Commit Graph

2640 Commits

Author SHA1 Message Date
Dmitry V. Levin
14ef9c185b treewide: fix incorrect spelling of indices in comments
Replace 'indeces' with 'indices', the most annoying of these typos were
those found in elf.h which is a public header file copied to other
projects.
2020-12-11 02:00:00 +00:00
Florian Weimer
880433de13 elf: Include <sys/param.h> in cache.c
The roundup macro is defined there.  Relying on an indirect
definition is brittle.
2020-12-10 15:47:26 +01:00
Florian Weimer
fdf8fbca45 s390x: Add glibc-hwcaps support
Subdirectories z13, z14, z15 can be selected, mostly based on the
level of support for vector instructions.

Co-Authored-By: Stefan Liebler <stli@linux.ibm.com>
2020-12-10 13:51:18 +01:00
Florian Weimer
1bb8d05b9c elf: Fix run-time dependencies of tst-dlopen-fail-2
The misattributed dependencies can cause failures in parallel testing
if the dependencies have not been built yet.

Fixes commit a332bd1518
("elf: Add elf/tst-dlopenfail-2 [BZ #25396]").
2020-12-10 12:44:25 +01:00
Florian Weimer
0d4ed9d40e elf: Fix incorrect comparison in sort_priorities_by_name
Reported-By: Stefan Liebler <stli@linux.ibm.com>
2020-12-09 18:56:14 +01:00
Florian Weimer
4c38c1a229 powerpc64le: Add glibc-hwcaps support
The "power10" and "power9" subdirectories are selected in a way
that matches the -mcpu=power10 and -mcpu=power9 options of GCC.
2020-12-04 14:50:49 +01:00
Matheus Castanho
4f4bd9e47b elf: Add missing <stddef.h> header to elf/dl-hwcaps.h
The lack of this header makes size_t unavailable on builds configured
with --disable-tunables, causing compilation errors.
2020-12-04 09:52:02 -03:00
Florian Weimer
f267e1c9dd x86_64: Add glibc-hwcaps support
The subdirectories match those in the x86-64 psABI:

77566eb03b

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:36:02 +01:00
Florian Weimer
600d9e0c87 elf: Add glibc-hwcaps subdirectory support to ld.so cache processing
This recognizes the DL_CACHE_HWCAP_EXTENSION flag in cache entries,
and picks the supported cache entry with the highest priority.

The elf/tst-glibc-hwcaps-prepend-cache test documents a non-desired
aspect of the current cache implementation: If the cache selects a DSO
that does not exist on disk, _dl_map_object falls back to open_path,
which may or may not find an alternative implementation.  This is an
existing limitation that also applies to the legacy hwcaps processing
for ld.so.cache.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:35:43 +01:00
Florian Weimer
b44ac4f4c7 elf: Process glibc-hwcaps subdirectories in ldconfig
Libraries from these subdirectories are added to the cache
with a special hwcap bit DL_CACHE_HWCAP_EXTENSION, so that
they are ignored by older dynamic loaders.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:16:41 +01:00
Florian Weimer
73b6e50a22 elf: Implement tail merging of strings in ldconfig
This simplifies the string table construction in elf/cache.c
because there is no more need to keep track of offsets explicitly;
the string table implementation does this internally.

This change slightly reduces the size of the cache on disk.  The
file format does not change as a result.  The strings are
null-terminated, without explicit length, so tail merging is
transparent to readers.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:16:41 +01:00
Florian Weimer
785969a047 elf: Implement a string table for ldconfig, with tail merging
This will be used in ldconfig to reduce the ld.so.cache size slightly.

Tail merging is an optimization where a pointer points into another
string if the first string is a suffix of the second string.

The hash function FNV-1a was chosen because it is simple and achieves
good dispersion even for short strings (so that the hash table bucket
count can be a power of two).  It is clearly superior to the hsearch
hash and the ELF hash in this regard.

The hash table uses chaining for collision resolution.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:16:41 +01:00
Florian Weimer
dfb3f101c5 elf: Add extension mechanism to ld.so.cache
A previously unused new-format header field is used to record
the address of an extension directory.

This change adds a demo extension which records the version of
ldconfig which builds a file.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:16:41 +01:00
Florian Weimer
84ba719b26 elf: Add endianness markup to ld.so.cache (bug 27008)
Use a reserved byte in the new format cache header to indicate whether
the file is in little endian or big endian format.  Eventually, this
information could be used to provide a unified cache for qemu-user
and similiar scenarios.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:16:30 +01:00
Florian Weimer
dad90d5282 elf: Add glibc-hwcaps support for LD_LIBRARY_PATH
This hacks non-power-set processing into _dl_important_hwcaps.
Once the legacy hwcaps handling goes away, the subdirectory
handling needs to be reworked, but it is premature to do this
while both approaches are still supported.

ld.so supports two new arguments, --glibc-hwcaps-prepend and
--glibc-hwcaps-mask.  Each accepts a colon-separated list of
glibc-hwcaps subdirectory names.  The prepend option adds additional
subdirectories that are searched first, in the specified order.  The
mask option restricts the automatically selected subdirectories to
those listed in the option argument.  For example, on systems where
/usr/lib64 is on the library search path,
--glibc-hwcaps-prepend=valgrind:debug causes the dynamic loader to
search the directories /usr/lib64/glibc-hwcaps/valgrind and
/usr/lib64/glibc-hwcaps/debug just before /usr/lib64 is searched.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-12-04 09:13:43 +01:00
Florian Weimer
c41d197ec4 elf: Synchronize <elf.h> section header flags with binutils
binutils 2.36 will add SHF_GNU_RETAIN support.  SHF_GNU_BUILD_NOTE
was also missing from the glibc header.
2020-12-03 14:17:29 +01:00
Florian Weimer
be5365e87b elf.h: Fix spelling of EM_TILE64 comment
Reported-By: Jakub Jelinek <jakub@redhat.com>
2020-12-02 13:58:08 +01:00
Florian Weimer
db07fae825 elf: Introduce enum opt_format in the ldconfig implementation
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-11-26 18:26:52 +01:00
Shuo Wang
df5f473ed5 elf: Fix uninitialized variable for _dl_write
Variable ret in elf/dl-write.c is uninitialized, which should get
return value from __writev.
2020-11-24 16:54:58 -03:00
Samuel Thibault
3dbbd2ff92 Add {,sysdep-}ld-library-path make variable
On GNU/Hurd we not only need $(common-objpfx) in LD_LIBRARY_PATH when loading
dynamic objects, but also $(common-objpfx)/mach and $(common-objpfx)/hurd. This
adds an ld-library-path variable to be used as LD_LIBRARY_PATH basis in
Makefiles, and a sysdep-ld-library-path variable for sysdeps to add some
more paths, here mach/ and hurd/.
2020-11-16 21:15:20 +00:00
Florian Weimer
1daccf403b nptl: Move stack list variables into _rtld_global
Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT,
formerly __wait_lookup_done) can be implemented directly in ld.so,
eliminating the unprotected GL (dl_wait_lookup_done) function
pointer.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-11-16 19:33:30 +01:00
Samuel Thibault
3d3316b1de hurd: keep only required PLTs in ld.so
We need NO_RTLD_HIDDEN because of the need for PLT calls in ld.so.
See Roland's comment in
https://sourceware.org/bugzilla/show_bug.cgi?id=15605
"in the Hurd it's crucial that calls like __mmap be the libc ones
instead of the rtld-local ones after the bootstrap phase, when the
dynamic linker is being used for dlopen and the like."

We used to just avoid all hidden use in the rtld ; this commit switches to
keeping only those that should use PLT calls, i.e. essentially those defined in
sysdeps/mach/hurd/dl-sysdep.c:

__assert_fail
__assert_perror_fail
__*stat64
_exit

This fixes a few startup issues, notably the call to __tunable_get_val that is
made before PLTs are set up.
2020-11-11 02:36:22 +01:00
Florian Weimer
5e598c2bbf elf: In ldconfig, extract the new_sub_entry function from search_dir
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-30 18:40:28 +01:00
Florian Weimer
de1a9197af elf: Unify old and new format cache handling code in ld.so
struct file_entry_new starts with the fields of struct file_entry,
so the code can be shared if the size computation is made dynamic.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-30 14:12:14 +01:00
Érico Rolim
9538f6b95a Make elf.h header self contained.
The elf/elf.h header is shared, verbatim, by the elfutils project.
However, elfutils can be used on systems with libcs other than glibc,
making the presence of __BEGIN_DECLS, __END_DECLS and <features.h> in
the file something that downstream distros may have to add patches for.

Furthermore, this file doesn't declare anything with language linkage,
so `extern "C" {}` blocks aren't necessary; it also doesn't have any
conditional definitions based on feature test macros, making inclusion
of features.h unnecessary.
2020-10-28 11:29:16 +01:00
Siddhesh Poyarekar
6c2b579962 Reword description of SXID_* tunable properties
The SXID_* tunable properties only influence processes that are
AT_SECURE, so make that a bit more explicit in the documentation and
comment.

