Joseph Myers [Fri, 30 Sep 2022 19:36:41 +0000 (19:36 +0000)]
Fix iseqsig for _FloatN and _FloatNx in C++ with GCC 13
With GCC 13, _FloatN and _FloatNx types, when they exist, are distinct
types like they are in C with GCC 7 and later, rather than typedefs
for types such as float, double or long double.
This breaks the templated iseqsig implementation for C++ in <math.h>,
when used with types that were previously implemented as aliases. Add
the necessary definitions for _Float32, _Float64, _Float128 (when the
same format as long double), _Float32x and _Float64x in this case, so
that iseqsig can be used with such types in C++ with GCC 13 as it
could with previous GCC versions.
Also add tests for calling iseqsig in C++ with arguments of such types
(more minimal than existing tests, so that they can work with older
GCC versions and without relying on any C++ library support for the
types or on hardcoding details of their formats). The LDBL_MANT_DIG
!= 106 conditionals on some tests are because the type-generic
comparison macros have undefined behavior when neither argument has a
type whose set of values is a subset of those for the type of the
other argument, which applies when one argument is IBM long double and
the other is an IEEE format wider than binary64.
Tested with build-many-glibcs.py glibcs build for aarch64-linux-gnu
i686-linux-gnu mips-linux-gnu mips64-linux-gnu-n32 powerpc-linux-gnu
powerpc64le-linux-gnu x86_64-linux-gnu.
Xi Ruoyao [Sat, 24 Sep 2022 07:45:34 +0000 (15:45 +0800)]
LoongArch: Add static PIE support
If the compiler is new enough, enable static PIE support. In the static
PIE version of _start (in rcrt1.o), use la.pcrel instead of la.got
because in a static PIE we cannot use GOT entries until the dynamic
relocations for GOT are resolved.
Joseph Myers [Wed, 28 Sep 2022 20:09:34 +0000 (20:09 +0000)]
Update _FloatN header support for C++ in GCC 13
GCC 13 adds support for _FloatN and _FloatNx types in C++, so breaking
the installed glibc headers that assume such support is not present.
GCC mostly works around this with fixincludes, but that doesn't help
for building glibc and its tests (glibc doesn't itself contain C++
code, but there's C++ code built for tests). Update glibc's
bits/floatn-common.h and bits/floatn.h headers to handle the GCC 13
support directly.
In general the changes match those made by fixincludes, though I think
the ones in sysdeps/powerpc/bits/floatn.h, where the header tests
__LDBL_MANT_DIG__ == 113 or uses #elif, wouldn't match the existing
fixincludes patterns.
Some places involving special C++ handling in relation to _FloatN
support are not changed. There's no need to change the
__HAVE_FLOATN_NOT_TYPEDEF definition (also in a form that wouldn't be
matched by the fixincludes fixes) because it's only used in relation
to macro definitions using features not supported for C++
(__builtin_types_compatible_p and _Generic). And there's no need to
change the inline function overloads for issignaling, iszero and
iscanonical in C++ because cases where types have the same format but
are no longer compatible types are handled automatically by the C++
overload resolution rules.
This patch also does not change the overload handling for iseqsig, and
there I think changes *are* needed, beyond those in this patch or made
by fixincludes. The way that overload is defined, via a template
parameter to a structure type, requires overloads whenever the types
are incompatible, even if they have the same format. So I think we
need to add overloads with GCC 13 for every supported _FloatN and
_FloatNx type, rather than just having one for _Float128 when it has a
different ABI to long double as at present (but for older GCC, such
overloads must not be defined for types that end up defined as
typedefs for another type).
Tested with build-many-glibcs.py: compilers build for
aarch64-linux-gnu ia64-linux-gnu mips64-linux-gnu powerpc-linux-gnu
powerpc64le-linux-gnu x86_64-linux-gnu; glibcs build for
aarch64-linux-gnu ia64-linux-gnu i686-linux-gnu mips-linux-gnu
mips64-linux-gnu-n32 powerpc-linux-gnu powerpc64le-linux-gnu
x86_64-linux-gnu.
nss: Use shared prefix in IPv4 address in tst-reload1
Otherwise, sorting based on the longest-matching prefix in
getaddrinfo can reorder the addresses in ways the test does not
expect, depending on the IPv4 address of the host.
Use C11 atomics instead of atomic_decrement_and_test
Replace atomic_decrement_and_test with atomic_fetch_add_relaxed.
