Commit Graph

221 Commits

Author SHA1 Message Date
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Stefan Liebler
807849965b Avoid padding in _init and _fini. [BZ #31042]
The linker just concatenates the .init and .fini sections which
results in the complete _init and _fini functions. If needed the
linker adds padding bytes due to an alignment. GNU ld is adding
NOPs, which is fine.  But e.g. mold is adding traps which results
in broken _init and _fini functions.

Thus this patch removes the alignment in .init and .fini sections
in crtn.S files.

We keep the 4 byte function alignment in crti.S files. As the
assembler now also outputs the start of _init and _fini functions
as multiples of 4 byte, it perhaps has to fill it. Although GNU as
is using NOPs here, to be sure, we just keep the alignment with
0x07 (=NOPs) at the end of crti.S.

In order to avoid an obvious NOP slide in _fini, this patch also
uses an lg instead of lgr instruction. Then the emitted instructions
needs a multiple of 4 bytes.
2023-11-30 13:31:23 +01:00
Adhemerval Zanella
55f41ef8de elf: Remove LD_PROFILE for static binaries
The _dl_non_dynamic_init does not parse LD_PROFILE, which does not
enable profile for dlopen objects.  Since dlopen is deprecated for
static objects, it is better to remove the support.

It also allows to trim down libc.a of profile support.

Checked on x86_64-linux-gnu.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-11-21 16:15:42 -03:00
Stefan Liebler
f5f96b784b s390x: Fix static PIE condition for toolchain bootstrapping.
The static PIE configure check uses link tests.  When bootstrapping
a cross-toolchain, the link tests fail due to missing crt-files /
libc.so.  As we explicitely want to test an issue in binutils (ld),
we now also explicitely check for known linker versions.

See also commit 368b7c614b
S390: Use compile-only instead of also link-tests in configure.
2023-08-18 10:57:59 +02:00
Siddhesh Poyarekar
c6cb8783b5 configure: Use autoconf 2.71
Bump autoconf requirement to 2.71 to allow regenerating configure on
more recent distributions.  autoconf 2.71 has been in Fedora since F36
and is the current version in Debian stable (bookworm).  It appears to
be current in Gentoo as well.

All sysdeps configure and preconfigure scripts have also been
regenerated; all changes are trivial transformations that do not affect
functionality.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-07-17 10:08:10 -04:00
Paul Pluzhnikov
65cc53fe7c Fix misspellings in sysdeps/ -- BZ 25337 2023-05-30 23:02:29 +00:00
Stefan Liebler
41f67ccbe9 S390: Influence hwcaps/stfle via GLIBC_TUNABLES.
This patch enables the option to influence hwcaps and stfle bits used
by the s390 specific ifunc-resolvers.  The currently x86-specific
tunable glibc.cpu.hwcaps is also used on s390x to achieve the task. In
addition the user can also set a CPU arch-level like z13 instead of
single HWCAP and STFLE features.

Note that the tunable only handles the features which are really used
in the IFUNC-resolvers.  All others are ignored as the values are only
used inside glibc.  Thus we can influence:
- HWCAP_S390_VXRS (z13)
- HWCAP_S390_VXRS_EXT (z14)
- HWCAP_S390_VXRS_EXT2 (z15)
- STFLE_MIE3 (z15)

The influenced hwcap/stfle-bits are stored in the s390-specific
cpu_features struct which also contains reserved fields for future
usage.

The ifunc-resolvers and users of stfle bits are adjusted to use the
information from cpu_features struct.

On 31bit, the ELF_MACHINE_IRELATIVE macro is now also defined.
Otherwise the new ifunc-resolvers segfaults as they depend on
the not yet processed_rtld_global_ro@GLIBC_PRIVATE relocation.
2023-02-07 09:19:27 +01:00
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Florian Weimer
58548b9d68 Use PTR_MANGLE and PTR_DEMANGLE unconditionally in C sources
In the future, this will result in a compilation failure if the
macros are unexpectedly undefined (due to header inclusion ordering
or header inclusion missing altogether).

