Commit Graph

30 Commits

Author SHA1 Message Date
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
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 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Adhemerval Zanella
5118dcac68 elf: Fix elf_get_dynamic_info() for bootstrap
THe d6d89608ac broke powerpc for --enable-bind-now because it turned
out that different than patch assumption rtld elf_get_dynamic_info()
does require to handle RTLD_BOOTSTRAP to avoid DT_FLAGS and
DT_RUNPATH (more specially the GLRO usage which is not reallocate
yet).

This patch fixes by passing two arguments to elf_get_dynamic_info()
to inform that by rtld (bootstrap) or static pie initialization
(static_pie_bootstrap).  I think using explicit argument is way more
clear and burried C preprocessor, and compiler should remove the
dead code.

I checked on x86_64 and i686 with default options, --enable-bind-now,
and --enable-bind-now and --enable--static-pie.  I also check on
aarch64, armhf, powerpc64, and powerpc with default and
--enable-bind-now.
2021-10-18 09:51:56 -03:00
Adhemerval Zanella
d6d89608ac elf: Fix dynamic-link.h usage on rtld.c
The 4af6982e4c fix does not fully handle RTLD_BOOTSTRAP usage on
rtld.c due two issues:

  1. RTLD_BOOTSTRAP is also used on dl-machine.h on various
     architectures and it changes the semantics of various machine
     relocation functions.

  2. The elf_get_dynamic_info() change was done sideways, previously
     to 490e6c62aa get-dynamic-info.h was included by the first
     dynamic-link.h include *without* RTLD_BOOTSTRAP being defined.
     It means that the code within elf_get_dynamic_info() that uses
     RTLD_BOOTSTRAP is in fact unused.

To fix 1. this patch now includes dynamic-link.h only once with
RTLD_BOOTSTRAP defined.  The ELF_DYNAMIC_RELOCATE call will now have
the relocation fnctions with the expected semantics for the loader.

And to fix 2. part of 4af6982e4c is reverted (the check argument
elf_get_dynamic_info() is not required) and the RTLD_BOOTSTRAP
pieces are removed.

To reorganize the includes the static TLS definition is moved to
its own header to avoid a circular dependency (it is defined on
dynamic-link.h and dl-machine.h requires it at same time other
dynamic-link.h definition requires dl-machine.h defitions).

Also ELF_MACHINE_NO_REL, ELF_MACHINE_NO_RELA, and ELF_MACHINE_PLT_REL
are moved to its own header.  Only ancient ABIs need special values
(arm, i386, and mips), so a generic one is used as default.

The powerpc Elf64_FuncDesc is also moved to its own header, since
csu code required its definition (which would require either include
elf/ folder or add a full path with elf/).

Checked on x86_64, i686, aarch64, armhf, powerpc64, powerpc32,
and powerpc64le.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-10-14 14:52:07 -03:00
Adhemerval Zanella
4af6982e4c elf: Fix elf_get_dynamic_info definition
Before to 490e6c62aa ('elf: Avoid nested functions in the loader
[BZ #27220]'), elf_get_dynamic_info() was defined twice on rtld.c: on
the first dynamic-link.h include and later within _dl_start().  The
former definition did not define DONT_USE_BOOTSTRAP_MAP and it is used
on setup_vdso() (since it is a global definition), while the former does
define DONT_USE_BOOTSTRAP_MAP and it is used on loader self-relocation.

With the commit change, the function is now included and defined once
instead of defined as a nested function.  So rtld.c defines without
defining RTLD_BOOTSTRAP and it brokes at least powerpc32.

This patch fixes by moving the get-dynamic-info.h include out of
dynamic-link.h, which then the caller can corirectly set the expected
semantic by defining STATIC_PIE_BOOTSTRAP, RTLD_BOOTSTRAP, and/or
RESOLVE_MAP.

It also required to enable some asserts only for the loader bootstrap
to avoid issues when called from setup_vdso().

As a side note, this is another issues with nested functions: it is
not clear from pre-processed output (-E -dD) how the function will
be build and its semantic (since nested function will be local and
extra C defines may change it).