These are simple counters which do not protect any shared data from
concurrent accesses. Also remove the unused file cond-perf.c.
Replace atomic_increment and atomic_increment_val with atomic_fetch_add_relaxed.
One case in sem_post.c uses release semantics (see comment above it).
The others are simple counters and do not protect any shared data from
concurrent accesses.
Remove the 4 uses of atomic_and and atomic_or with atomic_fetch_and_acquire
and atomic_fetch_or_acquire. This is preserves existing implied semantics,
however relaxed MO on FUTEX_OWNER_DIED accesses may be correct.
The need to maintain elf/elf.h and scripts/glibcelf.py in parallel
results in a backporting hazard: they need to be kept in sync to
avoid elf/tst-glibcelf consistency check failures. glibcelf (unlike
tst-glibcelf) does not use the C implementation to extract constants.
This applies the additional glibcpp syntax checks to <elf.h>.
This changereplaces the types derived from Python enum types with
custom types _TypedConstant, _IntConstant, and _FlagConstant. These
types have fewer safeguards, but this also allows incremental
construction and greater flexibility for grouping constants among
the types. Architectures-specific named constants are now added
as members into their superclasses (but value-based lookup is
still restricted to generic constants only).
Consequently, check_duplicates in elf/tst-glibcelf has been adjusted
to accept differently-named constants of the same value if their
subtypes are distinct. The ordering check for named constants
has been dropped because they are no longer strictly ordered.
Further test adjustments: Some of the type names are different.
The new types do not support iteration (because it is unclear
whether iteration should cover the all named values (including
architecture-specific constants), or only the generic named values),
so elf/tst-glibcelf now uses by_name explicit (to get all constants).
PF_HP_SBP and PF_PARISC_SBP are now of distinct types (PfHP and
PfPARISC), so they are how both present on the Python side. EM_NUM
and PT_NUM are filtered (which was an oversight in the old
conversion).
The new version of glibcelf should also be compatible with earlier
Python versions because it no longer depends on the enum module and its
advanced features.
m68k: Enforce 4-byte alignment on internal locks (BZ #29537)
A new internal definition, __LIBC_LOCK_ALIGNMENT, is used to force
the 4-byte alignment only for m68k, other architecture keep the
natural alignment of the type used internally (and hppa does not
require 16-byte alignment for kernel-assisted CAS).
nss: Fix tst-nss-files-hosts-long on single-stack hosts (bug 24816)
getent implicitly passes AI_ADDRCONFIG to getaddrinfo by default.
Use --no-addrconfig to suppress that, so that both IPv4 and IPv6
lookups succeed even if the address family is not supported by the
host.
gconv: Use 64-bit interfaces in gconv_parseconfdir (bug 29583)
It's possible that inode numbers are outside the 32-bit range.
The existing code only handles the in-libc case correctly, and
still uses the legacy interfaces when building iconv.
elf: Implement force_first handling in _dl_sort_maps_dfs (bug 28937)
The implementation in _dl_close_worker requires that the first
element of l_initfini is always this very map (“We are always the
zeroth entry, and since we don't include ourselves in the
dependency analysis start at 1.”). Rather than fixing that
assumption, this commit adds an implementation of the force_first
argument to the new dependency sorting algorithm. This also means
that the directly dlopen'ed shared object is always initialized last,
which is the least surprising behavior in the presence of cycles.
Samuel Thibault [Sat, 17 Sep 2022 15:42:42 +0000 (17:42 +0200)]
tst-sprintf-errno: Update Hurd message length
03ad444e8e08 ("mach: Fix incoherency between perror and strerror") fixesd
the output of error messages, but tst-sprintf-errno.c was still checking
the old (erroneous) format length. This updates the expected output length
according to the 03ad444e8e08 fix.
__syscall_error may end up farther than 1MiB away from a caller,
especially when linking statically large binaries. tail allows for
4GiB jumps and is reduced to j when a linked symbol is within range.
Fixes: 36960f0c76 ("RISC-V: Linux Syscall Interface") Fixes: 7f33b09c65 ("RISC-V: Linux ABI") Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Samuel Thibault [Thu, 15 Sep 2022 19:53:57 +0000 (21:53 +0200)]
hurd: Make readlink* just reopen the file used for stat
9e5c991106cb ("hurd: Fix readlink() hanging on fifo") separated opening
the file for the stat call from opening the file for the read call. That
however opened a small window for the file to change. Better make this
atomic by reopening the file with O_READ.
