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The rtld-audit interfaces introduces a slowdown due to enabling
profiling instrumentation (as if LD_AUDIT implied LD_PROFILE).
However, instrumenting is only necessary if one of audit libraries
provides PLT callbacks (la_pltenter or la_pltexit symbols). Otherwise,
the slowdown can be avoided.
The following patch adjusts the logic that enables profiling to iterate
over all audit modules and check if any of those provides a PLT hook.
To keep la_symbind to work even without PLT callbacks, _dl_fixup now
calls the audit callback if the modules implements it.
Co-authored-by: Alexander Monakov <amonakov@ispras.ru>
Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 063f9ba220f434c7f30dd65c4cff17c0c458a7cf)
Resolved conflicts:
NEWS
elf/Makefile
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We can't relocate entries in dynamic section if it is readonly:
1. Add a l_ld_readonly field to struct link_map to indicate if dynamic
section is readonly and set it based on p_flags of PT_DYNAMIC segment.
2. Replace DL_RO_DYN_SECTION with dl_relocate_ld to decide if dynamic
section should be relocated.
3. Remove DL_RO_DYN_TEMP_CNT.
4. Don't use a static dynamic section to make readonly dynamic section
in vDSO writable.
5. Remove the temp argument from elf_get_dynamic_info.
This fixes BZ #28340.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit b413280cfb16834450f66f554bc0d618bb513851)
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I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
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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>
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Commit a2e8aa0d9ea648068d8be52dd7b15f1b6a008e23 ("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>
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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
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l_audit ends up as an internal array with _rtld_global, and GCC 10
warns about this.
This commit does not change the layout of _rtld_global, so it is
suitable for backporting. Future changes could allocate more of the
audit state dynamically and remove it from always-allocated data
structures, to optimize the common case of inactive auditing.
Change-Id: Ic911100730f9124d4ea977ead8e13cee64b84d45
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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
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* All files with FSF copyright notices: Update copyright dates
using scripts/update-copyrights.
* locale/programs/charmap-kw.h: Regenerated.
* locale/programs/locfile-kw.h: Likewise.
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There is a data-dependency between the fields of struct l_reloc_result
and the field used as the initialization guard. Users of the guard
expect writes to the structure to be observable when they also observe
the guard initialized. The solution for this problem is to use an acquire
and release load and store to ensure previous writes to the structure are
observable if the guard is initialized.
The previous implementation used DL_FIXUP_VALUE_ADDR (l_reloc_result->addr)
as the initialization guard, making it impossible for some architectures
to load and store it atomically, i.e. hppa and ia64, due to its larger size.
This commit adds an unsigned int to l_reloc_result to be used as the new
initialization guard of the struct, making it possible to load and store
it atomically in all architectures. The fix ensures that the values
observed in l_reloc_result are consistent and do not lead to crashes.
The algorithm is documented in the code in elf/dl-runtime.c
(_dl_profile_fixup). Not all data races have been eliminated.
Tested with build-many-glibcs and on powerpc, powerpc64, and powerpc64le.
[BZ #23690]
* elf/dl-runtime.c (_dl_profile_fixup): Guarantee memory
modification order when accessing reloc_result->addr.
* include/link.h (reloc_result): Add field init.
* nptl/Makefile (tests): Add tst-audit-threads.
(modules-names): Add tst-audit-threads-mod1 and
tst-audit-threads-mod2.
Add rules to build tst-audit-threads.
* nptl/tst-audit-threads-mod1.c: New file.
* nptl/tst-audit-threads-mod2.c: Likewise.
* nptl/tst-audit-threads.c: Likewise.
* nptl/tst-audit-threads.h: Likewise.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
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* All files with FSF copyright notices: Update copyright dates
using scripts/update-copyrights.
* locale/programs/charmap-kw.h: Regenerated.
* locale/programs/locfile-kw.h: Likewise.
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To support Intel Control-flow Enforcement Technology (CET) run-time
control:
1. An architecture specific field in the writable ld.so namespace is
needed to indicate if CET features are enabled at run-time.
2. An architecture specific field in struct link_map is needed if
CET features are enabled in an ELF module.
This patch adds dl-procruntime.c to the writable ld.so namespace and
link_map.h to struct link_map.
Tested with build-many-glibcs.py.
* elf/dl-support.c: Include <dl-procruntime.c>.
* include/link.h: Include <link_map.h>.
* sysdeps/generic/dl-procruntime.c: New file.
* sysdeps/generic/link_map.h: Likewise.
* sysdeps/generic/ldsodefs.h: Include <dl-procruntime.c> in
the writable ld.so namespace.