I checked on x86_64-linux-gnu (w/o --enable-static-pie),
i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4,
aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and
s390x-linux-gnu.

Reviewed-by: Fangrui Song <maskray@google.com>
2021-10-12 13:25:43 -03:00
Fangrui Song
490e6c62aa elf: Avoid nested functions in the loader [BZ #27220]
dynamic-link.h is included more than once in some elf/ files (rtld.c,
dl-conflict.c, dl-reloc.c, dl-reloc-static-pie.c) and uses GCC nested
functions. This harms readability and the nested functions usage
is the biggest obstacle prevents Clang build (Clang doesn't support GCC
nested functions).

The key idea for unnesting is to add extra parameters (struct link_map
*and struct r_scope_elm *[]) to RESOLVE_MAP,
ELF_MACHINE_BEFORE_RTLD_RELOC, ELF_DYNAMIC_RELOCATE, elf_machine_rel[a],
elf_machine_lazy_rel, and elf_machine_runtime_setup. (This is inspired
by Stan Shebs' ppc64/x86-64 implementation in the
google/grte/v5-2.27/master which uses mixed extra parameters and static
variables.)

Future simplification:
* If mips elf_machine_runtime_setup no longer needs RESOLVE_GOTSYM,
  elf_machine_runtime_setup can drop the `scope` parameter.
* If TLSDESC no longer need to be in elf_machine_lazy_rel,
  elf_machine_lazy_rel can drop the `scope` parameter.

Tested on aarch64, i386, x86-64, powerpc64le, powerpc64, powerpc32,
sparc64, sparcv9, s390x, s390, hppa, ia64, armhf, alpha, and mips64.
In addition, tested build-many-glibcs.py with {arc,csky,microblaze,nios2}-linux-gnu
and riscv64-linux-gnu-rv64imafdc-lp64d.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-07 11:55:02 -07:00
H.J. Lu
b413280cfb ld.so: Replace DL_RO_DYN_SECTION with dl_relocate_ld [BZ #28340]
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>
2021-09-22 11:12:43 -07:00
Szabolcs Nagy
86a4d3fa7d elf: work around a gcc bug in elf_get_dynamic_info
Since commit 2f056e8a5d
"aarch64: define PI_STATIC_AND_HIDDEN",
building glibc with gcc-8 on aarch64 fails with

/BLD/elf/librtld.os: in function `elf_get_dynamic_info':
/SRC/elf/get-dynamic-info.h:70:(.text+0xad8): relocation truncated to
 fit: R_AARCH64_ADR_PREL_PG_HI21 against symbol `_rtld_local' defined
 in .data section in /BLD/elf/librtld.os

This is a gcc bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98618
The bug is fixed on gcc-10 and not yet backported. gcc-9 is affected,
but the issue happens to not trigger in glibc, gcc-8 and older seems
to miscompile rtld.os.

Rewriting the affected code in elf_get_dynamic_info seems to make the
issue go away on <= gcc-9.

The change makes the logic a bit clearer too (by separating the index
computation and array update) and drops an older gcc workaround (since
gcc 4.6 is no longer supported).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-01-13 13:35:00 +00:00
Paul Eggert
2b778ceb40 Update copyright dates with scripts/update-copyrights
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
2021-01-02 12:17:34 -08:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
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
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
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
Joseph Myers
34a5a1460e Break some lines before not after operators.
The GNU Coding Standards specify that line breaks in expressions
should go before an operator, not after one.  This patch fixes various
code to do this.  It only changes code that appears to be mostly
following GNU style anyway, not files and directories with
substantially different formatting.  It is not exhaustive even for
files using GNU style (for example, changes to sysdeps files are
deferred for subsequent cleanups).  Some files changed are shared with
gnulib, but most are specific to glibc.  Changes were made manually,
with places to change found by grep (so some cases, e.g. where the
operator was followed by a comment at end of line, are particularly
liable to have been missed by grep, but I did include cases where the
operator was followed by backslash-newline).

This patch generally does not attempt to address other coding style
issues in the expressions changed (for example, missing spaces before
'(', or lack of parentheses to ensure indentation of continuation
lines properly reflects operator precedence).

Tested for x86_64, and with build-many-glibcs.py.

