Commit Graph

37 Commits

Author SHA1 Message Date
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Fangrui Song
e89913d0aa aarch64: Handle fewer relocations for RTLD_BOOTSTRAP
The RTLD_BOOTSTRAP branch is used to relocate ld.so itself.  It only
needs to handle RELATIVE, GLOB_DAT, and JUMP_SLOT.
TLSDESC/TLS_DTPMOD/TLS_DTPREL handling can be removed.  Remove
`case AARCH64_R(RELATIVE)` as well as elf_machine_rela has checked it.

Tested on aarch64-linux-gnu.
2022-06-15 19:21:53 -07:00
Fangrui Song
e555954e02 Revert "[AArch64][BZ #17711] Fix extern protected data handling"
This reverts commit 0910702c4d.

Say both a.so and b.so define protected data symbol `var` and the executable
copy relocates var.  ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA has strange
semantics: a.so accesses the copy in the executable while b.so accesses its
own.  This behavior requires that (a) the compiler emits GOT-generating
relocations (b) the linker produces GLOB_DAT instead of RELATIVE.

Without the ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA code, b.so's GLOB_DAT
will bind to the executable (normal behavior).

For aarch64 it makes sense to restore the original behavior and don't
pay the ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA cost.  The behavior is very
unlikely used by anyone.

* Clang code generator treats STV_PROTECTED the same way as STV_HIDDEN:
  no GOT-generating relocation in the first place.
* gold and lld reject copy relocation on a STV_PROTECTED symbol.
* Nowadays -fpie/-fpic modes are popular.  GCC/Clang's codegen uses
  GOT-generating relocation when accessing an default visibility
  external symbol which avoids copy relocation.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2022-05-23 13:37:05 -07:00
Szabolcs Nagy
1da064c015 aarch64: Move ld.so _start to separate file and drop _dl_skip_args
A separate asm file is easier to maintain than a macro that expands to
inline asm.

The RTLD_START macro is only needed now because _dl_start is local in
rtld.c, but _start has to call it, if _dl_start was made hidden then it
could be empty.

_dl_skip_args is no longer needed.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2022-05-17 10:14:03 +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
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
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
Fangrui Song
43d06ed218 aarch64: Make elf_machine_{load_address,dynamic} robust [BZ #28203]
The AArch64 ABI is largely platform agnostic and does not specify
_GLOBAL_OFFSET_TABLE_[0] ([1]). glibc ld.so turns out to be probably the
only user of _GLOBAL_OFFSET_TABLE_[0] and GNU ld defines the value
to the link-time address _DYNAMIC. [2]

In 2012, __ehdr_start was implemented in GNU ld and gold in binutils
2.23.  Using adrp+add / (-mcmodel=tiny) adr to access
__ehdr_start/_DYNAMIC gives us a robust way to get the load address and
the link-time address of _DYNAMIC.

[1]: From a psABI maintainer, https://bugs.llvm.org/show_bug.cgi?id=49672#c2
[2]: LLD's aarch64 port does not set _GLOBAL_OFFSET_TABLE_[0] to the
link-time address _DYNAMIC.
LLD is widely used on aarch64 Android and ChromeOS devices.  Software
just works without the need for _GLOBAL_OFFSET_TABLE_[0].

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-08-11 09:00:38 -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
Szabolcs Nagy
558251bd87 aarch64: Fix DT_AARCH64_VARIANT_PCS handling [BZ #26798]
The variant PCS support was ineffective because in the common case
linkmap->l_mach.plt == 0 but then the symbol table flags were ignored
and normal lazy binding was used instead of resolving the relocs early.
(This was a misunderstanding about how GOT[1] is setup by the linker.)

In practice this mainly affects SVE calls when the vector length is
more than 128 bits, then the top bits of the argument registers get
clobbered during lazy binding.

Fixes bug 26798.
2020-11-02 09:39:24 +00:00
Szabolcs Nagy
5f846c8b0d aarch64: fix RTLD_START for BTI
Tailcalls must use x16 or x17 for the indirect branch instruction
to be compatible with code that uses BTI c at function entries.
(Other forms of indirect branches can only land on BTI j.)

