The child process of the tst-env-setuid process was failing correctly
with EXIT_UNSUPPORTED but the parent did not carry that status forward
and failed instead. This patch fixes this so that tests on nosuid
/tmp fails gracefully with UNSUPPORTED. Tested by making my tmpfs
nosuid.
* elf/tst-env-setuid.c (do_execve): Return EXIT_UNSUPPORTED in
parent if child exited in that manner. Print WEXITSTATUS
instead of the raw status.
(do_test_prep): Rename to do_test.
(do_test): Return the result of run_executable_sgid.
(TEST_FUNCTION_ARGV): Adjust.
In _dl_nothread_init_static_tls() and init_one_static_tls() we must not
touch the DTV of other threads since we do not have ownership of them.
The DTV need not be initialized at this point anyway since only LD/GD
accesses will use them. If LD/GD accesses occur they will take care to
initialize their own thread's DTV.
Concurrency comments were removed from the patch since they need to be
reworked along with a full description of DTV ownership and when it is
or is not safe to modify these structures.
Alexandre Oliva's original patch and discussion:
https://sourceware.org/ml/libc-alpha/2016-09/msg00512.html
A setxid program that uses a glibc with tunables disabled may pass on
GLIBC_TUNABLES as is to its child processes. If the child process
ends up using a different glibc that has tunables enabled, it will end
up getting access to unsafe tunables. To fix this, remove
GLIBC_TUNABLES from the environment for setxid process.
* sysdeps/generic/unsecvars.h: Add GLIBC_TUNABLES.
* elf/tst-env-setuid-tunables.c
(test_child_tunables)[!HAVE_TUNABLES]: Verify that
GLIBC_TUNABLES is removed in a setgid process.
Florian Weimer pointed out that we have three different kinds of
environment variables (and hence tunables):
1. Variables that are removed for setxid processes
2. Variables that are ignored in setxid processes but is passed on to
child processes
3. Variables that are passed on to child processes all the time
Tunables currently only does (2) and (3) when it should be doing (1)
for MALLOC_CHECK_. This patch enhances the is_secure flag in tunables
to an enum value that can specify which of the above three categories
the tunable (and its envvar alias) belongs to.
The default is for tunables to be in (1). Hence, all of the malloc
tunables barring MALLOC_CHECK_ are explicitly specified to belong to
category (2). There were discussions around abolishing category (2)
completely but we can do that as a separate exercise in 2.26.
Tested on x86_64 to verify that there are no regressions.
[BZ #21073]
* elf/dl-tunable-types.h (tunable_seclevel_t): New enum.
* elf/dl-tunables.c (tunables_strdup): Remove.
(get_next_env): Also return the previous envp.
(parse_tunables): Erase tunables of category
TUNABLES_SECLEVEL_SXID_ERASE.
(maybe_enable_malloc_check): Make MALLOC_CHECK_
TUNABLE_SECLEVEL_NONE if /etc/setuid-debug is accessible.
(__tunables_init)[TUNABLES_FRONTEND ==
TUNABLES_FRONTEND_valstring]: Update GLIBC_TUNABLES envvar
after parsing.
[TUNABLES_FRONTEND != TUNABLES_FRONTEND_valstring]: Erase
tunable envvars of category TUNABLES_SECLEVEL_SXID_ERASE.
* elf/dl-tunables.h (struct _tunable): Change member is_secure
to security_level.
* elf/dl-tunables.list: Add security_level annotations for all
tunables.
* scripts/gen-tunables.awk: Recognize and generate enum values
for security_level.
* elf/tst-env-setuid.c: New test case.
* elf/tst-env-setuid-tunables: new test case.
* elf/Makefile (tests-static): Add them.
(tunable_set_val_if_valid_range_signed) ... this, and ...
(tunable_set_val_if_valid_range_unsigned) ... this.
(tunable_initialize): Call the correct one of the above based on type.
The condition when the value of an envvar is empty (not just '\0'),
the loop in tunables_init gets stuck infinitely because envp is not
incremented. Fix that by always incrementing envp in the loop.
Added test case (tst-empty-env.c) verifies the fix when the source is
configured with --enable-hardcoded-path-in-tests, thanks Josh Stone for
providing the test case. Verified on x86_64.
