Commit Graph

836 Commits

Author SHA1 Message Date
Konstantin Belousov
1db23efb83 rtld: pass argc/argv/env to dso inits.
This is consistent with how array inits are called, and also makes us
more compatible with glibc environment.

Requested by:	Alex S <iwtcex@gmail.com>
PR:	249162
Reviewed by:	dim, emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D26351
2020-09-07 21:32:27 +00:00
Konstantin Belousov
12cb97fb37 Undo 'fix off by one' part of r365360.
Noted by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	6 days
2020-09-05 22:48:27 +00:00
Konstantin Belousov
500433057e rtld: do not refuse to relocate objects without dynamic symtabs.
Such objects can still have valid relocations not requiring symbolic
references.

PR:	249121
Reported by:	wsh@riski.sh
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-09-05 22:44:38 +00:00
Konstantin Belousov
2b49b95cfa rtld: do not process absent dynamic.
If object has no dynamic phdr, do not try to dereference NULL.  This
means that we cannot process any relocation, and that there cannot be
symbols defined, but it is up to static linker to produce meaningful
objects.

PR:	249121
Reported by:	wsh@riski.sh
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-09-05 22:41:31 +00:00
Konstantin Belousov
5d6d106cf6 rtld: Handle ELF dso with program headers outside the first page.
Reported by:	Alex Arslan <alex.arslan@julialang.org>
PR:	229708
Reviewed by:	dim (previous version), emaste
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D26323
2020-09-05 10:16:24 +00:00
Brooks Davis
29e1fceb73 Maintain a stack alignment of 16-bytes.
This violated the RISC-V 64-bit ABI.  On CheriBSD this manifested as
a trap when attempting to store 16-byte aligned types while zeroing
the stack.

Reported by:	CHERI, jrtc27
Reviewed by:	mhorne, br
Obtained from:	CheriBSD
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D26327
2020-09-04 21:46:10 +00:00
Xin LI
941791759c Don't explicitly specify c99 or gnu99 as the default is now gnu99.
MFC after:	2 weeks
2020-08-17 05:57:02 +00:00
John Baldwin
e9751a84dd Include FreeBSD ABI tag note in the ELF runtime loader.
Reviewed by:	kib
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D25306
2020-07-16 22:01:01 +00:00
Leandro Lupori
a5467d6ca2 Handle non-PLT GNU IFUNC relocations in rtld
In the last IFUNC related changes to rtld, the code that handled non-PLT
GNU IFUNC relocations ended up getting lost. This could leave some
relocations unhandled, causing crashes or misbehavior. This change restores
the handling of these relocations, but now together with the other IFUNC
relocations, allowing resolvers to reference external symbols.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D25550
2020-07-06 11:57:59 +00:00
Konstantin Belousov
7e400f1ade rtld: Apply relro to itself.
Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D25319
2020-06-18 23:07:58 +00:00
Konstantin Belousov
e0b322ae78 rtld: Parse own phdr and notes.
Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D25319
2020-06-18 23:06:05 +00:00
Konstantin Belousov
512baba6a5 rtld: Allow to load ET_DYN && DF_1_PIE when tracing.
This makes old ldd to still work on newer tagged PIE binaries.

Also move debug line for hashes before both decisions to not load are
done, so that the end of digest_dynamic() processing and reason to not
load or load is seen in debug trace.

Noted by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-06-16 21:29:02 +00:00
Konstantin Belousov
53b1c32035 rtld: Add debug line for dlopen_object().
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-06-16 21:25:58 +00:00
Konstantin Belousov
de34401534 Systematically pass RTLD_LO_TRACE to load_needed_objects().
Which makes all calls to load_object() to observe the flag, except the
calls for preloaded DSOs.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-06-16 21:23:39 +00:00
Konstantin Belousov
510b525fa5 rtld: set osrel when in the direct exec mode.
Rtld itself is a shared object which does not have vendor note, so
after the direct exec of ld-elf.so.1 process has p_osrel set to zero.
This affects the ABI of syscalls.

Set osrel to the __FreeBSD_version value at compile time right after
rtld identified direct exec mode.  Then, switch to the osrel read from
the binary note or zero if no note, right before starting calling
ifunc resolvers, which is the first byte of the user code.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-06-12 22:10:03 +00:00
Konstantin Belousov
daf5a897b9 Uppercase 'dso' to indicate that it is abbreviation.
Suggested by:	arichardson
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-06-02 17:33:10 +00:00
Konstantin Belousov
c1a813209c Do not allow to load ET_DYN object with DF_1_PIE flag set.
Linkers are supposed to mark PIE binaries with DF_1_PIE, such binary
cannot be correctly and usefully loaded neither by dlopen(3) nor as a
dependency of other object.  For instance, we cannot do anything
useful with COPY relocations, among other things.

Glibc already added similar restriction.

Requested and reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D25086
2020-06-02 16:20:58 +00:00
Konstantin Belousov
e82d19822e rtld: Add -b option to allow to specify image name different from arg0.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-05-31 22:37:33 +00:00
Konstantin Belousov
72bef4d8c6 rtld: Fix indent in print_usage().
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-05-31 21:56:07 +00:00
Konstantin Belousov
c8dd6c0599 rtld: Add -v switch to print some useful information about the rtld binary.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-05-31 21:53:15 +00:00
Konstantin Belousov
f393ade7c8 rtld: Add -p switch to direct exec mode summary line.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-05-31 21:34:21 +00:00
Konstantin Belousov
d89d55087f Add version indicators to rtld.
It is wrong to relate on __FreeBSD_version, either from
include/param.h, kernel, or libc, to check for rtld features.
Rtld might be from newer world than the running userspace.

