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.
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>
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>
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>
_dl_skip_args is always 0, so the target specific code that modifies
argv after relro protection is applied is no longer used.
After the patch relro protection is applied to _dl_argv consistently
on all targets.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
-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>
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>
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
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>
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>
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>
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/b5ecac94eabfd72ed2916d6d8157e7dchttps://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
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>
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
_init and _fini are special functions provided by glibc for linker to
define DT_INIT and DT_FINI in executable and shared library. They
should never be put in dynamic symbol table. This patch marks them as
hidden to remove them from dynamic symbol table.
Tested with build-many-glibcs.py.
[BZ #23145]
* elf/Makefile (tests-special): Add $(objpfx)check-initfini.out.
($(all-built-dso:=.dynsym): New target.
(common-generated): Add $(all-built-dso:$(common-objpfx)%=%.dynsym).
($(objpfx)check-initfini.out): New target.
(generated): Add check-initfini.out.
* scripts/check-initfini.awk: New file.
* sysdeps/aarch64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/alpha/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/arm/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/hppa/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/i386/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/ia64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/m68k/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/microblaze/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/mips/mips32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/mips/mips64/n32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/mips/mips64/n64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/nios2/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/powerpc/powerpc32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/powerpc/powerpc64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/s390/s390-32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/s390/s390-64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/sh/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/sparc/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/x86_64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
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>
In _dl_runtime_resolve[_vx], unwinding fails after the new stack frame
is created as there is no CFI rule for r15. This is also observeable in
GDB: Backtrace stopped: previous frame inner to this frame (corrupt stack?)
Therefore this patch is now storing r15 on stack and is using cfi_offset rule.
The stmg/lmg instruction is used to store/load r14 and r15 with one instruction.
On 64bit, the offsets of the fprs have moved to store r15 directly after r14.
On 31bit, the r14/r15 is now stored between the other gprs and fprs as the space
wasn't used.
ChangeLog:
* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_resolve):
Store r15 on stack and add cfi rule.
* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve):
Likewise.
GDB failed to detect the outermost frame while showing the backtrace
within a thread:
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
Before this patch, the start routines like thread_start had no cfi information.
GDB is then using the prologue unwinder if no cfi information is available.
This unwinder tries to unwind r15 and stops e.g. if r15 was updated or
on some jump-instructions.
On older glibc-versions (before commit "Remove cached PID/TID in clone"
c579f48edb), the thread_start function used
such a jump-instruction and GDB did not fail with an error.
This patch adds cfi information for _start, thread_start and __makecontext_ret
and marks r14 as undefined which marks the frame as outermost frame and GDB
stops the backtrace. Also tested different gcc versions in order to test
_Unwind_Backtrace() in libgcc as this is used by backtrace() in glibc.
ChangeLog:
* sysdeps/s390/s390-64/start.S (_start): Add cfi information for r14.
* sysdeps/s390/s390-32/start.S: (_start): Likewise
* sysdeps/unix/sysv/linux/s390/s390-64/clone.S
(thread_start): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/clone.S
(thread_start): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/__makecontext_ret.S
(__makecontext_ret): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S
(__makecontext_ret): Likewise.
The testcases elf/tst-tls1-static and elf/tst-tls2-static
are failing on s390 if gcc is configured with --enable-default-pie.
According to binutils, there are only four valid cases for IE -> LE transition:
lg %rx,(0,%ry) -> sllg %rx,%ry,0
lg %rx,(%ry,0) -> sllg %rx,%ry,0
lg %rx,(%ry,%r12) -> sllg %rx,%ry,0
lg %rx,(%r12,%ry) -> sllg %rx,%ry,0
Thus I've adjusted the TLS_IE macro in s390 tls-macros.h files in PIC case
in order to use r12 for the address of global offset table.
The adjusted macro definition is not used if gcc is not configured with
--enable-default-pie.
ChangeLog:
* sysdeps/s390/s390-32/tls-macros.h (TLS_IE): Use r12 for GOT address.
* sysdeps/s390/s390-64/tls-macros.h (TLS_IE): Likewise.
Building glibc with gcc configured with --enable-default-pie failed on s390
due to assembler messages:
../sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S:44:
Error: junk at end of line, first unrecognized character is `@'
HIDDEN_JUMPTARGET was expanded to exit@PLT@GOTOFF.
If SHARED is not defined, HIDDEN_JUMPTARGET is defined to JUMPTARGET
in sysdeps/s390/s390-32/sysdep.h. There it expanded to exit@PLT
in non SHARED case as PIC is defined if gcc is configured with
--enable-default-pie. Thus I've changed the "ifdef PIC" to "ifdef SHARED"
as we do not want PLTs in the static obj files. I've also changed this
in sysdeps/s390/s390-64/sysdep.h.
