This will be used to consolidate the libgcc_s access for backtrace
and pthread_cancel.
Unlike the existing backtrace implementations, it provides some
hardening based on pointer mangling.
Reviewed-by: Carlos O'Donell <carlos@redhat.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.
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>
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
GCC 6.5 fails to correctly build ldconfig with recent ld.so.cache
commits, e.g.:
785969a047
elf: Implement a string table for ldconfig, with tail merging
If glibc is build with gcc 6.5.0:
__builtin_add_overflow is used in
<glibc>/elf/stringtable.c:stringtable_finalize()
which leads to ldconfig failing with "String table is too large".
This is also recognizable in following tests:
FAIL: elf/tst-glibc-hwcaps-cache
FAIL: elf/tst-glibc-hwcaps-prepend-cache
FAIL: elf/tst-ldconfig-X
FAIL: elf/tst-ldconfig-bad-aux-cache
FAIL: elf/tst-ldconfig-ld_so_conf-update
FAIL: elf/tst-stringtable
See gcc "Bug 98269 - gcc 6.5.0 __builtin_add_overflow() with small
uint32_t values incorrectly detects overflow"
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98269)
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>
float_t supposedly represents the type that is used to evaluate float
expressions internally. While the isa supports single-precision float
operations, the port of glibc to s390 incorrectly deferred to the
generic definitions which, back then, tied float_t to double. gcc by
default evaluates float in single precision, so that scenario violates
the C standard (sections 5.2.4.2.2 and 7.12 in C11/C17). With
-fexcess-precision=standard, gcc evaluates float in double precision,
which aligns with the standard yet at the cost of added conversion
instructions.
With this patch, we drop the s390-specific definition of float_t and
defer to the default behavior, which aligns float_t with the
compiler-defined FLT_EVAL_METHOD in a standard-compliant way.
Checked on s390x-linux-gnu with 31-bit and 64-bit builds.
Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT,
formerly __wait_lookup_done) can be implemented directly in ld.so,
eliminating the unprotected GL (dl_wait_lookup_done) function
pointer.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
There are several compiler implementations that allow large stack
allocations to jump over the guard page at the end of the stack and
corrupt memory beyond that. See CVE-2017-1000364.
Compilers can emit code to probe the stack such that the guard page
cannot be skipped, but on aarch64 the probe interval is 64K by default
instead of the minimum supported page size (4K).
This patch enforces at least 64K guard on aarch64 unless the guard
is disabled by setting its size to 0. For backward compatibility
reasons the increased guard is not reported, so it is only observable
by exhausting the address space or parsing /proc/self/maps on linux.
On other targets the patch has no effect. If the stack probe interval
is larger than a page size on a target then ARCH_MIN_GUARD_SIZE can
be defined to get large enough stack guard on libc allocated stacks.
The patch does not affect threads with user allocated stacks.
Fixes bug 26691.
Unfortunately some HWCAP names like HWCAP_S390_VX differs between
kernel (see <kernel>/arch/s390/include/asm/elf.h) and glibc.
Therefore, those HWCAP names from kernel are now introduced as alias
It turned out that an 256b-mvc instruction which depends on the
result of a previous 256b-mvc instruction is counterproductive.
Therefore this patch adjusts the 256b-loop by storing the
first byte with stc and setting the remaining 255b with mvc.
Now the 255b-mvc instruction depends on the stc instruction.
This patch introduces an extra loop without pfd instructions
as it turned out that the pfd instructions are usefull
for copies >=64KB but are counterproductive for smaller copies.
Each symbol definitions are moved on a separated file and it
cover all symbol type definitions (float, double, long double,
and float128).
It allows to set support for architectures without the boiler
place of copying default values.
Checked with a build on the affected ABIs.
This consolidates the copy-pasted arch specific semaphore header into
single version (based on s390) which suffices 32-bit and and 64-bit
arch/ABI based on the canonical WORDSIZE.
For now I've left out arches which use alternate defines to choose for
32 vs 64-bit builds (aarch64, mips) which in theory can also use the same
header.
Passes build-many for
aarch64-linux-gnu arm-linux-gnueabi arm-linux-gnueabihf
riscv64-linux-gnu-rv64imac-lp64 riscv64-linux-gnu-rv64imafdc-lp64
x86_64-linux-gnu microblaze-linux-gnu nios2-linux-gnu
Suggested-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Most gmp-mparam.h headers in glibc define various macros to the same
values they would be defined to by the generic version of that header,
plus macros IEEE_DOUBLE_BIG_ENDIAN or IEEE_DOUBLE_MIXED_ENDIAN related
to the representation of double. The latter macros are in turn only
used in gmp-impl.h to define union ieee_double_extract, which is not
used in glibc. Thus all of these headers, except for the generic one
and those that define _LONG_LONG_LIMB for ILP32 configurations with
64-bit registers, are redundant, and this patch removes them.