Assembler sources are more difficult to convert.  In many cases,
they are hand-optimized for the mangling and no-mangling variants,
which is why they are not converted.

sysdeps/s390/s390-32/__longjmp.c and sysdeps/s390/s390-64/__longjmp.c
are special: These are C sources, but most of the implementation is
in assembler, so the PTR_DEMANGLE macro has to be undefined in some
cases, to match the assembler style.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-18 17:04:10 +02:00
Florian Weimer
88f4b6929c Introduce <pointer_guard.h>, extracted from <sysdep.h>
This allows us to define a generic no-op version of PTR_MANGLE and
PTR_DEMANGLE.  In the future, we can use PTR_MANGLE and PTR_DEMANGLE
unconditionally in C sources, avoiding an unintended loss of hardening
due to missing include files or unlucky header inclusion ordering.

In i386 and x86_64, we can avoid a <tls.h> dependency in the C
code by using the computed constant from <tcb-offsets.h>.  <sysdep.h>
no longer includes these definitions, so there is no cyclic dependency
anymore when computing the <tcb-offsets.h> constants.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-18 17:03:55 +02:00
Jason A. Donenfeld
eaad4f9e8f arc4random: simplify design for better safety
Rather than buffering 16 MiB of entropy in userspace (by way of
chacha20), simply call getrandom() every time.

This approach is doubtlessly slower, for now, but trying to prematurely
optimize arc4random appears to be leading toward all sorts of nasty
properties and gotchas. Instead, this patch takes a much more
conservative approach. The interface is added as a basic loop wrapper
around getrandom(), and then later, the kernel and libc together can
work together on optimizing that.

This prevents numerous issues in which userspace is unaware of when it
really must throw away its buffer, since we avoid buffering all
together. Future improvements may include userspace learning more from
the kernel about when to do that, which might make these sorts of
chacha20-based optimizations more possible. The current heuristic of 16
MiB is meaningless garbage that doesn't correspond to anything the
kernel might know about. So for now, let's just do something
conservative that we know is correct and won't lead to cryptographic
issues for users of this function.

This patch might be considered along the lines of, "optimization is the
root of all evil," in that the much more complex implementation it
replaces moves too fast without considering security implications,
whereas the incremental approach done here is a much safer way of going
about things. Once this lands, we can take our time in optimizing this
properly using new interplay between the kernel and userspace.

getrandom(0) is used, since that's the one that ensures the bytes
returned are cryptographically secure. But on systems without it, we
fallback to using /dev/urandom. This is unfortunate because it means
opening a file descriptor, but there's not much of a choice. Secondly,
as part of the fallback, in order to get more or less the same
properties of getrandom(0), we poll on /dev/random, and if the poll
succeeds at least once, then we assume the RNG is initialized. This is a
rough approximation, as the ancient "non-blocking pool" initialized
after the "blocking pool", not before, and it may not port back to all
ancient kernels, though it does to all kernels supported by glibc
(≥3.2), so generally it's the best approximation we can do.

The motivation for including arc4random, in the first place, is to have
source-level compatibility with existing code. That means this patch
doesn't attempt to litigate the interface itself. It does, however,
choose a conservative approach for implementing it.

Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Cristian Rodríguez <crrodriguez@opensuse.org>
Cc: Paul Eggert <eggert@cs.ucla.edu>
Cc: Mark Harris <mark.hsj@gmail.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-07-27 08:58:27 -03:00
Adhemerval Zanella Netto
3b56f944c5 s390x: Add optimized chacha20
It adds vectorized ChaCha20 implementation based on libgcrypt
cipher/chacha20-s390x.S.  The final state register clearing is
omitted.

