In some cases (e.g QEMU, non-Intel/AMD CPU) the cache information can
not be retrieved and the corresponding values are set to 0.
Commit 2d651eb926 ("x86: Move x86 processor cache info to
cpu_features") changed the behaviour in such case by defining the
__x86_shared_cache_size and __x86_data_cache_size variables to 0 instead
of using the default values. This cause an issue with the i686 SSE2
optimized bzero/routine which assumes that the cache size is at least
128 bytes, and otherwise tries to zero/set the whole address space minus
128 bytes.
Fix that by restoring the original code to only update
__x86_shared_cache_size and __x86_data_cache_size variables if the
corresponding cache sizes are not zero.
Fixes bug 28784
Fixes commit 2d651eb926
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
This ISA level covers the glibc build itself. <dl-hwcap-check.h>
cannot be used because this check (by design) happens before
DL_PLATFORM_INIT and the x86 CPU flags initialization.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
HAVE_X86_LAHF_SAHF is implied by x86-64-v2, and HAVE_X86_MOVBE by
x86-64-v3.
The individual flag does not appear in -fverbose-asm flag output
even if the ISA level implies it.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
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
Implement vectorized tan/tanf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector tan/tanf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized erfc/erfcf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector erfc/erfcf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized asinh/asinhf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector asinh/asinhf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized tanh/tanhf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector tanh/tanhf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized erf/erff containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector erf/erff with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized acosh/acoshf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector acosh/acoshf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized atanh/atanhf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector atanh/atanhf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized log1p/log1pf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector log1p/log1pf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized log2/log2f containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector log2/log2f with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized log10/log10f containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector log10/log10f with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized atan2/atan2f containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector atan2/atan2f with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized cbrt/cbrtf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector cbrt/cbrtf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized sinh/sinhf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector sinh/sinhf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized expm1/expm1f containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector expm1/expm1f with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized cosh/coshf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector cosh/coshf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized exp10/exp10f containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector exp10/exp10f with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized exp2/exp2f containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector exp2/exp2f with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized hypot/hypotf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector hypot/hypotf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized asin/asinf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector asin/asinf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Implement vectorized atan/atanf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector atan/atanf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
It can be used to speed up the libgcc unwinder, and the internal
_dl_find_dso_for_object function (which is used for caller
identification in dlopen and related functions, and in dladdr).
_dl_find_object is in the internal namespace due to bug 28503.
If libgcc switches to _dl_find_object, this namespace issue will
be fixed. It is located in libc for two reasons: it is necessary
to forward the call to the static libc after static dlopen, and
there is a link ordering issue with -static-libgcc and libgcc_eh.a
because libc.so is not a linker script that includes ld.so in the
glibc build tree (so that GCC's internal -lc after libgcc_eh.a does
not pick up ld.so).
It is necessary to do the i386 customization in the
sysdeps/x86/bits/dl_find_object.h header shared with x86-64 because
otherwise, multilib installations are broken.
The implementation uses software transactional memory, as suggested
by Torvald Riegel. Two copies of the supporting data structures are
used, also achieving full async-signal-safety.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Implement vectorized acos/acosf containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI. It also contains
accuracy and ABI tests for vector acos/acosf with regenerated ulps.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
On KVM guests running on some AMD systems, the IBRS feature is reported
as a synthetic feature using the Intel feature, while the cpuinfo entry
keeps the same. Handle that by first checking the presence of the Intel
feature on AMD systems.
Fixes bug 28704.
Remove the LD_PREFER_MAP_32BIT_EXEC environment variable support since
the first PT_LOAD segment is no longer executable due to defaulting to
-z separate-code.
This fixes [BZ #28656].
Reviewed-by: Florian Weimer <fweimer@redhat.com>
<tls.h> already contains a definition that is quite similar,
but it is not consistent across architectures.
Only architectures for which rseq support is added are covered.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Remove Prefer_AVX2_STRCMP to enable EVEX strcmp. When comparing 2 32-byte
strings, EVEX strcmp has been improved to require 1 load, 1 VPTESTM, 1
VPCMP, 1 KMOVD and 1 INCL instead of 2 loads, 3 VPCMPs, 2 KORDs, 1 KMOVD
and 1 TESTL while AVX2 strcmp requires 1 load, 2 VPCMPEQs, 1 VPMINU, 1
VPMOVMSKB and 1 TESTL. EVEX strcmp is now faster than AVX2 strcmp by up
to 40% on Tiger Lake and Ice Lake.
Intel MPX failed to gain wide adoption and has been deprecated for a
while. GCC 9.1 removed Intel MPX support. Linux kernel removed MPX in
2019.
This patch removes the support code from the dynamic loader.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
No bug.
This change adds a new macro ENTRY_P2ALIGN which takes a second
argument, log2 of the desired function alignment.
The old ENTRY(name) macro is just ENTRY_P2ALIGN(name, 4) so this
doesn't affect any existing functionality.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
1. Add GNU_PROPERTY_1_NEEDED:
#define GNU_PROPERTY_1_NEEDED GNU_PROPERTY_UINT32_OR_LO
to indicate the needed properties by the object file.
2. Add GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS:
#define GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS (1U << 0)
to indicate that the object file requires canonical function pointers and
cannot be used with copy relocation.
3. Scan GNU_PROPERTY_1_NEEDED property and store it in l_1_needed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It turns out the __SSE2_MATH__ conditional in sysdeps/x86/fpu/s_ffma.c
does not cover all cases where the x86 fenv_private.h macros might
manipulate one of the SSE and 387 floating-point state, while the
actual fma implementation uses the other. Specifically, in the 32-bit
case, with a compiler not defaulting to -mfpmath=sse, but testing on a
processor with hardware FMA support, the multiarch fma function
implementations will end up using SSE, while the fenv_private.h macros
will use the 387 state for double. Change the conditional to use the
default macros rather than the optimized ones in all cases except when
the compiler inlines an fma instruction (in which case, since all
those instructions are SSE instructions and -mfpmath=sse must be in
effect for them to be inlined, the optimized macros will only use the
SSE state and it's OK for them to only use the SSE state).
Tested for x86_64 and x86. H.J. reports in
<https://sourceware.org/pipermail/libc-alpha/2021-September/131367.html>
that it fixes the problems he observed.
On 32-bit x86 with -mfpmath=sse, and on x86_64 with
--disable-multi-arch, the tests of ffma and its aliases (fma narrowing
from binary64 to binary32) fail. This is probably the issue reported
by H.J. in
<https://sourceware.org/pipermail/libc-alpha/2021-September/131277.html>.
The problem is the use of fenv_private.h macros in the round-to-odd
implementation. Those macros are set up to manipulate only one of the
SSE and 387 floating-point state, whichever is relevant for the type
indicated by the suffix on the macro name. But x86 configurations
sometimes use the ldbl-96 implementation of binary64 fma (that's where
--disable-multi-arch is relevant for x86_64: it causes the ldbl-96
implementation to be used, instead of an IFUNC implementation that
falls back to the dbl-64 version), contrary to the expectations of
those macros for functions operating on double when __SSE2_MATH__ is
defined.
This can be addressed by using the default versions of those macros
(giving x86 its own version of s_ffma.c), as is done for the *f128
macro variants where it depends on the details of how GCC was
configured when building libgcc which floating-point state is affected
by _Float128 arithmetic. The issue only applies when __SSE2_MATH__ is
defined, and doesn't apply when __FP_FAST_FMA is defined (because in
that case, fma will be inlined by the compiler, meaning it's
definitely an SSE operation; for the same reason, this is not an issue
for narrowing sqrt, as hardware sqrt is always inlined in that
implementation for x86), but in other cases it's safest to use the
default versions of the fenv_private.h macros to ensure things work
whichever fma implementation is used.
Tested for x86_64 (with and without --disable-multi-arch) and x86
(with and without -mfpmath=sse).
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>
When using LLD (LLVM linker) as the linker, configure prints a confusing
message.
*** These critical programs are missing or too old: GNU ld
LLD>=13.0.0 can build glibc --enable-static-pie. (8.0.0 needs one
workaround for -Wl,-defsym=_begin=0. 9.0.0 works with
--disable-static-pie).
XFAIL two tests sysdeps/x86/tst-ifunc-isa-* which have the BZ #28154
issue (LLD follows the PowerPC port of GNU ld for ifunc by placing
IRELATIVE relocations in .rela.dyn, triggering a glibc ifunc fragility).
The set of dynamic symbols is the same with GNU ld and LLD,
modulo unused SHN_ABS version node symbols.
For comparison, gold does not support --enable-static-pie
yet (--no-dynamic-linker is unsupported BZ #22221), yet
has 6 failures more than LLD. gold linked libc.so has
larger .dynsym differences with GNU ld and LLD
(non-default version symbols are changed to default versions
by a version script BZ #28196).
The Autoconf documentation for the AC_CACHE_CHECK macro states:
The commands-to-set-it must have no side effects except for setting
the variable cache-id, see below.
However, the tests for support of -msahf and -mmovbe were embedded in
the commands-to-set-it for lib_cv_include_x86_isa_level. This had the
consequence that libc_cv_have_x86_lahf_sahf and libc_cv_have_x86_movbe
were not defined whenever lib_cv_include_x86_isa_level was read from
cache. These variables' being undefined meant that their unquoted use
in later test expressions led to the 'test' built-in's misparsing its
arguments and emitting errors like "test: =: unexpected operator" or
"test: =: unary operator expected", depending on the particular shell.
This commit refactors the tests for LAHF/SAHF and MOVBE instruction
support into their own AC_CACHE_CHECK macro invocations to obey the
rule that the commands-to-set-it must have no side effects other than
setting the variable named by cache-id.
Signed-off-by: Matt Whitlock <sourceware@mattwhitlock.name>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
commit 3ec5d83d2a
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Sat Jan 25 14:19:40 2020 -0800
x86-64: Avoid rep movsb with short distance [BZ #27130]
introduced some regressions on Intel processors without Fast Short REP
MOV (FSRM). Add Avoid_Short_Distance_REP_MOVSB to avoid rep movsb with
short distance only on Intel processors with FSRM. bench-memmove-large
on Skylake server shows that cycles of __memmove_evex_unaligned_erms
improves for the following data size:
before after Improvement
length=4127, align1=3, align2=0: 479.38 349.25 27%
length=4223, align1=9, align2=5: 405.62 333.25 18%
length=8223, align1=3, align2=0: 786.12 496.38 37%
length=8319, align1=9, align2=5: 727.50 501.38 31%
length=16415, align1=3, align2=0: 1436.88 840.00 41%
length=16511, align1=9, align2=5: 1375.50 836.38 39%
length=32799, align1=3, align2=0: 2890.00 1860.12 36%
length=32895, align1=9, align2=5: 2891.38 1931.88 33%
1. Install <bits/platform/x86.h> for <sys/platform/x86.h> which includes
<bits/platform/x86.h>.
2. Rename HAS_CPU_FEATURE to CPU_FEATURE_PRESENT which checks if the
processor has the feature.
3. Rename CPU_FEATURE_USABLE to CPU_FEATURE_ACTIVE which checks if the
feature is active. There may be other preconditions, like sufficient
stack space or further setup for AMX, which must be satisfied before the
feature can be used.