Also added a BTI c at the ELF entry point of rtld, this is not
strictly necessary since the kernel does not use indirect branch
to get there, but it seems safest once building glibc itself with
BTI is supported.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-07-08 15:02:37 +01:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Florian Weimer
4db71d2f98 elf: Do not run IFUNC resolvers for LD_DEBUG=unused [BZ #24214]
This commit adds missing skip_ifunc checks to aarch64, arm, i386,
sparc, and x86_64.  A new test case ensures that IRELATIVE IFUNC
resolvers do not run in various diagnostic modes of the dynamic
loader.

Reviewed-By: Szabolcs Nagy <szabolcs.nagy@arm.com>
2019-12-02 14:55:22 +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
Szabolcs Nagy
30ba037546 aarch64: simplify the DT_AARCH64_VARIANT_PCS handling code
Remove unnecessary variant_pcs field: the dynamic tag can be checked
directly.

	* sysdeps/aarch64/dl-machine.h (elf_machine_runtime_setup): Remove the
	DT_AARCH64_VARIANT_PCS check.
	(elf_machine_lazy_rel): Use l_info[DT_AARCH64 (VARIANT_PCS)].
	* sysdeps/aarch64/linkmap.h (struct link_map_machine): Remove
	variant_pcs.
2019-07-10 15:28:00 +01:00
Szabolcs Nagy
82bc69c012 aarch64: handle STO_AARCH64_VARIANT_PCS
Avoid lazy binding of symbols that may follow a variant PCS with different
register usage convention from the base PCS.

Currently the lazy binding entry code does not preserve all the registers
required for AdvSIMD and SVE vector calls.  Saving and restoring all
registers unconditionally may break existing binaries, even if they never
use vector calls, because of the larger stack requirement for lazy
resolution, which can be significant on an SVE system.

The solution is to mark all symbols in the symbol table that may follow
a variant PCS so the dynamic linker can handle them specially.  In this
patch such symbols are always resolved at load time, not lazily.

So currently LD_AUDIT for variant PCS symbols are not supported, for that
the _dl_runtime_profile entry needs to be changed e.g. to unconditionally
save/restore all registers (but pass down arg and retval registers to
pltentry/exit callbacks according to the base PCS).

This patch also removes a __builtin_expect from the modified code because
the branch prediction hint did not seem useful.

	* sysdeps/aarch64/dl-dtprocnum.h: New file.
	* sysdeps/aarch64/dl-machine.h (DT_AARCH64): Define.
	(elf_machine_runtime_setup): Handle DT_AARCH64_VARIANT_PCS.
	(elf_machine_lazy_rel): Check STO_AARCH64_VARIANT_PCS and bind such
	symbols at load time.
	* sysdeps/aarch64/linkmap.h (struct link_map_machine): Add variant_pcs.
2019-06-13 09:45:00 +01:00
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
10a446ddcc elf: Unify symbol address run-time calculation [BZ #19818]
Wrap symbol address run-time calculation into a macro and use it
throughout, replacing inline calculations.

There are a couple of variants, most of them different in a functionally
insignificant way.  Most calculations are right following RESOLVE_MAP,
at which point either the map or the symbol returned can be checked for
validity as the macro sets either both or neither.  In some places both
the symbol and the map has to be checked however.

My initial implementation therefore always checked both, however that
resulted in code larger by as much as 0.3%, as many places know from
elsewhere that no check is needed.  I have decided the size growth was
unacceptable.

Having looked closer I realized that it's the map that is the culprit.
Therefore I have modified LOOKUP_VALUE_ADDRESS to accept an additional
boolean argument telling it to access the map without checking it for
validity.  This in turn has brought quite nice results, with new code
actually being smaller for i686, and MIPS o32, n32 and little-endian n64
targets, unchanged in size for x86-64 and, unusually, marginally larger
for big-endian MIPS n64, as follows:

i686:
   text    data     bss     dec     hex filename
 152255    4052     192  156499   26353 ld-2.27.9000-base.so
 152159    4052     192  156403   262f3 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/el:
   text    data     bss     dec     hex filename
 142906    4396     260  147562   2406a ld-2.27.9000-base.so
 142890    4396     260  147546   2405a ld-2.27.9000-elf-symbol-value.so
MIPS/n32/el:
   text    data     bss     dec     hex filename
 142267    4404     260  146931   23df3 ld-2.27.9000-base.so
 142171    4404     260  146835   23d93 ld-2.27.9000-elf-symbol-value.so
MIPS/n64/el:
   text    data     bss     dec     hex filename
 149835    7376     408  157619   267b3 ld-2.27.9000-base.so
 149787    7376     408  157571   26783 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/eb:
   text    data     bss     dec     hex filename
 142870    4396     260  147526   24046 ld-2.27.9000-base.so
 142854    4396     260  147510   24036 ld-2.27.9000-elf-symbol-value.so
MIPS/n32/eb:
   text    data     bss     dec     hex filename
 142019    4404     260  146683   23cfb ld-2.27.9000-base.so
 141923    4404     260  146587   23c9b ld-2.27.9000-elf-symbol-value.so
MIPS/n64/eb:
   text    data     bss     dec     hex filename
 149763    7376     408  157547   2676b ld-2.27.9000-base.so
 149779    7376     408  157563   2677b ld-2.27.9000-elf-symbol-value.so
x86-64:
   text    data     bss     dec     hex filename
 148462    6452     400  155314   25eb2 ld-2.27.9000-base.so
 148462    6452     400  155314   25eb2 ld-2.27.9000-elf-symbol-value.so

	[BZ #19818]
	* sysdeps/generic/ldsodefs.h (LOOKUP_VALUE_ADDRESS): Add `set'
	parameter.
	(SYMBOL_ADDRESS): New macro.
	[!ELF_FUNCTION_PTR_IS_SPECIAL] (DL_SYMBOL_ADDRESS): Use
	SYMBOL_ADDRESS for symbol address calculation.
	* elf/dl-runtime.c (_dl_fixup): Likewise.
	(_dl_profile_fixup): Likewise.
	* elf/dl-symaddr.c (_dl_symbol_address): Likewise.
	* elf/rtld.c (dl_main): Likewise.
	* sysdeps/aarch64/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/alpha/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/arm/dl-machine.h (elf_machine_rel): Likewise.
	(elf_machine_rela): Likewise.
	* sysdeps/hppa/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/hppa/dl-symaddr.c (_dl_symbol_address): Likewise.
	* sysdeps/i386/dl-machine.h (elf_machine_rel): Likewise.
	(elf_machine_rela): Likewise.
	* sysdeps/ia64/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/m68k/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/microblaze/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/mips/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
	Likewise.
	(elf_machine_reloc): Likewise.
	(elf_machine_got_rel): Likewise.
	* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
	* sysdeps/nios2/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/riscv/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/s390/s390-32/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/s390/s390-64/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/sh/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/tile/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2018-04-04 23:09:37 +01:00
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
Szabolcs Nagy
91c5a366d8 aarch64: Remove barriers from TLS descriptor functions
Remove ldar synchronization and most lazy TLSDESC initialization
related code.

	* sysdeps/aarch64/dl-machine.h (elf_machine_runtime_setup): Remove
	DT_TLSDESC_GOT initialization.
	* sysdeps/aarch64/dl-tlsdesc.S (_dl_tlsdesc_return_lazy): Remove.
	(_dl_tlsdesc_resolve_rela): Likewise.
	(_dl_tlsdesc_resolve_hold): Likewise.
	(_dl_tlsdesc_undefweak): Remove ldar.
	(_dl_tlsdesc_dynamic): Likewise.
	* sysdeps/aarch64/dl-tlsdesc.h (_dl_tlsdesc_return_lazy): Remove.
	(_dl_tlsdesc_resolve_rela): Likewise.
	(_dl_tlsdesc_resolve_hold): Likewise.
	* sysdeps/aarch64/tlsdesc.c (_dl_tlsdesc_resolve_rela_fixup): Remove.
	(_dl_tlsdesc_resolve_hold_fixup): Likewise.
	(_dl_tlsdesc_resolve_rela): Likewise.
	(_dl_tlsdesc_resolve_hold): Likewise.
2017-11-03 14:43:32 +00:00
Szabolcs Nagy
b7cf203b5c aarch64: Disable lazy symbol binding of TLSDESC
Always do TLS descriptor initialization at load time during relocation
processing to avoid barriers at every TLS access. In non-dlopened shared
libraries the overhead of tls access vs static global access is > 3x
bigger when lazy initialization is used (_dl_tlsdesc_return_lazy)
compared to bind-now (_dl_tlsdesc_return) so the barriers dominate tls
access performance.

