Commit Graph

63 Commits

Author SHA1 Message Date
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Adhemerval Zanella
7e31d16651 elf: Fix GL(dl_phdr) and GL(dl_phnum) for static builds [BZ #29864]
The 73fc4e28b9 refactor did not add the GL(dl_phdr) and
GL(dl_phnum) for static build, relying on the __ehdr_start symbol,
which is always added by the static linker, to get the correct values.

This is problematic in some ways:

  - The segment may see its in-memory size differ from its in-file
    size (or the binary may have holes).  The Linux has fixed is to
    provide concise values for both AT_PHDR and AT_PHNUM (commit
    0da1d5002745c - "fs/binfmt_elf: Fix AT_PHDR for unusual ELF files")

  - Some archs (alpha for instance) the hidden weak reference is not
    correctly pulled by the static linker and  __ehdr_start address
    end up being 0, which makes GL(dl_phdr) and GL(dl_phnum) have both
    invalid values (and triggering a segfault later on libc.so while
    accessing TLS variables).

The safer fix is to just restore the previous behavior to setup
GL(dl_phdr) and GL(dl_phnum) for static based on kernel auxv.  The
__ehdr_start fallback can also be simplified by not assuming weak
linkage (as for PIE).

The libc-static.c auxv init logic is moved to dl-support.c, since
the later is build without SHARED and then GLRO macro is defined
to access the variables directly.

The _dl_phdr is also assumed to be always non NULL, since an invalid
NULL values does not trigger TLS initialization (which is used in
various libc systems).

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

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2023-01-12 13:54:34 -03:00
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Adhemerval Zanella
b46d250656 Remove kernel version check
The kernel version check is used to avoid glibc to run on older
kernels where some syscall are not available and fallback code are
not enabled to handle graciously fail.  However, it does not prevent
if the kernel does not correctly advertise its version through
vDSO note, uname or procfs.

Also kernel version checks are sometime not desirable by users,
where they want to deploy on different system with different kernel
version knowing the minimum set of syscall is always presented on
such systems.

The kernel version check has been removed along with the
LD_ASSUME_KERNEL environment variable.  The minimum kernel used to
built glibc is still provided through NT_GNU_ABI_TAG ELF note and
also printed when libc.so is issued.

Checked on x86_64-linux-gnu.
2022-05-16 15:03:49 -03:00
Fangrui Song
3e9acce8c5 elf: Remove __libc_init_secure
After 73fc4e28b9,
__libc_enable_secure_decided is always 0 and a statically linked
executable may overwrite __libc_enable_secure without considering
AT_SECURE.

The __libc_enable_secure has been correctly initialized in _dl_aux_init,
so just remove __libc_enable_secure_decided and __libc_init_secure.
This allows us to remove some startup_get*id functions from
22b79ed7f4.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-04-19 15:52:27 -07:00
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
0b98a87487 elf: Add _dl_audit_preinit
It consolidates the code required to call la_preinit audit
callback.

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

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-12-28 08:40:38 -03:00
Florian Weimer
7c241325d6 Force building with -fno-common
As a result, is not necessary to specify __attribute__ ((nocommon))
on individual definitions.

GCC 10 defaults to -fno-common on all architectures except ARC,
but this change is compatible with older GCC versions and ARC, too.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-09 20:09:14 +02:00
Adhemerval Zanella
eaa53d0f77 nptl: Remove exit-thread.h
No function change.  The code is used only for Linux, besides
being included in generic code.
2021-06-04 09:52:28 -03:00
Florian Weimer
130fca173f csu: Move calling main out of __libc_start_main_impl
This code depends on whether glibc has unwinding support for
a particular port.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-04-21 19:49:50 +02:00
Florian Weimer
035c012e32 Reduce the statically linked startup code [BZ #23323]
It turns out the startup code in csu/elf-init.c has a perfect pair of
ROP gadgets (see Marco-Gisbert and Ripoll-Ripoll, "return-to-csu: A
New Method to Bypass 64-bit Linux ASLR").  These functions are not
needed in dynamically-linked binaries because DT_INIT/DT_INIT_ARRAY
are already processed by the dynamic linker.  However, the dynamic
linker skipped the main program for some reason.  For maximum
backwards compatibility, this is not changed, and instead, the main
map is consulted from __libc_start_main if the init function argument
is a NULL pointer.

For statically linked binaries, the old approach based on linker
symbols is still used because there is nothing else available.