Revisiting the code after a few years I managed to confuse myself, so
I imagine there could be others who may have incorrectly assumed like
I did that the SXID_ERASE tunables are not inherited by children of
non-AT_SECURE processes.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2020-10-22 13:52:38 +05:30
Rolf Eike Beer
7ee881f1f4 rtld: fix typo in comment 2020-10-13 05:49:58 -07:00
Matheus Castanho
21181d1c7b elf: Add missing <dl-procinfo.h> header to elf/dl-usage.c 2020-10-12 11:28:18 +02:00
Florian Weimer
bb5fd5ce64 elf: Do not pass GLRO(dl_platform), GLRO(dl_platformlen) to _dl_important_hwcaps
In the current code, the function can easily obtain the information
on its own.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-10-09 10:22:19 +02:00
Florian Weimer
647103ea3a elf: Enhance ld.so --help to print HWCAP subdirectories
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-09 10:21:32 +02:00
Florian Weimer
10b39a5124 elf: Add library search path information to ld.so --help
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-09 10:19:09 +02:00
Florian Weimer
50b1b7a390 elf: Make __rtld_env_path_list and __rtld_search_dirs global variables
They have been renamed from env_path_list and rtld_search_dirs to
avoid linknamespace issues.

This change will allow future use these variables in diagnostics.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 17:12:28 +02:00
Florian Weimer
db03874df9 elf: Print the full name of the dynamic loader in the ld.so help message
This requires defining a macro for the full path, matching the
-Wl,--dynamic-link= arguments used for linking glibc programs,
and ldd script.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 17:12:05 +02:00
Florian Weimer
ca52c56abf elf: Use the term "program interpreter" in the ld.so help message
This is the term that the ELF standard itself uses.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 15:44:23 +02:00
Florian Weimer
542923d949 elf: Implement ld.so --version
This prints out version information for the dynamic loader and
exits immediately, without further command line processing
(which seems to match what some GNU tools do).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 15:33:00 +02:00
Florian Weimer
e0f1a58f3d elf: Implement ld.so --help
--help processing is deferred to the point where the executable has
been loaded, so that it is possible to eventually include information
from the main executable in the help output.

As suggested in the GNU command-line interface guidelines, the help
message is printed to standard output, and the exit status is
successful.

Handle usage errors closer to the GNU command-line interface
guidelines.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 15:00:39 +02:00
Florian Weimer
27316f4a23 elf: Record whether paths come from LD_LIBRARY_PATH or --library-path
This allows more precise LD_DEBUG diagnostics.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 14:29:49 +02:00
Florian Weimer
9590a71adc elf: Move ld.so error/help output to _dl_usage
Also add a comment to elf/Makefile, explaining why we cannot use
config.status for autoconf template processing.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 13:38:23 +02:00
Florian Weimer
2bf9e641fd elf: Extract command-line/environment variables state from rtld.c
Introduce struct dl_main_state and move it to <dl-main.h>.  Rename
enum mode to enum rtld_mode and add the rtld_mode_ prefix to the enum
constants.

This avoids the need for putting state that is only needed during
startup into the ld.so data segment.
2020-10-08 12:05:47 +02:00
Florian Weimer
72d36ffd7d elf: Implement __rtld_malloc_is_complete
In some cases, it is difficult to determine the kind of malloc
based on the execution context, so a function to determine that
is helpful.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 11:00:42 +02:00
Andreas Schwab
8f8052c2aa Revert "Fix missing redirects in testsuite targets"
This reverts commit d5afb38503.  The log files are actually created by the
various shell scripts that drive the tests.
2020-10-08 10:09:30 +02:00
Florian Weimer
b31d4355ae elf: Implement _dl_write
The generic version is parallel to _dl_writev.  It cannot use
_dl_writev directly because the errno value needs to be obtained
under a lock.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-07 16:41:30 +02:00
Florian Weimer
56f8d44294 elf: Do not search HWCAP subdirectories in statically linked binaries
This functionality does not seem to be useful since static dlopen
is mostly used for iconv/character set conversion and NSS support.
gconv modules are loaded with full paths anyway, so that the
HWCAP subdirectory logic does not apply.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-07 16:40:23 +02:00
H.J. Lu
dfb8e514cf Set tunable value as well as min/max values
Some tunable values and their minimum/maximum values must be determinted
at run-time.  Add TUNABLE_SET_WITH_BOUNDS and TUNABLE_SET_WITH_BOUNDS_FULL
to update tunable value together with minimum and maximum values.
__tunable_set_val is updated to set tunable value as well as min/max
values.
2020-09-29 09:03:47 -07:00
Vincent Mihalkovic
c670278934 ld.so: add an --argv0 option [BZ #16124] 2020-09-29 12:34:40 +02:00
Adhemerval Zanella
04986243d1 Remove internal usage of extensible stat functions
It replaces the internal usage of __{f,l}xstat{at}{64} with the
__{f,l}stat{at}{64}.  It should not change the generate code since
sys/stat.h explicit defines redirections to internal calls back to
xstat* symbols.

Checked with a build for all affected ABIs.  I also check on
x86_64-linux-gnu and i686-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
2020-09-11 14:35:32 -03:00
Mark Wielaard
721a853415 elf.h: Add aarch64 bti/pac dynamic tag constants
Constants double checked against binutils and the ELF for the Arm 64-bit
Architecture (AArch64) Release 2020Q2 document.

Only BTI PLT is used in glibc, there's no PAC PLT with glibc, and people
are expected to use BIND_NOW.
2020-09-07 09:12:04 +02:00
Alistair Francis
9bd8e3f99d elf/tst-libc_dlvsym: Add a TEST_COMPAT around some symbol tests
The _sys_errlist and _sys_siglist symbols are deprecated since 2.32.
This patch adds a TEST_COMPAT check around the tests. This fixes test
failures on new architectures (such as RV32) that don't have this
symbol defined.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-08-27 08:17:13 -07:00
Florian Weimer
07ed32f920 elf: Change TLS static surplus default back to 1664
Make the computation in elf/dl-tls.c more transparent, and add
an explicit test for the historic value.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-20 13:30:45 +02:00
Florian Weimer
efedd1ed3d Linux: Remove rseq support
The kernel ABI is not finalized, and there are now various proposals
to change the size of struct rseq, which would make the glibc ABI
dependent on the version of the kernels used for building glibc.
This is of course not acceptable.

This reverts commit 48699da1c4 ("elf:
Support at least 32-byte alignment in static dlopen"), commit
8f4632deb3 ("Linux: rseq registration
tests"), commit 6e29cb3f61 ("Linux: Use
rseq in sched_getcpu if available"), and commit
0c76fc3c2b ("Linux: Perform rseq
registration at C startup and thread creation"), resolving the conflicts
introduced by the ARC port and the TLS static surplus changes.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-16 17:55:35 +02:00
Szabolcs Nagy
ffb17e7ba3 rtld: Avoid using up static TLS surplus for optimizations [BZ #25051]
On some targets static TLS surplus area can be used opportunistically
for dynamically loaded modules such that the TLS access then becomes
faster (TLSDESC and powerpc TLS optimization). However we don't want
all surplus TLS to be used for this optimization because dynamically
loaded modules with initial-exec model TLS can only use surplus TLS.

The new contract for surplus static TLS use is:

- libc.so can have up to 192 bytes of IE TLS,
- other system libraries together can have up to 144 bytes of IE TLS.
- Some "optional" static TLS is available for opportunistic use.

The optional TLS is now tunable: rtld.optional_static_tls, so users
can directly affect the allocated static TLS size. (Note that module
unloading with dlclose does not reclaim static TLS. After the optional
TLS runs out, TLS access is no longer optimized to use static TLS.)

The default setting of rtld.optional_static_tls is 512 so the surplus
TLS is 3*192 + 4*144 + 512 = 1664 by default, the same as before.

Fixes BZ #25051.

Tested on aarch64-linux-gnu and x86_64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-08 17:32:56 +01:00
Szabolcs Nagy
17796419b5 rtld: Account static TLS surplus for audit modules
The new static TLS surplus size computation is

  surplus_tls = 192 * (nns-1) + 144 * nns + 512

where nns is controlled via the rtld.nns tunable. This commit
accounts audit modules too so nns = rtld.nns + audit modules.

rtld.nns should only include the namespaces required by the
application, namespaces for audit modules are accounted on top
of that so audit modules don't use up the static TLS that is
reserved for the application. This allows loading many audit
modules without tuning rtld.nns or using up static TLS, and it
fixes

FAIL: elf/tst-auditmany

Note that DL_NNS is currently a hard upper limit for nns, and
if rtld.nns + audit modules go over the limit that's a fatal
error. By default rtld.nns is 4 which allows 12 audit modules.

Counting the audit modules is based on existing audit string
parsing code, we cannot use GLRO(dl_naudit) before the modules
are actually loaded.
2020-07-08 17:32:56 +01:00
Szabolcs Nagy
0c7b002fac rtld: Add rtld.nns tunable for the number of supported namespaces
TLS_STATIC_SURPLUS is 1664 bytes currently which is not enough to
support DL_NNS (== 16) number of dynamic link namespaces, if we
assume 192 bytes of TLS are reserved for libc use and 144 bytes
are reserved for other system libraries that use IE TLS.

A new tunable is introduced to control the number of supported
namespaces and to adjust the surplus static TLS size as follows:

surplus_tls = 192 * (rtld.nns-1) + 144 * rtld.nns + 512

The default is rtld.nns == 4 and then the surplus TLS size is the
same as before, so the behaviour is unchanged by default. If an
application creates more namespaces than the rtld.nns setting
allows, then it is not guaranteed to work, but the limit is not
checked. So existing usage will continue to work, but in the
future if an application creates more than 4 dynamic link
namespaces then the tunable will need to be set.