	* benchtests/bench-memmem.c (simple_memmem): Break lines before
	rather than after operators.
	* benchtests/bench-skeleton.c (TIMESPEC_AFTER): Likewise.
	* crypt/md5.c (md5_finish_ctx): Likewise.
	* crypt/sha256.c (__sha256_finish_ctx): Likewise.
	* crypt/sha512.c (__sha512_finish_ctx): Likewise.
	* elf/cache.c (load_aux_cache): Likewise.
	* elf/dl-load.c (open_verify): Likewise.
	* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
	* elf/readelflib.c (process_elf_file): Likewise.
	* elf/rtld.c (dl_main): Likewise.
	* elf/sprof.c (generate_call_graph): Likewise.
	* hurd/ctty-input.c (_hurd_ctty_input): Likewise.
	* hurd/ctty-output.c (_hurd_ctty_output): Likewise.
	* hurd/dtable.c (reauth_dtable): Likewise.
	* hurd/getdport.c (__getdport): Likewise.
	* hurd/hurd/signal.h (_hurd_interrupted_rpc_timeout): Likewise.
	* hurd/hurd/sigpreempt.h (HURD_PREEMPT_SIGNAL_P): Likewise.
	* hurd/hurdfault.c (_hurdsig_fault_catch_exception_raise):
	Likewise.
	* hurd/hurdioctl.c (fioctl): Likewise.
	* hurd/hurdselect.c (_hurd_select): Likewise.
	* hurd/hurdsig.c (_hurdsig_abort_rpcs): Likewise.
	(STOPSIGS): Likewise.
	* hurd/hurdstartup.c (_hurd_startup): Likewise.
	* hurd/intr-msg.c (_hurd_intr_rpc_mach_msg): Likewise.
	* hurd/lookup-retry.c (__hurd_file_name_lookup_retry): Likewise.
	* hurd/msgportdemux.c (msgport_server): Likewise.
	* hurd/setauth.c (_hurd_setauth): Likewise.
	* include/features.h (__GLIBC_USE_DEPRECATED_SCANF): Likewise.
	* libio/libioP.h [IO_DEBUG] (CHECK_FILE): Likewise.
	* locale/programs/ld-ctype.c (set_class_defaults): Likewise.
	* localedata/tests-mbwc/tst_swscanf.c (tst_swscanf): Likewise.
	* login/tst-utmp.c (do_check): Likewise.
	(simulate_login): Likewise.
	* mach/lowlevellock.h (lll_lock): Likewise.
	(lll_trylock): Likewise.
	* math/test-fenv.c (ALL_EXC): Likewise.
	* math/test-fenvinline.c (ALL_EXC): Likewise.
	* misc/sys/cdefs.h (__attribute_deprecated_msg__): Likewise.
	* nis/nis_call.c (__do_niscall3): Likewise.
	* nis/nis_callback.c (cb_prog_1): Likewise.
	* nis/nis_defaults.c (searchaccess): Likewise.
	* nis/nis_findserv.c (__nis_findfastest_with_timeout): Likewise.
	* nis/nis_ismember.c (internal_ismember): Likewise.
	* nis/nis_local_names.c (nis_local_principal): Likewise.
	* nis/nss_nis/nis-rpc.c (_nss_nis_getrpcbyname_r): Likewise.
	* nis/nss_nisplus/nisplus-netgrp.c (_nss_nisplus_getnetgrent_r):
	Likewise.
	* nis/ypclnt.c (yp_match): Likewise.
	(yp_first): Likewise.
	(yp_next): Likewise.
	(yp_master): Likewise.
	(yp_order): Likewise.
	* nscd/hstcache.c (cache_addhst): Likewise.
	* nscd/initgrcache.c (addinitgroupsX): Likewise.
	* nss/nss_compat/compat-pwd.c (copy_pwd_changes): Likewise.
	(internal_getpwuid_r): Likewise.
	* nss/nss_compat/compat-spwd.c (copy_spwd_changes): Likewise.
	* posix/glob.h (__GLOB_FLAGS): Likewise.
	* posix/regcomp.c (peek_token): Likewise.
	(peek_token_bracket): Likewise.
	(parse_expression): Likewise.
	* posix/regexec.c (sift_states_iter_mb): Likewise.
	(check_node_accept_bytes): Likewise.
	* posix/tst-spawn3.c (do_test): Likewise.
	* posix/wordexp-test.c (testit): Likewise.
	* posix/wordexp.c (parse_tilde): Likewise.
	(exec_comm): Likewise.
	* posix/wordexp.h (__WRDE_FLAGS): Likewise.
	* resource/vtimes.c (TIMEVAL_TO_VTIMES): Likewise.
	* setjmp/sigjmp.c (__sigjmp_save): Likewise.
	* stdio-common/printf_fp.c (__printf_fp_l): Likewise.
	* stdio-common/tst-fileno.c (do_test): Likewise.
	* stdio-common/vfprintf-internal.c (vfprintf): Likewise.
	* stdlib/strfmon_l.c (__vstrfmon_l_internal): Likewise.
	* stdlib/strtod_l.c (round_and_return): Likewise.
	(____STRTOF_INTERNAL): Likewise.
	* stdlib/tst-strfrom.h (TEST_STRFROM): Likewise.
	* string/strcspn.c (STRCSPN): Likewise.
	* string/test-memmem.c (simple_memmem): Likewise.
	* termios/tcsetattr.c (tcsetattr): Likewise.
	* time/alt_digit.c (_nl_parse_alt_digit): Likewise.
	* time/asctime.c (asctime_internal): Likewise.
	* time/strptime_l.c (__strptime_internal): Likewise.
	* time/sys/time.h (timercmp): Likewise.
	* time/tzfile.c (__tzfile_compute): Likewise.
2019-02-22 01:32:36 +00:00
Joseph Myers
04277e02d7 Update copyright dates with scripts/update-copyrights.
* 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.
2019-01-01 00:11:28 +00:00
H.J. Lu
6a5cac49b6 Use ADDRIDX with DT_GNU_HASH
The only differences in ld.so are line numbers for asserts.