Samuel Thibault [Wed, 14 Sep 2022 16:52:52 +0000 (18:52 +0200)]
hurd: Fix readlink() hanging on fifo
readlink() opens the target with O_READ to be able to read the symlink
content. When the target is actually a fifo, that would hang waiting for a
writer (caught in the coreutils testsuite). We thus have to first lookup the
target without O_READ to perform io_stat and lookout for fifos, and only
after checking the symlink type, we can re-lookup with O_READ.
Makerules: fix MAKEFLAGS assignment for upcoming make-4.4 [BZ# 29564]
make-4.4 will add long flags to MAKEFLAGS variable:
* WARNING: Backward-incompatibility!
Previously only simple (one-letter) options were added to the MAKEFLAGS
variable that was visible while parsing makefiles. Now, all options
are available in MAKEFLAGS.
This causes locale builds to fail when long options are used:
$ make --shuffle
...
make -C localedata install-locales
make: invalid shuffle mode: '1662724426r'
The change fixes it by passing eash option via whitespace and dashes.
That way option is appended to both single-word form and whitespace
separated form.
While at it fixed --silent mode detection in $(MAKEFLAGS) by filtering
out --long-options. Otherwise options like --shuffle flag enable silent
mode unintentionally. $(silent-make) variable consolidates the checks.
Resolves: BZ# 29564
CC: Paul Smith <psmith@gnu.org> CC: Siddhesh Poyarekar <siddhesh@gotplt.org> Signed-off-by: Sergei Trofimovich <slyich@gmail.com> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Use relaxed atomics since there is no MO dependence
Replace the 3 uses of atomic_bit_set and atomic_bit_test_set with
atomic_fetch_or_relaxed. Using relaxed MO is correct since the
atomics are used to ensure memory is released only once.
makedb: fix build with libselinux >= 3.1 (Bug 26233)
glibc doesn't build with libselinux 3.1 that has been released recently
due to new deprecations introduced in that version and the fact that
glibc is built with -Werror by default:
| makedb.c: In function ‘set_file_creation_context’:
| makedb.c:849:3: error: ‘security_context_t’ is deprecated [-Werror=deprecated-declarations]
| 849 | security_context_t ctx;
| | ^~~~~~~~~~~~~~~~~~
| makedb.c:863:3: error: ‘matchpathcon’ is deprecated: Use selabel_lookup instead [-Werror=deprecated-declarations]
| 863 | if (matchpathcon (outname, S_IFREG | mode, &ctx) == 0 && ctx != NULL)
| | ^~
| In file included from makedb.c:50:
| /usr/include/selinux/selinux.h:500:12: note: declared here
| 500 | extern int matchpathcon(const char *path,
| | ^~~~~~~~~~~~
| cc1: all warnings being treated as errors
This patch fixes the makedb half of bug 26233 by moving to the new
SELinux APIs and removes the existing compiler pragmas as no longer
required. Upstream API usage feedback gathered by Arjun is integrated
into this version of the fix.
The built makedb was tested and operates as expected on x86_64 with
SELinu in enforcing mode.
Samuel Thibault [Sun, 11 Sep 2022 12:20:32 +0000 (14:20 +0200)]
tst-sprintf-errno: Update Hurd message output
03ad444e8e08 ("mach: Fix incoherency between perror and strerror")
fixesd the output of error messages, but tst-sprintf-errno.c was still
checking the old (erroneous) format. This updates the expected output
according to the 03ad444e8e08 fix.
Paul Eggert [Fri, 9 Sep 2022 01:08:32 +0000 (20:08 -0500)]
mktime: improve heuristic for ca-1986 Indiana DST
This patch syncs mktime.c from Gnulib, fixing a
problem reported by Mark Krenz <https://bugs.gnu.org/48085>,
and it should fix BZ#29035 too.
* time/mktime.c (__mktime_internal): Be more generous about
accepting arguments with the wrong value of tm_isdst, by falling
back to a one-hour DST difference if we find no nearby DST that is
unusual. This fixes a problem where "1986-04-28 00:00 EDT" was
rejected when TZ="America/Indianapolis" because the nearest DST
timestamp occurred in 1970, a temporal distance too great for the
old heuristic. This also also narrows the search a bit, which
is a minor performance win.