On a z15 it shows the following improvements (using formatted
bench-arc4random data):

GENERIC                                    MB/s
-----------------------------------------------
arc4random [single-thread]               198.92
arc4random_buf(16) [single-thread]       244.49
arc4random_buf(32) [single-thread]       282.73
arc4random_buf(48) [single-thread]       286.64
arc4random_buf(64) [single-thread]       320.06
arc4random_buf(80) [single-thread]       297.43
arc4random_buf(96) [single-thread]       310.96
arc4random_buf(112) [single-thread]      308.10
arc4random_buf(128) [single-thread]      309.90
-----------------------------------------------

VX.                                        MB/s
-----------------------------------------------
arc4random [single-thread]               430.26
arc4random_buf(16) [single-thread]       735.14
arc4random_buf(32) [single-thread]      1029.99
arc4random_buf(48) [single-thread]      1206.76
arc4random_buf(64) [single-thread]      1311.92
arc4random_buf(80) [single-thread]      1378.74
arc4random_buf(96) [single-thread]      1445.06
arc4random_buf(112) [single-thread]     1484.32
arc4random_buf(128) [single-thread]     1517.30
-----------------------------------------------

Checked on s390x-linux-gnu.
2022-07-22 11:58:27 -03:00
Sam James
2249ec60a9 s390: use LC_ALL=C for readelf call
Let's use LC_ALL=C as we do elsewhere for consistency.

Tested on s390x-ibm-linux-gnu.

See: 72bd208846
Signed-off-by: Sam James <sam@gentoo.org>
Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
2022-06-21 10:16:44 +02:00
Sam James
c376ff3287 s390: use $READELF
We already check for it in root configure.ac with AC_CHECK_TOOL. Let's
use the result.

Tested on s390x-ibm-linux-gnu.

Signed-off-by: Sam James <sam@gentoo.org>
Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
2022-06-21 10:16:44 +02:00
Adhemerval Zanella
22d8935d1d s390: Remove _dl_skip_args usage
Since ad43cac44a the generic code already shuffles the argv/envp/auxv
on the stack to remove the ld.so own arguments and thus _dl_skip_args
is always 0.   So there is no need to adjust the argc or argv.

Checked on s390x-linux-gnu and s390-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-05-30 16:33:25 -03:00
Stefan Liebler
728894dba4 S390: Enable static PIE
This commit enables static PIE on 64bit.  On 31bit, static PIE is
not supported.

A new configure check in sysdeps/s390/s390-64/configure.ac also performs
a minimal test for requirements in ld:
Ensure you also have those patches for:
- binutils (ld)
  - "[PR ld/22263] s390: Avoid dynamic TLS relocs in PIE"
    https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=26b1426577b5dcb32d149c64cca3e603b81948a9
    (Tested by configure check above)
    Otherwise there will be a R_390_TLS_TPOFF relocation, which fails to
    be processed in _dl_relocate_static_pie() as static TLS map is not setup.
  - "s390: Add DT_JMPREL pointing to .rela.[i]plt with static-pie"
    https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d942d8db12adf4c9e5c7d9ed6496a779ece7149e
    (We can't test it in configure as we are not able to link a static PIE
    executable if the system glibc lacks static PIE support)
    Otherwise there won't be DT_JMPREL, DT_PLTRELA, DT_PLTRELASZ entries
    and the IFUNC symbols are not processed, which leads to crashes.

- kernel (the mentioned links to the commits belong to 5.19 merge window):
  - "s390/mmap: increase stack/mmap gap to 128MB"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=f2f47d0ef72c30622e62471903ea19446ea79ee2
  - "s390/vdso: move vdso mapping to its own function"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=57761da4dc5cd60bed2c81ba0edb7495c3c740b8
  - "s390/vdso: map vdso above stack"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=9e37a2e8546f9e48ea76c839116fa5174d14e033
  - "s390/vdso: add vdso randomization"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=41cd81abafdc4e58a93fcb677712a76885e3ca25
  (We can't test the kernel of the target system)
  Otherwise if /proc/sys/kernel/randomize_va_space is turned off (0),
  static PIE executables like ldconfig will crash.  While startup sbrk is
  used to enlarge the HEAP.  Unfortunately the underlying brk syscall fails
  as there is not enough space after the HEAP.  Then the address of the TLS
  image is invalid and the following memcpy in __libc_setup_tls() leads
  to a segfault.
  If /proc/sys/kernel/randomize_va_space is activated (default: 2), there
  is enough space after HEAP.