This fixes BZ #27958.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Remove unused code and declare __libc_mallopt when !IS_IN (libc) to
allow the debug hook to build with --disable-tunables.
Also, run tst-ifunc-isa-2* tests only when tunables are enabled since
the result depends on it.
Tested on x86_64.
Reported-by: Matheus Castanho <msc@linux.ibm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The SSBD feature is implemented in 2 different ways on AMD processors:
newer systems (Zen3) provides AMD_SSBD (function 8000_0008, EBX[24]),
while older system provides AMD_VIRT_SSBD (function 8000_0008, EBX[25]).
However for AMD_VIRT_SSBD, kernel shows both 'ssdb' and 'virt_ssdb' on
/proc/cpuinfo; while for AMD_SSBD only 'ssdb' is provided.
This now check is AMD_SSBD is set to check for 'ssbd', otherwise check
if AMD_VIRT_SSDB is set to check for 'virt_ssbd'.
Checked on x86_64-linux-gnu on a Ryzen 9 5900x.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
From
https://www.intel.com/content/www/us/en/support/articles/000059422/processors.html
* Intel TSX will be disabled by default.
* The processor will force abort all Restricted Transactional Memory (RTM)
transactions by default.
* A new CPUID bit CPUID.07H.0H.EDX[11](RTM_ALWAYS_ABORT) will be enumerated,
which is set to indicate to updated software that the loaded microcode is
forcing RTM abort.
* On processors that enumerate support for RTM, the CPUID enumeration bits
for Intel TSX (CPUID.07H.0H.EBX[11] and CPUID.07H.0H.EBX[4]) continue to
be set by default after microcode update.
* Workloads that were benefited from Intel TSX might experience a change
in performance.
* System software may use a new bit in Model-Specific Register (MSR) 0x10F
TSX_FORCE_ABORT[TSX_CPUID_CLEAR] functionality to clear the Hardware Lock
Elision (HLE) and RTM bits to indicate to software that Intel TSX is
disabled.
1. Add RTM_ALWAYS_ABORT to CPUID features.
2. Set RTM usable only if RTM_ALWAYS_ABORT isn't set. This skips the
string/tst-memchr-rtm etc. testcases on the affected processors, which
always fail after a microcde update.
3. Check RTM feature, instead of usability, against /proc/cpuinfo.
This fixes BZ #28033.
AMD define different flags for IRPB, IBRS, and STIPBP [1], so new
x86_64_cpu are added and IBRS_IBPB is only tested for Intel.
The SSDB is also defined and implemented different on AMD [2],
and also a new AMD_SSDB flag is added. It should map to the
cpuinfo 'ssdb' on recent AMD cpus.
It fixes tst-cpu-features-cpuinfo and tst-cpu-features-cpuinfo-static
on recent AMD cpus.
Checked on x86_64-linux-gnu on AMD Ryzen 9 5900X.
[1] https://developer.amd.com/wp-content/resources/Architecture_Guidelines_Update_Indirect_Branch_Control.pdf
[2] https://bugzilla.kernel.org/show_bug.cgi?id=199889
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
IBT and SHSTK usable bits are copied from CPUID feature bits and later
cleared if kernel doesn't support CET. Copy IBT and SHSTK usable only
if CET is enabled so that they aren't set on CET capable processors
with non-CET enabled glibc.
This commit removes the ELF constructor and internal variables from
dlfcn/dlfcn.c. The file now serves the same purpose as
nptl/libpthread-compat.c, so it is renamed to dlfcn/libdl-compat.c.
The use of libdl-shared-only-routines ensures that libdl.a is empty.
This commit adjusts the test suite not to use $(libdl). The libdl.so
symbolic link is no longer installed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
1. Replace
if ((((uintptr_t) &_d) & (__alignof (double) - 1)) != 0)
which may be optimized out by compiler, with
int
__attribute__ ((weak, noclone, noinline))
is_aligned (void *p, int align)
{
return (((uintptr_t) p) & (align - 1)) != 0;
}
2. Add TEST_STACK_ALIGN_INIT to TEST_STACK_ALIGN.
3. Add a common TEST_STACK_ALIGN_INIT to check 16-byte stack alignment
for both i386 and x86-64.
4. Update powerpc to use TEST_STACK_ALIGN_INIT.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The definitions in libc are sufficient, the forwarders are no longer
needed.
The symbols have been moved using scripts/move-symbol-to-libc.py.
s390-linux-gnu and s390x-linux-gnu need a new version placeholder
to keep the GLIBC_2.19 symbol version in libpthread.
Tested on i386-linux-gnu, powerpc64le-linux-gnu, s390x-linux-gnu,
x86_64-linux-gnu. Built with build-many-glibcs.py.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
All of the isnan functions are in libc.so due to printf_fp, so move
__isnanf128 there too for consistency.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@ascii.art.br>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
At function exit, AVX optimized string/memory functions have VZEROUPPER
which triggers RTM abort. When such functions are called inside a
transactionally executing RTM region, RTM abort causes severe performance
degradation. Add tests to verify that string/memory functions won't
cause RTM abort in RTM region.
1. Set Prefer_No_VZEROUPPER if RTM is usable to avoid RTM abort triggered
by VZEROUPPER inside a transactionally executing RTM region.
2. Since to compare 2 32-byte strings, 256-bit EVEX strcmp requires 2
loads, 3 VPCMPs and 2 KORDs while AVX2 strcmp requires 1 load, 2 VPCMPEQs,
1 VPMINU and 1 VPMOVMSKB, AVX2 strcmp is faster than EVEX strcmp. Add
Prefer_AVX2_STRCMP to prefer AVX2 strcmp family functions.
1. Support GLIBC_TUNABLES=glibc.cpu.hwcaps=-XSAVE.
2. Disable all features which depend on XSAVE:
a. If OSXSAVE is disabled by glibc tunables. Or
b. If both XSAVE and XSAVEC aren't usable.
__x86_get_cpuid_feature_leaf is called during early startup, before
the stack check guard is initialized and is hence not safe to build
with stack-protector.
Additionally, IFUNC resolvers for static tst-ifunc-isa tests get
called too early for stack protector to be useful, so fix them to
disable stack protector for the resolver functions.
This fixes all failures seen with --enable-stack-protector=all
configuration.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
commit 2d651eb926
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Sep 18 07:55:14 2020 -0700
x86: Move x86 processor cache info to cpu_features
missed _SC_LEVEL1_ICACHE_LINESIZE.
1. Add level1_icache_linesize to struct cpu_features.
2. Initialize level1_icache_linesize by calling handle_intel,
handle_zhaoxin and handle_amd with _SC_LEVEL1_ICACHE_LINESIZE.
3. Return level1_icache_linesize for _SC_LEVEL1_ICACHE_LINESIZE.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Since the full ISA set used in an ELF binary is unknown to compiler,
an x86-64 ISA level marker indicates the minimum, not maximum, ISA set
required to run such an ELF binary. We never guarantee a library with
an x86-64 ISA level v3 marker doesn't contain other ISAs beyond x86-64
ISA level v3, like AVX VNNI. We check the x86-64 ISA level marker for
the minimum ISA set. Since -march=sandybridge enables only some ISAs
in x86-64 ISA level v3, we should set the needed ISA marker to v2.
Otherwise, libc is compiled with -march=sandybridge will fail to run on
Sandy Bridge:
$ ./elf/ld.so ./libc.so
./libc.so: (p) CPU ISA level is lower than required: needed: 7; got: 3
Set the minimum, instead of maximum, x86-64 ISA level marker should have
no impact on the glibc-hwcaps directory assignment logic in ldconfig nor
ld.so.
Remove the extra space between "# endif" left over from
commit f380868f6d
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu Dec 24 15:43:34 2020 -0800
Remove _ISOMAC check from <cpu-features.h>
The TUNABLE_SET interface took a primitive C type argument, which
resulted in inconsistent type conversions internally due to incorrect
dereferencing of types, especialy on 32-bit architectures. This
change simplifies the TUNABLE setting logic along with the interfaces.
Now all numeric tunable values are stored as signed numbers in
tunable_num_t, which is intmax_t. All calls to set tunables cast the
input value to its primitive type and then to tunable_num_t for
storage. This relies on gcc-specific (although I suspect other
compilers woul also do the same) unsigned to signed integer conversion
semantics, i.e. the bit pattern is conserved. The reverse conversion
is guaranteed by the standard.
1. Add CPUID_INDEX_14_ECX_0 for CPUID leaf 0x14 to detect PTWRITE feature
in EBX of CPUID leaf 0x14 with ECX == 0.
2. Add PTWRITE detection to CPU feature tests.
3. Add 2 static CPU feature tests.
In the process of optimizing memcpy for AMD machines, we have found the
vector move operations are outperforming enhanced REP MOVSB for data
transfers above the L2 cache size on Zen3 architectures.
To handle this use case, we are adding an upper bound parameter on
enhanced REP MOVSB:'__x86_rep_movsb_stop_threshold'.
As per large-bench results, we are configuring this parameter to the
L2 cache size for AMD machines and applicable from Zen3 architecture
supporting the ERMS feature.
For architectures other than AMD, it is the computed value of
non-temporal threshold parameter.
Reviewed-by: Premachandra Mallappa <premachandra.mallappa@amd.com>
Add _SC_MINSIGSTKSZ for the minimum signal stack size derived from
AT_MINSIGSTKSZ, which is the minimum number of bytes of free stack
space required in order to gurantee successful, non-nested handling
of a single signal whose handler is an empty function, and _SC_SIGSTKSZ
which is the suggested minimum number of bytes of stack space required
for a signal stack.
If AT_MINSIGSTKSZ isn't available, sysconf (_SC_MINSIGSTKSZ) returns
MINSIGSTKSZ. On Linux/x86 with XSAVE, the signal frame used by kernel
is composed of the following areas and laid out as:
------------------------------
| alignment padding |
------------------------------
| xsave buffer |
------------------------------
| fsave header (32-bit only) |
------------------------------
| siginfo + ucontext |
------------------------------
Compute AT_MINSIGSTKSZ value as size of xsave buffer + size of fsave
header (32-bit only) + size of siginfo and ucontext + alignment padding.
If _SC_SIGSTKSZ_SOURCE or _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ
are redefined as
/* Default stack size for a signal handler: sysconf (SC_SIGSTKSZ). */
# undef SIGSTKSZ
# define SIGSTKSZ sysconf (_SC_SIGSTKSZ)
/* Minimum stack size for a signal handler: SIGSTKSZ. */
# undef MINSIGSTKSZ
# define MINSIGSTKSZ SIGSTKSZ
Compilation will fail if the source assumes constant MINSIGSTKSZ or
SIGSTKSZ.
The reason for not simply increasing the kernel's MINSIGSTKSZ #define
(apart from the fact that it is rarely used, due to glibc's shadowing
definitions) was that userspace binaries will have baked in the old
value of the constant and may be making assumptions about it.
For example, the type (char [MINSIGSTKSZ]) changes if this #define
changes. This could be a problem if an newly built library tries to
memcpy() or dump such an object defined by and old binary.