TLSDESC relocs are in DT_JMPREL which are processed at load time using
elf_machine_lazy_rel which is only supposed to do lightweight
initialization using the DT_TLSDESC_PLT trampoline (the trampoline code
jumps to the entry point in DT_TLSDESC_GOT which does the lazy tlsdesc
initialization at runtime).  This patch changes elf_machine_lazy_rel
in aarch64 to do the symbol binding and initialization as if DF_BIND_NOW
was set, so the non-lazy code path of elf/do-rel.h was replicated.

The static linker could be changed to emit TLSDESC relocs in DT_REL*,
which are processed non-lazily, but the goal of this patch is to always
guarantee bind-now semantics, even if the binary was produced with an
old linker, so the barriers can be dropped in tls descriptor functions.

After this change the synchronizing ldar instructions can be dropped
as well as the lazy initialization machinery including the DT_TLSDESC_GOT
setup.

I believe this should be done on all targets, including ones where no
barrier is needed for lazy initialization.  There is very little gain in
optimizing for large number of symbolic tlsdesc relocations which is an
extremely uncommon case.  And currently the tlsdesc entries are only
readonly protected with -z now and some hardennings against writable
JUMPSLOT relocs don't work for TLSDESC so they are a security hazard.
(But to fix that the static linker has to be changed.)

	* sysdeps/aarch64/dl-machine.h (elf_machine_lazy_rel): Do symbol
	binding and initialization non-lazily for R_AARCH64_TLSDESC.
2017-11-03 14:41:35 +00:00
Szabolcs Nagy
a68ba2f3cd [AARCH64] Rewrite elf_machine_load_address using _DYNAMIC symbol
This patch rewrites aarch64 elf_machine_load_address to use special _DYNAMIC
symbol instead of _dl_start.

The static address of _DYNAMIC symbol is stored in the first GOT entry.
Here is the change which makes this solution work (part of binutils 2.24):
https://sourceware.org/ml/binutils/2013-06/msg00248.html

i386, x86_64 targets use the same method to do this as well.

The original implementation relies on a trick that R_AARCH64_ABS32 relocation
being resolved at link time and the static address fits in the 32bits.
However, in LP64, normally, the address is defined to be 64 bit.

Here is the C version one which should be portable in all cases.

	* sysdeps/aarch64/dl-machine.h (elf_machine_load_address): Use
	_DYNAMIC symbol to calculate load address.
2017-10-18 17:35:16 +01:00
Szabolcs Nagy
db4f87bad4 aarch64: don't use MIN in dl-machine.h
MIN is used, but param.h may not be included, so expand its
single use inline.

	* sysdeps/aarch64/dl-machine.h (elf_machine_rela): Expand MIN.
2017-10-04 17:49:38 +01:00
Szabolcs Nagy
e9177fba13 [AArch64] Use hidden __GI__dl_argv in rtld startup code
We rely on the symbol being locally defined so using extern symbol
is not correct and the linker may complain about the relocations.
2017-06-21 14:54:11 +01:00
Alan Modra
0572433b5b PowerPC64 ELFv2 PPC64_OPT_LOCALENTRY
ELFv2 functions with localentry:0 are those with a single entry point,
ie. global entry == local entry, that have no requirement on r2 or
r12 and guarantee r2 is unchanged on return.  Such an external
function can be called via the PLT without saving r2 or restoring it
on return, avoiding a common load-hit-store for small functions.

This patch implements the ld.so changes necessary for this
optimization.  ld.so needs to check that an optimized plt call
sequence is in fact calling a function implemented with localentry:0,
end emit a fatal error otherwise.

The elf/testobj6.c change is to stop "error while loading shared
libraries: expected localentry:0 `preload'" when running
elf/preloadtest, which we'd get otherwise.