A new symbol version __libc_start_main@@GLIBC_2.34 is introduced because
new binaries running on an old libc would not run their ELF
constructors, leading to difficult-to-debug issues.
2021-02-25 12:13:02 +01:00
Szabolcs Nagy
86d439b06f csu: Move static pie self relocation later [BZ #27072]
IFUNC resolvers may depend on tunables and cpu feature setup so
move static pie self relocation after those.

It is hard to guarantee that the ealy startup code does not rely
on relocations so this is a bit fragile. It would be more robust
to handle RELATIVE relocs early and only IRELATIVE relocs later,
but the current relocation processing code cannot do that.

The early startup code up to relocation processing includes

  _dl_aux_init (auxvec);
  __libc_init_secure ();
  __tunables_init (__environ);
  ARCH_INIT_CPU_FEATURES ();
  _dl_relocate_static_pie ();

These are simple enough that RELATIVE relocs can be avoided.

The following steps include

  ARCH_SETUP_IREL ();
  ARCH_SETUP_TLS ();
  ARCH_APPLY_IREL ();

On some targets IRELATIVE processing relies on TLS setup on
others TLS setup relies on IRELATIVE relocs, so the right
position for _dl_relocate_static_pie is target dependent.
For now move self relocation as early as possible on targets
that support static PIE.

Fixes bug 27072.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-01-21 15:55:10 +00:00
Szabolcs Nagy
47618209d0 Use hidden visibility for early static PIE code
Extern symbol access in position independent code usually involves GOT
indirection which needs RELATIVE reloc in a static linked PIE. (On
some targets this is avoided e.g. because the linker can relax a GOT
access to a pc-relative access, but this is not generally true.) Code
that runs before static PIE self relocation must avoid relying on
dynamic relocations which can be ensured by using hidden visibility.
However we cannot just make all symbols hidden:

On i386, all calls to IFUNC functions must go through PLT and calls to
hidden functions CANNOT go through PLT in PIE since EBX used in PIE PLT
may not be set up for local calls to hidden IFUNC functions.

This patch aims to make symbol references hidden in code that is used
before and by _dl_relocate_static_pie when building a static PIE libc.
Note: for an object that is used in the startup code, its references
and definition may not have consistent visibility: it is only forced
hidden in the startup code.

This is needed for fixing bug 27072.

Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-01-21 15:55:01 +00:00
Szabolcs Nagy
04af1eb313 csu: Avoid weak ref for __ehdr_start in static PIE
All linkers support __ehdr_start that support static PIE linking,
so there is no need to check for its presence via a weak reference.

This avoids a RELATIVE relocation in static PIE startup code on some
targets.

With non-PIE static linking the weak ref check is kept in case the
linker does not support __ehdr_start.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-01-21 15:54:55 +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
Florian Weimer
e7570f4131 Replace __libc_multiple_libcs with __libc_initial flag
Change sbrk to fail for !__libc_initial (in the generic
implementation).  As a result, sbrk is (relatively) safe to use
for the __libc_initial case (from the main libc).  It is therefore
no longer necessary to avoid using it in that case (or updating the
brk cache), and the __libc_initial flag does not need to be updated
as part of dlmopen or static dlopen.

As before, direct brk system calls on Linux may lead to memory
corruption.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-16 15:13:40 +01:00
Joseph Myers
2098d4034d Disable spurious -Wstringop-overflow for setjmp/longjmp (bug 26647)
Building glibc with GCC 11 fails with (among other warnings) spurious
-Wstringop-overflow warnings from calls to setjmp and longjmp with a
pointer to a pthread_unwind_buf that is smaller than jmp_buf.  As
discussed in bug 26647, the warning in libc-start.c is a false
positive, because setjmp and longjmp do not access anything (the
signal mask) beyond the common prefix of the two structures, so this
patch disables the warning for that call to setjmp, as well as for two
calls in NPTL code that produce the same warning and look like false
positives for the same reason.

Tested with build-many-glibcs.py for arm-linux-gnueabi, where this
allows the build to get further.

Reviewed-by: DJ Delorie <dj@redhat.com>
2020-10-30 21:38:31 +00:00
Florian Weimer
03e187a41d elf: Add initial flag argument to __libc_early_init
The rseq initialization should happen only for the libc in the base
namespace (in the dynamic case) or the statically linked libc.  The
__libc_multiple_libcs flag does not quite cover this case at present,
so this commit introduces a flag argument to __libc_early_init,
indicating whether the libc being libc is the primary one (of the main
program).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-29 15:44:03 +02:00
Florian Weimer
ec935dea63 elf: Implement __libc_early_init
This function is defined in libc.so, and the dynamic loader calls
right after relocation has been finished, before any ELF constructors
or the preinit function is invoked.  It is also used in the static
build for initializing parts of the static libc.