Bounds-checking and the stack sizes passed to things like sigaltstack()
and makecontext() could similarly go wrong.
commit 94cd37ebb2
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Sep 16 05:27:32 2020 -0700
x86: Use HAS_CPU_FEATURE with IBT and SHSTK [BZ #26625]
broke
GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK
since it can no longer disable IBT nor SHSTK. Handle IBT and SHSTK with:
1. Revert commit 94cd37ebb2.
2. Clears the usable CET feature bits if kernel doesn't support CET.
3. Add GLIBC_TUNABLES tests without dlopen.
4. Add tests to verify that CPU_FEATURE_USABLE on IBT and SHSTK matches
_get_ssp.
5. Update GLIBC_TUNABLES tests with dlopen to verify that CET is disabled
with GLIBC_TUNABLES.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Check ifunc resolver with CPU_FEATURE_USABLE and tunables in dynamic and
static executables to verify that CPUID features are initialized early in
static PIE.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Extern symbol access in position independent code usually involves GOT
indirection which needs RELATIVE reloc in a static linked PIE. (On
some targets this is avoided e.g. because the linker can relax a GOT
access to a pc-relative access, but this is not generally true.) Code
that runs before static PIE self relocation must avoid relying on
dynamic relocations which can be ensured by using hidden visibility.
However we cannot just make all symbols hidden:
On i386, all calls to IFUNC functions must go through PLT and calls to
hidden functions CANNOT go through PLT in PIE since EBX used in PIE PLT
may not be set up for local calls to hidden IFUNC functions.
This patch aims to make symbol references hidden in code that is used
before and by _dl_relocate_static_pie when building a static PIE libc.
Note: for an object that is used in the startup code, its references
and definition may not have consistent visibility: it is only forced
hidden in the startup code.
This is needed for fixing bug 27072.
Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
In <sys/platform/x86.h>, define CPU features as enum instead of using
the C preprocessor magic to make it easier to wrap this functionality
in other languages. Move the C preprocessor magic to internal header
for better GCC codegen when more than one features are checked in a
single expression as in x86-64 dl-hwcaps-subdirs.c.
1. Rename COMMON_CPUID_INDEX_XXX to CPUID_INDEX_XXX.
2. Move CPUID_INDEX_MAX to sysdeps/x86/include/cpu-features.h.
3. Remove struct cpu_features and __x86_get_cpu_features from
<sys/platform/x86.h>.
4. Add __x86_get_cpuid_feature_leaf to <sys/platform/x86.h> and put it
in libc.
5. Make __get_cpu_features() private to glibc.
6. Replace __x86_get_cpu_features(N) with __get_cpu_features().
7. Add _dl_x86_get_cpu_features to GLIBC_PRIVATE.
8. Use a single enum index for each CPU feature detection.
9. Pass the CPUID feature leaf to __x86_get_cpuid_feature_leaf.
10. Return zero struct cpuid_feature for the older glibc binary with a
smaller CPUID_INDEX_MAX [BZ #27104].
11. Inside glibc, use the C preprocessor magic so that cpu_features data
can be loaded just once leading to more compact code for glibc.
256 bits are used for each CPUID leaf. Some leaves only contain a few
features. We can add exceptions to such leaves. But it will increase
code sizes and it is harder to provide backward/forward compatibilities
when new features are added to such leaves in the future.
When new leaves are added, _rtld_global_ro offsets will change which
leads to race condition during in-place updates. We may avoid in-place
updates by
1. Rename the old glibc.
2. Install the new glibc.
3. Remove the old glibc.
NB: A function, __x86_get_cpuid_feature_leaf , is used to avoid the copy
relocation issue with IFUNC resolver as shown in IFUNC resolver tests.
1. Move x86 processor cache info to _dl_x86_cpu_features in ld.so.
2. Update tunable bounds with TUNABLE_SET_WITH_BOUNDS.
3. Move x86 cache info initialization to dl-cacheinfo.h and initialize
x86 cache info in init_cpu_features ().
4. Put x86 cache info for libc in cacheinfo.h, which is included in
libc-start.c in libc.a and is included in cacheinfo.c in libc.so.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Store ISA level in the portion of the unused upper 32 bits of the hwcaps
field in cache and the unused pad field in aux cache. ISA level is stored
and checked only for shared objects in glibc-hwcaps subdirectories. The
shared objects in the default directories aren't checked since there are
no fallbacks for these shared objects.
Tested on x86-64-v2, x86-64-v3 and x86-64-v4 machines with
--disable-hardcoded-path-in-tests and --enable-hardcoded-path-in-tests.
GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA
levels:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250
and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with
GNU_PROPERTY_X86_ISA_1_V[234] marker:
https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13
Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by
commit b0ab06937385e0ae25cebf1991787d64f439bf12
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Oct 30 06:49:57 2020 -0700
x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker
and
commit 32930e4edbc06bc6f10c435dbcc63131715df678
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Oct 9 05:05:57 2020 -0700
x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker
GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the
micro-architecture ISA level required to execute the binary. The marker
must be added by programmers explicitly in one of 3 ways:
1. Pass -mneeded to GCC.
2. Add the marker in the linker inputs as this patch does.
3. Pass -z x86-64-v[234] to the linker.
Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker support to ld.so if binutils 2.32 or newer is used to build glibc:
1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
markers to elf.h.
2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker to abi-note.o based on the ISA level used to compile abi-note.o,
assuming that the same ISA level is used to compile the whole glibc.
3. Add isa_1 to cpu_features to record the supported x86 ISA level.
4. Rename _dl_process_cet_property_note to _dl_process_property_note and
add GNU_PROPERTY_X86_ISA_1_V[234] marker detection.
5. Update _rtld_main_check and _dl_open_check to check loaded objects
with the incompatible ISA level.
6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails
on lesser platforms.
7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c.
Tested under i686, x32 and x86-64 modes on x86-64-v2, x86-64-v3 and
x86-64-v4 machines.
Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine
and got:
[hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1
./elf/tst-isa-level-1: CPU ISA level is lower than required
[hjl@gnu-cfl-2 build-x86_64-linux]$
Make the tests use TEST_COND_intel96 to decide on whether to build the
unnormal tests instead of the macro in nan-pseudo-number.h and then
drop the header inclusion. This unbreaks test runs on all
architectures that do not have ldbl-96.
Also drop the HANDLE_PSEUDO_NUMBERS macro since it is not used
anywhere.
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
Add support to treat pseudo-numbers specially and implement x86
version to consider all of them as signaling.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Do not attempt to fix the significand top bit in long double input
received in printf. The code should never reach here because isnan
should now detect unnormals as NaN. This is already a NOP for glibc
since it uses the gcc __builtin_isnan, which detects unnormals as NaN.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
This syncs up isnanl behaviour with gcc. Also move the isnanl
implementation to sysdeps/x86 and remove the sysdeps/x86_64 version.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Also move sysdeps/i386/fpu/s_fpclassifyl.c to
sysdeps/x86/fpu/s_fpclassifyl.c and remove
sysdeps/x86_64/fpu/s_fpclassifyl.c
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add Intel Linear Address Masking (LAM) support to <sys/platform/x86.h>.
HAS_CPU_FEATURE (LAM) can be used to detect if LAM is enabled in CPU.
LAM modifies the checking that is applied to 64-bit linear addresses,
allowing software to use of the untranslated address bits for metadata.
Since we can't tell if the tunable value is set by user or not:
https://sourceware.org/bugzilla/show_bug.cgi?id=27069
remove the default REP MOVSB threshold tunable value so that the correct
default value will be set correctly by init_cacheinfo ().
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
To handle GNU property notes on aarch64 some segments need to
be mmaped again, so the fd of the loaded ELF module is needed.
When the fd is not available (kernel loaded modules), then -1
is passed.
The fd is passed to both _dl_process_pt_gnu_property and
_dl_process_pt_note for consistency. Target specific note
processing functions are updated accordingly.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Check HAS_CPU_FEATURE instead of CPU_FEATURE_USABLE for FSGSBASE, IBT,
LM, SHSTK and XSAVES since FSGSBASE requires kernel support, IBT/SHSTK/LM
require OS support and XSAVES is supervisor-mode only.
The UP macro is never defined. Also define LOCK_PREFIX
unconditionally, to the same string.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Modifying the shareable cache '__x86_shared_cache_size', which is a
factor in computing the non-temporal threshold parameter
'__x86_shared_non_temporal_threshold' to optimize memcpy for AMD Zen
architectures.
In the existing implementation, the shareable cache is computed as 'L3
per thread, L2 per core'. Recomputing this shareable cache as 'L3 per
CCX(Core-Complex)' has brought in performance gains.
As per the large bench variant results, this patch also addresses the
regression problem on AMD Zen architectures.
Reviewed-by: Premachandra Mallappa <premachandra.mallappa@amd.com>
X86 CPU features in ld.so are initialized by init_cpu_features, which is
invoked by DL_PLATFORM_INIT from _dl_sysdep_start. But when ld.so is
loaded by static executable, DL_PLATFORM_INIT is never called. Also
x86 cache info in libc.o and libc.a is initialized by a constructor
which may be called too late. Since some fields in _rtld_global_ro
in ld.so are initialized by dynamic relocation, we can also initialize
x86 CPU features in _rtld_global_ro in ld.so and cache info in libc.so
by initializing dummy function pointers in ld.so and libc.so via IFUNC
relocation.
Key points:
1. IFUNC is always supported, independent of --enable-multi-arch or
--disable-multi-arch. Linker generates IFUNC relocations from input
IFUNC objects and ld.so performs IFUNC relocations.
2. There are no IFUNC dependencies in ld.so before dynamic relocation
have been performed,
3. The x86 CPU features in ld.so is initialized by DL_PLATFORM_INIT
in dynamic executable and by IFUNC relocation in dlopen in static
executable.
4. The x86 cache info in libc.o is initialized by IFUNC relocation.
5. In libc.a, both x86 CPU features and cache info are initialized from
ARCH_INIT_CPU_FEATURES, not by IFUNC relocation, before __libc_early_init
is called.
Note: _dl_x86_init_cpu_features can be called more than once from
DL_PLATFORM_INIT and during relocation in ld.so.
The __x86_shared_non_temporal_threshold determines when memcpy on x86
uses non_temporal stores to avoid pushing other data out of the last
level cache.
This patch proposes to revert the calculation change made by H.J. Lu's
patch of June 2, 2017.
H.J. Lu's patch selected a threshold suitable for a single thread
getting maximum performance. It was tuned using the single threaded
large memcpy micro benchmark on an 8 core processor. The last change
changes the threshold from using 3/4 of one thread's share of the
cache to using 3/4 of the entire cache of a multi-threaded system
before switching to non-temporal stores. Multi-threaded systems with
more than a few threads are server-class and typically have many
active threads. If one thread consumes 3/4 of the available cache for
all threads, it will cause other active threads to have data removed
from the cache. Two examples show the range of the effect. John
McCalpin's widely parallel Stream benchmark, which runs in parallel
and fetches data sequentially, saw a 20% slowdown with this patch on
an internal system test of 128 threads. This regression was discovered
when comparing OL8 performance to OL7. An example that compares
normal stores to non-temporal stores may be found at
https://vgatherps.github.io/2018-09-02-nontemporal/. A simple test
shows performance loss of 400 to 500% due to a failure to use
nontemporal stores. These performance losses are most likely to occur
when the system load is heaviest and good performance is critical.