Javier Pello [Mon, 5 Sep 2022 18:09:01 +0000 (20:09 +0200)]
elf: Fix hwcaps string size overestimation
Commit dad90d528259b669342757c37dedefa8577e2636 added glibc-hwcaps
support for LD_LIBRARY_PATH and, for this, it adjusted the total
string size required in _dl_important_hwcaps. However, in doing so
it inadvertently altered the calculation of the size required for
the power set strings, as the computation of the power set string
size depended on the first value assigned to the total variable,
which is later shifted, resulting in overallocation of string
space. Fix this now by using a different variable to hold the
string size required for glibc-hwcaps.
Andreas Schwab [Thu, 8 Sep 2022 08:25:21 +0000 (10:25 +0200)]
errlist: add missing entry for EDEADLOCK (bug 29545)
Some architectures (mips, powerpc and sparc) define separate values for
EDEADLOCK and EDEADLK. Readd the errlist entry for EDEADLOCK for those
configurations. Also use the dependency files from generating the
auxiliary errlist and siglist files.
Joseph Myers [Wed, 7 Sep 2022 18:39:28 +0000 (18:39 +0000)]
Do not define static_assert or thread_local in headers for C2x
C2x makes static_assert and thread_local into keywords, removing the
definitions as macros in assert.h and threads.h. Thus, disable those
macros in those glibc headers for C2x.
The disabling is done based on a combination of language version and
__GNUC_PREREQ, *not* based on __GLIBC_USE (ISOC2X), on the principle
that users of the header (when requesting C11 or later APIs - not
assert.h for C99 and older API versions) should always have the names
static_assert or thread_local available after inclusion of the header,
whether as a keyword or as a macro. Thus, when using a compiler
without the keywords (whether an older compiler, possibly in C2x mode,
or _GNU_SOURCE with any compiler but in an older language mode, for
example) the macros should be defined, even when C2x APIs have been
requested. The __GNUC_PREREQ conditionals here may well need updating
with the versions of other compilers that gained support for these
keywords in C2x mode.
scripts/dso-ordering-test.py: Generate program run-time dependencies
The main program needs to depend on all shared objects, even objects
that have link-time dependencies among shared objects. Filtering
out shared objects that already have an link-time dependencies is not
necessary here; make will do this automatically.
debug: test for more required cacellation points (BZ# 29274)
Generalize the test for cancellation point in __read_chk to also test
the other fortified functions with required cancellation points.
Since there is not easy way to force some syscalls to block (for
instance pread) the test tests two modes: cancellation on blocked
syscalls and early cancellation on pending request.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Co-authored-by: Andreas Schwab <schwab@suse.de> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
elf: Restore how vDSO dependency is printed with LD_TRACE_LOADED_OBJECTS (BZ #29539)
The d7703d3176d225d5743b21811d888619eba39e82 changed how vDSO like
dependencies are printed, instead of just the name and address it
follows other libraries mode and prints 'name => path'.
Unfortunately, this broke some ldd consumer that uses the output to
filter out the program's dependencies. For instance CMake
bundleutilities module [1], where GetPrequirite uses the regex to filter
out 'name => path' [2].
This patch restore the previous way to print just the name and the
mapping address.
nptl: x86_64: Use same code for CURRENT_STACK_FRAME and stackinfo_get_sp
It avoids the possible warning of uninitialized 'frame' variable when
building with clang:
../sysdeps/nptl/jmp-unwind.c:27:42: error: variable 'frame' is
uninitialized when used here [-Werror,-Wuninitialized]
__pthread_cleanup_upto (env->__jmpbuf, CURRENT_STACK_FRAME);
The resulting code is similar to CURRENT_STACK_FRAME.
Apply asm redirections in wchar.h before first use
Similar to d0fa09a770, but for wchar.h. Fixes [BZ #27087] by applying
all long double related asm redirections before using functions in
bits/wchar2.h.
Moves the function declarations from wcsmbs/bits/wchar2.h to a new file
wcsmbs/bits/wchar2-decl.h that will be included first in wcsmbs/wchar.h.
Tested with build-many-glibcs.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Florian Weimer [Tue, 30 Aug 2022 11:30:03 +0000 (13:30 +0200)]
resolv: Fix building tst-resolv-invalid-cname for earlier C standards
This fixes this compiler error:
tst-resolv-invalid-cname.c: In function ‘test_mode_to_string’:
tst-resolv-invalid-cname.c:164:10: error: label at end of compound statement
case test_mode_num:
^~~~~~~~~~~~~
The a583b6add407c17cd change did not handle large messages that
would require a heap allocation correctly, where the message itself
is not take in consideration.