* elf/dl-tunables (get_next_env): Always advance envp.
* stdlib/tst-empty-env.c: New test case.
* stdlib/Makefile (tests): Use it.
Building 64-bit glibc with GCC mainline fails with:
../elf/sotruss-lib.c: In function 'la_version':
../elf/sotruss-lib.c:91:28: error: '%lu' directive output may be truncated writing between 1 and 20 bytes into a region of size 11 [-Werror=format-truncation=]
snprintf (endp, 12, ".%lu", (unsigned long int) pid);
^~~
../elf/sotruss-lib.c:91:26: note: using the range [1, 18446744073709551615] for directive argument
snprintf (endp, 12, ".%lu", (unsigned long int) pid);
^~~~~~
../elf/sotruss-lib.c:91:6: note: format output between 3 and 22 bytes into a destination of size 12
snprintf (endp, 12, ".%lu", (unsigned long int) pid);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Pids from getpid cannot actually be negative, but the compiler doesn't
know this. Other places in this file use (signed) long int for
printing, so this patch makes this place do so as well. Then it
increases the buffer size by one byte to allow for the minus sign that
can't actually occur. It doesn't seem worth using diagnostic pragmas
to save one byte; other place in this file just use a cruder 3 *
sizeof (pid_t) calculation for number of digits.
Tested with GCC mainline with compilation for aarch64 with
build-many-glibcs.py, and with glibc testsuite for x86_64 (built with
GCC 6).
* elf/sotruss-lib.c (init): Increase space allocated for pid by
one byte. Print it with %ld, cast to long int.
Builds with --enable-tunables failed on i686 because a call to getenv
got snuck into tunables, which pulled in strncmp. This patch fixes
this build failure by making the glibc.malloc.check check even
simpler. The previous approach was convoluted where the tunable was
disabled using an unsetenv and overwriting the tunable value with
colons. The easier way is to simply mark the tunable as insecure by
default (i.e. won't be read for AT_SECURE programs) and then enabled
only when the /etc/suid-debug file is found.
This also ends up removing a bunch of functions that were specially
reimplemented (strlen, unsetenv) to avoid calling into string
routines.
Tested on x86_64 and i686.
* elf/dl-tunables.c (tunables_unsetenv): Remove function.
(min_strlen): Likewise.
(disable_tunable): Likewise.
(maybe_disable_malloc_check): Rename to
maybe_enable_malloc_check.
(maybe_enable_malloc_check): Enable glibc.malloc.check tunable
if /etc/suid-debug file exists.
(__tunables_init): Update caller.
* elf/dl-tunables.list (glibc.malloc.check): Don't mark as
secure.
This patch increases timeouts on some tests I've observed timing out.
elf/tst-tls13 and iconvdata/tst-loading both dynamically load many
objects and so are slow when testing over NFS. They had timeouts set
from before the default changed from 2 to 20 seconds; this patch
removes those old settings, so effectively increasing the timeout to
20 seconds (from 3 and 10 seconds respectively).
malloc/tst-malloc-thread-fail.c and malloc/tst-mallocfork2.c are slow
on slow systems and so I set a fairly arbitrary 100 second timeout,
which seems to suffice on the system where I saw them timing out.
nss/tst-cancel-getpwuid_r.c and nss/tst-nss-getpwent.c are slow on
systems with a large passwd file; I set timeouts that empirically
worked for me. (It seems tst-cancel-getpwuid_r.c is hitting the
100000 getpwuid_r call limit in my testing, with each call taking a
bit over 0.007 seconds, so 700 seconds for the test.)
* elf/tst-tls13.c (TIMEOUT): Remove.
* iconvdata/tst-loading.c (TIMEOUT): Likewise.
* malloc/tst-malloc-thread-fail.c (TIMEOUT): Increase to 100.
* malloc/tst-mallocfork2.c (TIMEOUT): Define to 100.
* nss/tst-cancel-getpwuid_r.c (TIMEOUT): Define to 900.
* nss/tst-nss-getpwent.c (TIMEOUT): Define to 300.
elf/Makefile passes arguments to tst-ldconfig-X.sh that are different
from what it expects, so resulting in the test failing in cross
testing. This patch corrects the arguments passed (the script itself
has correct logic for cross testing, it's just the Makefile that's
wrong).