- glibc
  - "Linux: Define MMAP_CALL_INTERNAL"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=c1b68685d438373efe64e5f076f4215723004dfb
  - "i386: Remove OPTIMIZE_FOR_GCC_5 from Linux libc-do-syscall.S"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=6e5c7a1e262961adb52443ab91bd2c9b72316402
  - "i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=60f0f2130d30cfd008ca39743027f1e200592dff
  - "ia64: Always define IA64_USE_NEW_STUB as a flag macro"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=18bd9c3d3b1b6a9182698c85354578d1d58e9d64
  - "Linux: Implement a useful version of _startup_fatal"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=a2a6bce7d7e52c1c34369a7da62c501cc350bc31
  - "Linux: Introduce __brk_call for invoking the brk system call"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=b57ab258c1140bc45464b4b9908713e3e0ee35aa
  - "csu: Implement and use _dl_early_allocate during static startup"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=f787e138aa0bf677bf74fa2a08595c446292f3d7
  The mentioned patch series by Florian Weimer avoids the mentioned failing
  sbrk syscall by falling back to mmap.

This commit also adjusts startup code in start.S to be ready for static PIE.
We have to add a wrapper function for main as we are not allowed to use
GOT relocations before __libc_start_main is called.
(Compare also to:
- commit 14d886edbd
  "aarch64: fix start code for static pie"
- commit 3d1d79283e
  "aarch64: fix static pie enabled libc when main is in a shared library"
)
2022-05-18 14:31:26 +02:00
Stefan Liebler
2376944b9e S390: Add new s390 platform z16.
The new IBM z16 is added to platform string array.
The macro _DL_PLATFORMS_COUNT is incremented.

_dl_hwcaps_subdir is extended by "z16" if HWCAP_S390_VXRS_PDE2
is set. HWCAP_S390_NNPA is not tested in _dl_hwcaps_subdirs_active
as those instructions may be replaced or removed in future.

tst-glibc-hwcaps.c is extended in order to test z16 via new marker5.

A fatal glibc error is dumped if glibc was build with architecture
level set for z16, but run on an older machine. (See dl-hwcap-check.h)
2022-04-14 10:37:45 +02:00
Fangrui Song
3ee318c923 Remove -z combreloc and HAVE_Z_COMBRELOC
-z combreloc has been the default regadless of the architecture since
binutils commit f4d733664aabd7bd78c82895e030ec9779a92809 (2002). The
configure check added in commit fdde83499a (2001) has long been
unneeded.

We can therefore treat HAVE_Z_COMBRELOC as always 1 and delete dead code
paths in dl-machine.h files (many were copied from commit a711b01d34
and ee0cb67ec2).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-04-04 17:19:07 -07:00
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
f01d482f03 s390x: Use <gcc-macros.h> in early HWCAP check
This is required so that the checks still work if $(early-cflags)
selects a different ISA level.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-01-14 20:17:58 +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
8c0664e2b8 elf: Add _dl_audit_pltexit
It consolidates the code required to call la_pltexit 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
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
Siddhesh Poyarekar
30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30
Fangrui Song
710ba420fd Remove sysdeps/*/tls-macros.h
They provide TLS_GD/TLS_LD/TLS_IE/TLS_IE macros for TLS testing.  Now
that we have migrated to __thread and tls_model attributes, these macros
are unused and the tls-macros.h files can retire.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-08-18 09:15:20 -07:00
Florian Weimer
1805bf753f s390x: Check HWCAP bits against compiler flags
When compiled with GCC 11.1 and -march=z14 -O3 build flags, running
ld.so (or any dynamically linked program) prints:

Fatal glibc error: CPU lacks VXE support (z14 or later required)

Co-Authored-By: Stefan Liebler <stli@linux.ibm.com>
Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
2021-05-19 11:09:57 +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
Wilco Dijkstra
9e97f239ea Remove dbl-64/wordsize-64 (part 2)
Remove the wordsize-64 implementations by merging them into the main dbl-64
directory.  The second patch just moves all wordsize-64 files and removes a
few wordsize-64 uses in comments and Implies files.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-01-07 15:26:26 +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
fdf8fbca45 s390x: Add glibc-hwcaps support
Subdirectories z13, z14, z15 can be selected, mostly based on the
level of support for vector instructions.

