Commit Graph

200 Commits

Author SHA1 Message Date
Joe Simmons-Talbott
5d00c201b9 elf: dl-lookup: Remove unused alloca.h include 2023-09-21 14:08:20 +00:00
Florian Weimer
d0f07f7df8 elf: Make more functions available for binding during dlclose (bug 30425)
Previously, after destructors for a DSO have been invoked, ld.so refused
to bind against that DSO in all cases.  Relax this restriction somewhat
if the referencing object is itself a DSO that is being unloaded.  This
assumes that the symbol reference is not going to be stored anywhere.

The situation in the test case can arise fairly easily with C++ and
objects that are built with different optimization levels and therefore
define different functions with vague linkage.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-05-30 13:25:50 +02:00
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Adhemerval Zanella
891a7958a2 elf: Reinstate on DL_DEBUG_BINDINGS _dl_lookup_symbol_x
The prelink removal done by 6628c742b2 wrongly removed the debug
support.

Checked on x86_64-linux-gnu.
2022-10-26 09:47:10 -03:00
Florian Weimer
a9f9ee2381 elf: Fix direction of NODELETE log messages during symbol lookup
NODELETE status is propagated from the referencing object to the
referenced object, not the other way round.  The code is correct, only
the log message has the wrong direction.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-07-05 14:40:38 +02:00
Fangrui Song
de38b2a343 elf: Remove ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA
If an executable has copy relocations for extern protected data, that
can only work if the library containing the definition is built with
assumptions (a) the compiler emits GOT-generating relocations (b) the
linker produces R_*_GLOB_DAT instead of R_*_RELATIVE.  Otherwise the
library uses its own definition directly and the executable accesses a
stale copy.  Note: the GOT relocations defeat the purpose of protected
visibility as an optimization, but allow rtld to make the executable and
library use the same copy when copy relocations are present, but it
turns out this never worked perfectly.

ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA has strange semantics when both
a.so and b.so define protected var and the executable copy relocates
var: b.so accesses its own copy even with GLOB_DAT.  The behavior change
is from commit 62da1e3b00 (x86) and then
copied to nios2 (ae5eae7cfc) and arc
(0e7d930c4c).

Without ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA, b.so accesses the copy
relocated data like a.so.

There is now a warning for copy relocation on protected symbol since
commit 7374c02b68.  It's extremely
unlikely anyone relies on the ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA
behavior, so let's remove it: this removes a check in the symbol lookup
code.
2022-06-15 11:29:55 -07:00
Noah Goldstein
c4bd509d47 elf: Refactor dl_new_hash so it can be tested / benchmarked
No change to the code other than moving the function to
dl-new-hash.h. Changed name so its now in the reserved namespace.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Noah Goldstein
535e935a28 Replace {u}int_fast{16|32} with {u}int32_t
On 32-bit machines this has no affect. On 64-bit machines
{u}int_fast{16|32} are set as {u}int64_t which is often not
ideal. Particularly x86_64 this change both saves code size and
may save instruction cost.

Full xcheck passes on x86_64.
2022-04-13 21:23:04 -05:00
Adhemerval Zanella
6628c742b2 elf: Remove prelink support
Prelinked binaries and libraries still work, the dynamic tags
DT_GNU_PRELINKED, DT_GNU_LIBLIST, DT_GNU_CONFLICT just ignored
(meaning the process is reallocated as default).

The loader environment variable TRACE_PRELINKING is also removed,
since it used solely on prelink.

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-02-10 09:16:12 -03:00
Florian Weimer
c90363403b elf: Move _dl_setup_hash to its own file
And compile it with the early CFLAGS.  _dl_setup_hash is called
very early for the ld.so link map, so it should be compiled
differently.

Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
Tested-by: Stefan Liebler <stli@linux.ibm.com>
2022-01-18 14:40:21 +01:00
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
H.J. Lu
349b0441da Add run-time check for indirect external access
When performing symbol lookup for references in executable without
indirect external access:

1. Disallow copy relocations in executable against protected data symbols
in a shared object with indirect external access.
2. Disallow non-zero symbol values of undefined function symbols in
executable, which are used as the function pointer, against protected
function symbols in a shared object with indirect external access.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-07 10:26:48 -07:00
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
Florian Weimer
50a2d83c08 elf: Introduce <elf_machine_sym_no_match.h>
MIPS needs to ignore certain existing symbols during symbol lookup.
The old scheme uses the ELF_MACHINE_SYM_NO_MATCH macro, with an
inline function, within its own header, with a sysdeps override for
MIPS.  This allows re-use of the function from another file (without
having to include <dl-machine.h> or providing the default definition
for ELF_MACHINE_SYM_NO_MATCH).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-24 22:13:03 +02:00
Florian Weimer
3a0ecccb59 ld.so: Do not export free/calloc/malloc/realloc functions [BZ #25486]
Exporting functions and relying on symbol interposition from libc.so
makes the choice of implementation dependent on DT_NEEDED order, which
is not what some compiler drivers expect.

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

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

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-02-15 11:01:23 +01:00
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
365624e2d2 dlopen: Fix issues related to NODELETE handling and relocations
The assumption behind the assert in activate_nodelete was wrong:

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

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

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

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

Fixes commit f63b73814f ("Remove all
loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]").
2019-12-13 10:18:24 +01:00
Florian Weimer
f63b73814f Remove all loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]
This introduces a “pending NODELETE” state in the link map, which is
flipped to the persistent NODELETE state late in dlopen, via
activate_nodelete.    During initial relocation, symbol binding
records pending NODELETE state only.  dlclose ignores pending NODELETE
state.  Taken together, this results that a partially completed dlopen
is rolled back completely because new NODELETE mappings are unloaded.

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

Change-Id: Ib2a3d86af6f92d75baca65431d74783ee0dbc292
2019-11-27 20:55:35 +01:00
Florian Weimer
ca136bb0a3 Clarify purpose of assert in _dl_lookup_symbol_x
Only one of the currently defined flags is incompatible with versioned
symbol lookups, so it makes sense to check for that flag and not its
complement.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Change-Id: I3384349cef90cfd91862ebc34a4053f0c0a99404
2019-11-12 20:11:04 +01:00
Paul Eggert
5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

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

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

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

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

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

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

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

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

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

	* elf/dl-addr.c (determine_info): Calculate the symbol index
	using the newly defined ELF_MACHINE_HASH_SYMIDX macro.
	* elf/dl-lookup.c (do_lookup_x): Ditto.
	(_dl_setup_hash): Initialize MIPS xhash translation table.
	* elf/elf.h (SHT_MIPS_XHASH): New define.
	(DT_MIPS_XHASH): New define.
	* sysdeps/generic/ldsodefs.h (ELF_MACHINE_GNU_HASH_ADDRIDX): New
	define.
	(ELF_MACHINE_HASH_SYMIDX): Ditto.
	(ELF_MACHINE_XHASH_SETUP): Ditto.
	* sysdeps/mips/ldsodefs.h (ELF_MACHINE_GNU_HASH_ADDRIDX): New
	define.
	(ELF_MACHINE_HASH_SYMIDX): Ditto.
	(ELF_MACHINE_XHASH_SETUP): Ditto.
	* sysdeps/mips/linkmap.h (struct link_map_machine): New member.
	* sysdeps/unix/sysv/linux/mips/ldsodefs.h: Increment valid ABI
	version.
	* sysdeps/unix/sysv/linux/mips/libc-abis: New ABI version.
2019-08-29 20:11:42 +00:00
Florian Weimer
f0b2132b35 ld.so: Support moving versioned symbols between sonames [BZ #24741]
This change should be fully backwards-compatible because the old
code aborted the load if a soname mismatch was encountered
(instead of searching further for a matching symbol).  This means
that no different symbols are found.