Tested for powerpc (cross testing) and for x86_64 (native testing).
* elf/Makefile ($(objpfx)tst-ldconfig-X.out): Correct arguments
passed to tst-ldconfig-X.sh.
At the GNU Tools Cauldron 2016, the state of the current tunables
patchset was considered OK with the addition of a way to select the
frontend to be used for the tunables. That is, to avoid being locked
in to one type of frontend initially, it should be possible to build
tunables with a different frontend with something as simple as a
configure switch.
To that effect, this patch enhances the --enable-tunables option to
accept more values than just 'yes' or 'no'. The current frontend (and
default when enable-tunables is 'yes') is called 'valstring', to
select the frontend where a single environment variable is set to a
colon-separated value string. More such frontends can be added in
future.
* Makeconfig (have-tunables): Check for non-negative instead
of positive.
* configure.ac: Add 'valstring' as a valid value for
--enable-tunables.
* configure: Regenerate.
* elf/Makefile (have-tunables): Check for non-negative instead
of positive.
(CPPFLAGS-dl-tunables.c): Define TUNABLES_FRONTEND for
dl-tunables.c.
* elf/dl-tunables.c (GLIBC_TUNABLES): Define only when
TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring.
(tunables_strdup): Likewise.
(disable_tunables): Likewise.
(parse_tunables): Likewise.
(__tunables_init): Process GLIBC_TUNABLES envvar only when.
TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring.
* elf/dl-tunables.h (TUNABLES_FRONTEND_valstring): New macro.
(TUNABLES_FRONTEND_yes): New macro, define as
TUNABLES_FRONTEND_valstring by default.
* manual/install.texi: Document new acceptable values for
--enable-tunables.
* INSTALL: Regenerate.
Read tunables values from the users using the GLIBC_TUNABLES
environment variable. The value of this variable is a colon-separated
list of name=value pairs. So a typical string would look like this:
GLIBC_TUNABLES=glibc.malloc.mmap_threshold=2048:glibc.malloc.trim_threshold=1024
* config.make.in (have-loop-to-function): Define.
* elf/Makefile (CFLAGS-dl-tunables.c): Add
-fno-tree-loop-distribute-patterns.
* elf/dl-tunables.c: Include libc-internals.h.
(GLIBC_TUNABLES): New macro.
(tunables_strdup): New function.
(parse_tunables): New function.
(min_strlen): New function.
(__tunables_init): Use the new functions and macro.
(disable_tunable): Disable tunable from GLIBC_TUNABLES.
* malloc/tst-malloc-usable-tunables.c: New test case.
* malloc/tst-malloc-usable-static-tunables.c: New test case.
* malloc/Makefile (tests, tests-static): Add tests.
The tunables framework allows us to uniformly manage and expose global
variables inside glibc as switches to users. tunables/README has
instructions for glibc developers to add new tunables.
Tunables support can be enabled by passing the --enable-tunables
configure flag to the configure script. This patch only adds a
framework and does not pose any limitations on how tunable values are
read from the user. It also adds environment variables used in malloc
behaviour tweaking to the tunables framework as a PoC of the
compatibility interface.
* manual/install.texi: Add --enable-tunables option.
* INSTALL: Regenerate.
* README.tunables: New file.
* Makeconfig (CPPFLAGS): Define TOP_NAMESPACE.
(before-compile): Generate dl-tunable-list.h early.
* config.h.in: Add HAVE_TUNABLES.
* config.make.in: Add have-tunables.
* configure.ac: Add --enable-tunables option.
* configure: Regenerate.
* csu/init-first.c (__libc_init_first): Move
__libc_init_secure earlier...
* csu/init-first.c (LIBC_START_MAIN):... to here.
Include dl-tunables.h, libc-internal.h.
(LIBC_START_MAIN) [!SHARED]: Initialize tunables for static
binaries.
* elf/Makefile (dl-routines): Add dl-tunables.
* elf/Versions (ld): Add __tunable_set_val to GLIBC_PRIVATE
namespace.
* elf/dl-support (_dl_nondynamic_init): Unset MALLOC_CHECK_
only when !HAVE_TUNABLES.
* elf/rtld.c (process_envvars): Likewise.
* elf/dl-sysdep.c [HAVE_TUNABLES]: Include dl-tunables.h
(_dl_sysdep_start): Call __tunables_init.