This patch fixes it and extend the tst-syslog to check for large
messages as well.
Stefan Liebler [Thu, 25 Aug 2022 10:17:48 +0000 (12:17 +0200)]
S390: Always use svc 0
On s390x syscalls are triggered by svc instruction. One can
pass the syscall number encoded in the instruction "svc 123"
or by storing it in r1:
lghi r1,123
svc 0
If the syscall number is encoded in the instruction, this can
cause broken syscall restarts. Therefore this patch is now just
passing the syscall number in r1.
See also kernel-commit:
"s390/signal: switch to using vdso for sigreturn and syscall restart"
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/s390/[%e2%80%a6]call.c?h=v6.0-rc1&id=df29a7440c4b5c65765c8f60396b3b13063e24e9
Florian Weimer [Tue, 30 Aug 2022 08:02:49 +0000 (10:02 +0200)]
nss_dns: Rewrite _nss_dns_gethostbyname4_r using current interfaces
Introduce struct alloc_buffer to this function, and use it and
struct ns_rr_cursor in gaih_getanswer_slice. Adjust gaih_getanswer
and gaih_getanswer_noaaaa accordingly.
Florian Weimer [Tue, 30 Aug 2022 08:02:49 +0000 (10:02 +0200)]
nss_dns: Rewrite _nss_dns_gethostbyaddr2_r and getanswer_ptr
The simplification takes advantage of the split from getanswer_r.
It fixes various aliases issues, and optimizes NSS buffer usage.
The new DNS packet parsing helpers are used, too.
Florian Weimer [Tue, 30 Aug 2022 08:02:49 +0000 (10:02 +0200)]
resolv: Add DNS packet parsing helpers geared towards wire format
The public parser functions around the ns_rr record type produce
textual domain names, but usually, this is not what we need while
parsing DNS packets within glibc. This commit adds two new helper
functions, __ns_rr_cursor_init and __ns_rr_cursor_next, for writing
packet parsers, and struct ns_rr_cursor, struct ns_rr_wire as
supporting types.
In theory, it is possible to avoid copying the owner name
into the rname field in __ns_rr_cursor_next, but this would need
more functions that work on compressed names.
Eventually, __res_context_send could be enhanced to preserve the
result of the packet parsing that is necessary for matching the
incoming UDP packets, so that this works does not have to be done
twice.
Florian Weimer [Tue, 30 Aug 2022 08:02:49 +0000 (10:02 +0200)]
resolv: Add the __ns_samebinaryname function
During packet parsing, only the binary name is available. If the name
equality check is performed before conversion to text, we can sometimes
skip the last step.
Florian Weimer [Tue, 30 Aug 2022 08:02:49 +0000 (10:02 +0200)]
resolv: Add internal __res_binary_hnok function
During package parsing, only the binary representation is available,
and it is convenient to check that directly for conformance with host
name requirements.
nscd: Fix netlink cache invalidation if epoll is used [BZ #29415]
Processes cache network interface information such as whether IPv4 or IPv6
are enabled. This is only checked again if the "netlink timestamp" provided
by nscd changed, which is triggered by netlink socket activity.
However, in the epoll handler for the netlink socket, it was missed to
assign the new timestamp to the nscd database. The handler for plain poll
did that properly, copy that over.
This bug caused that e.g. processes which started before network
configuration got unusuable addresses from getaddrinfo, like IPv6 only even
though only IPv4 is available:
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/1041
It's a bit hard to reproduce, so I verified this by checking the timestamp
on calls to __check_pf manually. Without this patch it's stuck at 1, now
it's increasing on network changes as expected.
Andreas Schwab [Mon, 29 Aug 2022 13:05:40 +0000 (15:05 +0200)]
Add test for bug 29530
This tests for a bug that was introduced in commit edc1686af0 ("vfprintf:
Reuse work_buffer in group_number") and fixed as a side effect of commit 6caddd34bd ("Remove most vfprintf width/precision-dependent allocations
(bug 14231, bug 26211).").
Makeconfig: Set pie-ccflag to -fPIE by default [BZ# 29514]
We should default to the larger code model, in order to support
larger applications built with -static -pie. This should be
consistent with pic-ccflag, which defaults to -fPIC.