The tunable x86_non_temporal_threshold can be used to override the
default for the knowledgable user who really wants maximum cache
allocation to a single thread in a multi-threaded system.
The manual entry for the tunable has been expanded to provide
more information about its purpose.
modified: sysdeps/x86/cacheinfo.c
modified: manual/tunables.texi
The behavior of isnan/__builtin_isnan on bit patterns that do not
correspond to something that the CPU would produce from valid inputs
is currently under-defined in the toolchain. (The GCC built-in and
glibc disagree.)
The isnan check in PRINTF_FP_FETCH in stdio-common/printf_fp.c
assumes the GCC behavior that returns true for non-normal numbers
which are not specified as NaN. (The glibc implementation returns
false for such numbers.)
At present, passing non-normal numbers to __mpn_extract_long_double
causes this function to produce irregularly shaped multi-precision
integers, triggering undefined behavior in __printf_fp_l.
With GCC 10 and glibc 2.32, this behavior is not visible because
__builtin_isnan is used, which avoids calling
__mpn_extract_long_double in this case. This commit updates the
implementation of __mpn_extract_long_double so that regularly shaped
multi-precision integers are produced in this case, avoiding
undefined behavior in __printf_fp_l.
commit 04bba1e5d8
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Aug 5 13:51:56 2020 -0700
x86: Set CPU usable feature bits conservatively [BZ #26552]
Set CPU usable feature bits only for CPU features which are usable in
user space and whose usability can be detected from user space, excluding
features like FSGSBASE whose enable bit can only be checked in the kernel.
no longer turns on the usable bits of IBT and SHSTK since we don't know
if IBT and SHSTK are usable until much later. Use HAS_CPU_FEATURE to
check if the processor supports IBT and SHSTK.
Add Intel Key Locker:
https://software.intel.com/content/www/us/en/develop/download/intel-key-locker-specification.html
support to <sys/platform/x86.h>. Intel Key Locker has
1. KL: AES Key Locker instructions.
2. WIDE_KL: AES wide Key Locker instructions.
3. AESKLE: AES Key Locker instructions are enabled by OS.
Applications should use
if (CPU_FEATURE_USABLE (KL))
and
if (CPU_FEATURE_USABLE (WIDE_KL))
to check if AES Key Locker instructions and AES wide Key Locker
instructions are usable.
Install <sys/platform/x86.h> so that programmers can do
#if __has_include(<sys/platform/x86.h>)
#include <sys/platform/x86.h>
#endif
...
if (CPU_FEATURE_USABLE (SSE2))
...
if (CPU_FEATURE_USABLE (AVX2))
...
<sys/platform/x86.h> exports only:
enum
{
COMMON_CPUID_INDEX_1 = 0,
COMMON_CPUID_INDEX_7,
COMMON_CPUID_INDEX_80000001,
COMMON_CPUID_INDEX_D_ECX_1,
COMMON_CPUID_INDEX_80000007,
COMMON_CPUID_INDEX_80000008,
COMMON_CPUID_INDEX_7_ECX_1,
/* Keep the following line at the end. */
COMMON_CPUID_INDEX_MAX
};
struct cpuid_features
{
struct cpuid_registers cpuid;
struct cpuid_registers usable;
};
struct cpu_features
{
struct cpu_features_basic basic;
struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
};
/* Get a pointer to the CPU features structure. */
extern const struct cpu_features *__x86_get_cpu_features
(unsigned int max) __attribute__ ((const));
Since all feature checks are done through macros, programs compiled with
a newer <sys/platform/x86.h> are compatible with the older glibc binaries
as long as the layout of struct cpu_features is identical. The features
array can be expanded with backward binary compatibility for both .o and
.so files. When COMMON_CPUID_INDEX_MAX is increased to support new
processor features, __x86_get_cpu_features in the older glibc binaries
returns NULL and HAS_CPU_FEATURE/CPU_FEATURE_USABLE return false on the
new processor feature. No new symbol version is neeeded.
Both CPU_FEATURE_USABLE and HAS_CPU_FEATURE are provided. HAS_CPU_FEATURE
can be used to identify processor features.
Note: Although GCC has __builtin_cpu_supports, it only supports a subset
of <sys/platform/x86.h> and it is equivalent to CPU_FEATURE_USABLE. It
doesn't support HAS_CPU_FEATURE.
Set CPU usable feature bits only for CPU features which are usable in
user space and whose usability can be detected from user space, excluding
features like FSGSBASE whose enable bit can only be checked in the kernel.
Intel64 and IA-32 Architectures Software Developer’s Manual has changed
the following CPU feature names:
1. The CPU feature of Enhanced Intel SpeedStep Technology is renamed
from EST to EIST.
2. The CPU feature which supports Platform Quality of Service Monitoring
(PQM) capability is changed to Intel Resource Director Technology
(Intel RDT) Monitoring capability, i.e. PQM is renamed to RDT_M.
3. The CPU feature which supports Platform Quality of Service
Enforcement (PQE) capability is changed to Intel Resource Director
Technology (Intel RDT) Allocation capability, i.e. PQE is renamed to
RDT_A.
Support usable check for all CPU features with the following changes:
1. Change struct cpu_features to
struct cpuid_features
{
struct cpuid_registers cpuid;
struct cpuid_registers usable;
};
struct cpu_features
{
struct cpu_features_basic basic;
struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
...
};
so that there is a usable bit for each cpuid bit.
2. After the cpuid bits have been initialized, copy the known bits to the
usable bits. EAX/EBX from INDEX_1 and EAX from INDEX_7 aren't used for
CPU feature detection.
3. Clear the usable bits which require OS support.
4. If the feature is supported by OS, copy its cpuid bit to its usable
bit.
5. Replace HAS_CPU_FEATURE and CPU_FEATURES_CPU_P with CPU_FEATURE_USABLE
and CPU_FEATURE_USABLE_P to check if a feature is usable.
6. Add DEPR_FPU_CS_DS for INDEX_7_EBX_13.
7. Unset MPX feature since it has been deprecated.
The results are
1. If the feature is known and doesn't requre OS support, its usable bit
is copied from the cpuid bit.
2. Otherwise, its usable bit is copied from the cpuid bit only if the
feature is known to supported by OS.
3. CPU_FEATURE_USABLE/CPU_FEATURE_USABLE_P are used to check if the
feature can be used.
4. HAS_CPU_FEATURE/CPU_FEATURE_CPU_P are used to check if CPU supports
the feature.
Since
commit 430388d5dc
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Aug 3 08:04:49 2018 -0700
x86: Don't include <init-arch.h> in assembly codes
removed all usages of <init-arch.h> from assembly codes, we can remove
__ASSEMBLER__ check in init-arch.h.
Since
commit c867597bff
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Jun 8 13:57:50 2016 -0700
X86-64: Remove previous default/SSE2/AVX2 memcpy/memmove
removed the only usage of __x86_prefetchw, we can remove the unused
__x86_prefetchw.
Add generic code to handle PT_GNU_PROPERTY notes. Invalid
content is ignored, _dl_process_pt_gnu_property is always called
after PT_LOAD segments are mapped and it has no failure modes.
Currently only one NT_GNU_PROPERTY_TYPE_0 note is handled, which
contains target specific properties: the _dl_process_gnu_property
hook is called for each property.
The old _dl_process_pt_note and _rtld_process_pt_note differ in how
the program header is read. The old _dl_process_pt_note is called
before PT_LOAD segments are mapped and _rtld_process_pt_note is called
after PT_LOAD segments are mapped. The old _rtld_process_pt_note is
removed and _dl_process_pt_note is always called after PT_LOAD
segments are mapped and now it has no failure modes.
The program headers are scanned backwards so that PT_NOTE can be
skipped if PT_GNU_PROPERTY exists.
Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add x86_rep_movsb_threshold and x86_rep_stosb_threshold to tunables
to update thresholds for "rep movsb" and "rep stosb" at run-time.
Note that the user specified threshold for "rep movsb" smaller than
the minimum threshold will be ignored.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
An extension called extended feature disable (XFD) is an extension added
for Intel AMX to the XSAVE feature set that allows an operating system
to enable a feature while preventing specific user threads from using
the feature.
Intel Advanced Matrix Extensions (Intel AMX) is a new programming
paradigm consisting of two components: a set of 2-dimensional registers
(tiles) representing sub-arrays from a larger 2-dimensional memory image,
and accelerators able to operate on tiles. Intel AMX is an extensible
architecture. New accelerators can be added and the existing accelerator
may be enhanced to provide higher performance. The initial features are
AMX-BF16, AMX-TILE and AMX-INT8, which are usable only if the operating
system supports both XTILECFG state and XTILEDATA state.
Add AMX-BF16, AMX-TILE and AMX-INT8 support to HAS_CPU_FEATURE and
CPU_FEATURE_USABLE.
1. Divide architecture features into the usable features and the preferred
features. The usable features are for correctness and can be exported in
a stable ABI. The preferred features are for performance and only for
glibc internal use.
2. Change struct cpu_features to
struct cpu_features
{
struct cpu_features_basic basic;
unsigned int *usable_p;
struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
unsigned int usable[USABLE_FEATURE_INDEX_MAX];
unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
...
};
and initialize usable_p to pointer to the usable arary so that
struct cpu_features
{
struct cpu_features_basic basic;
unsigned int *usable_p;
struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
};
can be exported via a stable ABI. The cpuid and usable arrays can be
expanded with backward binary compatibility for both .o and .so files.
3. Add COMMON_CPUID_INDEX_7_ECX_1 for AVX512_BF16.
4. Detect ENQCMD, PKS, AVX512_VP2INTERSECT, MD_CLEAR, SERIALIZE, HYBRID,
TSXLDTRK, L1D_FLUSH, CORE_CAPABILITIES and AVX512_BF16.
5. Rename CAPABILITIES to ARCH_CAPABILITIES.
6. Check if AVX512_VP2INTERSECT, AVX512_BF16 and PKU are usable.
7. Update CPU feature detection test.
When CET is enabled, it is an error to dlopen a non CET enabled shared
library in CET enabled application. It may be desirable to make CET
permissive, that is disable CET when dlopening a non CET enabled shared
library. With the new --enable-cet=permissive configure option, CET is
disabled when dlopening a non CET enabled shared library.
Add DEFAULT_DL_X86_CET_CONTROL to config.h.in:
/* The default value of x86 CET control. */
#define DEFAULT_DL_X86_CET_CONTROL cet_elf_property
which enables CET features based on ELF property note.
--enable-cet=permissive it to
/* The default value of x86 CET control. */
#define DEFAULT_DL_X86_CET_CONTROL cet_permissive
which enables CET features permissively.
Update tst-cet-legacy-5a, tst-cet-legacy-5b, tst-cet-legacy-6a and
tst-cet-legacy-6b to check --enable-cet and --enable-cet=permissive.
1. Include <dl-procruntime.c> to get architecture specific initializer in
rtld_global.
2. Change _dl_x86_feature_1[2] to _dl_x86_feature_1.
3. Add _dl_x86_feature_control after _dl_x86_feature_1, which is a
struct of 2 bitfields for IBT and SHSTK control
This fixes [BZ #25887].