* elf/dl-tunable-types.h: New file.
* elf/dl-tunables.c: New file.
* elf/dl-tunables.h: New file.
* elf/dl-tunables.list: New file.
* malloc/tst-malloc-usable-static.c: New test case.
* malloc/Makefile (tests-static): Add it.
* malloc/arena.c [HAVE_TUNABLES]: Include dl-tunables.h.
Define TUNABLE_NAMESPACE.
(DL_TUNABLE_CALLBACK (set_mallopt_check)): New function.
(DL_TUNABLE_CALLBACK_FNDECL): New macro. Use it to define
callback functions.
(ptmalloc_init): Set tunable values.
* scripts/gen-tunables.awk: New file.
* sysdeps/mach/hurd/dl-sysdep.c: Include dl-tunables.h.
(_dl_sysdep_start): Call __tunables_init.
The previous commit prevented rtld itself from being built with
-fstack-protector, but this is not quite enough. We identify which
objects belong in rtld via a test link and analysis of the resulting
mapfile. That link is necessarily done against objects that are
stack-protected, so drags in __stack_chk_fail_local, __stack_chk_fail,
and all the libc and libio code they use.
To stop this happening, use --defsym in the test librtld.map-production
link to force the linker to predefine these two symbols (to 0, but it
could be to anything). (In a real link, this would of course be
catastrophic, but these object files are never used for anything else.)
When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.
We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves. (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
There is at least one use case where during exit a library destructor
might call dlclose() on a valid handle and have it fail with an
assertion. We must allow this case, it is a valid handle, and dlclose()
should not fail with an assert. In the future we might be able to return
an error that the dlclose() could not be completed because the opened
library has already been unloaded and destructors have run as part of
exit processing.
For more details see:
https://www.sourceware.org/ml/libc-alpha/2016-12/msg00859.html
Commit 7a5e3d9d63 (elf: Assume TLS is
initialized in _dl_map_object_from_fd) removed the last call of
_dl_tls_setup, but did not remove the function itself.
The new test driver in <support/test-driver.c> has feature parity with
the old one. The main difference is that its hooking mechanism is
based on functions and function pointers instead of macros. This
commit also implements a new environment variable, TEST_COREDUMPS,
which disables the code which disables coredumps (that is, it enables
them if the invocation environment has not disabled them).
<test-skeleton.c> defines wrapper functions so that it is possible to
use existing macros with the new-style hook functionality.
This commit changes only a few test cases to the new test driver, to
make sure that it works as expected.
Some configurations may use NSS cryptographic routines but have no
static library for those routines. The following changes allow glibc to
be built and tested with --enable-nss-crypt, but without having a static
NSS library. At a high level the change does two things:
(1) Detect at configure time if static NSS crypto libraries are
available. Assumes libfreebl3.a (instead of the existing Fedora
libfreebl.a which is incomplete) which matches libfreebl3.so.
(2) If static NSS crypto libraries are _not_ available then adjust the
way in which we build tst-linkall-static. This includes excluding a
reference to crypt and not linking against libcrypt.a, all of which
will fail otherwise.
Testing assumptions:
* Static library is named libfreebl3.a (not libfreebl.a as is currently
provided in Fedora), matching libfreebl3.so shared link name.
Tested on x86_64 on Fedora with:
(a) --enable-nss-crypt, with no static NSS library support: PASS
(previous FAIL)
(b) --enable-nss-crypt, with faked static NSS library support: PASS
(unsupported)
* Requires changing elf/Makefile to include a stub
/lib64/libfreebl3.a for testing purposes.
(c) --disable-nss-crypt: PASS
(default)
No regressions on x86_64.
For details see:
https://www.sourceware.org/ml/libc-alpha/2016-11/msg00647.html
The first dlopen ("tst-latepthreadmod.so", RTLD_LOCAL | RTLD_LAZY) call
in elf/tst-latepthread.c fails on s390x with "error: dlopen failed:
.../build-s390x/elf/tst-latepthreadmod.so:
undefined symbol: this_function_is_not_defined".
In elf/tst-latepthreadmod.c, this_function_is_not_defined is a sibling
call which leads to a R_390_GLOB_DAT relocation in .rela.dyn instead of
a R_390_JMP_SLOT in .rela.plt.