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>

	* elf/dl-addr.c (determine_info): Use ADDRIDX with DT_GNU_HASH.
	* elf/dl-lookup.c (_dl_setup_hash): Likewise.
	* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
2018-02-05 14:58:57 -08:00
Joseph Myers
688903eb3e Update copyright dates with scripts/update-copyrights.
* 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.
2018-01-01 00:32:25 +00:00
H.J. Lu
9d7a3741c9 Add --enable-static-pie configure option to build static PIE [BZ #19574]
Static PIE extends address space layout randomization to static
executables.  It provides additional security hardening benefits at
the cost of some memory and performance.

Dynamic linker, ld.so, is a standalone program which can be loaded at
any address.  This patch adds a configure option, --enable-static-pie,
to embed the part of ld.so in static executable to create static position
independent executable (static PIE).  A static PIE is similar to static
executable, but can be loaded at any address without help from a dynamic
linker.  When --enable-static-pie is used to configure glibc, libc.a is
built as PIE and all static executables, including tests, are built as
static PIE.  The resulting libc.a can be used together with GCC 8 or
above to build static PIE with the compiler option, -static-pie.  But
GCC 8 isn't required to build glibc with --enable-static-pie.  Only GCC
with PIE support is needed.  When an older GCC is used to build glibc
with --enable-static-pie, proper input files are passed to linker to
create static executables as static PIE, together with "-z text" to
prevent dynamic relocations in read-only segments, which are not allowed
in static PIE.

The following changes are made for static PIE:

1. Add a new function, _dl_relocate_static_pie, to:
   a. Get the run-time load address.
   b. Read the dynamic section.
   c. Perform dynamic relocations.
Dynamic linker also performs these steps.  But static PIE doesn't load
any shared objects.
2. Call _dl_relocate_static_pie at entrance of LIBC_START_MAIN in
libc.a.  crt1.o, which is used to create dynamic and non-PIE static
executables, is updated to include a dummy _dl_relocate_static_pie.
rcrt1.o is added to create static PIE, which will link in the real
_dl_relocate_static_pie.  grcrt1.o is also added to create static PIE
with -pg.  GCC 8 has been updated to support rcrt1.o and grcrt1.o for
static PIE.