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__dl_iterate_phdr is hidden and should be accessed directly within
libc.so and libc.a without using GOT nor PLT.
[BZ #18822]
* elf/dl-iteratephdr.c (hidden_proto (__dl_iterate_phdr)): Moved
to ...
* include/link.h (hidden_proto (__dl_iterate_phdr)): Here.
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This adds a test to ensure that the problems fixed in the last several
patches do not recur. Each directory checks the headers that it
installs for two properties: first, each header must be compilable in
isolation, as both C and C++, under a representative combination of
language and library conformance levels; second, there is a blacklist
of identifiers that may not appear in any installed header, currently
consisting of the legacy BSD typedefs. (There is an exemption for the
headers that define those typedefs, and for the RPC headers. It may be
necessary to make this more sophisticated if we add more stuff to the
blacklist in the future.)
In order for this test to work correctly, every wrapper header
that actually defines something must guard those definitions with
#ifndef _ISOMAC. This is the existing mechanism used by the conform/
tests to tell wrapper headers not to define anything that the public
header wouldn't, and not to use anything from libc-symbols.h. conform/
only cares for headers that we need to check for standards conformance,
whereas this test applies to *every* header. (Headers in include/ that
are either installed directly, or are internal-use-only and do *not*
correspond to any installed header, are not affected.)
* scripts/check-installed-headers.sh: New script.
* Rules: In each directory that defines header files to be installed,
run check-installed-headers.sh on them as a special test.
* Makefile: Likewise for the headers installed at top level.
* include/aliases.h, include/alloca.h, include/argz.h
* include/arpa/nameser.h, include/arpa/nameser_compat.h
* include/elf.h, include/envz.h, include/err.h
* include/execinfo.h, include/fpu_control.h, include/getopt.h
* include/gshadow.h, include/ifaddrs.h, include/libintl.h
* include/link.h, include/malloc.h, include/mcheck.h
* include/mntent.h, include/netinet/ether.h
* include/nss.h, include/obstack.h, include/printf.h
* include/pty.h, include/resolv.h, include/rpc/auth.h
* include/rpc/auth_des.h, include/rpc/auth_unix.h
* include/rpc/clnt.h, include/rpc/des_crypt.h
* include/rpc/key_prot.h, include/rpc/netdb.h
* include/rpc/pmap_clnt.h, include/rpc/pmap_prot.h
* include/rpc/pmap_rmt.h, include/rpc/rpc.h
* include/rpc/rpc_msg.h, include/rpc/svc.h
* include/rpc/svc_auth.h, include/rpc/xdr.h
* include/rpcsvc/nis_callback.h, include/rpcsvc/nislib.h
* include/rpcsvc/yp.h, include/rpcsvc/ypclnt.h
* include/rpcsvc/ypupd.h, include/shadow.h
* include/stdio_ext.h, include/sys/epoll.h
* include/sys/file.h, include/sys/gmon.h, include/sys/ioctl.h
* include/sys/prctl.h, include/sys/profil.h
* include/sys/statfs.h, include/sys/sysctl.h
* include/sys/sysinfo.h, include/ttyent.h, include/utmp.h
* sysdeps/arm/nacl/include/bits/setjmp.h
* sysdeps/mips/include/sys/asm.h
* sysdeps/unix/sysv/linux/include/sys/sysinfo.h
* sysdeps/unix/sysv/linux/include/sys/timex.h
* sysdeps/x86/fpu/include/bits/fenv.h:
Add #ifndef _ISOMAC guard around internal declarations.
Add multiple-inclusion guard if not already present.
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It was noted in
<https://sourceware.org/ml/libc-alpha/2012-09/msg00305.html> that the
bits/*.h naming scheme should only be used for installed headers.
This patch renames bits/libc-lock.h to plain libc-lock.h and
bits/libc-lockP.h to plain libc-lockP.h to follow that convention.
Note that I don't know where libc-lockP.h comes from for Hurd (the
Hurd libc-lock.h includes libc-lockP.h, but the only libc-lockP.h in
the glibc source tree is for NPTL) - some unmerged patch? - but I
updated the #include in the Hurd libc-lock.h anyway.
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch).
[BZ #14912]
* bits/libc-lock.h: Move to ...
* sysdeps/generic/libc-lock.h: ...here.
(_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H.
* sysdeps/mach/hurd/bits/libc-lock.h: Move to ...
* sysdeps/mach/hurd/libc-lock.h: ...here.
(_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H.
[_LIBC]: Include <libc-lockP.h> instead of <bits/libc-lockP.h>.