	* elf/elf.h (PPC64_OPT_LOCALENTRY): Define.
	* sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Add
	refsym and sym parameters.  Adjust callers.
	* sysdeps/aarch64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/hppa/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/m68k/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/microblaze/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/mips/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/nios2/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_fixup_plt):
	Likewise.
	* sysdeps/s390/s390-32/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/s390/s390-64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/sh/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/tile/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/x86_64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/powerpc/powerpc64/dl-machine.c (_dl_error_localentry): New.
	(_dl_reloc_overflow): Increase buffser size.  Formatting.
	* sysdeps/powerpc/powerpc64/dl-machine.h (ppc64_local_entry_offset):
	Delete reloc param, add refsym and sym.  Check optimized plt
	call stubs for localentry:0 functions.  Adjust callers.
	(elf_machine_fixup_plt, elf_machine_plt_conflict): Add refsym
	and sym parameters.  Adjust callers.
	(_dl_reloc_overflow): Move attribute.
	(_dl_error_localentry): Declare.
	* elf/dl-runtime.c (_dl_fixup): Save original sym.  Pass
	refsym and sym to elf_machine_fixup_plt.
	* elf/testobj6.c (preload): Call printf.
2017-06-14 10:47:25 +09:30
Steve Ellcey
d2e4346a30 Add ifunc support for aarch64.
* sysdeps/aarch64/dl-machine.h: Include cpu-features.c.
	(DL_PLATFORM_INIT): New define.
	(dl_platform_init): New function.
	* sysdeps/aarch64/ldsodefs.h: Include cpu-features.h.
	* sysdeps/unix/sysv/linux/aarch64/cpu-features.c: New file.
	* sysdeps/unix/sysv/linux/aarch64/cpu-features.h: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/libc-start.c: Likewise.
2017-03-15 16:46:26 -07:00
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Steve Ellcey
389d1f1b23 Partial ILP32 support for aarch64.
* sysdeps/aarch64/crti.S: Add include of sysdep.h.
	(call_weak_fn): Use PTR_REG to get correct reg name in ILP32.
	* sysdeps/aarch64/dl-irel.h: Add include of sysdep.h.
	(elf_irela): Use AARCH64_R macro to get correct relocation in ILP32.
	* sysdeps/aarch64/dl-machine.h: Add include of sysdep.h.
	(elf_machine_load_address, RTLD_START, RTLD_START_1, RTLD_START,
	elf_machine_type_class, ELF_MACHINE_JMP_SLOT, elf_machine_rela,
	elf_machine_lazy_rel): Add ifdef's for ILP32 support.
	* sysdeps/aarch64/dl-tlsdesc.S (_dl_tlsdesc_return,
	_dl_tlsdesc_return_lazy, _dl_tlsdesc_dynamic,
	_dl_tlsdesc_resolve_hold): Extend pointers in ILP32, use PTR_REG
	to get correct reg name for ILP32.
	* sysdeps/aarch64/dl-trampoline.S (ip01): New Macro.
	(RELA_SIZE): New Macro.
	(_dl_runtime_resolve, _dl_runtime_profile): Use new macros and PTR_REG
	to support ILP32.
	* sysdeps/aarch64/jmpbuf-unwind.h (_JMPBUF_CFA_UNWINDS_ADJ): Add
	cast for ILP32 mode.
	* sysdeps/aarch64/memcmp.S (memcmp): Extend arg pointers for ILP32 mode.
	* sysdeps/aarch64/memcpy.S (memmove, memcpy): Ditto.
	* sysdeps/aarch64/memset.S (__memset): Ditto.
	* sysdeps/aarch64/strchr.S (strchr): Ditto.
	* sysdeps/aarch64/strchrnul.S (__strchrnul): Ditto.
	* sysdeps/aarch64/strcmp.S (strcmp): Ditto.
	* sysdeps/aarch64/strcpy.S (strcpy): Ditto.
	* sysdeps/aarch64/strlen.S (__strlen): Ditto.
	* sysdeps/aarch64/strncmp.S (strncmp): Ditto.
	* sysdeps/aarch64/strnlen.S (strnlen): Ditto.
	* sysdeps/aarch64/strrchr.S (strrchr): Ditto.
	* sysdeps/unix/sysv/linux/aarch64/clone.S: Ditto.
	* sysdeps/unix/sysv/linux/aarch64/setcontext.S (__setcontext): Ditto.
	* sysdeps/unix/sysv/linux/aarch64/swapcontext.S (__swapcontext): Ditto.
	* sysdeps/aarch64/__longjmp.S (__longjmp): Extend pointers in ILP32,
	change PTR_MANGLE call to use register numbers instead of names.
	* sysdeps/unix/sysv/linux/aarch64/getcontext.S (__getcontext): Ditto.
	* sysdeps/aarch64/setjmp.S (__sigsetjmp): Extend arg pointers for
	ILP32 mode, change PTR_MANGLE calls to use register numbers.
	* sysdeps/aarch64/start.S (_start): Ditto.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h
	(__PTHREAD_RWLOCK_INT_FLAGS_SHARED): New define.
	(__SIZEOF_PTHREAD_ATTR_T, __SIZEOF_PTHREAD_MUTEX_T,
	__SIZEOF_PTHREAD_MUTEXATTR_T, __SIZEOF_PTHREAD_COND_T,
	__SIZEOF_PTHREAD_COND_COMPAT_T, __SIZEOF_PTHREAD_CONDATTR_T,
	__SIZEOF_PTHREAD_RWLOCK_T, __SIZEOF_PTHREAD_RWLOCKATTR_T,
	__SIZEOF_PTHREAD_BARRIER_T, __SIZEOF_PTHREAD_BARRIERATTR_T):
	Make defined values dependent on __ILP32__.
	* sysdeps/aarch64/nptl/bits/semaphore.h (__SIZEOF_SEM_T): Change define.
	(sem_t): Change __align type.
	* sysdeps/aarch64/sysdep.h (AARCH64_R, PTR_REG, PTR_LOG_SIZE, DELOUSE,
	PTR_SIZE): New Macros.
	(LDST_PCREL, LDST_GLOBAL) Update to use PTR_REG.
	* sysdeps/unix/sysv/linux/aarch64/bits/fcntl.h (O_LARGEFILE):
	Set when in ILP32 mode.
	(F_GETLK64, F_SETLK64, F_SETLKW64): Only set in LP64 mode.
	* sysdeps/unix/sysv/linux/aarch64/dl-cache.h (DL_CACHE_DEFAULT_ID):
	Set elf flags for ILP32.
	(add_system_dir): Set ILP32 library directories.
	* sysdeps/unix/sysv/linux/aarch64/init-first.c
	(_libc_vdso_platform_setup): Set minimum kernel version for ILP32.
	* sysdeps/unix/sysv/linux/aarch64/ldconfig.h
	(SYSDEP_KNOWN_INTERPRETER_NAMES): Add ILP32 names.
	* sysdeps/unix/sysv/linux/aarch64/sigcontextinfo.h (GET_PC, SET_PC):
	New Macros.
	* sysdeps/unix/sysv/linux/aarch64/sysdep.h: Handle ILP32 pointers.
2016-11-28 09:01:23 -08:00
Joseph Myers
f7a9f785e5 Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
Szabolcs Nagy
0910702c4d [AArch64][BZ #17711] Fix extern protected data handling
Fixes elf/tst-protected1a and elf/tst-protected1b tests.