I've also adjusted sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S.
If glibc is configured with --disable-hidden-plt, then NO_HIDDEN is defined.
In SHARED case HIDDEN_JUMPTARGET would be expanded to exit@PLT@GOTOFF
instead of __GI_exit@GOTOFF.
Now we jump to:
- __GI_exit if SHARED is defined
- exit@PLT if SHARED and NO_HIDDEN is defined
- exit if both are not defined.
On s390 31bit we have to setup GOT pointer in r12 if we use a PLT stub.
Therefore I use SYSCALL_PIC_SETUP from sysdep.h and added the missing semicolons.
ChangeLog:
[BZ #21537]
* sysdeps/s390/s390-32/sysdep.h (JUMPTARGET, SYSCALL_PIC_SETUP):
Check SHARED instead of PIC.
(SYSCALL_PIC_SETUP): Add missing semicolons.
* sysdeps/s390/s390-64/sysdep.h (JUMPTARGET, SYSCALL_PIC_SETUP):
Check SHARED instead of PIC.
* sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S
(__makecontext_ret): Adjust code to jump to exit.
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.
As noted in [1], divdi3 object is only exported in a handful ABIs
(i386, m68k, powerpc32, s390-32, and ia64), however it is built
for all current architectures regardless.
This patch refact the make rules for this object to so only the
aforementioned architectures that actually require it builds it.
Also, to avoid internal PLT calls to the exported symbol from the
module, glibc uses an internal header (symbol-hacks.h) which is
unrequired (and in fact breaks the build for architectures that
intend to get symbol definitions from libgcc.a). The patch also
changes it to create its own header (divdi3-symbol-hacks.h) and
adjust the architectures that require it accordingly.
I checked the build/check (with run-built-tests=no) on the
following architectures (which I think must cover all supported
ABI/builds) using GCC 6.3:
aarch64-linux-gnu
alpha-linux-gnu
arm-linux-gnueabihf
hppa-linux-gnu
ia64-linux-gnu
m68k-linux-gnu
microblaze-linux-gnu
mips64-n32-linux-gnu
mips-linux-gnu
mips64-linux-gnu
nios2-linux-gnu
powerpc-linux-gnu
powerpc-linux-gnu-power4
powerpc64-linux-gnu
powerpc64le-linux-gnu
s390x-linux-gnu
s390-linux-gnu
sh4-linux-gnu
sh4-linux-gnu-soft
sparc64-linux-gnu
sparcv9-linux-gnu
tilegx-linux-gnu
tilegx-linux-gnu-32
tilepro-linux-gnu
x86_64-linux-gnu
x86_64-linux-gnu-x32
i686-linux-gnu
I only saw one regression on sparcv9-linux-gnu (extra PLT call to
.udiv) which I address in next patch in the set. It also correctly
build SH with GCC 7.0.1 (without any regression from c89721e25d).
[1] https://sourceware.org/ml/libc-alpha/2017-03/msg00243.html
* sysdeps/i386/symbol-hacks.h: New file.
* sysdeps/m68k/symbol-hacks.h: New file.
* sysdeps/powerpc/powerpc32/symbol-hacks.h: New file.
* sysdeps/s390/s390-32/symbol-hacks.h: New file.
* sysdeps/unix/sysv/linux/i386/Makefile
[$(subdir) = csu] (sysdep_routines): New rule: divdi3 object.
[$(subdir) = csu] (sysdep-only-routines): Likewise.
[$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
* sysdeps/unix/sysv/linux/m68k/Makefile
[$(subdir) = csu] (sysdep_routines): Likewise.
[$(subdir) = csu] (sysdep-only-routines): Likewise.
[$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/Makefile
[$(subdir) = csu] (sysdep_routines): Likewise.
[$(subdir) = csu] (sysdep-only-routines): Likewise.
[$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/Makefile
[$(subdir) = csu] (sysdep_routines): Likewise.
[$(subdir) = csu] (sysdep-only-routines): Likewise.
[$(subdir) = csu] (CFLAGS-divdi3.c): Likewise.
* sysdeps/wordsize-32/Makefile: Remove file.
* sysdeps/wordsize-32/symbol-hacks.h: Definitions move to ...
* sysdeps/wordsize-32/divdi3-symbol-hacks.h: ... here.
This patch also clobbers r14 in TLS_LD, TLS_GD macros on 31bit.
This ensures that r14 isn't used to save and restore r12 while
r14 is clobbered by the bas-instruction.
As note:
r12 can't be added to clobber list as gcc would fail with:
error: PIC register clobbered by ‘12’ in ‘asm’
For 64bit this fix was already done in 2004 in the
commit b80af23ac6.