Static PIE can work on all architectures which support PIE, provided:

1. Target must support accessing of local functions without dynamic
relocations, which is needed in start.S to call __libc_start_main with
function addresses of __libc_csu_init, __libc_csu_fini and main.  All
functions in static PIE are local functions.  If PIE start.S can't reach
main () defined in a shared object, the code sequence:

	pass address of local_main to __libc_start_main
	...

local_main:
	tail call to main via PLT

can be used.
2. start.S is updated to check PIC instead SHARED for PIC code path and
avoid dynamic relocation, when PIC is defined and SHARED isn't defined,
to support static PIE.
3. All assembly codes are updated check PIC instead SHARED for PIC code
path to avoid dynamic relocations in read-only sections.
4. All assembly codes are updated check SHARED instead PIC for static
symbol name.
5. elf_machine_load_address in dl-machine.h are updated to support static
PIE.
6. __brk works without TLS nor dynamic relocations in read-only section
so that it can be used by __libc_setup_tls to initializes TLS in static
PIE.

NB: When glibc is built with GCC defaulted to PIE, libc.a is compiled
with -fPIE, regardless if --enable-static-pie is used to configure glibc.
When glibc is configured with --enable-static-pie, libc.a is compiled
with -fPIE, regardless whether GCC defaults to PIE or not.  The same
libc.a can be used to build both static executable and static PIE.
There is no need for separate PIE copy of libc.a.

On x86-64, the normal static sln:

   text	   data	    bss	    dec	    hex	filename
 625425	   8284	   5456	 639165	  9c0bd	elf/sln

the static PIE sln:

   text	   data	    bss	    dec	    hex	filename
 657626	  20636	   5392	 683654	  a6e86	elf/sln

The code size is increased by 5% and the binary size is increased by 7%.

Linker requirements to build glibc with --enable-static-pie:

1. Linker supports --no-dynamic-linker to remove PT_INTERP segment from
static PIE.
2. Linker can create working static PIE.  The x86-64 linker needs the
fix for

https://sourceware.org/bugzilla/show_bug.cgi?id=21782

The i386 linker needs to be able to convert "movl main@GOT(%ebx), %eax"
to "leal main@GOTOFF(%ebx), %eax" if main is defined locally.

Binutils 2.29 or above are OK for i686 and x86-64.  But linker status for
other targets need to be verified.

3. Linker should resolve undefined weak symbols to 0 in static PIE:

https://sourceware.org/bugzilla/show_bug.cgi?id=22269

4. Many ELF backend linkers incorrectly check bfd_link_pic for TLS
relocations, which should check bfd_link_executable instead:

https://sourceware.org/bugzilla/show_bug.cgi?id=22263

Tested on aarch64, i686 and x86-64.

Using GCC 7 and binutils master branch, build-many-glibcs.py with
--enable-static-pie with all patches for static PIE applied have the
following build successes:

PASS: glibcs-aarch64_be-linux-gnu build
PASS: glibcs-aarch64-linux-gnu build
PASS: glibcs-armeb-linux-gnueabi-be8 build
PASS: glibcs-armeb-linux-gnueabi build
PASS: glibcs-armeb-linux-gnueabihf-be8 build
PASS: glibcs-armeb-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabi build
PASS: glibcs-arm-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabihf-v7a build
PASS: glibcs-arm-linux-gnueabihf-v7a-disable-multi-arch build
PASS: glibcs-m68k-linux-gnu build
PASS: glibcs-microblazeel-linux-gnu build
PASS: glibcs-microblaze-linux-gnu build
PASS: glibcs-mips64el-linux-gnu-n32 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n32-soft build
PASS: glibcs-mips64el-linux-gnu-n64 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n64-soft build
PASS: glibcs-mips64-linux-gnu-n32 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n32-soft build
PASS: glibcs-mips64-linux-gnu-n64 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n64-soft build
PASS: glibcs-mipsel-linux-gnu build
PASS: glibcs-mipsel-linux-gnu-nan2008 build
PASS: glibcs-mipsel-linux-gnu-nan2008-soft build
PASS: glibcs-mipsel-linux-gnu-soft build
PASS: glibcs-mips-linux-gnu build
PASS: glibcs-mips-linux-gnu-nan2008 build
PASS: glibcs-mips-linux-gnu-nan2008-soft build
PASS: glibcs-mips-linux-gnu-soft build
PASS: glibcs-nios2-linux-gnu build
PASS: glibcs-powerpc64le-linux-gnu build
PASS: glibcs-powerpc64-linux-gnu build
PASS: glibcs-tilegxbe-linux-gnu-32 build
PASS: glibcs-tilegxbe-linux-gnu build
PASS: glibcs-tilegx-linux-gnu-32 build
PASS: glibcs-tilegx-linux-gnu build
PASS: glibcs-tilepro-linux-gnu build