Add special private symbols exported by rtld itself, to indicate the
changes in runtime behavior, and features that cannot be otherwise
detected or deduced at runtime.

Note that the symbols are not exported from libc, so they intentionally
cannot be linked against, and exported from the private namespace from rtld.
Consumers are required to use dlsym(3).  For instance, for
_rtld_version_laddr_offset, user should do
	ptr = dlsym(RTLD_DEFAULT, "_rtld_version_laddr_offset")
or even
	ptr = dlvsym(RTLD_DEFAULT,  "_rtld_version_laddr_offset",
	    "FBSDprivate_1.0");
Non-null ptr means that the change is present.

Also add _rtld_version__FreeBSD_version indicator to report the
headers version used at time of the rtld build.

Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D24982
2020-05-26 19:22:46 +00:00
Konstantin Belousov
c8ad15b6ff Implement Solaris-like link_map l_refname member.
The implementation is based on the public documentation, in particular
dlinfo(3) from Solaris.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-05-22 17:52:09 +00:00
Konstantin Belousov
24ea64ded2 Convert linkmap_add() and linkmap_delete() to style(8).
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-05-22 17:23:09 +00:00
Konstantin Belousov
d0ca9a7fe4 Restore the binary compatibility for link_map l_addr.
Keep link_map l_addr binary layout compatible, rename l_addr to l_base
where rtld returns map base.  Provide relocbase in newly added l_addr.

This effectively reverts the patch to the initial version of D24918.

Reported by: antoine (portmgr)
Reviewed by:	jhb, markj
Tested by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D24946
2020-05-21 22:24:23 +00:00
Konstantin Belousov
2c6d9dc0bb Change the samantic of struct link_map l_addr member.
It previously returned the object map base address, while all other
ELF operating systems return load offset, i.e. the difference between
map base and the link base.

Explain the meaning of the field in the man page.

Stop filling the mips-only l_offs member, which is apparently unused.

PR:	246561
Requested by:	Damjan Jovanovic <damjan.jov@gmail.com>
Reviewed by:	emaste, jhb, cem (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D24918
2020-05-20 22:08:26 +00:00
Konstantin Belousov
1659238a0c Implement RTLD_DEEPBIND.
PR:	246462
Tested by:	Martin Birgmeier <d8zNeCFG@aon.at>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D24841
2020-05-15 11:58:01 +00:00
Eric van Gyzen
fac6dee9eb Remove tests for obsolete compilers in the build system
Assume gcc is at least 6.4, the oldest xtoolchain in the ports tree.
Assume clang is at least 6, which was in 11.2-RELEASE.  Drop conditions
for older compilers.

Reviewed by:	imp (earlier version), emaste, jhb
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D24802
2020-05-12 15:22:40 +00:00
Michal Meloun
5a77ce24b6 Move ARM specific flags to arm/Makefile.inc
Requested by:	kib
MFC with:	r360463
2020-04-29 16:05:50 +00:00
Michal Meloun
7838a78269 Don't allow to use FPU inside of rtld library.
Clang10 may use FPU instructions for optimizing operations with
memory blocks. But we don't want to do lengthy save/restore of all
FPU registers across each rtld_start() call.

MFC after:	3 week
2020-04-29 14:06:42 +00:00
Konstantin Belousov
62af2dc3fb rtld: ignore static TLS segments when tracing.
For PIE binaries, ldd(1) performs dlopen(RTLD_TRACE) on the binary.
It is legal for binary to use initial exec TLS mode, but when such
binary (actually dso) is dlopened, we might not have enough free space
in the finalized static TLS segment.  Make ldd operational by skipping
TLS space allocation, we are not going to execute any code from the
dso anyway.

Reported by:	tobik
PR:	245677
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-04-22 18:39:45 +00:00
Konstantin Belousov
e5c3405ce8 Align initial-exec TLS segments to the p_vaddr % align.
This is continuation of D21163/r359634, which handled the alignment
for global mode.

Non-x86 arches are not handled, maintainers are welcomed.

Tested by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D24366
2020-04-19 09:28:59 +00:00
Konstantin Belousov
2f06c66ad5 Make p_vaddr % p_align == p_offset % p_align for (some) TLS segments.
See https://sourceware.org/bugzilla/show_bug.cgi?id=24606 for the test case.
See https://reviews.llvm.org/D64930 for the background and more discussion.

Also this fixes another bug in malloc_aligned() where total size of
the allocated memory might be not enough to fit the aligned requested
block after the initial pointer is incremented by the pointer size.

Reviewed by:	bdragon
Tested by:	antoine (exp-run PR 244866), bdragon, emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D21163
2020-04-04 22:37:50 +00:00
Warner Losh
600ee699ed Remove sparc64 source files from rtld-elf
These were missed in the prior sweep.

Submitted by:	jhb@
2020-02-26 23:17:16 +00:00
Warner Losh
8e0ff10d4b Remove sparc64 specific parts of rtld-elf. 2020-02-26 18:49:25 +00:00
Mateusz Guzik
0573d0a9b8 vfs: add realpathat syscall
realpath(3) is used a lot e.g., by clang and is a major source of getcwd
and fstatat calls. This can be done more efficiently in the kernel.

This works by performing a regular lookup while saving the name and found
parent directory. If the terminal vnode is a directory we can resolve it using
usual means. Otherwise we can use the name saved by lookup and resolve the
parent.

See the review for sample syscall counts.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D23574
2020-02-20 16:58:19 +00:00
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