, for binaries
with more that one executable segments.

Sponsored by:	The FreeBSD Foundation
2018-11-04 00:32:28 +00:00
Konstantin Belousov
f846c80a9c Flush data cache for executable loadable segments explicitly.
Do not use textsize and do not flush everything between map base and
base + textsize, because unmapped areas cannot be flushed.

This makes Obj_Entry textsize only use go away, and I will remove it
later.

Reported by:	tuexen
Tested by:	Mark Millard <marklmi26-fbsd@yahoo.com>
Sponsored by:	The FreeBSD Foundation
2018-11-03 20:39:16 +00:00
Konstantin Belousov
ca2b9726c3 Remove rtld use of libc amd64_set_fsbase().
One less non-trivial dependency of rtld on libc.  Also,
amd64_set_fsbase() is to be converted to ifunc, which I do not want to
support inside rtld.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2018-10-29 23:59:26 +00:00
Konstantin Belousov
29ea8142f8 Initialize ifunc calling machinery earlier.
In particular, do it before the first call to allocate_initial_tls(),
which contains MD parts to set the initial thread' TLS pointer.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2018-10-29 23:56:39 +00:00
Alex Richardson
3ab5b6bd97 rtld-elf: fix more warnings to allow compiling with WARNS=6
Reviewed By:	kib
Approved By:	brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17154
2018-10-29 21:08:28 +00:00
Alex Richardson
903e0ffd07 rtld-elf: compile with WANRS=4 warnings other than -Wcast-align
Reviewed By:	kib
Approved By:	brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17153
2018-10-29 21:08:19 +00:00
Alex Richardson
78b648465d rtld-elf: make it compile with WARNS=3
Reviewed By:	kib
Approved By:	brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17150
2018-10-29 21:08:11 +00:00
Alex Richardson
ca7e27bbce rtld: set obj->textsize correctly
With lld-generated binaries the first PT_LOAD will usually be a read-only
segment unless you pass --no-rosegment. For those binaries the textsize is
determined by the next PT_LOAD. To allow both LLD and bfd 2.17 binaries to
be parsed correctly use the end of the last PT_LOAD that is marked as
executable instead.

I noticed that the value was wrong while adding some debug prints for some rtld
changes for CHERI binaries. `obj->textsize` only seems to be used by PPC so the
effect is untested. However, the value before was definitely wrong and the new
result matches the phdrs.

Reviewed By:	kib
Approved By:	brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17117
2018-10-29 21:08:02 +00:00
Andreas Tobler
953cba365f This commit reverts 338930. The approach was wrong.
Fix the issue with subtracting the TLS_TCB_SIZE too when we are trying to get
the 'where' in the R_PPC_TPREL32 case. At allocation time we added an offset
and the TLS_TCB_SIZE. This has to be subtracted as well.

Now all the issues reported are fixed. Tests were done on G4 and G5 PowerMac's.
Additionally I ran the tls tests from the gcc test suite and made sure the
results are as good as pre 338486.

Thanks to tuexen for reporting the malfunction and for patient testing.
Also testing thanks goes to jhibbits.

Reported by:	tuexen
Discussed with:	jhibbits, nwhitehorn
Approved by:	re (gjb)
Pointyhat to:	andreast
2018-10-01 18:46:35 +00:00
Andrew Turner
6e4fdb5c9d Add STT_GNU_IFUNC and R_AARCH64_IRELATIVE support on arm64.
This is based on the amd64 implementation. Support for both PLT and
non-PLT (e.g. a global variable initilised with a pointer to an ifunc)
cases are supported.

We don't pass anything to the resolver as it is expected they will read
the ID registers directly, with the number of registers with CPU info
likely to increase in the future.

Reviewed by:	kib
Approved by:	re (gjb)
Differential Revision:	https://reviews.freebsd.org/D17341
2018-10-01 14:02:29 +00:00
Konstantin Belousov
d2f2e4c02d Provide refobj context when doing libmap substitution inside
search_library_path().

This corrects the scope of libmap matches.

Reported and tested by:	Andreas Longwitz <longwitz@incore.de>
Sponsored by:	The FreeBSD Foundation
Approved by:	re (gjb)
MFC after:	1 week
2018-09-26 21:28:14 +00:00
Konstantin Belousov
6c30676522 When doing lm_add(), check for duplicates.
This is useful when lm_find() moves the match to the global mapping,
since lm_find() could be called with a same path more than once.

Reported and tested by:	Andreas Longwitz <longwitz@incore.de>
Sponsored by:	The FreeBSD Foundation
Approved by:	re (gjb)
MFC after:	1 week
2018-09-26 21:27:08 +00:00
Andreas Tobler
28337eb676 Bring the 32-bit powerpc (PowerMac) back to live. The commit 338486 reworked
some TLS bits. This broke operation on the PowerMac. Namely one could not login.
At login the screen/shell was giving back lots of backslashes and the login
shell dumped core.