and the following build failures:

FAIL: glibcs-alpha-linux-gnu build

elf/sln is failed to link due to:

assertion fail bfd/elf64-alpha.c:4125

This is caused by linker bug and/or non-PIC code in PIE libc.a.

FAIL: glibcs-hppa-linux-gnu build

elf/sln is failed to link due to:

collect2: fatal error: ld terminated with signal 11 [Segmentation fault]

https://sourceware.org/bugzilla/show_bug.cgi?id=22537

FAIL: glibcs-ia64-linux-gnu build

elf/sln is failed to link due to:

collect2: fatal error: ld terminated with signal 11 [Segmentation fault]

FAIL: glibcs-powerpc-linux-gnu build
FAIL: glibcs-powerpc-linux-gnu-soft build
FAIL: glibcs-powerpc-linux-gnuspe build
FAIL: glibcs-powerpc-linux-gnuspe-e500v1 build

elf/sln is failed to link due to:

ld: read-only segment has dynamic relocations.

This is caused by linker bug and/or non-PIC code in PIE libc.a.  See:

https://sourceware.org/bugzilla/show_bug.cgi?id=22264

FAIL: glibcs-powerpc-linux-gnu-power4 build

elf/sln is failed to link due to:

findlocale.c:96:(.text+0x22c): @local call to ifunc memchr

This is caused by linker bug and/or non-PIC code in PIE libc.a.

FAIL: glibcs-s390-linux-gnu build

elf/sln is failed to link due to:

collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped

assertion fail bfd/elflink.c:14299

This is caused by linker bug and/or non-PIC code in PIE libc.a.

FAIL: glibcs-sh3eb-linux-gnu build
FAIL: glibcs-sh3-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu-soft build
FAIL: glibcs-sh4-linux-gnu build
FAIL: glibcs-sh4-linux-gnu-soft build

elf/sln is failed to link due to:

ld: read-only segment has dynamic relocations.

This is caused by linker bug and/or non-PIC code in PIE libc.a.  See:

https://sourceware.org/bugzilla/show_bug.cgi?id=22263

Also TLS code sequence in SH assembly syscalls in glibc doesn't match TLS
code sequence expected by ld:

https://sourceware.org/bugzilla/show_bug.cgi?id=22270

FAIL: glibcs-sparc64-linux-gnu build
FAIL: glibcs-sparcv9-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu-32 build
FAIL: glibcs-tilegx-linux-gnu build
FAIL: glibcs-tilegx-linux-gnu-32 build
FAIL: glibcs-tilepro-linux-gnu build

elf/sln is failed to link due to:

ld: read-only segment has dynamic relocations.

This is caused by linker bug and/or non-PIC code in PIE libc.a.  See:

https://sourceware.org/bugzilla/show_bug.cgi?id=22263

	[BZ #19574]
	* INSTALL: Regenerated.
	* Makeconfig (real-static-start-installed-name): New.
	(pic-default): Updated for --enable-static-pie.
	(pie-default): New for --enable-static-pie.
	(default-pie-ldflag): Likewise.
	(+link-static-before-libc): Replace $(DEFAULT-LDFLAGS-$(@F))
	with $(if $($(@F)-no-pie),$(no-pie-ldflag),$(default-pie-ldflag)).
	Replace $(static-start-installed-name) with
	$(real-static-start-installed-name).
	(+prectorT): Updated for --enable-static-pie.
	(+postctorT): Likewise.
	(CFLAGS-.o): Add $(pie-default).
	(CFLAGS-.op): Likewise.
	* NEWS: Mention --enable-static-pie.
	* config.h.in (ENABLE_STATIC_PIE): New.
	* configure.ac (--enable-static-pie): New configure option.
	(have-no-dynamic-linker): New LIBC_CONFIG_VAR.
	(have-static-pie): Likewise.
	Enable static PIE if linker supports --no-dynamic-linker.
	(ENABLE_STATIC_PIE): New AC_DEFINE.
	(enable-static-pie): New LIBC_CONFIG_VAR.
	* configure: Regenerated.
	* csu/Makefile (omit-deps): Add r$(start-installed-name) and
	gr$(start-installed-name) for --enable-static-pie.
	(extra-objs): Likewise.
	(install-lib): Likewise.
	(extra-objs): Add static-reloc.o and static-reloc.os
	($(objpfx)$(start-installed-name)): Also depend on
	$(objpfx)static-reloc.o.
	($(objpfx)r$(start-installed-name)): New.
	($(objpfx)g$(start-installed-name)): Also depend on
	$(objpfx)static-reloc.os.
	($(objpfx)gr$(start-installed-name)): New.
	* csu/libc-start.c (LIBC_START_MAIN): Call _dl_relocate_static_pie
	in libc.a.
	* csu/libc-tls.c (__libc_setup_tls): Add main_map->l_addr to
	initimage.
	* csu/static-reloc.c: New file.
	* elf/Makefile (routines): Add dl-reloc-static-pie.
	(elide-routines.os): Likewise.
	(DEFAULT-LDFLAGS-tst-tls1-static-non-pie): Removed.
	(tst-tls1-static-non-pie-no-pie): New.
	* elf/dl-reloc-static-pie.c: New file.
	* elf/dl-support.c (_dl_get_dl_main_map): New function.
	* elf/dynamic-link.h (ELF_DURING_STARTUP): Also check
	STATIC_PIE_BOOTSTRAP.
	* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
	* gmon/Makefile (tests): Add tst-gmon-static-pie.
	(tests-static): Likewise.
	(DEFAULT-LDFLAGS-tst-gmon-static): Removed.
	(tst-gmon-static-no-pie): New.
	(CFLAGS-tst-gmon-static-pie.c): Likewise.
	(CRT-tst-gmon-static-pie): Likewise.
	(tst-gmon-static-pie-ENV): Likewise.
	(tests-special): Likewise.
	($(objpfx)tst-gmon-static-pie.out): Likewise.
	(clean-tst-gmon-static-pie-data): Likewise.
	($(objpfx)tst-gmon-static-pie-gprof.out): Likewise.
	* gmon/tst-gmon-static-pie.c: New file.
	* manual/install.texi: Document --enable-static-pie.
	* sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New.
	(_dl_get_dl_main_map): Likewise.
	* sysdeps/i386/configure.ac: Check if linker supports static PIE.
	* sysdeps/x86_64/configure.ac: Likewise.
	* sysdeps/i386/configure: Regenerated.
	* sysdeps/x86_64/configure: Likewise.
	* sysdeps/mips/Makefile (ASFLAGS-.o): Add $(pie-default).
	(ASFLAGS-.op): Likewise.
2017-12-15 17:12:14 -08:00
Florian Weimer
a10e9c4e53 Remove header file inclusion guard from elf/get-dynamic-info.h
This file is included multiple times, so the guard is harmful.
Fixes commit 9090848d06.
2017-03-02 17:28:41 +01:00
Zack Weinberg
9090848d06 Narrowing the visibility of libc-internal.h even further.
posix/wordexp-test.c used libc-internal.h for PTR_ALIGN_DOWN; similar
to what was done with libc-diag.h, I have split the definitions of
cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN
to a new header, libc-pointer-arith.h.

It then occurred to me that the remaining declarations in libc-internal.h
are mostly to do with early initialization, and probably most of the
files including it, even in the core code, don't need it anymore.  Indeed,
only 19 files actually need what remains of libc-internal.h.  23 others
need libc-diag.h instead, and 12 need libc-pointer-arith.h instead.
No file needs more than one of them, and 16 don't need any of them!