Co-Authored-By: Stefan Liebler <stli@linux.ibm.com>
2020-12-10 13:51:18 +01:00
Stefan Liebler
1301097665 S390: Remove backchain-based fallback and use generic backtrace.c.
After recent discussions:
- "[PATCH] s390: Remove backchain-based fallback from backtrace"
  https://www.sourceware.org/ml/libc-alpha/2020-02/msg00287.html

- "Re: [PATCH 07/11] s390: Implement backtrace on top of <unwind-link.h>"
  https://www.sourceware.org/ml/libc-alpha/2020-02/msg00637.html

We've checked and decided to remove the backchain:
We don't know of any environments without libgcc. Thus the backchain
unwinder is not used. If somebody builds with -mbackchain and without
fasynchronous-unwind-tables and has libgcc installed, then the
libgcc unwinder is called but not the backchain-based fallback.

This step allows to get rid of the s390x specific backtrace.c files at all.
Furthermore the now used debug/backtrace.c version has some more
advantages:
- Free all resources if necessary. (libc_freeres_fn)
- Remove NULL address above _start.
- Check whether we make any progress while getting addresses.
2020-03-05 12:52:19 +01:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Stefan Liebler
fcee34cc37 S390: Use sysdeps/ieee754/dbl-64/wordsize-64 on s390x.
This patch enables the usage of implementations in
sysdeps/ieee754/dbl-64/wordsize-64 on 64bit s390x.
2019-12-11 15:12:26 +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
Stefan Liebler
ce6ddae036 S390: Increase function alignment to 16 bytes.
Set the default function alignment to 16 bytes in order to
get rid of some unwanted performance effects.

Please see also GCC commit "S/390: Set default function
alignment to 16." (Subversion revision 262817)

ChangeLog:

	* sysdeps/s390/s390-64/sysdep.h(ENTRY): Use alignment of 16byte.
	* sysdeps/s390/s390-32/sysdep.h: Likewise.
2019-03-04 10:48:42 +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
Stefan Liebler
581a051c2e S390: Refactor memchr ifunc handling.
The ifunc handling for memchr is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

Note: The fallback s390-32/s390-64 ifunc variants with srst instruction
are now moved to the unified memchr-z900.S file which can be used for
31/64bit. The s390-32/s390-64 files multiarch/memchr.c and memchr.S
are deleted.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove memchr variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add memchr variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for memchr.
	* sysdeps/s390/multiarch/memchr-vx.S: Move to ...
	* sysdeps/s390/memchr-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/memchr.c: Move to ...
	* sysdeps/s390/memchr.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-memchr.h: New file.
	* sysdeps/s390/s390-64/memchr.S: Move to ...
	* sysdeps/s390/memchr-z900.S: ... here and adjust to be usable
	for 31/64bit and ifunc handling.
	* sysdeps/s390/s390-32/multiarch/memchr.c: Delete file.
	* sysdeps/s390/s390-64/multiarch/memchr.c: Likewise.
	* sysdeps/s390/s390-32/memchr.S: Likewise.
2018-12-18 13:57:16 +01:00
Stefan Liebler
cdab85fe33 S390: Refactor strcmp ifunc handling.
The ifunc handling for strcmp is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