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch.
With mathinline removal there is no need to keep building and testing
inline math tests.
The gen-libm-tests.py support to generate ULP_I_* is removed and all
libm-test-ulps files are updated to longer have the
i{float,double,ldouble} entries. The support for no-test-inline is
also removed from both gen-auto-libm-tests and the
auto-libm-test-out-* were regenerated.
Checked on x86_64-linux-gnu and i686-linux-gnu.
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.
This supersedes the init_array sysdeps directory. It allows us to
check for ELF_INITFINI in both C and assembler code, and skip DT_INIT
and DT_FINI processing completely on newer architectures.
A new header file is needed because <dl-machine.h> is incompatible
with assembler code. <sysdep.h> is compatible with assembler code,
but it cannot be included in all assembler files because on some
architectures, it redefines register names, and some assembler files
conflict with that.
<elf-initfini.h> is replicated for legacy architectures which need
DT_INIT/DT_FINI support. New architectures follow the generic default
and disable it.
The comment "isn't" contained a non-ascii character which leads to
an error if compiled with -finput-charset=ascii:
error: failure to convert ascii to UTF-8
This is observable in GCC testsuite:
FAIL: 17_intro/headers/c++1998/charset.cc (test for excess errors)
FAIL: 17_intro/headers/c++2011/charset.cc (test for excess errors)
FAIL: 17_intro/headers/c++2014/charset.cc (test for excess errors)
FAIL: 17_intro/headers/c++2017/charset.cc (test for excess errors)
FAIL: 17_intro/headers/c++2020/charset.cc (test for excess errors)
Also rewrite the comment above.
Reported-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
This patch adds a new macro, libm_alias_finite, to define all _finite
symbol. It sets all _finite symbol as compat symbol based on its first
version (obtained from the definition at built generated first-versions.h).
The <fn>f128_finite symbols were introduced in GLIBC 2.26 and so need
special treatment in code that is shared between long double and float128.
It is done by adding a list, similar to internal symbol redifinition,
on sysdeps/ieee754/float128/float128_private.h.
Alpha also needs some tricky changes to ensure we still emit 2 compat
symbols for sqrt(f).
Passes buildmanyglibc.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This patch implements roundtoint and convertoint for s390
by using the load-fp-integer and convert-to-fixed instructions.
Both functions are using "round to nearest with ties away from zero"
rounding mode and do not raise inexact exceptions.
This patch updates the s390 specific functions fegetround,
fesetround, feholdexcept, fesetenv, feupdateenv, fegetexceptflag,
fetestexcept, fesetexceptflag, fetestexceptflag.
Now those functions are using the libc_fe* macros if possible.
Furthermore fegetexceptflag is now returning the exception from
dxc field shifted to the usual exception-flags.
Thus a special fetestexceptflag implementation is not needed anymore.
This patch provides the s390 specific implementation for
libc_feholdexcept, libc_fesetround, libc_feholdexcept_setround,
libc_fetestexcept, libc_fesetenv, libc_feupdateenv_test,
libc_feupdateenv, libc_feholdsetround_ctx, libc_feresetround_ctx,
libc_feholdsetround_noex_ctx and libc_feresetround_noex_ctx.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement llround, llroundf, llroundl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement lround, lroundf, lroundl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement llrint, llrintf, llrintl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement lrint, lrintf, lrintl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the load-fp-integer instruction
is used to implement roundeven, roundevenf, roundevenl.
Otherwise the common-code implementation is used.
This patch is always using the corresponding GCC builtin for copysignf, copysign,
and is using the builtin for copysignl, copysignf128 if the USE_FUNCTION_BUILTIN
macros are defined to one in math-use-builtins.h.
Altough the long double version is enabled by default we still need
the macro and the alternative implementation as the _Float128 version
of the builtin is not available with all supported GCC versions.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for roundf, round,
roundl and roundf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for truncf, trunc,
truncl and truncf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for ceilf, ceil,
ceill and ceilf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for floorf, floor,
floorl and floorf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for rintf, rint,
rintl and rintf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for nearbyintf, nearbyint,
nearbintl and nearbyintf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
If the specified needle crosses a page-boundary, the s390-z15 ifunc variant of
strstr truncates the needle which results in invalid results.
This is fixed by loading the needle beyond the page boundary to v18 instead of v16.
The bug is sometimes observable in test-strstr.c in check1 and check2 as the
haystack and needle is stored on stack. Thus the needle can be on a page boundary.
check2 is now extended to test haystack / needles located on stack, at end of page
and on two pages.
This bug was introduced with commit 6f47401bd5
("S390: Add arch13 strstr ifunc variant.") and is already released in glibc 2.30.