In this patch DL_NNS is a fixed value and provides a maximum to
the rtld.nns setting.

Static linking used fixed 2048 bytes surplus TLS, this is changed
so the same contract is used as for dynamic linking.  With static
linking DL_NNS == 1 so rtld.nns tunable is forced to 1, so by
default the surplus TLS is reduced to 144 + 512 = 656 bytes. This
change is not expected to cause problems.

Tested on aarch64-linux-gnu and x86_64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-08 17:32:56 +01:00
Szabolcs Nagy
c7aa8596de rtld: Clean up PT_NOTE and add PT_GNU_PROPERTY handling
Add generic code to handle PT_GNU_PROPERTY notes. Invalid
content is ignored, _dl_process_pt_gnu_property is always called
after PT_LOAD segments are mapped and it has no failure modes.
Currently only one NT_GNU_PROPERTY_TYPE_0 note is handled, which
contains target specific properties: the _dl_process_gnu_property
hook is called for each property.

The old _dl_process_pt_note and _rtld_process_pt_note differ in how
the program header is read.  The old _dl_process_pt_note is called
before PT_LOAD segments are mapped and _rtld_process_pt_note is called
after PT_LOAD segments are mapped. The old _rtld_process_pt_note is
removed and _dl_process_pt_note is always called after PT_LOAD
segments are mapped and now it has no failure modes.

The program headers are scanned backwards so that PT_NOTE can be
skipped if PT_GNU_PROPERTY exists.

Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-07-08 14:28:53 +01:00
Florian Weimer
3ad5dab476 elf: Do not signal LA_ACT_CONSISTENT for an empty namespace [BZ #26076]
The auditing interface identifies namespaces by their first loaded
module.  Once the namespace is empty, it is no longer possible to signal
LA_ACT_CONSISTENT for it because the first loaded module is already gone
at that point.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-07 09:58:45 +02:00
Florian Weimer
706ad1e7af Add the __libc_single_threaded variable
The variable is placed in libc.so, and it can be true only in
an outer libc, not libcs loaded via dlmopen or static dlopen.
Since thread creation from inner namespaces does not work,
pthread_create can update __libc_single_threaded directly.

Using __libc_early_init and its initial flag, implementation of this
variable is very straightforward.  A future version may reset the flag
during fork (but not in an inner namespace), or after joining all
threads except one.

Reviewed-by: DJ Delorie <dj@redhat.com>
2020-07-06 11:15:58 +02:00
Mathieu Desnoyers
0c76fc3c2b Linux: Perform rseq registration at C startup and thread creation
Register rseq TLS for each thread (including main), and unregister for
each thread (excluding main).  "rseq" stands for Restartable Sequences.

See the rseq(2) man page proposed here:
  https://lkml.org/lkml/2018/9/19/647

Those are based on glibc master branch commit 3ee1e0ec5c.
The rseq system call was merged into Linux 4.18.

The TLS_STATIC_SURPLUS define is increased to leave additional room for
dlopen'd initial-exec TLS, which keeps elf/tst-auditmany working.

The increase (76 bytes) is larger than 32 bytes because it has not been
increased in quite a while.  The cost in terms of additional TLS storage
is quite significant, but it will also obscure some initial-exec-related
dlopen failures.
2020-07-06 10:21:16 +02:00
Florian Weimer
6f3331f26d elf: Include <stdbool.h> in <dl-tunables.h> because bool is used 2020-06-24 11:02:34 +02:00
Florian Weimer
e221c512c7 ld.so: Check for new cache format first and enhance corruption check
Now that ldconfig defaults to the new format (only), check for it
first.  Also apply the corruption check added in commit 2954daf00b
("Add more checks for valid ld.so.cache file (bug 18093)") to the
new-format-only case.

Suggested-by: Josh Triplett <josh@joshtriplett.org>
2020-06-15 09:50:14 +02:00
H.J. Lu
533dd2acf7 Add "%d" support to _dl_debug_vdprintf
"%d" will be used to print out signed value.
2020-06-09 12:15:01 -07:00
Vineet Gupta
8dbb7a08ec dl-runtime: reloc_{offset,index} now functions arch overide'able
The existing macros are fragile and expect local variables with a
certain name. Fix this by defining them as functions with default
implementation in a new header dl-runtime.h which arches can override
if need be.

This came up during ARC port review, hence the need for argument pltgot
in reloc_index() which is not needed by existing ports.

This patch potentially only affects hppa/x86 ports,
build tested for both those configs and a few more.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-06-05 13:45:46 -07:00
H.J. Lu
9b7424215b Replace val with __val in TUNABLE_SET_VAL_IF_VALID_RANGE
There are:

 #define TUNABLE_SET_VAL_IF_VALID_RANGE(__cur, __val, __type)                 \
({                                                                            \
  __type min = (__cur)->type.min;                                             \
  __type max = (__cur)->type.max;                                             \
                                                                              \
  if ((__type) (__val) >= min && (__type) (val) <= max)                       \
                                           ^^^ Should be __val
    {                                                                         \
      (__cur)->val.numval = val;                                              \
                            ^^^ Should be __val
      (__cur)->initialized = true;                                            \
    }                                                                         \
})

Luckily since all TUNABLE_SET_VAL_IF_VALID_RANGE usages are

TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, int64_t);

this didn't cause any issues.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-06-04 14:01:14 -07:00
Florian Weimer
31563b6841 elf: Remove extra hwcap mechanism from ldconfig
Historically, this mechanism was used to process "nosegneg"
subdirectories, and it is still used to include the "tls"
subdirectories.  With nosegneg support gone from ld.so, this is part
no longer useful.

The entire mechanism is not well-designed because it causes the
meaning of hwcap bits in ld.so.cache to depend on the kernel version
that was used to generate the cache, which makes it difficult to use
this mechanism for anything else in the future.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-05-28 10:21:17 +02:00
Florian Weimer
dcbc6b83ef elf: Do not read hwcaps from the vDSO in ld.so
This was only ever used for the "nosegneg" flag.  This approach for
passing hardware capability information creates a subtle dependency
between the kernel and userspace, and ld.so.cache contents.  It seems
inappropriate for toady, where people expect to be able to run
system images which very different kernel versions.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-05-28 10:20:57 +02:00
Florian Weimer
de42613540 elf: Turn _dl_printf, _dl_error_printf, _dl_fatal_printf into functions
This change makes it easier to set a breakpoint on these calls.

This also addresses the issue that including <ldsodefs.h> without
<unistd.h> does not result usable _dl_*printf macros because of the
use of the STD*_FILENO macros there.

(The private symbol for _dl_fatal_printf will go away again
once the exception handling implementation is unified between
libc and ld.so.)

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-05-25 18:17:27 +02:00
Szabolcs Nagy
03acbc1f71 elf.h: add aarch64 property definitions
These property values are specified by the AArch64 ELF ABI and
binutils can create binaries marked with them.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-05-21 09:55:43 +01:00
Szabolcs Nagy
7787a35fd0 elf.h: Add PT_GNU_PROPERTY
This program header type is already used in binaries on x86 and
aarch64 targets.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-05-21 09:55:43 +01:00
Josh Triplett
cad64f778a ldconfig: Default to the new format for ld.so.cache
glibc has supported this format for close to 20 years.
2020-05-19 14:41:48 +02:00
Florian Weimer
ce12fc7113 Remove NO_CTORS_DTORS_SECTIONS macro
This was originally added to support binutils older than version
2.22:

  <https://sourceware.org/ml/libc-alpha/2010-12/msg00051.html>

Since 2.22 is older than the minimum required binutils version
for building glibc, we no longer need this.  (The changes do
not impact the statically linked startup code.)
2020-05-18 15:39:34 +02:00
Florian Weimer
7b5bfe7783 elf: Assert that objects are relocated before their constructors run
If we try to run constructors before relocation, this is always
a dynamic linker bug.  An assert is easier to notice than a call
via an invalid function pointer (which may not even produce a valid
call stack).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-05-18 15:30:09 +02:00
H.J. Lu
674ea88294 x86: Move CET control to _dl_x86_feature_control [BZ #25887]
1. Include <dl-procruntime.c> to get architecture specific initializer in
rtld_global.
2. Change _dl_x86_feature_1[2] to _dl_x86_feature_1.
3. Add _dl_x86_feature_control after _dl_x86_feature_1, which is a
struct of 2 bitfields for IBT and SHSTK control

This fixes [BZ #25887].
2020-05-18 06:15:02 -07:00
Florian Weimer
ad78d70275 elf: Remove redundant add_to_global_resize_failure call from dl_open_args
The second call does not do anything because the data structures have
already been resized by the call that comes before the demarcation
point.  Fixes commit a509eb117f
("Avoid late dlopen failure due to scope, TLS slotinfo updates
[BZ #25112]").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-05-12 19:06:18 +02:00
Paul E. Murphy
e2239af353 Rename __LONG_DOUBLE_USES_FLOAT128 to __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI
Improve the commentary to aid future developers who will stumble
upon this novel, yet not always perfect, mechanism to support
alternative formats for long double.

Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to
__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work
has settled down.  The command used was

git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \
  xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g'

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-04-30 08:52:08 -05:00
Florian Weimer
03e187a41d elf: Add initial flag argument to __libc_early_init
The rseq initialization should happen only for the libc in the base
namespace (in the dynamic case) or the statically linked libc.  The
__libc_multiple_libcs flag does not quite cover this case at present,
so this commit introduces a flag argument to __libc_early_init,
indicating whether the libc being libc is the primary one (of the main
program).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-29 15:44:03 +02:00
Florian Weimer
ec935dea63 elf: Implement __libc_early_init
This function is defined in libc.so, and the dynamic loader calls
right after relocation has been finished, before any ELF constructors
or the preinit function is invoked.  It is also used in the static
build for initializing parts of the static libc.

To locate __libc_early_init, a direct symbol lookup function is used,
_dl_lookup_direct.  It does not search the entire symbol scope and
consults merely a single link map.  This function could also be used
to implement lookups in the vDSO (as an optimization).

A per-namespace variable (libc_map) is added for locating libc.so,
to avoid repeated traversals of the search scope.  It is similar to
GL(dl_initfirst).  An alternative would have been to thread a context
argument from _dl_open down to _dl_map_object_from_fd (where libc.so
is identified).  This could have avoided the global variable, but
the change would be larger as a result.  It would not have been
possible to use this to replace GL(dl_initfirst) because that global
variable is used to pass the function pointer past the stack switch
from dl_main to the main program.  Replacing that requires adding
a new argument to _dl_init, which in turn needs changes to the
architecture-specific libc.so startup code written in assembler.

__libc_early_init should not be used to replace _dl_var_init (as
it exists today on some architectures).  Instead, _dl_lookup_direct
should be used to look up a new variable symbol in libc.so, and
that should then be initialized from the dynamic loader, immediately
after the object has been loaded in _dl_map_object_from_fd (before
relocation is run).  This way, more IFUNC resolvers which depend on
these variables will work.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-24 22:32:09 +02:00
Florian Weimer
50a2d83c08 elf: Introduce <elf_machine_sym_no_match.h>
MIPS needs to ignore certain existing symbols during symbol lookup.
The old scheme uses the ELF_MACHINE_SYM_NO_MATCH macro, with an
inline function, within its own header, with a sysdeps override for
MIPS.  This allows re-use of the function from another file (without
having to include <dl-machine.h> or providing the default definition
for ELF_MACHINE_SYM_NO_MATCH).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-24 22:13:03 +02:00
Fangrui Song
eb06601bb4 elf: Support lld-style link map for librtld.map
GNU ld and gold's -Map include a line like:

  path/to/build/libc_pic.a(check_fds.os)

lld -Map does not have the archive member list, but we can still derive the
members from the following output

             VMA              LMA     Size Align Out     In      Symbol
...
           1a1c0            1a1c0       e2    16         path/to/build/libc_pic.a(check_fds.os):(.text)
2020-04-21 15:10:10 -03:00
Florian Weimer
8f7a75d700 elf: Implement DT_AUDIT, DT_DEPAUDIT support [BZ #24943]
binutils ld has supported --audit, --depaudit for a long time,
only support in glibc has been missing.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-03 16:26:10 +02:00
Florian Weimer
4c6e0415ef elf: Simplify handling of lists of audit strings
All list elements are colon-separated strings, and there is a hard
upper limit for the number of audit modules, so it is possible to
pre-allocate a fixed-size array of strings to which the LD_AUDIT
environment variable and --audit arguments are added.

Also eliminate the global variables for the audit list because
the list is only needed briefly during startup.

There is a slight behavior change: All duplicate LD_AUDIT environment
variables are now processed, not just the last one as before.  However,
such environment vectors are invalid anyway.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-03 16:26:10 +02:00
Vineet Gupta
e8a0f5831e ARC: add definitions to elf/elf.h
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2020-03-25 18:48:48 -07:00
Paul E. Murphy
d0d1811fb9 Fix tests which expose ldbl -> _Float128 redirects
The ldbl redirects for ieee128 have some jagged edges when
inspecting and manipulating symbols directly.

e.g asprintf is unconditionally redirected to __asprintfieee128
thus any tests relying on GCC's redirect behavior will encounter
problems if they inspect the symbol names too closely.

I've mitigated tests which expose the limitations of the
ldbl -> f128 redirects by giving them knowledge about the
redirected symbol names.

Hopefully there isn't much user code which depends on this
implementation specific behavior.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-03-25 14:34:23 -05:00
Jonathan Wakely
2de7fe6253 parse_tunables: Fix typo in comment 2020-03-13 10:27:23 +00:00
DJ Delorie
b7176cc2af ldconfig: trace origin paths with -v
With this patch, -v turns on a "from" trace for each directory
searched, that tells you WHY that directory is being searched -
is it a builtin, from the command line, or from some config file?
2020-03-11 16:02:05 -04:00
Adhemerval Zanella
fbaf0bae57 elf: Fix wrong indentation from commit eb447b7b4b 2020-03-10 16:11:29 -03:00
Florian Weimer
0499a353a6 elf: Add elf/check-wx-segment, a test for the presence of WX segments
Writable, executable segments defeat security hardening.  The
existing check for DT_TEXTREL does not catch this.

hppa and SPARC currently keep the PLT in an RWX load segment.
2020-03-02 14:25:20 +01:00
Florian Weimer
758599bc9d elf: Apply attribute_relro to pointers in elf/dl-minimal.c
The present code leaves the function pointers unprotected, but moves
some of the static functions into .data.rel.ro instead.  This causes
the linker to produce an allocatable, executable, writable section
and eventually an RWX load segment.  Not only do we really do not
want that, it also breaks valgrind because valgrind does not load
debuginfo from the mmap interceptor if all it sees are RX and RWX
mappings.

Fixes commit 3a0ecccb59 ("ld.so: Do not
export free/calloc/malloc/realloc functions [BZ #25486]").
2020-02-26 16:53:38 +01:00
Florian Weimer
783e641fba csu: Use ELF constructor instead of _init in libc.so
On !ELF_INITFINI architectures, _init is no longer called by the
dynamic linker.  We can use an ELF constructor instead because the
constructor order does not matter.  (The other constructors are used
to set up libio vtable bypasses and do not depend on this
initialization routine.)
2020-02-25 14:58:52 +01:00
Florian Weimer
f4349837d9 Introduce <elf-initfini.h> and ELF_INITFINI for all architectures
This supersedes the init_array sysdeps directory.  It allows us to
check for ELF_INITFINI in both C and assembler code, and skip DT_INIT
and DT_FINI processing completely on newer architectures.

A new header file is needed because <dl-machine.h> is incompatible
with assembler code.  <sysdep.h> is compatible with assembler code,
but it cannot be included in all assembler files because on some
architectures, it redefines register names, and some assembler files
conflict with that.

<elf-initfini.h> is replicated for legacy architectures which need
DT_INIT/DT_FINI support.  New architectures follow the generic default
and disable it.
2020-02-18 15:12:25 +01:00
Florian Weimer
3a0ecccb59 ld.so: Do not export free/calloc/malloc/realloc functions [BZ #25486]
Exporting functions and relying on symbol interposition from libc.so
makes the choice of implementation dependent on DT_NEEDED order, which
is not what some compiler drivers expect.

This commit replaces one magic mechanism (symbol interposition) with
another one (preprocessor-/compiler-based redirection).  This makes
the hand-over from the minimal malloc to the full malloc more
explicit.

Removing the ABI symbols is backwards-compatible because libc.so is
always in scope, and the dynamic loader will find the malloc-related
symbols there since commit f0b2132b35
("ld.so: Support moving versioned symbols between sonames
[BZ #24741]").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-02-15 11:01:23 +01:00
Florian Weimer
c76147afe9 elf: Extract _dl_sym_post, _dl_sym_find_caller_map from elf/dl-sym.c
The definitions are moved into a new file, elf/dl-sym-post.h, so that
this code can be used by the dynamic loader as well.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-02-15 11:00:45 +01:00
Florian Weimer
abcc039d2e elf: Introduce the rtld-stubbed-symbols makefile variable
This generalizes a mechanism used for stack-protector support, so
that it can be applied to other symbols if required.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-02-15 11:00:27 +01:00
David Kilroy
0a8ce6a096 elf: avoid stack allocation in dl_open_worker
As the sort was removed, there's no need to keep a separate map of
links. Instead, when relocating objects iterate over l_initfini
directly.

This allows us to remove the loop copying l_initfini elements into
map. We still need a loop to identify the first and last elements that
need relocation.

Tested by running the testsuite on x86_64.
2020-02-12 14:31:17 -03:00
David Kilroy
71bcfa6245 elf: avoid redundant sort in dlopen
l_initfini is already sorted by dependency in _dl_map_object_deps(),
so avoid sorting again in dl_open_worker().

Tested by running the testsuite on x86_64.
2020-02-12 14:30:31 -03:00
David Kilroy
eb447b7b4b elf: Allow dlopen of filter object to work [BZ #16272]
There are two fixes that are needed to be able to dlopen filter
objects. First _dl_map_object_deps cannot assume that map will be at
the beginning of l_searchlist.r_list[], as filtees are inserted before
map. Secondly dl_open_worker needs to ensure that filtees get
relocated.

In _dl_map_object_deps:

* avoiding removing relocation dependencies of map by setting
  l_reserved to 0 and otherwise processing the rest of the search
  list.