* sysdeps/mach/bits/libc-lock.h: Move to ...
* sysdeps/mach/libc-lock.h: ...here.
(_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H.
* sysdeps/nptl/bits/libc-lock.h: Move to ...
* sysdeps/nptl/libc-lock.h: ...here.
(_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H.
* sysdeps/nptl/bits/libc-lockP.h: Move to ...
* sysdeps/nptl/libc-lockP.h: ...here.
(_BITS_LIBC_LOCKP_H): Rename macro to _LIBC_LOCKP_H.
* crypt/crypt_util.c: Include <libc-lock.h> instead of
<bits/libc-lock.h>.
* dirent/scandir-tail.c: Likewise.
* dlfcn/dlerror.c: Likewise.
* elf/dl-close.c: Likewise.
* elf/dl-iteratephdr.c: Likewise.
* elf/dl-lookup.c: Likewise.
* elf/dl-open.c: Likewise.
* elf/dl-support.c: Likewise.
* elf/dl-writev.h: Likewise.
* elf/rtld.c: Likewise.
* grp/fgetgrent.c: Likewise.
* gshadow/fgetsgent.c: Likewise.
* gshadow/sgetsgent.c: Likewise.
* iconv/gconv_conf.c: Likewise.
* iconv/gconv_db.c: Likewise.
* iconv/gconv_dl.c: Likewise.
* iconv/gconv_int.h: Likewise.
* iconv/gconv_trans.c: Likewise.
* include/link.h: Likewise.
* inet/getnameinfo.c: Likewise.
* inet/getnetgrent.c: Likewise.
* inet/getnetgrent_r.c: Likewise.
* intl/bindtextdom.c: Likewise.
* intl/dcigettext.c: Likewise.
* intl/finddomain.c: Likewise.
* intl/gettextP.h: Likewise.
* intl/loadmsgcat.c: Likewise.
* intl/localealias.c: Likewise.
* intl/textdomain.c: Likewise.
* libidn/idn-stub.c: Likewise.
* libio/libioP.h: Likewise.
* locale/duplocale.c: Likewise.
* locale/freelocale.c: Likewise.
* locale/newlocale.c: Likewise.
* locale/setlocale.c: Likewise.
* login/getutent_r.c: Likewise.
* login/getutid_r.c: Likewise.
* login/getutline_r.c: Likewise.
* login/utmp-private.h: Likewise.
* login/utmpname.c: Likewise.
* malloc/mtrace.c: Likewise.
* misc/efgcvt.c: Likewise.
* misc/error.c: Likewise.
* misc/fstab.c: Likewise.
* misc/getpass.c: Likewise.
* misc/mntent.c: Likewise.
* misc/syslog.c: Likewise.
* nis/nis_call.c: Likewise.
* nis/nis_callback.c: Likewise.
* nis/nss-default.c: Likewise.
* nis/nss_compat/compat-grp.c: Likewise.
* nis/nss_compat/compat-initgroups.c: Likewise.
* nis/nss_compat/compat-pwd.c: Likewise.
* nis/nss_compat/compat-spwd.c: Likewise.
* nis/nss_nis/nis-alias.c: Likewise.
* nis/nss_nis/nis-ethers.c: Likewise.
* nis/nss_nis/nis-grp.c: Likewise.
* nis/nss_nis/nis-hosts.c: Likewise.
* nis/nss_nis/nis-network.c: Likewise.
* nis/nss_nis/nis-proto.c: Likewise.
* nis/nss_nis/nis-pwd.c: Likewise.
* nis/nss_nis/nis-rpc.c: Likewise.
* nis/nss_nis/nis-service.c: Likewise.
* nis/nss_nis/nis-spwd.c: Likewise.
* nis/nss_nisplus/nisplus-alias.c: Likewise.
* nis/nss_nisplus/nisplus-ethers.c: Likewise.
* nis/nss_nisplus/nisplus-grp.c: Likewise.
* nis/nss_nisplus/nisplus-hosts.c: Likewise.
* nis/nss_nisplus/nisplus-initgroups.c: Likewise.
* nis/nss_nisplus/nisplus-network.c: Likewise.
* nis/nss_nisplus/nisplus-proto.c: Likewise.
* nis/nss_nisplus/nisplus-pwd.c: Likewise.
* nis/nss_nisplus/nisplus-rpc.c: Likewise.
* nis/nss_nisplus/nisplus-service.c: Likewise.
* nis/nss_nisplus/nisplus-spwd.c: Likewise.
* nis/ypclnt.c: Likewise.
* nptl/libc_pthread_init.c: Likewise.