As RTLD_LAZY skips the JMP_SLOT relocations, but not GLOB_DAT ones,
the dlopen call fails. If elf/tst-latepthreadmod.c is build with
-fno-optimize-sibling-calls, a JMP_SLOT relocation is generated for
this_function_is_not_defined and the test passes.
ChangeLog:
* elf/Makefile (CFLAGS-tst-latepthreadmod.c):
Add -fno-optimize-sibling-calls.
It is no longer needed since commit 6c444ad6e9
(elf: Do not use memalign for TCB/TLS blocks allocation [BZ #17730]).
Applications do not link against ld.so and will use the definition in
libc.so, so there is no ABI impact.
This change moves the main implementation of _dl_catch_error,
_dl_signal_error to libc.so, where TLS variables can be used
directly. This removes a writable function pointer from the
rtld_global variable.
For use during initial relocation, minimal implementations of these
functions are provided in ld.so. These are eventually interposed
by the libc.so implementations. This is implemented by compiling
elf/dl-error-skeleton.c twice, via elf/dl-error.c and
elf/dl-error-minimal.c.
As a side effect of this change, the static version of dl-error.c
no longer includes support for the
_dl_signal_cerror/_dl_receive_error mechanism because it is only
used in ld.so.
The function _dl_addr_inside_object is simplified by removing
the conditional 'reladdr - l->l_phdr[n].p_vaddr >= 0' which is
always true. The function is refactored into it's own object file
and a unit test added to verify the correct behaviour of the
function.
An earlier fix for TLS dropped early initialization of DTV entries for
modules using static TLS, leaving it for __tls_get_addr to set them
up. That worked on platforms that require the GD access model to be
relaxed to LE in the main executable, but it caused a regression on
platforms that allow GD in the main executable, particularly in
statically-linked programs: they use a custom __tls_get_addr that does
not update the DTV, which fails when the DTV early initialization is
not performed.
In static programs, __libc_setup_tls performs the DTV initialization
for the main thread, but the DTV of other threads is set up in
_dl_allocate_tls_init, so that's the fix that matters.
Restoring the initialization in the remaining functions modified by
this patch was just for uniformity. It's not clear that it is ever
needed: even on platforms that allow GD in the main executable, the
dynamically-linked version of __tls_get_addr would set up the DTV
entries, even for static TLS modules, while updating the DTV counter.
for ChangeLog
[BZ #19826]
* elf/dl-tls.c (_dl_allocate_tls_init): Restore DTV early
initialization of static TLS entries.
* elf/dl-reloc.c (_dl_nothread_init_static_tls): Likewise.
* nptl/allocatestack.c (init_one_static_tls): Likewise.
The commit b632bdd3 moved the setting of the DF_1_NODELETE flag earlier
in the dl_open_worker function. However when calling dlopen with both
RTLD_NODELETE and RTLD_NOLOAD, the pointer returned by _dl_map_object is
NULL. This condition is checked just after setting the flag, while it
should be done before. Fix that.
Changelog:
[BZ #19810]
* elf/dl-open.c (dl_open_worker): Set DF_1_NODELETE flag later.
* elf/tst-noload.c: New test case.
* elf/Makefile (tests): Add tst-noload.
Instead, call malloc and explicitly align the pointer.
There is no external location to store the original (unaligned)
pointer, and this commit increases the allocation size to store
the pointer at a fixed location relative to the TCB pointer.
The manual alignment means that some space goes unused which
was previously made available for subsequent allocations.
However, in the TLS_DTV_AT_TP case, the manual alignment code
avoids aligning the pre-TCB to the TLS block alignment. (Even
while using memalign, the allocation had some unused padding
in front.)
This concludes the removal of memalign calls from the TLS code,
and the new tst-tls3-malloc test verifies that only core malloc
routines are used.
Instead of a flag which indicates the pointer can be freed, dtv_t
now includes the pointer which should be freed. Due to padding,
the size of dtv_t does not increase.
To avoid using memalign, the new allocate_dtv_entry function
allocates a sufficiently large buffer so that a sub-buffer
can be found in it which starts with an aligned pointer. Both
the aligned and original pointers are kept, the latter for calling
free later.