* ensure that map remains at the beginning of l_initfini - the list
  of things that need initialisation (and destruction). Do this by
  splitting the copy up. This may not be required, but matches the
  initialization order without dlopen.

Modify dl_open_worker to relocate the objects in new->l_inifini.
new->l_initfini is constructed in _dl_map_object_deps, and lists the
objects that need initialization and destruction. Originally the list
of objects in new->l_next are relocated. All of these objects should
also be included in new->l_initfini (both lists are populated with
dependencies in _dl_map_object_deps). We can't use new->l_prev to pick
up filtees, as during a recursive dlopen from an interposed malloc
call, l->prev can contain objects that are not ready for relocation.

Add tests to verify that symbols resolve to the filtee implementation
when auxiliary and filter objects are used, both as a normal link and
when dlopen'd.

Tested by running the testsuite on x86_64.
2020-02-12 14:29:48 -03:00
Fangrui Song
ec44e1efcd elf.h: Add R_RISCV_IRELATIVE
The number has been officially assigned by
https://github.com/riscv/riscv-elf-psabi-doc/pull/131
d21ca40a7f
2020-02-12 01:14:38 -05:00
Joseph Myers
d01fd5f0ce Fix elf/tst-rtld-preload cross-testing.
As noted in
<https://sourceware.org/ml/libc-alpha/2019-06/msg00824.html>,
elf/tst-rtld-preload fails when cross-testing because it attempts to
run the test wrapper with itself.  Unfortunately, that thread never
resulted in a complete and correct patch for that test.

This patch addresses the issues with that test more thoroughly.  The
test is changed not to use the wrapper twice, including updating the
message it prints about the command it runs to be more complete and
accurate after the change; the Makefile is changed not to pass the
redundant '$(test-wrapper)' argument.

Tested for Arm that this fixes the failure seen for that test in
cross-testing.
2020-01-24 17:22:13 +00:00
Joseph Myers
00167b531d Fix cross-testing of tst-ifunc-fault-* tests.
The tests elf/tst-ifunc-fault-bindnow and elf/tst-ifunc-fault-lazy
fail in cross-testing because they run the dynamic linker directly
without using the test wrapper.  This patch fixes them to use the test
wrapper instead.

Tested that this fixes the failure of those two tests for powerpc
soft-float.
2020-01-23 14:34:59 +00:00
Tulio Magno Quites Machado Filho
18363b4f01 powerpc: Move cache line size to rtld_global_ro
GCC 10.0 enabled -fno-common by default and this started to point that
__cache_line_size had been implemented in 2 different places: loader and
libc.

In order to avoid this duplication, the libc variable has been removed
and the loader variable is moved to rtld_global_ro.

File sysdeps/unix/sysv/linux/powerpc/dl-auxv.h has been added in order
to reuse code for both static and dynamic linking scenarios.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-01-17 09:05:03 -03:00
Florian Weimer
a332bd1518 elf: Add elf/tst-dlopenfail-2 [BZ #25396]
Without CET, a jump into a newly loaded object through an overwritten
link map often does not crash, it just executes some random code.
CET detects this in some cases because the function pointer does not
point to the start of a function in the replacement shared object,
so there is no ENDBR instruction.

The new test uses a small shared object and the existing dangling
link map to trigger the bug.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-16 16:53:58 +01:00
H.J. Lu
5177d85b0c Clear GL(dl_initfirst) when freeing its link_map memory [BZ# 25396]
We should clear GL(dl_initfirst) when freeing its link_map memory.

Tested on Fedora 31/x86-64 with CET.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2020-01-16 07:41:53 -08:00
Stefan Liebler
3c8639b02e Fix "elf: Add tst-ldconfig-ld_so_conf-update test" on 32bit.
This new test was introduced with recent commit
591236f1a3.
If run on 32bit, it fails while renaming tst-ldconfig-ld-mod.so as there is no
/usr/lib64 directory. This patch is constructing the file name with help of
support_libdir_prefix.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-13 11:06:41 +01:00
Alexandra Hájková
591236f1a3 elf: Add tst-ldconfig-ld_so_conf-update test
Test ldconfig after /etc/ld.so.conf update and verify a running process
 observes changes to /etc/ld.so.cache.
 The test uses the test-in-container framework.

 Reviewed-by: Arjun Shankar <arjun@redhat.com>
2020-01-09 20:47:19 +01:00
Adhemerval Zanella
1bdda52fe9 elf: Move vDSO setup to rtld (BZ#24967)
This patch moves the vDSO setup from libc to loader code, just after
the vDSO link_map setup.  For static case the initialization
is moved to _dl_non_dynamic_init instead.

Instead of using the mangled pointer, the vDSO data is set as
attribute_relro (on _rtld_global_ro for shared or _dl_vdso_* for
static).  It is read-only even with partial relro.

It fixes BZ#24967 now that the vDSO pointer is setup earlier than
malloc interposition is called.

Also, vDSO calls should not be a problem for static dlopen as
indicated by BZ#20802.  The vDSO pointer would be zero-initialized
and the syscall will be issued instead.

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
arm-linux-gnueabihf, powerpc64le-linux-gnu, powerpc64-linux-gnu,
powerpc-linux-gnu, s390x-linux-gnu, sparc64-linux-gnu, and
sparcv9-linux-gnu.  I also run some tests on mips.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-03 11:22:07 -03:00
Adhemerval Zanella
57013650f7 elf: Enable relro for static build
The code is similar to the one at elf/dl-reloc.c, where it checks for
the l_relro_size from the link_map (obtained from PT_GNU_RELRO header
from program headers) and calls_dl_protected_relro.

For testing I will use the ones proposed by Florian's patch
'elf: Add tests for working RELRO protection' [1].

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
aarch64-linux-gnu, s390x-linux-gnu, and sparc64-linux-gnu.  I also
check with --enable-static pie on x86_64-linux-gnu, i686-linux-gnu,
and aarch64-linux-gnu which seems the only architectures where
static PIE is actually working (as per 9d7a3741c9, on
arm-linux-gnueabihf, powerpc64{le}-linux-gnu, and s390x-linux-gnu
I am seeing runtime issues not related to my patch).

[1] https://sourceware.org/ml/libc-alpha/2019-10/msg00059.html

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-03 11:22:07 -03:00
Joseph Myers
5f72f9800b Update copyright dates not handled by scripts/update-copyrights.
I've updated copyright dates in glibc for 2020.  This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files.  As well as the usual annual
updates, mainly dates in --version output (minus libc.texinfo which
previously had to be handled manually but is now successfully updated
by update-copyrights), there is a fix to
sysdeps/unix/sysv/linux/powerpc/bits/termios-c_lflag.h where a typo in
the copyright notice meant it failed to be updated automatically.

Please remember to include 2020 in the dates for any new files added
in future (which means updating any existing uncommitted patches you
have that add new files to use the new copyright dates in them).
2020-01-01 00:21:22 +00:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Florian Weimer
6a265e577e Fix test isolation for elf/tst-ifunc-fault-lazy, elf/tst-ifunc-fault-bindnow
Previously, ld.so was invoked only with the elf subdirectory on the
library search path.  Since the soname link for libc.so only exists in
the top-level build directory, this leaked the system libc into the
test.
2019-12-19 16:06:50 +01:00
DJ Delorie
a059f9505b tunables: report sbrk() failure
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2019-12-16 16:51:00 -05:00
Florian Weimer
f7649d5780 dlopen: Do not block signals
Blocking signals causes issues with certain anti-malware solutions
which rely on an unblocked SIGSYS signal for system calls they
intercept.

This reverts commit a2e8aa0d9e
("Block signals during the initial part of dlopen") and adds
comments related to async signal safety to active_nodelete and
its caller.

Note that this does not make lazy binding async-signal-safe with regards
to dlopen.  It merely avoids introducing new async-signal-safety hazards
as part of the NODELETE changes.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2019-12-13 10:23:10 +01:00
Florian Weimer
f8ed116aa5 dlopen: Rework handling of pending NODELETE status
Commit a2e8aa0d9e ("Block signals during
the initial part of dlopen") was deemed necessary because of
read-modify-write operations like the one in  add_dependency in
elf/dl-lookup.c.  In the old code, we check for any kind of NODELETE
status and bail out:

      /* Redo the NODELETE check, as when dl_load_lock wasn't held
	 yet this could have changed.  */
      if (map->l_nodelete != link_map_nodelete_inactive)
	goto out;

And then set pending status (during relocation):

	  if (flags & DL_LOOKUP_FOR_RELOCATE)
	    map->l_nodelete = link_map_nodelete_pending;
	  else
	    map->l_nodelete = link_map_nodelete_active;

If a signal arrives during relocation and the signal handler, through
lazy binding, adds a global scope dependency on the same map, it will
set map->l_nodelete to link_map_nodelete_active.  This will be
overwritten with link_map_nodelete_pending by the dlopen relocation
code.

To avoid such problems in relation to the l_nodelete member, this
commit introduces two flags for active NODELETE status (irrevocable)
and pending NODELETE status (revocable until activate_nodelete is
invoked).  As a result, NODELETE processing in dlopen does not
introduce further reasons why lazy binding from signal handlers
is unsafe during dlopen, and a subsequent commit can remove signal
blocking from dlopen.