Remove the now redundant override from sysdeps/sparc/Makefile.
Note that -fno-pie and -fno-PIE have the same effect.
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
Samuel Thibault [Sun, 28 Aug 2022 23:42:47 +0000 (01:42 +0200)]
hurd: Fix vm_size_t incoherencies
In gnumach, 3e1702a65fb3 ("add rpc_versions for vm types") changed the type
of vm_size_t, making it always a unsigned long. This made it incompatible on
x86 with size_t. Even if we may want to revert it to unsigned int, it's
better to fix the types of parameters according to the .defs files.
Samuel Thibault [Sat, 27 Aug 2022 11:52:46 +0000 (13:52 +0200)]
mach: Fix incoherency between perror and strerror
08d2024b4167 ("string: Simplify strerror_r") inadvertently made
__strerror_r print unknown error system in decimal while the original
code was printing it in hexadecimal. perror was kept printing in
hexadecimal in 725eeb4af14c ("string: Use tls-internal on strerror_l"),
let us keep both coherent.
This also fixes a duplicate ':'
Spotted by the libunistring testsuite test-perror2
Florian Weimer [Fri, 26 Aug 2022 19:15:43 +0000 (21:15 +0200)]
elf: Call __libc_early_init for reused namespaces (bug 29528)
libc_map is never reset to NULL, neither during dlclose nor on a
dlopen call which reuses the namespace structure. As a result, if a
namespace is reused, its libc is not initialized properly. The most
visible result is a crash in the <ctype.h> functions.
To prevent similar bugs on namespace reuse from surfacing,
unconditionally initialize the chosen namespace to zero using memset.
Szabolcs Nagy [Mon, 22 Aug 2022 13:21:53 +0000 (14:21 +0100)]
csu: Change start code license to have link exception
The start code can get linked into dynamic linked executables where
LGPL would require shipping the source or linkable binaries when the
executable is distributed.
On some targets the license exception was missing in start.S (which
is compiled into crt1.o and Scrt1.o which may end up linked into PDE
and PIE binaries).
I did not review what other code may end up in executables, just
fixed the start.S license inconsistency across targets.
Florian Weimer [Thu, 25 Aug 2022 14:34:20 +0000 (16:34 +0200)]
s390: Move hwcaps/platform names out of _rtld_global_ro
Changes to these arrays are often backported to stable releases,
but additions to these arrays shift the offsets of the following
_rltd_global_ro members, thus breaking the GLIBC_PRIVATE ABI.
Obviously, this change is itself an internal ABI break, but at least
it will avoid further ABI breaks going forward.
Once this change hits the release branches, it will require relinking
of all statically linked applications before static dlopen works
again, for the majority of updates on release branches: The NEWS file
is regularly updated with bug references, so the __libc_early_init
suffix changes, and static dlopen cannot find the function anymore.
While this ABI check is still technically correct (we do require
rebuilding & relinking after glibc updates to keep static dlopen
working), it is too drastic for stable release branches.
Florian Weimer [Wed, 24 Aug 2022 15:35:36 +0000 (17:35 +0200)]
Detect ld.so and libc.so version inconsistency during startup
The files NEWS, include/link.h, and sysdeps/generic/ldsodefs.h
contribute to the version fingerprint used for detection. The
fingerprint can be further refined using the --with-extra-version-id
configure argument.
_dl_call_libc_early_init is replaced with _dl_lookup_libc_early_init.
The new function is used store a pointer to libc.so's
__libc_early_init function in the libc_map_early_init member of the
ld.so namespace structure. This function pointer can then be called
directly, so the separate invocation function is no longer needed.
The versioned symbol lookup needs the symbol versioning data
structures, so the initialization of libc_map and libc_map_early_init
is now done from _dl_check_map_versions, after this information
becomes available. (_dl_map_object_from_fd does not set this up
in time, so the initialization code had to be moved from there.)
This means that the separate initialization code can be removed from
dl_main because _dl_check_map_versions covers all maps, including
the initial executable loaded by the kernel. The lookup still happens
before relocation and the invocation of IFUNC resolvers, so IFUNC
resolvers are protected from ABI mismatch.
The __libc_early_init function pointer is not protected because
so little code runs between the pointer write and the invocation
(only dynamic linker code and IFUNC resolvers).