To locate __libc_early_init, a direct symbol lookup function is used,
_dl_lookup_direct.  It does not search the entire symbol scope and
consults merely a single link map.  This function could also be used
to implement lookups in the vDSO (as an optimization).

A per-namespace variable (libc_map) is added for locating libc.so,
to avoid repeated traversals of the search scope.  It is similar to
GL(dl_initfirst).  An alternative would have been to thread a context
argument from _dl_open down to _dl_map_object_from_fd (where libc.so
is identified).  This could have avoided the global variable, but
the change would be larger as a result.  It would not have been
possible to use this to replace GL(dl_initfirst) because that global
variable is used to pass the function pointer past the stack switch
from dl_main to the main program.  Replacing that requires adding
a new argument to _dl_init, which in turn needs changes to the
architecture-specific libc.so startup code written in assembler.

__libc_early_init should not be used to replace _dl_var_init (as
it exists today on some architectures).  Instead, _dl_lookup_direct
should be used to look up a new variable symbol in libc.so, and
that should then be initialized from the dynamic loader, immediately
after the object has been loaded in _dl_map_object_from_fd (before
relocation is run).  This way, more IFUNC resolvers which depend on
these variables will work.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-24 22:32:09 +02:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Florian Weimer
e1d559f337 Introduce link_map_audit_state accessor function
To improve GCC 10 compatibility, it is necessary to remove the l_audit
zero-length array from the end of struct link_map.  In preparation of
that, this commit introduces an accessor function for the audit state,
so that it is possible to change the representation of the audit state
without adjusting the code that accesses it.

Tested on x86_64-linux-gnu.  Built on i686-gnu.

Change-Id: Id815673c29950fc011ae5301d7cde12624f658df
2019-11-15 13:03:40 +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
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
Samuel Thibault
bcfa607b26 hurd: Initialize TLS and libpthread before signal thread start
* sysdeps/generic/libc-start.h [!SHARED] (ARCH_SETUP_TLS): Define to
__libc_setup_tls.
* sysdeps/unix/sysv/linux/powerpc/libc-start.h [!SHARED]
(ARCH_SETUP_TLS): Likewise.
* sysdeps/mach/hurd/libc-start.h: New file copied from
sysdeps/generic/libc-start.h, but define ARCH_SETUP_TLS to empty.
* csu/libc-start.c [!SHARED] (LIBC_START_MAIN): Call ARCH_SETUP_TLS instead
of __libc_setup_tls.
* sysdeps/mach/hurd/i386/init-first.c [!SHARED] (init1): Call
__libc_setup_tls before initializing libpthread and running _hurd_init which
starts the signal thread.
2018-03-25 00:52:39 +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
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
H.J. Lu
54e4b8f215 Mark __libc_multiple_libcs with attribute_hidden [BZ #18822]
Since __libc_multiple_libcs is defined as hidden symbol in init-first.c,
it should be always marked with attribute_hidden.

	[BZ #18822]
	* csu/libc-start.c (__libc_multiple_libcs): Removed.
	* elf/dl-open.c: Include <libc-internal.h>.
	(__libc_multiple_libcs): Removed.
	* elf/dl-sysdep.c: Include <libc-internal.h> instead of
	<hp-timing.h>.
	* include/libc-internal.h (__libc_multiple_libcs): New.
	* misc/sbrk.c: Include <libc-internal.h>.
	(__libc_multiple_libcs): Removed.
2017-08-21 05:32:39 -07:00
Tulio Magno Quites Machado Filho
91ac3a7d84 powerpc: Fix float128 IFUNC relocations [BZ #21707]
The patch proposed by Peter Bergner [1] to libgcc in order to fix
[BZ #21707] adds a dependency on a symbol provided by the loader,
forcing the loader to be linked to tests after libgcc was linked.

It also requires to read the thread pointer during IRELA relocations.

Tested on powerpc, powerpc64, powerpc64le, s390x and x86_64.