ChangeLog:
* sysdeps/s390/s390-32/tls-macros.h (TLS_LD, TLS_GD):
Clobber also r14.
Information about whether the ABI of long double is the same as that
of double is split between bits/mathdef.h and bits/wordsize.h.
When the ABIs are the same, bits/mathdef.h defines
__NO_LONG_DOUBLE_MATH. In addition, in the case where the same glibc
binary supports both -mlong-double-64 and -mlong-double-128,
bits/wordsize.h defines __LONG_DOUBLE_MATH_OPTIONAL, along with
__NO_LONG_DOUBLE_MATH if this particular compilation is with
-mlong-double-64.
As part of the refactoring I proposed in
<https://sourceware.org/ml/libc-alpha/2016-11/msg00745.html>, this
patch puts all that information in a single header,
bits/long-double.h. It is included from sys/cdefs.h alongside the
include of bits/wordsize.h, so other headers generally do not need to
include bits/long-double.h directly.
Previously, various bits/mathdef.h headers and bits/wordsize.h headers
had this long double information (including implicitly in some
bits/mathdef.h headers through not having the defines present in the
default version). After the patch, it's all in six bits/long-double.h
headers. Furthermore, most of those new headers are not
architecture-specific. Architectures with optional long double all
use the ldbl-opt sysdeps directory, either in the order (ldbl-64-128,
ldbl-opt, ldbl-128) or (ldbl-128ibm, ldbl-opt). Thus a generic header
for the case where long double = double, and headers in ldbl-128,
ldbl-96 and ldbl-opt, suffices to cover every architecture except for
cases where long double properties vary between different ABIs sharing
a set of installed headers; fortunately all the ldbl-opt cases share a
single compiler-predefined macro __LONG_DOUBLE_128__ that can be used
to tell whether this compilation is -mlong-double-64 or
-mlong-double-128.
The two cases where a set of headers is shared between ABIs with
different long double properties, MIPS (o32 has long double = double,
other ABIs use ldbl-128) and SPARC (32-bit has optional long double,
64-bit has required long double), need their own bits/long-double.h
headers.
As with bits/wordsize.h, multiple-include protection for this header
is generally implicit through the include guards on sys/cdefs.h, and
multiple inclusion is harmless in any case. There is one subtlety:
the header must not define __LONG_DOUBLE_MATH_OPTIONAL if
__NO_LONG_DOUBLE_MATH was defined before its inclusion, because doing
so breaks how sysdeps/ieee754/ldbl-opt/nldbl-compat.h defines
__NO_LONG_DOUBLE_MATH itself before including system headers. Subject
to keeping that working, it would be reasonable to move these macros
from defined/undefined #ifdef to always-defined 1/0 #if semantics, but
this patch does not attempt to do so, just rearranges where the macros
are defined.
After this patch, the only use of bits/mathdef.h is the alpha one for
modifying complex function ABIs for old GCC. Thus, all versions of
the header other than the default and alpha versions are removed, as
is the include from math.h.
Tested for x86_64 and x86. Also did compilation-only testing with
build-many-glibcs.py.
* bits/long-double.h: New file.
* sysdeps/ieee754/ldbl-128/bits/long-double.h: Likewise.
* sysdeps/ieee754/ldbl-96/bits/long-double.h: Likewise.
* sysdeps/ieee754/ldbl-opt/bits/long-double.h: Likewise.
* sysdeps/mips/bits/long-double.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/long-double.h: Likewise.
* math/Makefile (headers): Add bits/long-double.h.
* misc/sys/cdefs.h: Include <bits/long-double.h>.
* stdlib/strtold.c: Include <bits/long-double.h> instead of
<bits/wordsize.h>.
* bits/mathdef.h [!_COMPLEX_H]: Do not allow inclusion.
[!__NO_LONG_DOUBLE_MATH]: Remove conditional code.
* math/math.h: Do not include <bits/mathdef.h>.
* sysdeps/aarch64/bits/mathdef.h: Remove file.
* sysdeps/alpha/bits/mathdef.h [!_COMPLEX_H]: Do not allow
inclusion.
* sysdeps/ia64/bits/mathdef.h: Remove file.
* sysdeps/m68k/m680x0/bits/mathdef.h: Likewise.
* sysdeps/mips/bits/mathdef.h: Likewise.
* sysdeps/powerpc/bits/mathdef.h: Likewise.
* sysdeps/s390/bits/mathdef.h: Likewise.
* sysdeps/sparc/bits/mathdef.h: Likewise.
* sysdeps/x86/bits/mathdef.h: Likewise.
* sysdeps/s390/s390-32/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]: Remove
conditional code.
* sysdeps/s390/s390-64/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
* sysdeps/unix/sysv/linux/alpha/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/wordsize.h
[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
Likewise.