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>
Commit a98dc92dd1 ("x86: Add cache
information support for Zhaoxin processors") introduced an unused
variable warning in the default i686-linux-gnu build:
In file included from ../sysdeps/i386/cacheinfo.c:3:
../sysdeps/x86/cacheinfo.c: In function 'init_cacheinfo':
../sysdeps/x86/cacheinfo.c:762:16: error: unused variable 'eax' [-Werror=unused-variable]
762 | unsigned int eax;
| ^~~
To obtain Zhaoxin CPU cache information, add a new function
handle_zhaoxin().
Add a new function get_common_cache_info() that extracts the code
in init_cacheinfo() to get the value of the variable shared, threads.
Add Zhaoxin branch in init_cacheinfo() for initializing variables,
such as __x86_shared_cache_size.
The __sfp_handle_exceptions is not fully correct regarding raising
exceptions, since there is no direct way to raise only FP_EX_OVERFLOW
nor FP_EX_UNDERFLOW for SSE mode. Both libgcc and feraiseexcept rely
on x87 mode to accomplish it.
This reverts commit 460ee50de0.
Checked on x86_64.
The exported x86_64 fenv.h functions operate on both i387 and SSE (since
they should work on both float, double, and long double) while the
internal libc_fe* set either SSE (float, double, and float128) or
i387 (long double).
The libgcc __sfp_handle_exceptions (used on float128 implementation),
however, will set either SEE or i387 exception depending of the
exception to raise. This broke the internal assumption of float128
where only SSE operations will be used.
This patch reimplements the libgcc __sfp_handle_exceptions to use only
SSE operations and sets libgcc to use it instead of its own
implementation.
And I think we should fix libgcc in a similar manner, since checking on
config/i386/64/sfp-machine.h it already only supports SSE rounding mode
and x86_64 ABI also expectes float128 to use SSE registers [1]
(although it is not clear on how future implementation might implement
it).
Checked on x86_64-linux-gnu.
[1] https://github.com/hjl-tools/x86-psABI/wiki/X86-psABI
Similar to fenvinline.h removal, this kind of optimization is better
implemented by the compiler. Also newer code avoid setting exceptions
directly (for instance the code to make new logf, log2f and powf
implementatation to now support SVID compat).
The BZ#94194 [1] the corresponding GCC bug for adding replacements
for these on x86.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94194
Since legacy bitmap doesn't cover jitted code generated by legacy JIT
engine, it isn't very useful. This patch removes ARCH_CET_LEGACY_BITMAP
and treats indirect branch tracking similar to shadow stack by removing
legacy bitmap support.
Tested on CET Linux/x86-64 and non-CET Linux/x86-64.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
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.
Particularly on CPUs without ERMS, the string instructions are slow,
so it is unclear whether this architecture-specific implementation is
in fact an optimization.
We shouldn't make 2 calls to dlerror () in a row since the first call
will clear the error. We should just use the return value from the
first call.
Tested on Linux/x86-64.
Reviewed-by: Florian Weimer <fweimer@redhat.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 adds a new generic __pthread_rwlock_arch_t definition meant
to be used by new ports. Its layout mimics the current usage on some
64 bits ports and it allows some ports to use the generic definition.
The arch __pthread_rwlock_arch_t definition is moved from
pthreadtypes-arch.h to another arch-specific header (struct_rwlock.h).
Also the static intialization macro for pthread_rwlock_t is set to use
an arch defined on (__PTHREAD_RWLOCK_INITIALIZER) which simplifies its
implementation.
The default pthread_rwlock_t layout differs from current ports with:
1. Internal layout is the same for 32 bits and 64 bits.
2. Internal flag is an unsigned short so it should not required
additional padding to align for word boundary (if it is the case
for the ABI).
Checked with a build on affected abis.
Change-Id: I776a6a986c23199929d28a3dcd30272db21cd1d0
The current way of defining the common mutex definition for POSIX and
C11 on pthreadtypes-arch.h (added by commit 06be6368da) is
not really the best options for newer ports. It requires define some
misleading flags that should be always defined as 0
(__PTHREAD_COMPAT_PADDING_MID and __PTHREAD_COMPAT_PADDING_END), it
exposes options used solely for linuxthreads compat mode
(__PTHREAD_MUTEX_USE_UNION and __PTHREAD_MUTEX_NUSERS_AFTER_KIND), and
requires newer ports to explicit define them (adding more boilerplate
code).
This patch adds a new default __pthread_mutex_s definition meant to
be used by newer ports. Its layout mimics the current usage on both
32 and 64 bits ports and it allows most ports to use the generic
definition. Only ports that use some arch-specific definition (such
as hardware lock-elision or linuxthreads compat) requires specific
headers.
For 32 bit, the generic definitions mimic the other 32-bit ports
of using an union to define the fields uses on adaptive and robust
mutexes (thus not allowing both usage at same time) and by using a
single linked-list for robust mutexes. Both decisions seemed to
follow what recent ports have done and make the resulting
pthread_mutex_t/mtx_t object smaller.
Also the static intialization macro for pthread_mutex_t is set to use
a macro __PTHREAD_MUTEX_INITIALIZER where the architecture can redefine
in its struct_mutex.h if it requires additional fields to be
initialized.
Checked with a build on affected abis.
Change-Id: I30a22c3e3497805fd6e52994c5925897cffcfe13
The new rwlock implementation added by cc25c8b4c1 (2.25) removed
support for lock-elision. This patch removes remaining the
arch-specific unused definitions.
Checked with a build against all affected ABIs.
Change-Id: I5dec8af50e3cd56d7351c52ceff4aa3771b53cd6
With only two exceptions (sys/types.h and sys/param.h, both of which
historically might have defined BYTE_ORDER) the public headers that
include <endian.h> only want to be able to test __BYTE_ORDER against
__*_ENDIAN.
This patch creates a new bits/endian.h that can be included by any
header that wants to be able to test __BYTE_ORDER and/or
__FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs
__LONG_LONG_PAIR. It only defines macros in the implementation
namespace.
The existing bits/endian.h (which could not be included independently
of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER)
is renamed to bits/endianness.h. I also took the opportunity to
canonicalize the form of this header, which we are stuck with having
one copy of per architecture. Since they are so short, this means git
doesn’t understand that they were renamed from existing headers, sigh.
endian.h itself is a nonstandard header and its only remaining use
from a standard header is guarded by __USE_MISC, so I dropped the
__USE_MISC conditionals from around all of the public-namespace things
it defines. (This means, an application that requests strict library
conformance but includes endian.h will still see the definition of
BYTE_ORDER.)
A few changes to specific bits/endian(ness).h variants deserve
mention:
- sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to
sysdeps/ia64/bits/endianness.h. If I remember correctly, ia64 did
have selectable endianness, but we have assembly code in
sysdeps/ia64 that assumes it’s little-endian, so there is no reason
to treat the ia64 endianness.h as linux-specific.
- The C-SKY port does not fully support big-endian mode, the compile
will error out if __CSKYBE__ is defined.
- The PowerPC port had extra logic in its bits/endian.h to detect a
broken compiler, which strikes me as unnecessary, so I removed it.
- The only files that defined __FLOAT_WORD_ORDER always defined it to
the same value as __BYTE_ORDER, so I removed those definitions.
The SH bits/endian(ness).h had comments inconsistent with the
actual setting of __FLOAT_WORD_ORDER, which I also removed.
- I *removed* copyright boilerplate from the few bits/endian(ness).h
headers that had it; these files record a single fact in a fashion
dictated by an external spec, so I do not think they are copyrightable.
As long as I was changing every copy of ieee754.h in the tree, I
noticed that only the MIPS variant includes float.h, because it uses
LDBL_MANT_DIG to decide among three different versions of
ieee854_long_double. This patch makes it not include float.h when
GCC’s intrinsic __LDBL_MANT_DIG__ is available.
* string/endian.h: Unconditionally define LITTLE_ENDIAN,
BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER. Condition byteswapping
macros only on !__ASSEMBLER__. Move the definitions of
__BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER,
and __LONG_LONG_PAIR to...
* string/bits/endian.h: ...this new file, which includes
the renamed header bits/endianness.h for the definition of
__BYTE_ORDER and possibly __FLOAT_WORD_ORDER.
* string/Makefile: Install bits/endianness.h.
* include/bits/endian.h: New wrapper.
* bits/endian.h: Rename to bits/endianness.h.
Add multiple-include guard. Rewrite the comment explaining what
the machine-specific variants of this file should do.
* sysdeps/unix/sysv/linux/ia64/bits/endian.h:
Move to sysdeps/ia64.
* sysdeps/aarch64/bits/endian.h
* sysdeps/alpha/bits/endian.h
* sysdeps/arm/bits/endian.h
* sysdeps/csky/bits/endian.h
* sysdeps/hppa/bits/endian.h
* sysdeps/ia64/bits/endian.h
* sysdeps/m68k/bits/endian.h
* sysdeps/microblaze/bits/endian.h
* sysdeps/mips/bits/endian.h
* sysdeps/nios2/bits/endian.h
* sysdeps/powerpc/bits/endian.h
* sysdeps/riscv/bits/endian.h
* sysdeps/s390/bits/endian.h
* sysdeps/sh/bits/endian.h
* sysdeps/sparc/bits/endian.h
* sysdeps/x86/bits/endian.h:
Rename to endianness.h; canonicalize form of file; remove
redundant definitions of __FLOAT_WORD_ORDER.
* sysdeps/powerpc/bits/endianness.h: Remove logic to check for
broken compilers.
* ctype/ctype.h
* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
* sysdeps/csky/nptl/bits/pthreadtypes-arch.h
* sysdeps/ia64/ieee754.h
* sysdeps/ieee754/ieee754.h
* sysdeps/ieee754/ldbl-128/ieee754.h
* sysdeps/ieee754/ldbl-128ibm/ieee754.h
* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
* sysdeps/mips/ieee754/ieee754.h
* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
* sysdeps/nptl/pthread.h
* sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
* sysdeps/sparc/sparc32/ieee754.h
* sysdeps/unix/sysv/linux/generic/bits/stat.h
* sysdeps/unix/sysv/linux/generic/bits/statfs.h
* sysdeps/unix/sysv/linux/sys/acct.h
* wctype/bits/wctype-wchar.h:
Include bits/endian.h, not endian.h.
* sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h.
* sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__
in ifdefs, instead of LDBL_MANT_DIG. Only include float.h
when __LDBL_MANT_DIG__ is not predefined, in which case
define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.
Since sysdeps/i386/dl-lookupcfg.h and sysdeps/x86_64/dl-lookupcfg.h are
identical, we can replace them with sysdeps/x86/dl-lookupcfg.h.
* sysdeps/i386/dl-lookupcfg.h: Moved to ...
* sysdeps/x86/dl-lookupcfg.h: Here.
* sysdeps/x86_64/dl-lookupcfg.h: Removed.
This patch refactor how hp-timing is used on loader code for statistics
report. The HP_TIMING_AVAIL and HP_SMALL_TIMING_AVAIL are removed and
HP_TIMING_INLINE is used instead to check for hp-timing avaliability.
For alpha, which only defines HP_SMALL_TIMING_AVAIL, the HP_TIMING_INLINE
is set iff for IS_IN(rtld).
Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. I also
checked the builds for all afected ABIs.
* benchtests/bench-timing.h: Replace HP_TIMING_AVAIL with
HP_TIMING_INLINE.