This does not address pre-existing issues (unrelated to the NODELETE
changes) which make lazy binding in a signal handler during dlopen
unsafe, such as the use of malloc in both cases.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2019-12-13 10:18:46 +01:00
Florian Weimer
365624e2d2 dlopen: Fix issues related to NODELETE handling and relocations
The assumption behind the assert in activate_nodelete was wrong:

Inconsistency detected by ld.so: dl-open.c: 459: activate_nodelete:
Assertion `!imap->l_init_called || imap->l_type != lt_loaded' failed! (edit)

It can happen that an already-loaded object that is in the local
scope is promoted to NODELETE status, via binding to a unique
symbol.

Similarly, it is possible that such NODELETE promotion occurs to
an already-loaded object from the global scope.  This is why the
loop in activate_nodelete has to cover all objects in the namespace
of the new object.

In do_lookup_unique, it could happen that the NODELETE status of
an already-loaded object was overwritten with a pending NODELETE
status.  As a result, if dlopen fails, this could cause a loss of
the NODELETE status of the affected object, eventually resulting
in an incorrect unload.

Fixes commit f63b73814f ("Remove all
loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]").
2019-12-13 10:18:24 +01:00
Florian Weimer
b5a1271c76 ldconfig: Do not print a warning for a missing ld.so.conf file
The configuration file is not needed for working system, so printing a
warning is not helpful.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2019-12-11 09:19:39 +01:00
Florian Weimer
8b196ac4b8 Expand $(as-needed) and $(no-as-needed) throughout the build system
Since commit a3cc4f48e9 ("Remove
--as-needed configure test."), --as-needed support is no longer
optional.

The macros are not much shorter and do not provide documentary
value, either, so this commit removes them.
2019-12-03 21:37:50 +01:00
Florian Weimer
4db71d2f98 elf: Do not run IFUNC resolvers for LD_DEBUG=unused [BZ #24214]
This commit adds missing skip_ifunc checks to aarch64, arm, i386,
sparc, and x86_64.  A new test case ensures that IRELATIVE IFUNC
resolvers do not run in various diagnostic modes of the dynamic
loader.

Reviewed-By: Szabolcs Nagy <szabolcs.nagy@arm.com>
2019-12-02 14:55:22 +01:00
Florian Weimer
61a7c9df71 elf/tst-dlopenfail: Disable --no-as-needed for tst-dlopenfailmod1.so
Otherwise, the shared object dependency which triggers the load
failure is dropped, invalidating the test.
2019-12-02 14:54:38 +01:00
Florian Weimer
e37c2cf299 Move _dl_open_check to its original place in dl_open_worker
This reverts the non-test change from commit d0093c5cef
("Call _dl_open_check after relocation [BZ #24259]"), given that
the underlying bug has been fixed properly in commit 61b74477fa7f63
("Remove all loaded objects if dlopen fails, ignoring NODELETE
[BZ #20839]").

Tested on x86-64-linux-gnu, with and without --enable-cet.

Change-Id: I995a6cfb89f25d2b0cf5e606428c2a93eb48fc33
2019-11-27 20:55:35 +01:00
Florian Weimer
a2e8aa0d9e Block signals during the initial part of dlopen
Lazy binding in a signal handler that interrupts a dlopen sees
intermediate dynamic linker state.  This has likely been always
unsafe, but with the new pending NODELETE state, this is clearly
incorrect.  Other threads are excluded via the loader lock, but the
current thread is not.  Blocking signals until right before ELF
constructors run is the safe thing to do.

Change-Id: Iad079080ebe7442c13313ba11dc2797953faef35
2019-11-27 20:55:35 +01:00
Florian Weimer
f63b73814f Remove all loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]
This introduces a “pending NODELETE” state in the link map, which is
flipped to the persistent NODELETE state late in dlopen, via
activate_nodelete.    During initial relocation, symbol binding
records pending NODELETE state only.  dlclose ignores pending NODELETE
state.  Taken together, this results that a partially completed dlopen
is rolled back completely because new NODELETE mappings are unloaded.

Tested on x86_64-linux-gnu and i386-linux-gnu.

Change-Id: Ib2a3d86af6f92d75baca65431d74783ee0dbc292
2019-11-27 20:55:35 +01:00
Florian Weimer
a509eb117f Avoid late dlopen failure due to scope, TLS slotinfo updates [BZ #25112]
This change splits the scope and TLS slotinfo updates in dlopen into
two parts: one to resize the data structures, and one to actually apply
the update.  The call to add_to_global_resize in dl_open_worker is moved
before the demarcation point at which no further memory allocations are
allowed.

_dl_add_to_slotinfo is adjusted to make the list update optional.  There
is some optimization possibility here because we could grow the slotinfo
list of arrays in a single call, one the largest TLS modid is known.

This commit does not fix the fatal meory allocation failure in
_dl_update_slotinfo.  Ideally, this error during dlopen should be
recoverable.

The update order of scopes and TLS data structures is retained, although
it appears to be more correct to fully initialize TLS first, and then
expose symbols in the newly loaded objects via the scope update.

Tested on x86_64-linux-gnu.

Change-Id: I240c58387dabda3ca1bcab48b02115175fa83d6c
2019-11-27 20:55:35 +01:00
Florian Weimer
440b7f8653 Avoid late failure in dlopen in global scope update [BZ #25112]
The call to add_to_global in dl_open_worker happens after running ELF
constructors for new objects.  At this point, proper recovery from
malloc failure would be quite complicated: We would have to run the
ELF destructors and close all opened objects, something that we
currently do not do.

Instead, this change splits add_to_global into two phases,
add_to_global_resize (which can raise an exception, called before ELF
constructors run), and add_to_global_update (which cannot, called
after ELF constructors).  A complication arises due to recursive
dlopen: After the inner dlopen consumes some space, the pre-allocation
in the outer dlopen may no longer be sufficient.  A new member in the
namespace structure, _ns_global_scope_pending_adds keeps track of the
maximum number of objects that need to be added to the global scope.
This enables the inner add_to_global_resize call to take into account
the needs of an outer dlopen.

Most code in the dynamic linker assumes that the number of global
scope entries fits into an unsigned int (matching the r_nlist member
of struct r_scop_elem).  Therefore, change the type of
_ns_global_scope_alloc to unsigned int (from size_t), and add overflow
checks.

Change-Id: Ie08e2f318510d5a6a4bcb1c315f46791b5b77524
2019-11-27 20:55:35 +01:00
Florian Weimer
79e0cd7b3c Lazy binding failures during dlopen/dlclose must be fatal [BZ #24304]
If a lazy binding failure happens during the execution of an ELF
constructor or destructor, the dynamic loader catches the error
and reports it using the dlerror mechanism.  This is undesirable
because there could be other constructors and destructors that
need processing (which are skipped), and the process is in an
inconsistent state at this point.  Therefore, we have to issue
a fatal dynamic loader error error and terminate the process.

Note that the _dl_catch_exception in _dl_open is just an inner catch,
to roll back some state locally.  If called from dlopen, there is
still an outer catch, which is why calling _dl_init via call_dl_init
and a no-exception is required and cannot be avoiding by moving the
_dl_init call directly into _dl_open.

_dl_fini does not need changes because it does not install an error
handler, so errors are already fatal there.

Change-Id: I6b1addfe2e30f50a1781595f046f44173db9491a
2019-11-27 20:55:35 +01:00
Florian Weimer
4a2ab5843a dlsym: Do not determine caller link map if not needed
Obtaining the link map is potentially very slow because it requires
iterating over all loaded objects in the current implementation.  If
the caller supplied an explicit handle (i.e., not one of the RTLD_*
constants), the dlsym implementation does not need the identity of the
caller (except in the special case of auditing), so this change
avoids computing it in that case.

Even in the minimal case (dlsym called from a main program linked with
-dl), this shows a small speedup, perhaps around five percent.  The
performance improvement can be arbitrarily large in principle (if
_dl_find_dso_for_object has to iterate over many link maps).

Change-Id: Ide5d9e2cc7ac25a0ffae8fb4c26def0c898efa29
2019-11-27 20:19:22 +01:00
Sandra Loosemore
c72e5cd87d Compile elf/rtld.c with -fno-tree-loop-distribute-patterns.
In GCC 10, the default at -O2 is now -ftree-loop-distribute-patterns.
This optimization causes GCC to "helpfully" convert the hand-written
loop in _dl_start into a call to memset, which is not available that
early in program startup.  Similar problems in other places in GLIBC
have been addressed by explicitly building with
-fno-tree-loop-distribute-patterns, but this one may have been
overlooked previously because it only affects targets where
HAVE_BUILTIN_MEMSET is not defined.

This patch fixes a bug observed on nios2-linux-gnu target that caused
all programs to segv on startup.
2019-11-26 19:18:23 +01:00
Florian Weimer
fcb04b9aed Introduce DL_LOOKUP_FOR_RELOCATE flag for _dl_lookup_symbol_x
This will allow changes in dependency processing during non-lazy
binding, for more precise processing of NODELETE objects: During
initial relocation in dlopen, the fate of NODELETE objects is still
unclear, so objects which are depended upon by NODELETE objects
cannot immediately be marked as NODELETE.

Change-Id: Ic7b94a3f7c4719a00ca8e6018088567824da0658
2019-11-21 13:31:29 +01:00
Florian Weimer
2a764c6ee8 Enhance _dl_catch_exception to allow disabling exception handling
In some cases, it is necessary to introduce noexcept regions
where raised dynamic loader exceptions (e.g., from lazy binding)
are fatal, despite being nested in a code region with an active
exception handler.  This change enhances _dl_catch_exception with
to provide such a capability.  The existing function is reused,
so that it is not necessary to introduce yet another function with
a similar purpose.