Depends on a gcc patch that makes protected visibility data non-local:
https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01871.html
and on a binutils patch so R_*_GLOB_DAT relocs are used for it:
https://sourceware.org/ml/binutils/2015-07/msg00246.html
2015-07-24 09:57:32 +01:00
Joseph Myers
b168057aaa Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
Andrew Pinski
6d3db89b12 AArch64: Reformat inline-asm in elf_machine_load_address
This patch reformats the inline-asm in elf_machine_load_address so it is
easier to change only part of the inline-asm.  That is using string
concatenating instead of string continuation.

Also document why this inline-asm works - it depends on the 32bit
relocation being resolved at link time.

ChangeLog:

2014-11-21  Will Newton  <will.newton@linaro.org>
	    Andrew Pinski  <andrew.pinski@caviumnetworks.com>

	* sysdeps/aarch64/dl-machine.h (elf_machine_load_address):
	Refactor inline-asm.  Also add comment.
2014-11-21 14:45:11 +00:00
Will Newton
01194ba18d AArch64: Use ELF macros rather than Elf64 throughout
Using the macros for ELF types is required for adding ILP32 support.
In the standard AArch64 configuration this makes no difference to
the types used.

ChangeLog:

2014-11-21  Will Newton  <will.newton@linaro.org>
	    Andrew Pinski  <andrew.pinski@caviumnetworks.com>

	* sysdeps/aarch64/bits/link.h (la_aarch64_gnu_pltenter): Use
	ElfW macro instead of hardcoded Elf64 types.
	(la_aarch64_gnu_pltenter): Likewise.
	* sysdeps/aarch64/dl-machine.h
	(elf_machine_runtime_setup): Use ElfW(Addr).
2014-11-21 14:44:23 +00:00
Will Newton
8c230039a0 AArch64: Update relocations for ILP32
The latest version of the binutils ELF header defines a new set of
dynamic relocations for ILP32 and renames some to make the naming
more uniform.