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

The error check was already explicitly disabled for the skip_map !=
NULL case, that is, when dl(v)sym was called with RTLD_NEXT.  But
_dl_vsym always sets filename in the struct r_found_version argument
to NULL, so the check was not active anyway.  This means that
symbol lookup results for the skip_map != NULL case do not change,
either.
2019-06-28 10:15:38 +02:00
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
Maciej W. Rozycki
bac15a72fc elf: Accept absolute (SHN_ABS) symbols whose value is zero [BZ #23307]
We have this condition in `check_match' (in elf/dl-lookup.c):

  if (__glibc_unlikely ((sym->st_value == 0 /* No value.  */
                         && stt != STT_TLS)
                        || ELF_MACHINE_SYM_NO_MATCH (sym)
                        || (type_class & (sym->st_shndx == SHN_UNDEF))))
    return NULL;

which causes all !STT_TLS symbols whose value is zero to be silently
ignored in lookup.  This may make sense for regular symbols, however not
for absolute (SHN_ABS) ones, where zero is like any value, there's no
special meaning attached to it.

Consequently legitimate programs fail, for example taking the
`elf/tst-absolute-sym' test case, substituting 0 for 0x55aa in
`elf/tst-absolute-sym-lib.lds' and then trying to run the resulting
program we get this:

$ .../elf/tst-absolute-sym
.../elf/tst-absolute-sym: symbol lookup error: .../elf/tst-absolute-sym-lib.so: undefined symbol: absolute
$

even though the symbol clearly is there:

$ readelf --dyn-syms .../elf/tst-absolute-sym-lib.so | grep '\babsolute\b'
     7: 00000000     0 NOTYPE  GLOBAL DEFAULT  ABS absolute
$

The check for the zero value has been there since forever or commit
d66e34cd4234/08162fa88891 ("Implemented runtime dynamic linker to
support ELF shared libraries.") dating back to May 2nd 1995, and the
problem triggers regardless of commit e7feec374c ("elf: Correct
absolute (SHN_ABS) symbol run-time calculation [BZ #19818]") being
present or not.

Fix the issue then, by permitting `sym->st_value' to be 0 for SHN_ABS
symbols in lookup.

	[BZ #23307]
	* elf/dl-lookup.c (check_match): Do not reject a symbol whose
	`st_value' is 0 if `st_shndx' is SHN_ABS.
	* elf/tst-absolute-zero.c: New file.
	* elf/tst-absolute-zero-lib.c: New file.
	* elf/tst-absolute-zero-lib.lds: New file.
	* elf/Makefile (tests): Add `tst-absolute-zero'.
	(modules-names): Add `tst-absolute-zero-lib'.
	(LDLIBS-tst-absolute-zero-lib.so): New variable.
	($(objpfx)tst-absolute-zero-lib.so): New dependency.
	($(objpfx)tst-absolute-zero: New dependency.
2018-06-29 17:10:43 +01:00
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
Florian Weimer
17e00cc69e elf: Remove internal_function attribute 2017-08-31 16:59:37 +02:00
Florian Weimer
2449ae7b2d ld.so: Introduce struct dl_exception
This commit separates allocating and raising exceptions.  This
simplifies catching and re-raising them because it is no longer
necessary to make a temporary, on-stack copy of the exception message.
2017-08-10 16:54:57 +02:00
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Maciej W. Rozycki
b6084a958f Treat STV_HIDDEN and STV_INTERNAL symbols as STB_LOCAL
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.
2016-07-01 23:48:52 +01:00
Florian Weimer
7d45c163d0 Report dlsym, dlvsym lookup errors using dlerror [BZ #19509]
* 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.
2016-03-31 11:26:55 +02:00
Joseph Myers
f7a9f785e5 Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
H.J. Lu
f3d18efb8a Keep only ELF_RTYPE_CLASS_{PLT|COPY} bits for prelink
prelink runs ld.so with the environment variable LD_TRACE_PRELINKING
set to dump the relocation type class from _dl_debug_bindings.  prelink
has the following relocation type classes:

 #define RTYPE_CLASS_VALID       8
 #define RTYPE_CLASS_PLT         (8|1)
 #define RTYPE_CLASS_COPY        (8|2)
 #define RTYPE_CLASS_TLS         (8|4)

where ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA has a conflict with
RTYPE_CLASS_TLS.