[1] https://sourceware.org/ml/libc-alpha/2017-06/msg01383.html

	[BZ #21707]
	* csu/libc-start.c (LIBC_START_MAIN): Perform IREL{,A}
	relocations before or after initializing the TCB on statically
	linked executables.  That's a per-architecture definition.
	* elf/rtld.c (dl_main): Add a comment about thread-local
	variables initialization.
	* sysdeps/generic/libc-start.h: New file.  Define
	ARCH_APPLY_IREL and ARCH_SETUP_IREL.
	* sysdeps/powerpc/Makefile:
	[$(subdir) = elf && $(multi-arch) != no] (tests-static-internal): Add tst-tlsifunc-static.
	[$(subdir) = elf && $(multi-arch) != no && $(build-shared) == yes]
	(tests-internal): Add tst-tlsifunc.
	* sysdeps/powerpc/tst-tlsifunc.c: New file.
	* sysdeps/powerpc/tst-tlsifunc-static.c: Likewise.
	* sysdeps/powerpc/powerpc64le/Makefile (f128-loader-link): New
	variable.
	[$(subdir) = math] (test-float128% test-ifloat128%): Force
	linking to the loader after linking to libgcc.
	[$(subdir) = wcsmbs || $(subdir) = stdlib] (bug-strtod bug-strtod2)
	(bug-strtod2 tst-strtod-round tst-wcstod-round tst-strtod6 tst-strrom)
	(tst-strfrom-locale strfrom-skeleton): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/libc-start.h: New file.  Define
	ARCH_APPLY_IREL and ARCH_SETUP_IREL.
2017-07-17 17:49:26 -03:00
Siddhesh Poyarekar
4158ba082c Delay initialization of CPU features struct in static binaries
Allow the CPU features structure set up to be overridden by tunables
by delaying it to until after tunables are initialized.  The
initialization is already delayed in dynamically linked glibc, it is
only in static binaries that the initialization is set early to allow
it to influence IFUNC relocations that happen in libc-start.  It is a
bit too early however and there is a good place between tunables
initialization and IFUNC relocations where this can be done.

Verified that this does not regress the testsuite.

	* csu/libc-start.c [!ARCH_INIT_CPU_FEATURES]: Define
	ARCH_INIT_CPU_FEATURES.
	(LIBC_START_MAIN): Call it.
	* sysdeps/unix/sysv/linux/aarch64/libc-start.c
	(__libc_start_main): Remove.
	(ARCH_INIT_CPU_FEATURES): New macro.
	* sysdeps/x86/libc-start.c (__libc_start_main): Remove.
	(ARCH_INIT_CPU_FEATURES): New macro.
2017-05-31 06:38:33 +05:30
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Siddhesh Poyarekar
67e58f3941 Add framework for tunables
The tunables framework allows us to uniformly manage and expose global
variables inside glibc as switches to users.  tunables/README has
instructions for glibc developers to add new tunables.

Tunables support can be enabled by passing the --enable-tunables
configure flag to the configure script.  This patch only adds a
framework and does not pose any limitations on how tunable values are
read from the user.  It also adds environment variables used in malloc
behaviour tweaking to the tunables framework as a PoC of the
compatibility interface.

	* manual/install.texi: Add --enable-tunables option.
	* INSTALL: Regenerate.
	* README.tunables: New file.
	* Makeconfig (CPPFLAGS): Define TOP_NAMESPACE.
	(before-compile): Generate dl-tunable-list.h early.
	* config.h.in: Add HAVE_TUNABLES.
	* config.make.in: Add have-tunables.
	* configure.ac: Add --enable-tunables option.
	* configure: Regenerate.
	* csu/init-first.c (__libc_init_first): Move
	__libc_init_secure earlier...
	* csu/init-first.c (LIBC_START_MAIN):... to here.
	Include dl-tunables.h, libc-internal.h.
	(LIBC_START_MAIN) [!SHARED]: Initialize tunables for static
	binaries.
	* elf/Makefile (dl-routines): Add dl-tunables.
	* elf/Versions (ld): Add __tunable_set_val to GLIBC_PRIVATE
	namespace.
	* elf/dl-support (_dl_nondynamic_init): Unset MALLOC_CHECK_
	only when !HAVE_TUNABLES.
	* elf/rtld.c (process_envvars): Likewise.
	* elf/dl-sysdep.c [HAVE_TUNABLES]: Include dl-tunables.h
	(_dl_sysdep_start): Call __tunables_init.
	* elf/dl-tunable-types.h: New file.
	* elf/dl-tunables.c: New file.
	* elf/dl-tunables.h: New file.
	* elf/dl-tunables.list: New file.
	* malloc/tst-malloc-usable-static.c: New test case.
	* malloc/Makefile (tests-static): Add it.
	* malloc/arena.c [HAVE_TUNABLES]: Include dl-tunables.h.
	Define TUNABLE_NAMESPACE.
	(DL_TUNABLE_CALLBACK (set_mallopt_check)): New function.
	(DL_TUNABLE_CALLBACK_FNDECL): New macro.  Use it to define
	callback functions.
	(ptmalloc_init): Set tunable values.
	* scripts/gen-tunables.awk: New file.
	* sysdeps/mach/hurd/dl-sysdep.c: Include dl-tunables.h.
	(_dl_sysdep_start): Call __tunables_init.
2016-12-31 23:49:24 +05:30
Nick Alcock
003a27e819 Initialize the stack guard earlier when linking statically [BZ #7065]
The address of the stack canary is stored in a per-thread variable,
which means that we must ensure that the TLS area is intialized before
calling any -fstack-protector'ed functions.  For dynamically linked
applications, we ensure this (in a later patch) by disabling
-fstack-protector for the whole dynamic linker, but for static
applications, the AT_ENTRY address is called directly by the kernel, so
we must deal with the problem differently.