The fix to this issue is to revert the powerpc commit from 338486 and to
increase the TLS_TCB_SIZE to 16.
Reverting only did not help, login was possible but userland applications
aborted with strange messages.

I tested this patch with world/kernel builds and with port upgrades.
Additionally a full gcc8 bootstrap was successfully completed.

Reviewed by: jhibbits@
Approved by: re (Glen)
2018-09-25 19:29:35 +00:00
Brad Davis
9a537769d6 Move libmap.conf to libexec/rtld-elf/
This leverages CONFS to handle the config file install.

Approved by:	re (gjb), will (mentor)
Differential Revision:	https://reviews.freebsd.org/D17161
2018-09-18 00:25:00 +00:00
Brooks Davis
17fb2856c3 Rework rtld's TLS Variant I implementation to match r326794
The above commit fixed handling overaligned TLS segments in libc's
TLS Variant I implementation, but rtld provides its own implementation
for dynamically-linked executables which lacks these fixes.  Thus,
port these changes to rtld.

This was previously commited as r337978 and reverted in r338149 due to
exposing a bug the ARM rtld.  This bug was fixed in r338317 by mmel.

Submitted by:	James Clarke
Approved by:	re (kib)
Reviewed by:	kbowling
Testing by:	kbowling (powerpc64), br (riscv), kevans (armv7)
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D16510
2018-09-05 23:23:16 +00:00
Konstantin Belousov
c1a0a86ed4 Style cleanup. No functional changes.
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
Approved by:    re (rgrimes)
2018-09-02 15:42:37 +00:00
Michal Meloun
ee6281c3d3 Fix wrong offset calculation for R_ARM_TLS_TPOFF32 relocations.
TLS_TCB_SIZE is already accounted in defobj-> tlsoffset so all these symbols
were incorrectly relocated by +8.

Note:
The only consumer (for all binaries on my ARM board) of R_ARM_TLS_TPOFF32
relocation is _ThreadRuneLocale variable. And the incorrectly relocated
ThreadRuneLocale accidentally pointed to zeroed memory before memory layout
change from D16510 had changed status quo.

MFC after:	3 weeks
Reviewed by:	imp, jhb
Approved by:	re (marius)
2018-08-25 16:54:37 +00:00
Brooks Davis
a5207d3ef6 Revert r337978: Rework rtld's TLS Variant I implementation to match r326794
Michal Meloun reports that it breaks ctype (isspace()..) related
functions on armv7 so back out while we diagnose the issue.

Reported by:	Michal Meloun <melounmichal@gmail.com>
2018-08-21 18:22:12 +00:00
Brooks Davis
9b50d81646 Rework rtld's TLS Variant I implementation to match r326794
The above commit fixed handling overaligned TLS segments in libc's
TLS Variant I implementation, but rtld provides its own implementation
for dynamically-linked executables which lacks these fixes.  Thus,
port these changes to rtld.

Submitted by:	James Clarke
Reviewed by:	kbowling
Testing byL	kbowling (powerpc64), br (riscv), kevans (armv7)
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D16510
2018-08-17 16:19:47 +00:00
Ruslan Bukin
f00ebc42b5 Save and restore floating-point arguments.
Sponsored by:	DARPA, AFRL
2018-08-02 12:21:39 +00:00
Edward Tomasz Napierala
50cf3bac62 Fix regression tests broken by r337067.
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2018-08-02 11:55:16 +00:00
Edward Tomasz Napierala
711a4538f8 Make sure the rtld(1) error messages go to stderr, not stdout.
While here fix capitalization of a few nearby strings, add the
rtld's file name prefix so it's obvious where the message come
from, and return zero when "-h" is used.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D16530
2018-08-02 07:43:28 +00:00
Konstantin Belousov
0725fca53d Make rtld use libc_nossp_pic.a. Remove SSP shims.
Submitted by:	Luis Pires
Reviewed by:	brooks
Differential revision:	https://reviews.freebsd.org/D15341
2018-05-09 10:30:56 +00:00
Michal Meloun
fad101b3f2 Make rtld_bind_start() debugger friendly.
Save link register and annotate call frame structure so debugger can unwind
call frame created by rtld_bind_start().

MFC after:	2 weeks
2018-02-27 15:35:11 +00:00
Marius Strobl
41fc6f680b o Let rtld(1) set up psABI user trap handlers prior to executing the
objects' init functions instead of doing the setup via a constructor
  in libc as the init functions may already depend on these handlers
  to be in place. This gets us rid of:
  - the undefined order in which libc constructors as __guard_setup()
    and jemalloc_constructor() are executed WRT __sparc_utrap_setup(),
  - the requirement to link libc last so __sparc_utrap_setup() gets
    called prior to constructors in other libraries (see r122883).
  For static binaries, crt1.o still sets up the user trap handlers.
o Move misplaced prototypes for MD functions in to the MD prototype
  section of rtld.h.
o Sprinkle nitems().
2018-02-03 23:14:11 +00:00
Pedro F. Giffuni
e6209940de libexec: adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:25:02 +00:00
Pedro F. Giffuni
8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00