The dynamic linker currently uses __libc_memalign for TLS-related
allocations. The goal is to switch to malloc instead. If the minimal
malloc follows the ABI fundamental alignment, we can assume that malloc
provides this alignment, and thus skip explicit alignment in a few
cases as an optimization.
It was requested on libc-alpha that MALLOC_ALIGNMENT should be used,
although this results in wasted space if MALLOC_ALIGNMENT is larger
than the fundamental alignment. (The dynamic linker cannot assume
that the non-minimal malloc will provide an alignment of
MALLOC_ALIGNMENT; the ABI provides _Alignof (max_align_t) only.)
Since _dl_tlsdesc_dynamic is called via PLT, we need to add 8 bytes for
push in the PLT entry to align the stack.
[BZ #20309]
* configure.ac (have-mtls-dialect-gnu2): Set to yes if
-mtls-dialect=gnu2 works.
* configure: Regenerated.
* elf/Makefile [have-mtls-dialect-gnu2 = yes]
(tests): Add tst-gnu2-tls1.
(modules-names): Add tst-gnu2-tls1mod.
($(objpfx)tst-gnu2-tls1): New.
(tst-gnu2-tls1mod.so-no-z-defs): Likewise.
(CFLAGS-tst-gnu2-tls1mod.c): Likewise.
* elf/tst-gnu2-tls1.c: New file.
* elf/tst-gnu2-tls1mod.c: Likewise.
* sysdeps/x86_64/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Add 8
bytes for push in the PLT entry to align the stack.
In a reference to PR ld/19908 make ld.so respect symbol export classes
aka visibility and treat STV_HIDDEN and STV_INTERNAL symbols as local,
preventing such symbols from preempting exported symbols.
According to the ELF gABI[1] neither STV_HIDDEN nor STV_INTERNAL symbols
are supposed to be present in linked binaries:
"A hidden symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
"An internal symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
however some GNU binutils versions produce such symbols in some cases.
PR ld/19908 is one and we also have this note in scripts/abilist.awk:
so clearly there is linked code out there which contains such symbols
which is prone to symbol table misinterpretation, and it'll be more
productive if we handle this gracefully, under the Robustness Principle:
"be liberal in what you accept, and conservative in what you produce",
especially as this is a simple (STV_HIDDEN|STV_INTERNAL) => STB_LOCAL
mapping.
References:
[1] "System V Application Binary Interface - DRAFT - 24 April 2001",
The Santa Cruz Operation, Inc., "Symbol Table",
<http://www.sco.com/developers/gabi/2001-04-24/ch4.symtab.html>
* sysdeps/generic/ldsodefs.h
(dl_symbol_visibility_binds_local_p): New inline function.
* elf/dl-addr.c (determine_info): Treat hidden and internal
symbols as local.
* elf/dl-lookup.c (do_lookup_x): Likewise.
* elf/dl-reloc.c (RESOLVE_MAP): Likewise.
The EM_BPF number has been officially assigned, though it
has not yet been posted to the gabi webpage yet.
* elf/elf.h (EM_BPF): New.
(EM_NUM): Update.
(R_BPF_NONE, R_BPF_MAP_FD): New.
__libc_memalign in ld.so allocates one page at a time and tries to
optimize consecutive __libc_memalign calls by hoping that the next
mmap is after the current memory allocation.
However, the kernel hands out mmap addresses in top-down order, so
this optimization in practice never happens, with the result that we
have more mmap calls and waste a bunch of space for each __libc_memalign.
This change makes __libc_memalign to mmap one page extra. Worst case,
the kernel never puts a backing page behind it, but best case it allows
__libc_memalign to operate much much better. For elf/tst-align --direct,
it reduces number of mmap calls from 12 to 9.
* elf/dl-minimal.c (__libc_memalign): Mmap one extra page.
This patch fixes the new test tst-dlsym-error build on aarch64
(and possible other architectures as well) due missing strchrnul
definition.
* elf/tst-dlsym-error.c: Include <string.h> for strchrnul.
* elf/dl-lookup.c (_dl_lookup_symbol_x): Report error even if
skip_map != NULL.
* elf/tst-dlsym-error.c: New file.
* elf/Makefile (tests): Add tst-dlsym-error.
(tst-dlsym-error): Link against libdl.