In static appliations, __libc_setup_tls performs the TCB setup and TLS
initialization, so this commit arranges for it to be called early and
unconditionally.  The call (and the stack guard initialization) is
before the DL_SYSDEP_OSCHECK hook, which if set will probably call
functions which are stack-protected (it does on Linux and NaCL too).  We
also move apply_irel up, so that we can still safely call functions that
require ifuncs while in __libc_setup_tls (though if stack-protection is
enabled we still have to avoid calling functions that are not
stack-protected at this stage).
2016-12-26 10:08:34 +01:00
Siddhesh Poyarekar
71756f069a Remove __libc_csu_irel declaration
21ad055803 removed the function, but
missed the declaration in libc-start.  Removed and verified that the
generated assembly is unchanged.

	* csu/libc-start.c (__libc_csu_irel): Remove declaration.
2016-09-10 15:50:53 +05:30
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
Roland McGrath
e0db65176f Clean up __exit_thread. 2014-05-13 09:49:20 -07:00
Carlos O'Donell
f737dfd071 Support _r_debug for static binaries.
We initialize _r_debug for static binaries to allows debug
agents to treat static binaries a little more like dyanmic
ones. This simplifies the work a debug agent has to do to
access TLS in a static binary via libthread_db.

Tested on x86_64.

See:
https://sourceware.org/ml/libc-alpha/2014-04/msg00183.html

	[BZ #16831]
	* csu/libc-start.c (LIBC_START_MAIN) [!SHARED]: Call
	_dl_debug_initialize.
2014-04-14 15:45:40 -04:00
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
Carlos O'Donell
c61b4d41c9 BZ #15754: CVE-2013-4788
The pointer guard used for pointer mangling was not initialized for
static applications resulting in the security feature being disabled.
The pointer guard is now correctly initialized to a random value for
static applications. Existing static applications need to be
recompiled to take advantage of the fix.

The test tst-ptrguard1-static and tst-ptrguard1 add regression
coverage to ensure the pointer guards are sufficiently random
and initialized to a default value.
2013-09-23 00:52:09 -04:00
Maciej W. Rozycki
ae9552cf7b Declare __ehdr_start with hidden visibility.
This avoids a linker bug triggering for MIPS SVR4 binaries:

http://sourceware.org/bugzilla/show_bug.cgi?id=15365

and regardless serves as a documentation of intent.
2013-04-25 16:14:49 +01:00
Roland McGrath
288f7d79fe Use __ehdr_start, if available, as fallback for AT_PHDR. 2013-03-28 16:15:48 -07:00
Carlos O'Donell
4e9b599577 Revert GLIBC_PTHREAD_DEFAULT_STACKSIZE changes.
This reverts the change that allows the POSIX Thread default stack size
to be changed by the environment variable
GLIBC_PTHREAD_DEFAULT_STACKSIZE. It has been requested that more
discussion happen before this change goes into 2.18.
2013-03-01 16:18:08 -05:00
Siddhesh Poyarekar
e23872c8db Set default stack size from program environment
New environment variable GLIBC_PTHREAD_DEFAULT_STACKSIZE to do this.
2013-03-01 14:15:39 +05:30
Joseph Myers
e97ed6ddbe Remove bp-sym.h and BP_SYM uses from C code. 2013-02-14 13:12:02 +00:00
Joseph Myers
70d9946a44 Remove __ptrvalue, __bounded and __unbounded. 2013-02-13 23:30:40 +00:00
Joseph Myers
3a7ac8a0f5 Remove bp-start.h and INIT_ARGV_and_ENVIRON. 2013-02-01 00:06:18 +00:00
Joseph Myers
568035b787 Update copyright notices with scripts/update-copyrights. 2013-01-02 19:05:09 +00:00
Thomas Schwinge
e10bb1072c [BZ #5246] Conditionalize use of PTR_DEMANGLE. 2012-11-04 21:46:30 +01:00
Roland McGrath
35a5b08bd4 Fix libc-start change for IRELless machines. 2012-08-22 12:53:38 -07:00