Change-Id: Iec1bf642ff95a349fdde8040e9baf851ac7b8904
2019-11-16 15:57:01 +01:00
Florian Weimer
e1d559f337 Introduce link_map_audit_state accessor function
To improve GCC 10 compatibility, it is necessary to remove the l_audit
zero-length array from the end of struct link_map.  In preparation of
that, this commit introduces an accessor function for the audit state,
so that it is possible to change the representation of the audit state
without adjusting the code that accesses it.

Tested on x86_64-linux-gnu.  Built on i686-gnu.

Change-Id: Id815673c29950fc011ae5301d7cde12624f658df
2019-11-15 13:03:40 +01:00
Florian Weimer
c7bf5ceab6 Properly initialize audit cookie for the dynamic loader [BZ #25157]
The l_audit array is indexed by audit module, not audit function.

Change-Id: I180eb3573dc1c57433750f5d8cb18271460ba5f2
2019-11-15 13:03:32 +01:00
Florian Weimer
ca136bb0a3 Clarify purpose of assert in _dl_lookup_symbol_x
Only one of the currently defined flags is incompatible with versioned
symbol lookups, so it makes sense to check for that flag and not its
complement.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Change-Id: I3384349cef90cfd91862ebc34a4053f0c0a99404
2019-11-12 20:11:04 +01:00
Leandro Pereira
95c1056962 elf: Use nocancel pread64() instead of lseek()+read()
Transforms this, when linking in a shared object:

  openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
  read(3, "\177ELF\2\1\1\3"..., 832) = 832
  lseek(3, 792, SEEK_SET)           = 792
  read(3, "\4\0\0\0\24\0\0\0"..., 68) = 68
  fstat(3, {st_mode=S_IFREG|0755, st_size=6699224, ...}) = 0
  lseek(3, 792, SEEK_SET)           = 792
  read(3, "\4\0\0\0\24\0\0\0"..., 68) = 68
  lseek(3, 864, SEEK_SET)           = 864
  read(3, "\4\0\0\0\20\0\0\0"..., 32) = 32

Into this:

  openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
  read(3, "\177ELF\2\1\1\3"..., 832) = 832
  pread(3, "\4\0\0\0\24\0\0\0"..., 68, 792) = 68
  fstat(3, {st_mode=S_IFREG|0755, st_size=6699224, ...}) = 0
  pread(3, "\4\0\0\0\24\0\0\0"..., 68, 792) = 68
  pread(3, "\4\0\0\0\20\0\0\0"..., 32, 864) = 32

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2019-10-18 15:55:33 -04:00
Florian Weimer
7d3db434f9 Rename and split elf/tst-dlopen-aout collection of tests
From the beginning, elf/tst-dlopen-aout has exercised two different
bugs: (a) failure to report errors for a dlopen of the executable
itself in some cases (bug 24900) and (b) incorrect rollback of the
TLS modid allocation in case of a dlopen failure (bug 16634).

This commit replaces the test with elf/tst-dlopen-self for (a) and
elf/tst-dlopen-tlsmodid for (b).  The latter tests use the
elf/tst-dlopen-self binaries (or iconv) with dlopen, so they are
no longer self-dlopen tests.

Tested on x86_64-linux-gnu and i686-linux-gnu, with a toolchain that
does not default to PIE.
2019-10-17 08:51:21 +02:00
Andreas Schwab
58e8f5fd2b ldconfig: handle .dynstr located in separate segment (bug 25087)
To determine the load offset of the DT_STRTAB section search for the
segment containing it, instead of using the load offset of the first
segment.
2019-10-16 15:54:44 +02:00
Florian Weimer
e7c8ffe4ec ldd: Print "not a dynamic executable" on standard error [BZ #24150]
Tested with the testsuite on x86_64-linux-gnu, and manually.

Reviewed-By: Richard W.M. Jones <rjones@redhat.com>
2019-10-15 16:41:51 +02:00
Andreas Schwab
8a3ca0fdd3 Simplify note processing
This removes dead code during note processing.
2019-10-10 13:01:38 +02:00
Florian Weimer
77523d5e43 elf: Assign TLS modid later during dlopen [BZ #24930]
Commit a42faf59d6 ("Fix BZ #16634.")
attempted to fix a TLS modid consistency issue by adding additional
checks to the open_verify function.  However, this is fragile
because open_verify cannot reliably predict whether
_dl_map_object_from_fd will later fail in the more complex cases
(such as memory allocation failures).  Therefore, this commit
assigns the TLS modid as late as possible.  At that point, the link
map pointer will eventually be passed to _dl_close, which will undo
the TLS modid assignment.

Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
2019-10-04 21:23:51 +02:00
Florian Weimer
2b26b084e4 elf: Never use the file ID of the main executable [BZ #24900]
If the loader is invoked explicitly and loads the main executable,
it stores the file ID of the main executable in l_file_id.  This
information is not available if the main excutable is loaded by the
kernel, so this is another case where the two cases differ.

This enhances commit 23d2e5faf0
("elf: Self-dlopen failure with explict loader invocation
[BZ #24900]").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
2019-10-04 21:22:54 +02:00
Stefan Liebler
2f9046fb05 Add UNSUPPORTED check in elf/tst-pldd.
The testcase forks a child process and runs pldd with PID of
this child.  On systems where /proc/sys/kernel/yama/ptrace_scope
differs from zero, pldd will fail with
/usr/bin/pldd: cannot attach to process 3: Operation not permitted

This patch checks if ptrace_scope exists, is zero "classic ptrace permissions"
or one "restricted ptrace".  If ptrace_scope exists and has a higher
restriction, then the test is marked as UNSUPPORTED.

The case "restricted ptrace" is handled by rearranging the processes involved
during the test.  Now we have the following process tree:
-parent: do_test (performs output checks)
--subprocess 1: pldd_process (becomes pldd via execve)
---subprocess 2: target_process (ptraced via pldd)

ChangeLog:

	* elf/tst-pldd.c (do_test): Add UNSUPPORTED check.
	Rearrange subprocesses.
	(pldd_process): New function.
	* support/Makefile (libsupport-routines): Add support_ptrace.
	* support/xptrace.h: New file.
	* support/support_ptrace.c: Likewise.
2019-09-18 12:42:39 +02:00
Paul Eggert
5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00
Mihailo Stojanovic
23c1c256ae MIPS support for GNU hash
This patch is a reimplementation of [1], which was submitted back in
2015. Copyright issue has been sorted [2] last year. It proposed a new
section (.gnu.xhash) and related dynamic tag (GT_GNU_XHASH). The new
section would be virtually identical to the existing .gnu.hash except
for the translation table (xlat) which would contain correct MIPS
.dynsym indexes corresponding to the hashvals in chains. This is because
MIPS ABI imposes a different ordering of the dynsyms than the one
expected by the .gnu.hash section. Another addition would be a leading
word at the beggining of the section, which would contain the number of
entries in the translation table.

In this patch, the new section name and dynamic tag are changed to
reflect the fact that the section should be treated as MIPS specific
(.MIPS.xhash and DT_MIPS_XHASH).

This patch addresses the alignment issue reported in [3] which is caused
by the leading word of the .MIPS.xhash section. Leading word is now
removed in the corresponding binutils patch, and the number of entries
in the translation table is computed using DT_MIPS_SYMTABNO dynamic tag.

Since the MIPS specific dl-lookup.c file was removed following the
initial patch submission, I opted for the definition of three new macros
in the generic ldsodefs.h. ELF_MACHINE_GNU_HASH_ADDRIDX defines the
index of the dynamic tag in the l_info array. ELF_MACHINE_HASH_SYMIDX is
used to calculate the index of a symbol in GNU hash. On MIPS, it is
defined to look up the symbol index in the translation table.
ELF_MACHINE_XHASH_SETUP is defined for MIPS only. It initializes the
.MIPS.xhash pointer in the link_map_machine struct.

The other major change is bumping the highest EI_ABIVERSION value for
MIPS to suggest that the dynamic linker now supports GNU hash.

The patch was tested by running the glibc testsuite for the three MIPS
ABIs (o32, n32 and n64) and for x86_64-linux-gnu.

[1] https://sourceware.org/ml/binutils/2015-10/msg00057.html
[2] https://sourceware.org/ml/binutils/2018-03/msg00025.html
[3] https://sourceware.org/ml/binutils/2016-01/msg00006.html

	* elf/dl-addr.c (determine_info): Calculate the symbol index
	using the newly defined ELF_MACHINE_HASH_SYMIDX macro.
	* elf/dl-lookup.c (do_lookup_x): Ditto.
	(_dl_setup_hash): Initialize MIPS xhash translation table.
	* elf/elf.h (SHT_MIPS_XHASH): New define.
	(DT_MIPS_XHASH): New define.
	* sysdeps/generic/ldsodefs.h (ELF_MACHINE_GNU_HASH_ADDRIDX): New
	define.
	(ELF_MACHINE_HASH_SYMIDX): Ditto.
	(ELF_MACHINE_XHASH_SETUP): Ditto.
	* sysdeps/mips/ldsodefs.h (ELF_MACHINE_GNU_HASH_ADDRIDX): New
	define.
	(ELF_MACHINE_HASH_SYMIDX): Ditto.
	(ELF_MACHINE_XHASH_SETUP): Ditto.
	* sysdeps/mips/linkmap.h (struct link_map_machine): New member.
	* sysdeps/unix/sysv/linux/mips/ldsodefs.h: Increment valid ABI
	version.
	* sysdeps/unix/sysv/linux/mips/libc-abis: New ABI version.
2019-08-29 20:11:42 +00:00
Florian Weimer
23d2e5faf0 elf: Self-dlopen failure with explict loader invocation [BZ #24900]
In case of an explicit loader invocation, ld.so essentially performs
a dlopen call to load the main executable.  Since the pathname of
the executable is known at this point, it gets stored in the link
map.  In regular mode, the pathname is not known and "" is used
instead.