Note: The fallback s390-32/s390-64 ifunc variants with clst instruction
are now moved to the unified strcmp-z900.S file which can be used for
31/64bit. The s390-32/s390-64 files multiarch/strcmp.c and strcmp.S
are deleted.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strcmp variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strcmp variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strcmp.
	* sysdeps/s390/multiarch/strcmp-vx.S: Move to ...
	* sysdeps/s390/strcmp-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strcmp.c: Move to ...
	* sysdeps/s390/strcmp.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strcmp.h: New file.
	* sysdeps/s390/s390-64/strcmp.S: Move to ...
	* sysdeps/s390/strcmp-z900.S: ... here and adjust to be usable
	for 31/64bit and ifunc handling.
	* sysdeps/s390/s390-32/multiarch/strcmp.c: Delete file.
	* sysdeps/s390/s390-64/multiarch/strcmp.c: Likewise.
	* sysdeps/s390/s390-32/strcmp.S: Likewise.
2018-12-18 13:57:13 +01:00
Stefan Liebler
d1bdbf3809 S390: Refactor strncpy ifunc handling.
The ifunc handling for strncpy is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

Note: The fallback s390-32/s390-64 ifunc variants are now moved to
the strncpy-z900.S files. The s390-32/s390-64 files multiarch/strncpy.c
and strncpy.S are deleted.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strncpy variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strncpy variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strncpy.
	* sysdeps/s390/multiarch/strncpy-vx.S: Move to ...
	* sysdeps/s390/strncpy-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strncpy.c: Move to ...
	* sysdeps/s390/strncpy.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strncpy.h: New file.
	* sysdeps/s390/s390-64/strncpy.S: Move to ...
	* sysdeps/s390/s390-64/strncpy-z900.S: ... here
	and adjust ifunc handling.
	* sysdeps/s390/s390-32/strncpy.S: Move to ...
	* sysdeps/s390/s390-32/strncpy-z900.S: ... here
	and adjust ifunc handling.
	* sysdeps/s390/s390-32/multiarch/strncpy.c: Delete file.
	* sysdeps/s390/s390-64/multiarch/strncpy.c: Likewise.
2018-12-18 13:57:11 +01:00
Stefan Liebler
914a4e0557 S390: Refactor strcpy ifunc handling.
The ifunc handling for strcpy is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

Note: The fallback s390-32/s390-64 ifunc variants with mvst instruction
are now moved to the unified strcpy-z900.S file which can be used for
31/64bit. The s390-32/s390-64 files multiarch/strcpy.c and strcpy.S
are deleted.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strcpy variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strcpy variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strcpy.
	* sysdeps/s390/multiarch/strcpy-vx.S: Move to ...
	* sysdeps/s390/strcpy-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strcpy.c: Move to ...
	* sysdeps/s390/strcpy.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strcpy.h: New file.
	* sysdeps/s390/s390-64/strcpy.S: Move to ...
	* sysdeps/s390/strcpy-z900.S: ... here and adjust to be usable
	for 31/64bit and ifunc handling.
	* sysdeps/s390/s390-32/multiarch/strcpy.c: Delete file.
	* sysdeps/s390/s390-64/multiarch/strcpy.c: Likewise.
	* sysdeps/s390/s390-32/strcpy.S: Likewise.
2018-12-18 13:57:10 +01:00
Stefan Liebler
e099aab060 S390: Remove s390 specific implementation of bcopy.
Nowadays gcc is automatically replacing a call to bcopy
with a call to memmove.  Thus only old binaries will call
the s390 specific bcopy implementation.

The s390 specific implementation is using an own
implementation for memcpy in the forward case and is
relying on memmove in the backward case.

After removing the s390 specific bcopy, the common code
bcopy is used.  It just performs a tail call to memmove.

ChangeLog:
	* sysdeps/s390/s390-32/bcopy.S: Remove.
	* sysdeps/s390/s390-64/bcopy.S: Likewise.
2018-12-18 13:57:07 +01:00
Stefan Liebler
df3eb8de31 S390: Unify 31/64bit memcpy.
The implementation of memcpy/mempcpy for s390-32 (31bit)
and s390-64 (64bit) is nearly the same.
This patch unifies it for maintability reasons.

__mem[p]cpy_z10 and __mem[p]cpy_z196 differs between 31 and 64bit:
-31bit needs .machinemode "zarch_nohighgprs" and llgfr   %r4,%r4
-lr vs lgr; lgr can be also used on 31bit as this ifunc variant
is only called if we are on a zarch machine.