* nss/getXXbyYY.c: Likewise.
* nss/getXXent.c: Likewise.
* nss/getXXent_r.c: Likewise.
* nss/nss_db/db-XXX.c: Likewise.
* nss/nss_db/db-netgrp.c: Likewise.
* nss/nss_db/nss_db.h: Likewise.
* nss/nss_files/files-XXX.c: Likewise.
* nss/nss_files/files-alias.c: Likewise.
* nss/nsswitch.c: Likewise.
* posix/regex_internal.h: Likewise.
* posix/wordexp.c: Likewise.
* pwd/fgetpwent.c: Likewise.
* resolv/res_hconf.c: Likewise.
* resolv/res_libc.c: Likewise.
* shadow/fgetspent.c: Likewise.
* shadow/lckpwdf.c: Likewise.
* shadow/sgetspent.c: Likewise.
* socket/opensock.c: Likewise.
* stdio-common/reg-modifier.c: Likewise.
* stdio-common/reg-printf.c: Likewise.
* stdio-common/reg-type.c: Likewise.
* stdio-common/vfprintf.c: Likewise.
* stdio-common/vfscanf.c: Likewise.
* stdlib/abort.c: Likewise.
* stdlib/cxa_atexit.c: Likewise.
* stdlib/fmtmsg.c: Likewise.
* stdlib/random.c: Likewise.
* stdlib/setenv.c: Likewise.
* string/strsignal.c: Likewise.
* sunrpc/auth_none.c: Likewise.
* sunrpc/bindrsvprt.c: Likewise.
* sunrpc/create_xid.c: Likewise.
* sunrpc/key_call.c: Likewise.
* sunrpc/rpc_thread.c: Likewise.
* sysdeps/arm/backtrace.c: Likewise.
* sysdeps/generic/ldsodefs.h: Likewise.
* sysdeps/generic/stdio-lock.h: Likewise.
* sysdeps/generic/unwind-dw2-fde.c: Likewise.
* sysdeps/i386/backtrace.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-compat.c: Likewise.
* sysdeps/m68k/backtrace.c: Likewise.
* sysdeps/mach/hurd/cthreads.c: Likewise.
* sysdeps/mach/hurd/dirstream.h: Likewise.
* sysdeps/mach/hurd/malloc-machine.h: Likewise.
* sysdeps/nptl/malloc-machine.h: Likewise.
* sysdeps/nptl/stdio-lock.h: Likewise.
* sysdeps/posix/dirstream.h: Likewise.
* sysdeps/posix/getaddrinfo.c: Likewise.
* sysdeps/posix/system.c: Likewise.
* sysdeps/pthread/aio_suspend.c: Likewise.
* sysdeps/s390/s390-32/backtrace.c: Likewise.
* sysdeps/s390/s390-64/backtrace.c: Likewise.
* sysdeps/unix/sysv/linux/check_pf.c: Likewise.
* sysdeps/unix/sysv/linux/if_index.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/getutent_r.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/getutid_r.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/getutline_r.c: Likewise.
* sysdeps/unix/sysv/linux/shm-directory.c: Likewise.
* sysdeps/unix/sysv/linux/system.c: Likewise.
* sysdeps/x86_64/backtrace.c: Likewise.
* time/alt_digit.c: Likewise.
* time/era.c: Likewise.
* time/tzset.c: Likewise.
* wcsmbs/wcsmbsload.c: Likewise.
* nptl/tst-initializers1.c (do_test): Refer to <libc-lock.h>
instead of <bits/libc-lock.h> in comment.
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It was noted in
<https://sourceware.org/ml/libc-alpha/2012-09/msg00305.html> that the
bits/*.h naming scheme should only be used for installed headers.
This patch renames bits/linkmap.h to plain linkmap.h to follow that
convention.
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch).
[BZ #14912]
* bits/linkmap.h: Move to ...
* sysdeps/generic/linkmap.h: ...here.
* sysdeps/aarch64/bits/linkmap.h: Move to ...
* sysdeps/aarch64/linkmap.h: ...here.
* sysdeps/arm/bits/linkmap.h: Move to ...
* sysdeps/arm/linkmap.h: ...here.
* sysdeps/hppa/bits/linkmap.h: Move to ...
* sysdeps/hppa/linkmap.h: ...here.
* sysdeps/ia64/bits/linkmap.h: Move to ...
* sysdeps/ia64/linkmap.h: ...here.
* sysdeps/mips/bits/linkmap.h: Move to ...
* sysdeps/mips/linkmap.h: ...here.
* sysdeps/s390/bits/linkmap.h: Move to ...