Since prelink only uses ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY
bits, we should clear the other bits when the DL_DEBUG_PRELINK bit is
set.

	[BZ #19178]
	* elf/dl-lookup.c (RTYPE_CLASS_VALID): New.
	(RTYPE_CLASS_PLT): Likewise.
	(RTYPE_CLASS_COPY): Likewise.
	(RTYPE_CLASS_TLS): Likewise.
	(_dl_debug_bindings): Use RTYPE_CLASS_TLS and RTYPE_CLASS_VALID
	to set relocation type class for DL_DEBUG_PRELINK.  Keep only
	ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY bits for
	DL_DEBUG_PRELINK.
2015-11-07 06:32:30 -08:00
Joseph Myers
ec999b8e5e Move bits/libc-lock.h and bits/libc-lockP.h out of bits/ (bug 14912).
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.
2015-09-08 21:11:03 +00:00
H.J. Lu
62da1e3b00 Add ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA to x86
With copy relocation, address of protected data defined in the shared
library may be external.   When there is a relocation against the
protected data symbol within the shared library, we need to check if we
should skip the definition in the executable copied from the protected
data.  This patch adds ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA and defines
it for x86.  If ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA isn't 0, do_lookup_x
will skip the data definition in the executable from copy reloc.

	[BZ #17711]
	* elf/dl-lookup.c (do_lookup_x): When UNDEF_MAP is NULL, which
	indicates it is called from do_lookup_x on relocation against
	protected data, skip the data definion in the executable from
	copy reloc.
	(_dl_lookup_symbol_x): Pass ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA,
	instead of ELF_RTYPE_CLASS_PLT, to do_lookup_x for
	EXTERN_PROTECTED_DATA relocation against STT_OBJECT symbol.
	* sysdeps/generic/ldsodefs.h * (ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA):
	New.  Defined to 4 if DL_EXTERN_PROTECTED_DATA is defined,
	otherwise to 0.
	* sysdeps/i386/dl-lookupcfg.h (DL_EXTERN_PROTECTED_DATA): New.
	* sysdeps/i386/dl-machine.h (elf_machine_type_class): Set class
	to ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA for R_386_GLOB_DAT.
	* sysdeps/x86_64/dl-lookupcfg.h (DL_EXTERN_PROTECTED_DATA): New.
	* sysdeps/x86_64/dl-machine.h (elf_machine_type_class): Set class
	to ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA for R_X86_64_GLOB_DAT.
2015-03-31 05:16:57 -07:00
Joseph Myers
b168057aaa Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
Roland McGrath
7b8fb2b8db Remove unnecessarily nested function in do_lookup_unique. 2014-10-08 15:18:02 -07:00
Will Newton
cc7d044752 elf/dl-lookup.c: Use __glibc_likely and __glibc_unlikely
Convert all uses of __builtin_expect to __glibc_likely and
__glibc_unlikely. Most of these are trivial boolean expressions
but a few were not. In particular the use of __builtin_expect in
the switch expression in do_lookup_x has been removed. Verified
that there are no code changes on x86_64 and ARM aside from line
numbers.

ChangeLog:

2014-06-23  Will Newton  <will.newton@linaro.org>

	* elf/dl-lookup.c: Use __glibc_unlikely and __glibc_likely
	rather than __builtin_expect.
2014-06-23 14:13:31 +01:00
Will Newton
d6d0622554 elf/dl-lookup.c: Remove unnecessary static variable
undefined_msg is only used once contrary to the comment.