So, with this patch, libc-internal.h stops including libc-diag.h as
well as losing the pointer arithmetic macros, and all including files
are adjusted.

        * include/libc-pointer-arith.h: New file.  Define
	cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and
        PTR_ALIGN_DOWN here.
        * include/libc-internal.h: Definitions of above macros
	moved from here.  Don't include libc-diag.h anymore either.
	* posix/wordexp-test.c: Include stdint.h and libc-pointer-arith.h.
        Don't include libc-internal.h.

	* debug/pcprofile.c, elf/dl-tunables.c, elf/soinit.c, io/openat.c
	* io/openat64.c, misc/ptrace.c, nptl/pthread_clock_gettime.c
	* nptl/pthread_clock_settime.c, nptl/pthread_cond_common.c
	* string/strcoll_l.c, sysdeps/nacl/brk.c
	* sysdeps/unix/clock_settime.c
	* sysdeps/unix/sysv/linux/i386/get_clockfreq.c
	* sysdeps/unix/sysv/linux/ia64/get_clockfreq.c
	* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
	* sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c:
	Don't include libc-internal.h.

	* elf/get-dynamic-info.h, iconv/loop.c
	* iconvdata/iso-2022-cn-ext.c, locale/weight.h, locale/weightwc.h
	* misc/reboot.c, nis/nis_table.c, nptl_db/thread_dbP.h
	* nscd/connections.c, resolv/res_send.c, soft-fp/fmadf4.c
	* soft-fp/fmasf4.c, soft-fp/fmatf4.c, stdio-common/vfscanf.c
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c
	* sysdeps/ieee754/ldbl-128/k_tanl.c
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c
	* sysdeps/ieee754/ldbl-96/k_tanl.c, sysdeps/nptl/futex-internal.h:
	Include libc-diag.h instead of libc-internal.h.

        * elf/dl-load.c, elf/dl-reloc.c, locale/programs/locarchive.c
        * nptl/nptl-init.c, string/strcspn.c, string/strspn.c
	* malloc/malloc.c, sysdeps/i386/nptl/tls.h
	* sysdeps/nacl/dl-map-segments.h, sysdeps/x86_64/atomic-machine.h
	* sysdeps/unix/sysv/linux/spawni.c
        * sysdeps/x86_64/nptl/tls.h:
        Include libc-pointer-arith.h instead of libc-internal.h.

	* elf/get-dynamic-info.h, sysdeps/nacl/dl-map-segments.h
	* sysdeps/x86_64/atomic-machine.h:
        Add multiple include guard.
2017-03-01 20:33:46 -05:00
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Joseph Myers
f7a9f785e5 Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
Joseph Myers
b168057aaa Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
David S. Miller
6d4188dd7f Fix array bounds warnings in elf_get_dyanmic_info() on sparc with gcc-4.6
* get-dynamic-info.h (elf_get_dynamic_info): Ignore -Warray-bounds for a
	link_map->l_info array access.
2014-12-19 13:45:28 -08:00
Allan McRae
d4697bc93d Update copyright notices with scripts/update-copyrights 2014-01-01 22:00:23 +10:00
Adhemerval Zanella
c6bb4f23b0 Revert wrong commit. 2013-12-05 07:47:34 -06:00
Adhemerval Zanella
76a4a26979 Fix elf/get-dynamic-info.h for AT 2013-12-05 05:53:10 -06:00
Joseph Myers
568035b787 Update copyright notices with scripts/update-copyrights. 2013-01-02 19:05:09 +00:00
Carlos O'Donell
c93ec1f091 Warn about unsupported DT_FLAGS_1 flags.
The dynamic loader will now warn about unsupported DT_FLAGS_1
flags when run with LD_DEBUG=files or LD_DEBUG=all.
2012-11-29 18:12:23 -08:00
H.J. Lu
7e1be74125 Check supported DF_1_XXX bits 2012-11-21 06:33:19 -08:00
H.J. Lu
9cee558564 Set up the data structures for vDSO in libc.a 2012-10-05 10:20:39 -07:00