ChangeLog:

2014-11-21  Will Newton  <will.newton@linaro.org>
	    Andrew Pinski  <andrew.pinski@caviumnetworks.com>

	* elf/elf.h (R_AARCH64_P32_ABS32, R_AARCH64_P32_COPY,
	R_AARCH64_P32_GLOB_DAT, R_AARCH64_P32_JUMP_SLOT,
	R_AARCH64_P32_RELATIVE, R_AARCH64_P32_TLS_DTPMOD,
	R_AARCH64_P32_TLS_DTPREL, R_AARCH64_P32_TLS_TPREL,
	R_AARCH64_P32_TLSDESC, R_AARCH64_P32_IRELATIVE): Define.
	(R_AARCH64_TLS_DTPMOD64): Rename to ..
	(R_AARCH64_TLS_DTPMOD): This.
	(R_AARCH64_TLS_DTPREL64): Rename to ...
	(R_AARCH64_TLS_DTPREL): This.
	(R_AARCH64_TLS_TPREL64): Rename to ...
	(R_AARCH64_TLS_TPREL): This.
	* sysdeps/aarch64/dl-machine.h (elf_machine_type_class): Update
	R_AARCH64_TLS_DTPMOD64, R_AARCH64_TLS_DTPREL64, and
	R_AARCH64_TLS_TPREL64.
	(elf_machine_rela): Likewise.
2014-11-21 14:43:16 +00:00
Joseph Myers
c5684fdb2b Don't use INTDEF/INTUSE with _dl_init (bug 14132).
Continuing the removal of the obsolete INTDEF / INTUSE mechanism, this
patch eliminates its use for _dl_init.  Since _dl_init was already
declared with hidden visibility, creating a second hidden alias for it
was completely pointless, so this patch replaces all uses of
_dl_init_internal with plain _dl_init instead of using hidden_proto /
hidden_def (which are only needed when you want a hidden alias for a
non-hidden symbol; it's quite possible there are cases where they are
used but don't need to be because the symbol in question is not part
of the public ABI and is only used within a single library, so using
attributes_hidden instead would suffice).

Tested for x86_64 that installed stripped shared libraries are
unchanged by the patch.

	[BZ #14132]
	* elf/dl-init.c (_dl_init): Don't use INTDEF.
	* sysdeps/aarch64/dl-machine.h (RTLD_START): Use _dl_init instead
	of _dl_init_internal.
	* sysdeps/alpha/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/arm/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/hppa/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/i386/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/ia64/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/m68k/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/microblaze/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/mips/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/powerpc/powerpc32/dl-start.S (_start): Likewise.
	* sysdeps/s390/s390-32/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/s390/s390-64/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/sh/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/sparc/sparc32/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/sparc/sparc64/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/tile/dl-start.S (_start): Likewise.
	* sysdeps/x86_64/dl-machine.h (RTLD_START): Likewise.
	* sysdeps/x86_64/x32/dl-machine.h (RTLD_START): Likewise.
2014-11-04 23:26:39 +00:00
Siddhesh Poyarekar
4cf5b6d0d7 Fix Wundef warning for ELF_MACHINE_NO_RELA
This patch defines ELF_MACHINE_NO_RELA on all architectures.  Tested
only on x86_64 to verify that the sources before and after are
identical except for two instructions that pass the current line
number in dl-machine.h to assert_fail.
2014-06-26 22:30:40 +05:30
Marcus Shawcroft
75eff3fe90 Relocate AArch64 from ports to libc.
This patch moves the AArch64 port to the main sysdeps hierarchy.  The
move is essentially:

  git mv ports/sysdeps/aarch64 sysdeps/aarch64
  git mv ports/sysdeps/unix/sysv/linux/aarch64 sysdeps/unix/sysv/linux/aarch64

The README is updated and I've updated ChangeLog.aarch64 along the
lines of the ARM move.  The AArch64 build has been tested to confirm
that there were no changes in objdump -dr output or the shared
objects.
2014-02-11 11:36:00 +00:00