* nptl/descr.h: Likewise.
* elf/rtld.c (RLTD_TIMING_DECLARE, RTLD_TIMING_NOW, RTLD_TIMING_DIFF,
RTLD_TIMING_ACCUM_NT, RTLD_TIMING_SET): Define.
(dl_start_final_info, _dl_start_final, dl_main, print_statistics):
Abstract hp-timing usage with RTLD_* macros.
* sysdeps/alpha/hp-timing.h (HP_TIMING_INLINE): Define iff IS_IN(rtld).
(HP_TIMING_AVAIL, HP_SMALL_TIMING_AVAIL): Remove.
* sysdeps/generic/hp-timing.h (HP_TIMING_AVAIL, HP_SMALL_TIMING_AVAIL,
HP_TIMING_NONAVAIL): Likewise.
* sysdeps/ia64/hp-timing.h (HP_TIMING_AVAIL, HP_SMALL_TIMING_AVAIL):
Likewise.
* sysdeps/powerpc/powerpc32/power4/hp-timing.h (HP_TIMING_AVAIL,
HP_SMALL_TIMING_AVAIL): Likewise.
* sysdeps/powerpc/powerpc64/hp-timing.h (HP_TIMING_AVAIL,
HP_SMALL_TIMING_AVAIL): Likewise.
* sysdeps/sparc/sparc32/sparcv9/hp-timing.h (HP_TIMING_AVAIL,
HP_SMALL_TIMING_AVAIL): Likewise.
* sysdeps/sparc/sparc64/hp-timing.h (HP_TIMING_AVAIL,
HP_SMALL_TIMING_AVAIL): Likewise.
* sysdeps/x86/hp-timing.h (HP_TIMING_AVAIL, HP_SMALL_TIMING_AVAIL):
Likewise.
* sysdeps/generic/hp-timing-common.h: Update comment with
HP_TIMING_AVAIL removal.
The stub implementations are turned into compat symbols.
Linux actually has two reserved system call numbers (for getpmsg
and putpmsg), but these system calls have never been implemented,
and there are no plans to implement them, so this patch replaces
the wrappers with the generic stubs.
According to <https://bugzilla.redhat.com/show_bug.cgi?id=436349>,
the presence of the XSI STREAMS declarations is a minor portability
hazard because they are not actually implemented.
This commit does not change the TIRPC support code in
sunrpc/rpc_svcout.c. It uses additional XTI functionality and
therefore never worked with glibc.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This patch adds fall-through comments in some cases where -Wextra
produces implicit-fallthrough warnings.
The patch is non-exhaustive. Apart from architecture-specific code
for non-x86_64 architectures, it does not change sunrpc/xdr.c (legacy
code, probably should have such changes, but left to be dealt with
separately), or places that already had comments about the
fall-through but not matching the form expected by
-Wimplicit-fallthrough=3 (the default level with -Wextra; my
inclination is to adjust those comments to match rather than
downgrading to -Wimplicit-fallthrough=1 to allow any comment), or one
place where I thought the implicit fallthrough was not correct and so
should be handled separately as a bug fix. I think the key thing to
consider in review of this patch is whether the fall-through is indeed
intended and correct in each place where such a comment is added.
Tested for x86_64.
* elf/dl-exception.c (_dl_exception_create_format): Add
fall-through comments.
* elf/ldconfig.c (parse_conf_include): Likewise.
* elf/rtld.c (print_statistics): Likewise.
* locale/programs/charmap.c (parse_charmap): Likewise.
* misc/mntent_r.c (__getmntent_r): Likewise.
* posix/wordexp.c (parse_arith): Likewise.
(parse_backtick): Likewise.
* resolv/ns_ttl.c (ns_parse_ttl): Likewise.
* sysdeps/x86/cpu-features.c (init_cpu_features): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise.
Add <sincosf_poly.h> and include it in s_sincosf.h to allow vectorized
sincosf_poly. Add x86 sincosf_poly.h to vectorize sincosf_poly. On
Broadwell, bench-sincosf shows:
Before After Improvement
max 160.273 114.198 40%
min 6.25 5.625 11%
mean 13.0325 10.6462 22%
Vectorized sincosf_poly shows
Before After Improvement
max 138.653 114.198 21%
min 5.004 5.625 -11%
mean 11.5934 10.6462 9%
Tested on x86-64 and i686 as well as with build-many-glibcs.py.
* sysdeps/ieee754/flt-32/s_sincosf.h: Include <sincosf_poly.h>.
(sincos_t, sincosf_poly, sinf_poly): Moved to ...
* sysdeps/ieee754/flt-32/sincosf_poly.h: Here. New file.
* sysdeps/x86/fpu/s_sincosf_data.c: New file.
* sysdeps/x86/fpu/sincosf_poly.h: Likewise.
* sysdeps/x86_64/fpu/multiarch/s_sincosf-fma.c: Just include
<sysdeps/ieee754/flt-32/s_sincosf.c>.
After previous cleanups, the only code in the x86 bits/mathinline.h
that is relevant with current compilers is the inline of
__ieee754_atan2l that is conditional on __LIBC_INTERNAL_MATH_INLINES
(i.e. for when libm itself is being built).
This inline is something that does belong in glibc not GCC, since
__ieee754_atan2l is a purely internal function name. This patch moves
that inline to a new sysdeps/x86/fpu/math_private.h, removing the
bits/mathinline.h header.
Note that previously the inline was only for non-SSE 32-bit x86. That
condition does not make sense, however, for a long double function; if
it's not inlined, exactly the same x87 instruction will end up getting
used by the out-of-line function, for both 32-bit and 64-bit. So that
condition is not retained in the new version.
Tested for x86_64 and x86. As expected, installed stripped shared
libraries are unchanged for 32-bit x86, but installed stripped libm.so
is changed for x86_64 because calls to __ieee754_atan2l start being
inlined where previously they were out of line calls. (The same
change to start inlining the function would presumably also apply for
32-bit built with -mfpmath=sse, but that's not a configuration I've
tested.)
* sysdeps/x86/fpu/math_private.h: New file.
* sysdeps/x86/fpu/bits/mathinline.h: Remove.
Continuing the removal of bits/mathinline.h inlines that would better
be done by the compiler, this patch removes x86 inlines for sinh, cosh
and tanh functions (inlines only previously present for fast-math,
non-SSE 32-bit x86). I've filed
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88556> for adding such
inlines as an optimization in GCC.
I believe the only remaining part of the x86 bits/mathinline.h that
does anything useful with current compilers after this patch is the
__LIBC_INTERNAL_MATH_INLINES inline of __ieee754_atan2l; I intend to
remove the whole header and move that inline to a sysdeps
math_private.h header in a subsequent patch.
Tested for x86_64 and x86.
* sysdeps/x86/fpu/bits/mathinline.h (sinh): Remove inline
definition.
(cosh): Likewise.
(tanh): Likewise.
Merge i386 and x86_64 atomic-machine.h to x86 atomic-machine.h.
Tested on i686 and x86_64 as well as with build-many-glibcs.py.
* sysdeps/i386/atomic-machine.h: Merged with ...
* sysdeps/x86_64/atomic-machine.h: To ...
* sysdeps/x86/atomic-machine.h: This. New file.
Continuing the removal of bits/mathinline.h inlines that would better
be done by the compiler, this patch removes x86 inlines for asinh,
acosh and atanh functions (only for fast-math, non-SSE 32-bit x86).
I've filed <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88502> for
adding such inlines as an optimization in GCC.
Tested for x86_64 and x86.
* sysdeps/x86/fpu/bits/mathinline.h (asinh): Remove inline
definition.
(acosh): Likewise.
(atanh): Likewise.
This patch fix Hygon Dhyana processor CPU Vendor ID detection
problem in glibc sysdep module, current glibc codes doesn't
recognize Dhyana CPU Vendor ID("HygonGenuine") and set kind to
arch_kind_other, which result to incorrect zero value for
__cache_sysconf() syscall. As Hygon Dhyana share most
architecture feature as AMD Family 17h, this patch add Hygon CPU
Vendor ID check and setup kind to arch_kind_amd and reuse AMD
code path, which lead to correct return value in
__cache_sysconf() syscall. we run the glibc test suite for both
Hygon Dhyana and AMD EPYC and found no failure case.
Background:
Chengdu Haiguang IC Design Co., Ltd (Hygon) is a Joint Venture
between AMD and Haiguang Information Technology Co.,Ltd., aims at
providing high performance x86 processor for China server market.
Its first generation processor codename is Dhyana, which
originates from AMD technology and shares most of the
architecture with AMD's family 17h, but with different CPU Vendor
ID("HygonGenuine")/Family series number(Family 18h).
Related Hygon kernel patch can be found on
http://lkml.kernel.org/r/5ce86123a7b9dad925ac583d88d2f921040e859b.1538583282.git.puwen@hygon.cn
Signed-off-by: fanjinke <fanjinke@hygon.cn>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Continuing the removal of bits/mathinline.h inlines that would better
be done by the compiler, this patch removes an x86 inline for hypot
functions (only for fast-math, only for non-SSE 32-bit x86). I've
filed <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88474> for adding
such an inline as an optimization in GCC.
Tested for x86_64 and x86.
* sysdeps/x86/fpu/bits/mathinline.h (hypot): Remove inline
definition.
Extend CPUID support for all feature bits from CPUID. Add a new macro,
CPU_FEATURE_USABLE, which can be used to check if a feature is usable at
run-time, instead of HAS_CPU_FEATURE and HAS_ARCH_FEATURE.
Add COMMON_CPUID_INDEX_D_ECX_1, COMMON_CPUID_INDEX_80000007 and
COMMON_CPUID_INDEX_80000008 to check CPU feature bits in them.
Tested on i686 and x86-64 as well as using build-many-glibcs.py with
x86 targets.
* sysdeps/x86/cacheinfo.c (intel_check_word): Updated for
cpu_features_basic.
(__cache_sysconf): Likewise.
(init_cacheinfo): Likewise.
* sysdeps/x86/cpu-features.c (get_extended_indeces): Also
populate COMMON_CPUID_INDEX_80000007 and
COMMON_CPUID_INDEX_80000008.
(get_common_indices): Also populate COMMON_CPUID_INDEX_D_ECX_1.
Use CPU_FEATURES_CPU_P (cpu_features, XSAVEC) to check if
XSAVEC is available. Set the bit_arch_XXX_Usable bits.
(init_cpu_features): Use _Static_assert on
index_arch_Fast_Unaligned_Load.
__get_cpuid_registers and __get_arch_feature. Updated for
cpu_features_basic. Set stepping in cpu_features.
* sysdeps/x86/cpu-features.h: (FEATURE_INDEX_1): Changed to enum.
(FEATURE_INDEX_2): New.
(FEATURE_INDEX_MAX): Changed to enum.
(COMMON_CPUID_INDEX_D_ECX_1): New.
(COMMON_CPUID_INDEX_80000007): Likewise.
(COMMON_CPUID_INDEX_80000008): Likewise.
(cpuid_registers): Likewise.
(cpu_features_basic): Likewise.
(CPU_FEATURE_USABLE): Likewise.
(bit_arch_XXX_Usable): Likewise.
(cpu_features): Use cpuid_registers and cpu_features_basic.