As a result, if a program calls dlopen on the pathname of the main
program, the dlopen call succeeds and returns a handle for the main
map.  This results in an unnecessary difference between glibc
testing (without --enable-hardcoded-path-in-tests) and production
usage.

This commit discards the names when building the link map in
_dl_new_object for the main executable, but it still determines
the origin at this point in case of an explict loader invocation.
The reason is that the specified pathname has to be used; the kernel
has a different notion of the main executable.
2019-08-15 18:53:32 +02:00
Florian Weimer
9b9670fcd8 elf: Support elf/tst-dlopen-aout in more configurations
dlopen can no longer open PIE binaries, so it is not necessary
to link the executable as non-PIE to trigger a dlopen failure.

If we hard-code the path to the real executable, we can run the test
with and without hard-coded paths because the dlopen path will not
be recognized as the main program in both cases.  (With an explict
loader invocation, the loader currently adds argv[0] to l_libname
for the main map and the dlopen call suceeds as a result; it does
not do that in standard mode.)
2019-08-12 17:59:13 +02:00
DJ Delorie
c48d92b430 Add glibc.malloc.mxfast tunable
* elf/dl-tunables.list: Add glibc.malloc.mxfast.
* manual/tunables.texi: Document it.
* malloc/malloc.c (do_set_mxfast): New.
(__libc_mallopt): Call it.
* malloc/arena.c: Add mxfast tunable.
* malloc/tst-mxfast.c: New.
* malloc/Makefile: Add it.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2019-08-09 14:04:03 -04:00
Alexandra Hájková
a6c1ce778e elf: tst-ldconfig-bad-aux-cache: use support_capture_subprocess 2019-08-05 13:18:57 +02:00
H.J. Lu
d0093c5cef Call _dl_open_check after relocation [BZ #24259]
This is a workaround for [BZ #20839] which doesn't remove the NODELETE
object when _dl_open_check throws an exception.  Move it after relocation
in dl_open_worker to avoid leaving the NODELETE object mapped without
relocation.

	[BZ #24259]
	* elf/dl-open.c (dl_open_worker): Call _dl_open_check after
	relocation.
	* sysdeps/x86/Makefile (tests): Add tst-cet-legacy-5a,
	tst-cet-legacy-5b, tst-cet-legacy-6a and tst-cet-legacy-6b.
	(modules-names): Add tst-cet-legacy-mod-5a, tst-cet-legacy-mod-5b,
	tst-cet-legacy-mod-5c, tst-cet-legacy-mod-6a, tst-cet-legacy-mod-6b
	and tst-cet-legacy-mod-6c.
	(CFLAGS-tst-cet-legacy-5a.c): New.
	(CFLAGS-tst-cet-legacy-5b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-5a.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-5b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-5c.c): Likewise.
	(CFLAGS-tst-cet-legacy-6a.c): Likewise.
	(CFLAGS-tst-cet-legacy-6b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-6a.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-6b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-6c.c): Likewise.
	($(objpfx)tst-cet-legacy-5a): Likewise.
	($(objpfx)tst-cet-legacy-5a.out): Likewise.
	($(objpfx)tst-cet-legacy-mod-5a.so): Likewise.
	($(objpfx)tst-cet-legacy-mod-5b.so): Likewise.
	($(objpfx)tst-cet-legacy-5b): Likewise.
	($(objpfx)tst-cet-legacy-5b.out): Likewise.
	(tst-cet-legacy-5b-ENV): Likewise.
	($(objpfx)tst-cet-legacy-6a): Likewise.
	($(objpfx)tst-cet-legacy-6a.out): Likewise.
	($(objpfx)tst-cet-legacy-mod-6a.so): Likewise.
	($(objpfx)tst-cet-legacy-mod-6b.so): Likewise.
	($(objpfx)tst-cet-legacy-6b): Likewise.
	($(objpfx)tst-cet-legacy-6b.out): Likewise.
	(tst-cet-legacy-6b-ENV): Likewise.
	* sysdeps/x86/tst-cet-legacy-5.c: New file.
	* sysdeps/x86/tst-cet-legacy-5a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-5b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-6.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-6a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-6b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5c.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6c.c: Likewise.
2019-07-01 12:23:22 -07:00
Florian Weimer
f0b2132b35 ld.so: Support moving versioned symbols between sonames [BZ #24741]
This change should be fully backwards-compatible because the old
code aborted the load if a soname mismatch was encountered
(instead of searching further for a matching symbol).  This means
that no different symbols are found.

The soname check was explicitly disabled for the skip_map != NULL
case.  However, this only happens with dl(v)sym and RTLD_NEXT,
and those lookups do not come with a verneed entry that could be used
for the check.

The error check was already explicitly disabled for the skip_map !=
NULL case, that is, when dl(v)sym was called with RTLD_NEXT.  But
_dl_vsym always sets filename in the struct r_found_version argument
to NULL, so the check was not active anyway.  This means that
symbol lookup results for the skip_map != NULL case do not change,
either.
2019-06-28 10:15:38 +02:00
Florian Weimer
2c75b545de elf: Refuse to dlopen PIE objects [BZ #24323]
Another executable has already been mapped, so the dynamic linker
cannot perform relocations correctly for the second executable.
2019-06-18 16:42:10 +02:00
Szabolcs Nagy
55f82d328d aarch64: add STO_AARCH64_VARIANT_PCS and DT_AARCH64_VARIANT_PCS
STO_AARCH64_VARIANT_PCS is a non-visibility st_other flag for marking
symbols that reference functions that may follow a variant PCS with
different register usage convention from the base PCS.

DT_AARCH64_VARIANT_PCS is a dynamic tag that marks ELF modules that
have R_*_JUMP_SLOT relocations for symbols marked with
STO_AARCH64_VARIANT_PCS (i.e. have variant PCS calls via a PLT).

	* elf/elf.h (STO_AARCH64_VARIANT_PCS): Define.
	(DT_AARCH64_VARIANT_PCS): Define.
2019-06-13 09:44:44 +01:00
Alexandra Hájková
481c30cb95 elf: Add tst-ldconfig-bad-aux-cache test [BZ #18093]
This test corrupts /var/cache/ldconfig/aux-cache and executes ldconfig
to check it will not segfault using the corrupted aux_cache. The test
uses the test-in-container framework. Verified no regressions on
x86_64.
2019-05-23 11:49:44 +02:00
Joseph Myers
1388600877 Add NT_ARM_PACA_KEYS and NT_ARM_PACG_KEYS from Linux 5.1 to elf.h.
This patch adds the new NT_ARM_PACA_KEYS and NT_ARM_PACG_KEYS from
Linux 5.1 to glibc's elf.h.

Tested for x86_64.

	* elf/elf.h (NT_ARM_PACA_KEYS): New macro.
	(NT_ARM_PACG_KEYS): Likewise.
2019-05-20 11:51:58 +00:00
Adhemerval Zanella
da2b83ef6b elf: Fix tst-pldd for non-default --prefix and/or --bindir (BZ#24544)
Use a new libsupport support_bindir_prefix instead of a hardcoded
/usr/bin to create the pldd path on container directory.

Checked on x86_64-linux-gnu with default and non-default --prefix and
--bindir paths, as well with --enable-hardcoded-path-in-tests.

	[BZ #24544]
	* elf/tst-pldd.c (do_test): Use support_bindir_prefix instead of
	pre-defined value.

Reviewed-by: DJ Delorie <dj@redhat.com>
2019-05-14 11:04:41 -03:00
Adhemerval Zanella
b2af6fb2ed elf: Fix elf/tst-pldd with --enable-hardcoded-path-in-tests (BZ#24506)
The elf/tst-pldd (added by 1a4c27355e to fix BZ#18035) test does
not expect the hardcoded paths that are output by pldd when the test
is built with --enable-hardcoded-path-in-tests.  Instead of showing
the ABI installed library names for loader and libc (such as
ld-linux-x86-64.so.2 and libc.so.6 for x86_64), pldd shows the default
built ld.so and libc.so.

It makes the tests fail with an invalid expected loader/libc name.

This patch fixes the elf-pldd test by adding the canonical ld.so and
libc.so names in the expected list of possible outputs when parsing
the result output from pldd.  The test now handles both default
build and --enable-hardcoded-path-in-tests option.

Checked on x86_64-linux-gnu (built with and without
--enable-hardcoded-path-in-tests) and i686-linux-gnu.

	* elf/tst-pldd.c (in_str_list): New function.
	(do_test): Add default names for ld and libc as one option.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2019-05-02 08:44:12 -03:00