__mem[p]cpy_default differs between 31 and 64bit:
-Some 31bit vs 64bit instructions (e.g. ltr vs ltgr.
Solved with 31/64 specific instruction macros).
-The address of mvc instruction is setup in different ways
(larl vs bras). Solved with #if defined __s390x__.

__memcpy_mvcle differs between 31 and 64bit:
-lr vs lgr; ahi vs aghi;
Solved with 31/64bit specific instruction macros.

Otherwise 31/64bit implementation has the same structure of the code.

ChangeLog:

	* sysdeps/s390/s390-64/memcpy.S: Move to ...
	* sysdeps/s390/memcpy.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/memcpy.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add memcpy.
	* sysdeps/s390/s390-32/multiarch/Makefile: Delete file.
	* sysdeps/s390/s390-64/multiarch/Makefile: Likewise.
	* sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Move to ...
	* sysdeps/s390/multiarch/memcpy-s390x.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Delete File.
	* sysdeps/s390/s390-64/multiarch/memcpy.c: Move to ...
	* sysdeps/s390/multiarch/memcpy.c: ... here.
	* sysdeps/s390/s390-32/multiarch/memcpy.c: Delete File.
2018-12-18 13:57:06 +01:00
Stefan Liebler
6c6b8c7470 S390: Unify 31/64bit memcmp.
The implementation of memcmp for s390-32 (31bit) and
s390-64 (64bit) is nearly the same.
This patch unifies it for maintability reasons.

__memcmp_z10 and __memcmp_z196 differs between 31 and 64bit:
-31bit needs .machinemode "zarch_nohighgprs" and llgfr   %r4,%r4
-lr vs lgr and some other instructions:
But lgr and co can be also used on 31bit as this ifunc variant
is only called if we are on a zarch machine.

__memcmp_default differs between 31 and 64bit:
-Some 31bit vs 64bit instructions (e.g. ltr vs ltgr.
Solved with 31/64 specific instruction macros).
-The address of mvc instruction is setup in different ways
(larl vs bras). Solved with #if defined __s390x__.

Otherwise 31/64bit implementation has the same structure of the code.

ChangeLog:

	* sysdeps/s390/s390-64/memcmp.S: Move to ...
	* sysdeps/s390/memcmp.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/memcmp.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add memcmp.
	* sysdeps/s390/s390-32/multiarch/Makefile (sysdep_routines):
	Remove memcmp.
	* sysdeps/s390/s390-64/multiarch/Makefile: Likewise.
	* sysdeps/s390/s390-64/multiarch/memcmp-s390x.S: Move to ...
	* sysdeps/s390/multiarch/memcmp-s390x.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/multiarch/memcmp-s390.S: Delete File.
	* sysdeps/s390/s390-64/multiarch/memcmp.c: Move to ...
	* sysdeps/s390/multiarch/memcmp.c: ... here.
	* sysdeps/s390/s390-32/multiarch/memcmp.c: Delete File.
2018-12-18 13:57:05 +01:00
Stefan Liebler
07be392807 S390: Implement bzero with memset.
This patch removes the bzero s390 implementation with mvcle and
adds entry points for bzero in memset ifunc variants.
Therefore an ifunc resolver is implemented for bzero, too.

ChangeLog:

	* sysdeps/s390/s390-32/bzero.S: Delete file.
	* sysdeps/s390/s390-64/bzero.S: Likewise.
	* sysdeps/s390/Makefile (sysdep_routines): Add bzero.
	* sysdeps/s390/bzero.c: New file.
	* sysdeps/s390/memset-z900.S: Add bzero entry points.
	* sysdeps/s390/ifunc-memset.h: Add bzero function macros.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add bzero ifunc variants.
2018-12-18 13:57:05 +01:00
Stefan Liebler
5f1743d118 S390: Unify 31/64bit memset.
The implementation of memset for s390-32 (31bit) and
s390-64 (64bit) is nearly the same.
This patch unifies it for maintability reasons.