(bit_arch_XXX): Reweritten.
(bit_cpu_XXX): Likewise.
(index_cpu_XXX): Likewise.
(reg_XXX): Likewise.
* sysdeps/x86/tst-get-cpu-features.c: Include <stdio.h> and
<support/check.h>.
(CHECK_CPU_FEATURE): New.
(CHECK_CPU_FEATURE_USABLE): Likewise.
(cpu_kinds): Likewise.
(do_test): Print vendor, family, model and stepping. Check
HAS_CPU_FEATURE and CPU_FEATURE_USABLE.
(TEST_FUNCTION): Removed.
Include <support/test-driver.c> instead of
"../../test-skeleton.c".
* sysdeps/x86_64/multiarch/sched_cpucount.c (__sched_cpucount):
Check POPCNT instead of POPCOUNT.
* sysdeps/x86_64/multiarch/test-multiarch.c (do_test): Likewise.
Add a re-exec test with legacy bitmap to verify that legacy bitmap is
properly hanlded by kernel.
* sysdeps/x86/Makefile (tests): Add tst-cet-legacy-1a.
(tst-cet-legacy-1a-ARGS): New.
($(objpfx)tst-cet-legacy-1a): New target.
* sysdeps/x86/tst-cet-legacy-1a.c: New file.
Linkers group input note sections with the same name into one output
note section with the same name. One output note section is placed in
one PT_NOTE segment. Since new linkers merge input .note.gnu.property
sections into one output .note.gnu.property section, there is only
one NT_GNU_PROPERTY_TYPE_0 note in one PT_NOTE segment with new linkers.
Since older linkers treat input .note.gnu.property section as a generic
note section and just concatenate all input .note.gnu.property sections
into one output .note.gnu.property section without merging them, we may
see multiple NT_GNU_PROPERTY_TYPE_0 notes in one PT_NOTE segment with
older linkers.
When an older linker is used to created the program on CET-enabled OS,
the linker output has a single .note.gnu.property section with multiple
NT_GNU_PROPERTY_TYPE_0 notes, some of which have IBT and SHSTK enable
bits set even if the program isn't CET enabled. Such programs will
crash on CET-enabled machines. This patch updates the note parser:
1. Skip note parsing if a NT_GNU_PROPERTY_TYPE_0 note has been processed.
2. Check multiple NT_GNU_PROPERTY_TYPE_0 notes.
[BZ #23509]
* sysdeps/x86/dl-prop.h (_dl_process_cet_property_note): Skip
note parsing if a NT_GNU_PROPERTY_TYPE_0 note has been processed.
Update the l_cet field when processing NT_GNU_PROPERTY_TYPE_0 note.
Check multiple NT_GNU_PROPERTY_TYPE_0 notes.
* sysdeps/x86/link_map.h (l_cet): Expand to 3 bits, Add
lc_unknown.
RDTSCP waits until all previous instructions have executed and all
previous loads are globally visible before reading the counter. RDTSC
doesn't wait until all previous instructions have been executed before
reading the counter. All x86 processors since 2010 support RDTSCP
instruction. This patch adds RDTSCP support to benchtests.
* benchtests/Makefile (CPPFLAGS-nonlib): Add -DUSE_RDTSCP if
USE_RDTSCP is defined.
* sysdeps/x86/hp-timing.h (HP_TIMING_NOW): Use RDTSCP if
USE_RDTSCP is defined.
Th commit 'Disable TSX on some Haswell processors.' (2702856bf4) changed the
default flags for Haswell models. Previously, new models were handled by the
default switch path, which assumed a Core i3/i5/i7 if AVX is available. After
the patch, Haswell models (0x3f, 0x3c, 0x45, 0x46) do not set the flags
Fast_Rep_String, Fast_Unaligned_Load, Fast_Unaligned_Copy, and
Prefer_PMINUB_for_stringop (only the TSX one).
This patch fixes it by disentangle the TSX flag handling from the memory
optimization ones. The strstr case cited on patch now selects the
__strstr_sse2_unaligned as expected for the Haswell cpu.
Checked on x86_64-linux-gnu.
[BZ #23709]
* sysdeps/x86/cpu-features.c (init_cpu_features): Set TSX bits
independently of other flags.
Use __builtin_ia32_rdtsc directly since including <x86intrin.h> makes
building glibc very slow. On Intel Core i5-6260U, this patch reduces
x86-64 build time from 8 minutes 33 seconds to 3 minutes 48 seconds
with "make -j4" and GCC 8.2.1.
* sysdeps/x86/hp-timing.h: Don't include <x86intrin.h>.
(HP_TIMING_NOW): Replace _rdtsc with __builtin_ia32_rdtsc.
Since _rdtsc intrinsic is supported in GCC 4.9, we can use it for
HP_TIMING_NOW. This patch
1. Create x86 hp-timing.h to replace i686 and x86_64 hp-timing.h.
2. Move MINIMUM_ISA from init-arch.h to isa.h so that x86 hp-timing.h
can check minimum x86 ISA to decide if _rdtsc can be used.
NB: Checking if __i686__ isn't sufficient since __i686__ may not be
defined when building for i686 class processors.
* sysdeps/i386/init-arch.h: Removed.
* sysdeps/i386/i586/init-arch.h: Likewise.
* sysdeps/i386/i686/init-arch.h: Likewise.
* sysdeps/i386/i686/hp-timing.h: Likewise.
* sysdeps/x86_64/hp-timing.h: Likewise.
* sysdeps/i386/isa.h: New file.
* sysdeps/i386/i586/isa.h: Likewise.
* sysdeps/i386/i686/isa.h: Likewise.
* sysdeps/x86_64/isa.h: Likewise.
* sysdeps/x86/hp-timing.h: New file.
* sysdeps/x86/init-arch.h: Include <isa.h>.
Continuing the move to use, within libm, public names for libm
functions that can be inlined as built-in functions on many
architectures, this patch moves calls to __round functions to call the
corresponding round names instead, with asm redirection to __round
when the calls are not inlined.
An additional complication arises in
sysdeps/ieee754/ldbl-128ibm/e_expl.c, where a call to roundl, with the
result converted to int, gets converted by the compiler to call
lroundl in the case of 32-bit long, so resulting in localplt test
failures. It's logically correct to let the compiler make such an
optimization; an appropriate asm redirection of lroundl to __lroundl
is thus added to that file (it's not needed anywhere else).
Tested for x86_64, and with build-many-glibcs.py.
* include/math.h [!_ISOMAC && !(__FINITE_MATH_ONLY__ &&
__FINITE_MATH_ONLY__ > 0) && !NO_MATH_REDIRECT] (round): Redirect
using MATH_REDIRECT.
* sysdeps/aarch64/fpu/s_round.c: Define NO_MATH_REDIRECT before
header inclusion.
* sysdeps/aarch64/fpu/s_roundf.c: Likewise.
* sysdeps/ieee754/dbl-64/s_round.c: Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_round.c: Likewise.
* sysdeps/ieee754/float128/s_roundf128.c: Likewise.
* sysdeps/ieee754/flt-32/s_roundf.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_roundl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_roundl.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_round.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_roundf.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_round.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_roundf.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_round.c: Likewise.
* sysdeps/riscv/rvf/s_roundf.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_roundl.c: Likewise.
(round): Redirect to __round.
(__roundl): Call round instead of __round.
* sysdeps/powerpc/fpu/math_private.h [_ARCH_PWR5X] (__round):
Remove macro.
[_ARCH_PWR5X] (__roundf): Likewise.
* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Use round
functions instead of __round variants.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Likewise.
* sysdeps/ieee754/ldbl-128/e_gammal_r.c (gammal_positive):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (gammal_positive):
Likewise.
* sysdeps/ieee754/ldbl-96/e_gammal_r.c (gammal_positive):
Likewise.
* sysdeps/x86/fpu/powl_helper.c (__powl_helper): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_expl.c (lroundl): Redirect to
__lroundl.
(__ieee754_expl): Call roundl instead of __roundl.
I noticed that sysdeps/x86/cpu-features.h had conditionals on whether
to define HAS_CPUID, HAS_I586 and HAS_I686 with a long list of
preprocessor macros for i686-and-later processors which however was
out of date. This patch avoids the problem of the list getting out of
date by instead having conditionals on all the (few, old) pre-i686
processors for which GCC has preprocessor macros, rather than the
(many, expanding list) i686-and-later processors. It seems HAS_I586
and HAS_I686 are unused so the only effect of these macros being
missing is that 32-bit glibc built for one of these processors would
end up doing runtime detection of CPUID availability.
i386 builds are prevented by a configure test so there is no need to
allow for them here. __geode__ (no long nops?) and __k6__ (no CMOV,
at least according to GCC) are conservatively handled as i586, not
i686, here (as noted above, this is a theoretical distinction at
present in that only HAS_CPUID appears to be used).
Tested for x86.
* sysdeps/x86/cpu-features.h [__geode__ || __k6__]: Handle like
[__i586__ || __pentium__].
[__i486__]: Handle explicitly.
(HAS_CPUID): Define to 1 if above macros are undefined.
(HAS_I586): Likewise.
(HAS_I686): Likewise.
On some architectures, the parts of math_private.h relating to the
floating-point environment are in a separate file fenv_private.h
included from math_private.h. As this is purely an
architecture-specific convention used by several architectures,
however, all such architectures still need their own math_private.h,
even if it has nothing to do beyond #include <fenv_private.h> and
peculiarity of including the i386 file directly instead of having a
shared file in sysdeps/x86.
This patch makes the fenv_private.h name an architecture-independent
convention in glibc. The include of fenv_private.h from
math_private.h becomes architecture-independent (until callers are
updated to include fenv_private.h directly so the include from
math_private.h is no longer needed). Some architecture math_private.h
headers are removed if no longer needed, or renamed to fenv_private.h
if all they define belongs in that header; architecture fenv_private.h
headers now do require #include_next <fenv_private.h>. The i386
fenv_private.h file moves to sysdeps/x86/fpu/ to reflect how it is
actually shared with x86_64. The generic math_private.h gets a new
include of <stdbool.h>, as needed for bool in some prototypes in that
header (previously that was indirectly included via include/fenv.h,
which now only gets included too late in math_private.h, after those
prototypes).
Tested for x86_64 and x86, and tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by the patch.
* sysdeps/aarch64/fpu/fenv_private.h: New file. Based on ....
* sysdeps/aarch64/fpu/math_private.h: ... this file. All contents
moved to fenv_private.h except for ...
(TOINT_INTRINSICS): Kept in math_private.h.
(roundtoint): Likewise.
(converttoint): Likewise.
* sysdeps/arm/fenv_private.h: Change multiple-include guard to
[ARM_FENV_PRIVATE_H]. Include next <fenv_private.h>.
* sysdeps/arm/math_private.h: Remove.
* sysdeps/generic/fenv_private.h: New file. Contents moved from
....
* sysdeps/generic/math_private.h: ... this file. Include
<stdbool.h>. Do not include <fenv.h> or <get-rounding-mode.h>.
Include <fenv_private.h>. Remove functions and macros moved to
fenv_private.h.
* sysdeps/i386/fpu/math_private.h: Remove.
* sysdeps/mips/math_private.h: Move to ....