* sysdeps/s390/linkmap.h: ...here.
* sysdeps/sh/bits/linkmap.h: Move to ...
* sysdeps/sh/linkmap.h: ...here.
* sysdeps/x86/bits/linkmap.h: Move to ...
* sysdeps/x86/linkmap.h: ...here.
* include/link.h: Include <linkmap.h> instead of <bits/linkmap.h>.
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When an TLS destructor is registered, we set the DF_1_NODELETE flag to
signal that the object should not be destroyed. We then clear the
DF_1_NODELETE flag when all destructors are called, which is wrong -
the flag could have been set by other means too.
This patch replaces this use of the flag by using l_tls_dtor_count
directly to determine whether it is safe to unload the object. This
change has the added advantage of eliminating the lock taking when
calling the destructors, which could result in a deadlock. The patch
also fixes the test case tst-tls-atexit - it was making an invalid
dlclose call, which would just return an error silently.
I have also added a detailed note on concurrency which also aims to
justify why I chose the semantics I chose for accesses to
l_tls_dtor_count. Thanks to Torvald for his help in getting me
started on this and (literally) teaching my how to approach the
problem.
Change verified on x86_64; the test suite does not show any
regressions due to the patch.
ChangeLog:
[BZ #18657]
* elf/dl-close.c (_dl_close_worker): Don't unload DSO if there
are pending TLS destructor calls.
* include/link.h (struct link_map): Add concurrency note for
L_TLS_DTOR_COUNT.
* stdlib/cxa_thread_atexit_impl.c (__cxa_thread_atexit_impl):
Don't touch the link map flag. Atomically increment
l_tls_dtor_count.
(__call_tls_dtors): Atomically decrement l_tls_dtor_count.
Avoid taking the load lock and don't touch the link map flag.
* stdlib/tst-tls-atexit-nodelete.c: New test case.
* stdlib/Makefile (tests): Use it.
* stdlib/tst-tls-atexit.c (do_test): dlopen
tst-tls-atexit-lib.so again before dlclose. Add conditionals
to allow tst-tls-atexit-nodelete test case to use it.
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This feature is specifically for the C++ compiler to offload calling
thread_local object destructors on thread program exit, to glibc.
This is to overcome the possible complication of destructors of
thread_local objects getting called after the DSO in which they're
defined is unloaded by the dynamic linker. The DSO is marked as
'unloadable' if it has a constructed thread_local object and marked as
'unloadable' again when all the constructed thread_local objects
defined in it are destroyed.
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* include/link.h (FORCED_DYNAMIC_TLS_OFFSET) [NO_TLS_OFFSET == 0]:
Change to -1.
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[BZ #13579] Do not free l_initfini and allow it to be reused
on subsequent dl_open calls for the same library. This fixes
the invalid memory access in do_lookup_x when the previously
free'd l_initfini was accessed through l_searchlist when a
library had been opened for the second time.
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On some architectures the update of the l_used field in the lookup
functions races with setting the other bits in the bitfield. Simply
avoid this and optimize use of l_used in general.
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* elf/dl-close.c (_dl_close): Check for it.
* elf/dl-reloc.c (CHECK_STATIC_TLS): Likewise.
(_dl_allocate_static_tls): Likewise.
* elf/dl-tls.c (_dl_allocate_tls_init): Likewise.
(__tls_get_addr): Protect from race conditions in setting l_tls_offset
to it.
* elf/tst-tls16.c: New file.
* elf/tst-tlsmod16a.c: New file.
* elf/tst-tlsmod16b.c: New file.
* elf/Makefile: Add rules to build and run tst-tls16.
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void * pointers instead of struct link_map **.
(_dl_scope_free): Change argument type to void *.
* include/link.h (struct link_map): Change type of l_reldeps
to struct link_map_reldeps, move l_reldepsact into that
struct too.
* elf/dl-deps.c: Include atomic.h.
(_dl_map_object_deps): Only change l->l_initfini when it is
fully populated, use _dl_scope_free for freeing it. Optimize
removal of libs from reldeps by using l_reserved flag, when
some removal is needed, allocate a new list instead of
reallocating and free the old with _dl_scope_free. Adjust
for l_reldeps and l_reldepsact changes.
* elf/dl-lookup.c (add_dependency): Likewise. Reorganize to allow
searching in l_initfini and l_reldeps without holding dl_load_lock.
* elf/dl-fini.c (_dl_sort_fini): Adjust for l_reldeps and
l_reldepsact changes.
* elf/dl-close.c (_dl_close_worker): Likewise.
* elf/dl-open.c (_dl_scop |