__memset_z10 and __memset_z196 differs between 31 and 64bit:
-31bit needs .machinemode "zarch_nohighgprs" and llgfr   %r4,%r4
-lr vs lgr and some other instructions:
But lgr and co can be also used on 31bit as this ifunc variant
is only called if we are on a zarch machine.

__memset_default differs between 31 and 64bit:
-Some 31bit vs 64bit instructions (e.g. ltr vs ltgr.
Solved with 31/64 specific instruction macros).
-The address of mvc instruction is setup in different ways
(larl vs bras). Solved with #if defined __s390x__.

Otherwise 31/64bit implementation has the same structure of the code.

ChangeLog:

	* sysdeps/s390/s390-64/memset.S: Move to ...
	* sysdeps/s390/memset.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/memset.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add memset.
	* sysdeps/s390/s390-32/multiarch/Makefile (sysdep_routines):
	Remove memset.
	* sysdeps/s390/s390-64/multiarch/Makefile: Likewise.
	* sysdeps/s390/s390-64/multiarch/memset-s390x.S: Move to ...
	* sysdeps/s390/multiarch/memset-s390x.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/multiarch/memset-s390.S: Delete File.
	* sysdeps/s390/s390-64/multiarch/memset.c: Move to ...
	* sysdeps/s390/multiarch/memset.c: ... here.
	* sysdeps/s390/s390-32/multiarch/memset.c: Delete File.
2018-12-18 13:57:04 +01:00
Ilya Leoshkevich
71c01af52f S390: Implement 64-bit __fentry__
* Since __fentry__ is almost the same as _mcount, reuse the code by
  #including it twice with different #defines around.
* Remove LA usages - they are needed in 31-bit mode to clear the top
  bit, but in 64-bit they appear to do nothing.
* Add CFI rule for the nonstandard return register. This rule applies
  to the current function (binutils generates a new CIE - see
  gas/dw2gencfi.c:select_cie_for_fde()), so it is not necessary to put
  __fentry__ into a new file.
* Fix CFI offset for %r14.
* Add CFI rule for %r0.
* Fix unwound value of %r15 being off by 244 bytes.
* Unwinding in __fentry__@plt does not work, no plan to fix it - it
  would require asking linker to generate CFI for return address in
  %r0.  From functional perspective keeping it broken is fine, since
  the callee did not have a chance to do anything yet.  From
  convenience perspective it would be possible to enhance GDB in the
  future to treat __fentry__@plt in a special way.
* Fix whitespace.
* Fix offsets in comments, which were copied from 32-bit code.
* 32-bit version will not be implemented, since it's not compatible
  with the corresponding PLT stubs: they assume %r12 points to GOT,
  which is not the case for gcc-emitted __fentry__ stub, which runs
  before the prolog.

This patch adds the runtime support in glibc for the -mfentry
gcc feature introduced in [1] and [2].

[1] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00784.html
[2] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00912.html

ChangeLog:

	* sysdeps/s390/s390-64/Versions (__fentry__): Add.
	* sysdeps/s390/s390-64/s390x-mcount.S: Move the common
	code to s390x-mcount.h and #include it.
	* sysdeps/s390/s390-64/s390x-mcount.h: New file.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
	(__fentry__): Add.
2018-08-10 09:07:44 +02:00
Ilya Leoshkevich
bde6320f39 S390: Do not clobber R0 in 64-bit _dl_runtime_profile
Preparation for the usage of R0 by __fentry__.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_profile):
	Do not clobber R0.
2018-08-10 09:07:43 +02:00
Ilya Leoshkevich
5755f5e4cc S390: Do not clobber R0 in 64-bit _dl_runtime_resolve
Preparation for the usage of R0 by __fentry__.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_resolve):
	Do not clobber R0.
2018-08-10 09:07:43 +02:00
Ilya Leoshkevich
329c6fec8b S390: Use symbolic offsets for stack variables in 64-bit _dl_runtime_profile
Maintainability improvement.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_profile):
	Use symbolic offsets for stack variables.
2018-08-10 09:07:42 +02:00