ChangeLog:

2014-06-23  Will Newton  <will.newton@linaro.org>

	* elf/dl-lookup.c (undefined_msg): Remove variable.
	(_dl_lookup_symbol_x): Replace undefined_msg with string
	literal.
2014-06-23 14:13:30 +01:00
Will Newton
f393b4aaed elf/dl-lookup.c: Move STB_GNU_UNIQUE handling to a function
Move handling of STB_GNU_UNIQUE symbols to a separate function
from do_lookup_x in order to make the code more readable.

The new function gets inlined with gcc 4.8 on ARM and the
do_lookup_x code becomes a few bytes smaller.

ChangeLog:

2014-06-23  Will Newton  <will.newton@linaro.org>

	* elf/dl-lookup.c (do_lookup_unique): New function.
	(do_lookup_x): Move STB_GNU_UNIQUE handling code
	to a separate function.
2014-06-23 14:13:30 +01:00
Will Newton
f6488e2b7f elf/dl-lookup.c: Remove obsolete comment about nested function
The nested function referred to has gone away so remove the
comment. Also move the variable declaration down to where other
variables of a similar lifetime are declared for clarity.

2014-04-03  Will Newton  <will.newton@linaro.org>

	* elf/dl-lookup.c (do_lookup_x): Remove comment
	referring to nested function and move variable
	declarations down to before first use.
2014-04-03 09:58:30 +01:00
Carlos O'Donell
8e25d1e772 Promote do_lookup_x:check_match to a full function.
While it may be argued that nested functions make the resulting
code easier to read, or worse to read the following two bugs
make it difficult to debug:

Bug 8300 - no local symbol information within nested or nesting
procedures
https://sourceware.org/bugzilla/show_bug.cgi?id=8300

Bug 53927 - wrong value for DW_AT_static_link
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53927

Until these are fixed I've made check_match a full function.
After they are fixed we can resume arguing about the merits
of nested functions on readability and maintenance.
2014-02-28 18:15:10 -05:00
Joseph Myers
cb4a292812 Merge MIPS dl-lookup.c into generic file.
MIPS has its own version of dl-lookup.c to deal with differences
between undefined symbol semantics in the PIC and non-PIC ABIs.  This
is often liable to get out of date with respect to the generic file
(for example, the recent __builtin_expect changes didn't cover ports,
and it's not obvious to anyone changing dl-lookup.c that there would
be architecture-specific versions).

This patch adds a macro that dl-machine.h can define that is used in
the appropriate place in dl-lookup.c, so that MIPS no longer needs its
own version of that file.

Tested for mips64 that the only changes to disassembly of installed
shared libraries appear to be ld.so changes attributable to different
line numbers and paths in assertions.

	* elf/dl-lookup.c (ELF_MACHINE_SYM_NO_MATCH): Define if not
	already defined.
	(do_lookup_x): Use ELF_MACHINE_SYM_NO_MATCH.
	* sysdeps/mips/dl-lookup.c: Remove.
	* sysdeps/mips/dl-machine.h (ELF_MACHINE_SYM_NO_MATCH): New macro.
2014-02-11 22:33:07 +00:00
Ondřej Bílka
a1ffb40e32 Use glibc_likely instead __builtin_expect. 2014-02-10 15:07:12 +01:00
Allan McRae
d4697bc93d Update copyright notices with scripts/update-copyrights 2014-01-01 22:00:23 +10:00
Marcus Shawcroft
50727aa76b Avoid passing NULL to DSO_FILENAME. 2013-11-13 12:40:31 +00:00
Siddhesh Poyarekar
b937534868 Avoid crashing in LD_DEBUG when program name is unavailable
Resolves: #15465

The program name may be unavailable if the user application tampers
with argc and argv[].  Some parts of the dynamic linker caters for
this while others don't, so this patch consolidates the check and
fallback into a single macro and updates all users.
2013-05-29 21:34:12 +05:30
Joseph Myers
568035b787 Update copyright notices with scripts/update-copyrights. 2013-01-02 19:05:09 +00:00
Roland McGrath
1ec79f2673 Add a missing #include. 2012-08-14 16:44:27 -07:00