* sysdeps/mips/fpu/fenv_private.h: ... here. Change
multiple-include guard to [MIPS_FENV_PRIVATE_H]. Remove
[__mips_hard_float] conditional. Include next <fenv_private.h>.
* sysdeps/powerpc/fpu/fenv_private.h: Change multiple-include
guard to [POWERPC_FENV_PRIVATE_H]. Include next <fenv_private.h>.
* sysdeps/powerpc/fpu/math_private.h: Do not include
<fenv_private.h>.
* sysdeps/riscv/rvf/math_private.h: Move to ....
* sysdeps/riscv/rvf/fenv_private.h: ... here. Change
multiple-include guard to [RISCV_FENV_PRIVATE_H]. Include next
<fenv_private.h>.
* sysdeps/sparc/fpu/fenv_private.h: Change multiple-include guard
to [SPARC_FENV_PRIVATE_H]. Include next <fenv_private.h>.
* sysdeps/sparc/fpu/math_private.h: Remove.
* sysdeps/i386/fpu/fenv_private.h: Move to ....
* sysdeps/x86/fpu/fenv_private.h: ... here. Change
multiple-include guard to [X86_FENV_PRIVATE_H]. Include next
<fenv_private.h>.
* sysdeps/x86_64/fpu/math_private.h: Do not include
<sysdeps/i386/fpu/fenv_private.h>.
Continuing moving macros out of math-tests.h to smaller headers
following typo-proof conventions instead of using #ifndef, this patch
moves the SNAN_TESTS_* macros for individual types out to their own
sysdeps header (while the type-generic SNAN_TESTS wrapper for those
macros remains in math-tests.h).
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/generic/math-tests-snan.h: New file.
* sysdeps/generic/math-tests.h: Include <math-tests-snan.h>.
(SNAN_TESTS_float): Do not define here.
(SNAN_TESTS_double): Likewise.
(SNAN_TESTS_long_double): Likewise.
(SNAN_TESTS_float128): Likewise.
* sysdeps/i386/fpu/math-tests-snan.h: New file.
* sysdeps/i386/fpu/math-tests.h: Remove file.
* sysdeps/ia64/math-tests-snan.h: New file.
* sysdeps/ia64/math-tests.h: Remove file.
* sysdeps/x86/math-tests.h: Likewise.
* sysdeps/x86_64/fpu/math-tests-snan.h: New file.
Move STATE_SAVE_OFFSET and STATE_SAVE_MASK to sysdep.h to make
sysdeps/x86/cpu-features.h a C header file.
* sysdeps/x86/cpu-features.h (STATE_SAVE_OFFSET): Removed.
(STATE_SAVE_MASK): Likewise.
Don't check __ASSEMBLER__ to include <cpu-features-offsets.h>.
* sysdeps/x86/sysdep.h (STATE_SAVE_OFFSET): New.
(STATE_SAVE_MASK): Likewise.
* sysdeps/x86_64/dl-trampoline.S: Include <cpu-features-offsets.h>
instead of <cpu-features.h>.
The glibc.tune namespace is vaguely named since it is a 'tunable', so
give it a more specific name that describes what it refers to. Rename
the tunable namespace to 'cpu' to more accurately reflect what it
encompasses. Also rename glibc.tune.cpu to glibc.cpu.name since
glibc.cpu.cpu is weird.
* NEWS: Mention the change.
* elf/dl-tunables.list: Rename tune namespace to cpu.
* sysdeps/powerpc/dl-tunables.list: Likewise.
* sysdeps/x86/dl-tunables.list: Likewise.
* sysdeps/aarch64/dl-tunables.list: Rename tune.cpu to
cpu.name.
* elf/dl-hwcaps.c (_dl_important_hwcaps): Adjust.
* elf/dl-hwcaps.h (GET_HWCAP_MASK): Likewise.
* manual/README.tunables: Likewise.
* manual/tunables.texi: Likewise.
* sysdeps/powerpc/cpu-features.c: Likewise.
* sysdeps/unix/sysv/linux/aarch64/cpu-features.c
(init_cpu_features): Likewise.
* sysdeps/x86/cpu-features.c: Likewise.
* sysdeps/x86/cpu-features.h: Likewise.
* sysdeps/x86/cpu-tunables.c: Likewise.
* sysdeps/x86_64/Makefile: Likewise.
* sysdeps/x86/dl-cet.c: Likewise.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
GNU_PROPERTY_X86_FEATURE_1_AND may not be the first property item. We
need to check each property item until we reach the end of the property
or find GNU_PROPERTY_X86_FEATURE_1_AND.
This patch adds 2 tests. The first test checks if IBT is enabled and
the second test reads the output from the first test to check if IBT
is is enabled. The second second test fails if IBT isn't enabled
properly.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
[BZ #23467]
* sysdeps/unix/sysv/linux/x86/Makefile (tests): Add
tst-cet-property-1 and tst-cet-property-2 if CET is enabled.
(CFLAGS-tst-cet-property-1.o): New.
(ASFLAGS-tst-cet-property-dep-2.o): Likewise.
($(objpfx)tst-cet-property-2): Likewise.
($(objpfx)tst-cet-property-2.out): Likewise.
* sysdeps/unix/sysv/linux/x86/tst-cet-property-1.c: New file.
* sysdeps/unix/sysv/linux/x86/tst-cet-property-2.c: Likewise.
* sysdeps/unix/sysv/linux/x86/tst-cet-property-dep-2.S: Likewise.
* sysdeps/x86/dl-prop.h (_dl_process_cet_property_note): Parse
each property item until GNU_PROPERTY_X86_FEATURE_1_AND is found.
All tests should be added to $(tests).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
[BZ #23458]
* sysdeps/x86/Makefile (tests): Add tst-get-cpu-features-static.
Simply check if "ptr < ptr_end" since "ptr" is always incremented by 8.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/x86/dl-prop.h (_dl_process_cet_property_note): Don't
parse beyond the note end.
cpu-features.h has
#define bit_cpu_LZCNT (1 << 5)
#define index_cpu_LZCNT COMMON_CPUID_INDEX_1
#define reg_LZCNT
But the LZCNT feature bit is in COMMON_CPUID_INDEX_80000001:
Initial EAX Value: 80000001H
ECX Extended Processor Signature and Feature Bits:
Bit 05: LZCNT available
index_cpu_LZCNT should be COMMON_CPUID_INDEX_80000001, not
COMMON_CPUID_INDEX_1. The VMX feature bit is in COMMON_CPUID_INDEX_1:
Initial EAX Value: 01H
Feature Information Returned in the ECX Register:
5 VMX
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
[BZ # 23456]
* sysdeps/x86/cpu-features.h (index_cpu_LZCNT): Set to
COMMON_CPUID_INDEX_80000001.
CET arch_prctl bits should be defined in <asm/prctl.h> from Linux kernel
header files. Add x86 <include/asm/prctl.h> for pre-CET kernel header
files.
Note: sysdeps/unix/sysv/linux/x86/include/asm/prctl.h should be removed
if <asm/prctl.h> from the required kernel header files contains CET
arch_prctl bits.
/* CET features:
IBT: GNU_PROPERTY_X86_FEATURE_1_IBT
SHSTK: GNU_PROPERTY_X86_FEATURE_1_SHSTK
*/
/* Return CET features in unsigned long long *addr:
features: addr[0].
shadow stack base address: addr[1].
shadow stack size: addr[2].
*/
# define ARCH_CET_STATUS 0x3001
/* Disable CET features in unsigned int features. */
# define ARCH_CET_DISABLE 0x3002
/* Lock all CET features. */
# define ARCH_CET_LOCK 0x3003
/* Allocate a new shadow stack with unsigned long long *addr:
IN: requested shadow stack size: *addr.
OUT: allocated shadow stack address: *addr.
*/
# define ARCH_CET_ALLOC_SHSTK 0x3004
/* Return legacy region bitmap info in unsigned long long *addr:
address: addr[0].
size: addr[1].
*/
# define ARCH_CET_LEGACY_BITMAP 0x3005
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/unix/sysv/linux/x86/include/asm/prctl.h: New file.
* sysdeps/unix/sysv/linux/x86/cpu-features.c: Include
<sys/prctl.h> and <asm/prctl.h>.
(get_cet_status): Call arch_prctl with ARCH_CET_STATUS.
* sysdeps/unix/sysv/linux/x86/dl-cet.h: Include <sys/prctl.h>
and <asm/prctl.h>.
(dl_cet_allocate_legacy_bitmap): Call arch_prctl with
ARCH_CET_LEGACY_BITMAP.
(dl_cet_disable_cet): Call arch_prctl with ARCH_CET_DISABLE.
(dl_cet_lock_cet): Call arch_prctl with ARCH_CET_LOCK.
* sysdeps/x86/libc-start.c: Include <startup.h>.
Add <bits/indirect-return.h> and include it in <ucontext.h>.
__INDIRECT_RETURN defined in <bits/indirect-return.h> indicates if
swapcontext requires special compiler treatment. The default
__INDIRECT_RETURN is empty.
On x86, when shadow stack is enabled, __INDIRECT_RETURN is defined
with indirect_return attribute, which has been added to GCC 9, to
indicate that swapcontext returns via indirect branch. Otherwise
__INDIRECT_RETURN is defined with returns_twice attribute.
When shadow stack is enabled, remove always_inline attribute from
prepare_test_buffer in string/tst-xbzero-opt.c to avoid:
tst-xbzero-opt.c: In function ‘prepare_test_buffer’:
tst-xbzero-opt.c:105:1: error: function ‘prepare_test_buffer’ can never be inlined because it uses setjmp
prepare_test_buffer (unsigned char *buf)
when indirect_return attribute isn't available.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* bits/indirect-return.h: New file.
* misc/sys/cdefs.h (__glibc_has_attribute): New.
* sysdeps/x86/bits/indirect-return.h: Likewise.
* stdlib/Makefile (headers): Add bits/indirect-return.h.
* stdlib/ucontext.h: Include <bits/indirect-return.h>.
(swapcontext): Add __INDIRECT_RETURN.
* string/tst-xbzero-opt.c (ALWAYS_INLINE): New.
(prepare_test_buffer): Use it.
Always include <dl-cet.h> and cet-tunables.h> when CET is enabled.
Otherwise, configure glibc with --enable-cet --disable-tunables will
fail to build.
* sysdeps/x86/cpu-features.c: Always include <dl-cet.h> and
cet-tunables.h> when CET is enabled.
Intel Control-flow Enforcement Technology (CET) instructions:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-en
forcement-technology-preview.pdf
includes Indirect Branch Tracking (IBT) and Shadow Stack (SHSTK).
GNU_PROPERTY_X86_FEATURE_1_IBT is added to GNU program property to
indicate that all executable sections are compatible with IBT when
ENDBR instruction starts each valid target where an indirect branch
instruction can land. Linker sets GNU_PROPERTY_X86_FEATURE_1_IBT on
output only if it is set on all relocatable inputs.
On an IBT capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable IBT and
lock IBT if GNU_PROPERTY_X86_FEATURE_1_IBT is set on the executable.
2. When loading an executable with an interpreter, enable IBT if
GNU_PROPERTY_X86_FEATURE_1_IBT is set on the interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_IBT isn't set on the executable,
disable IBT.
b. Lock IBT.
3. If IBT is enabled, when loading a shared object without
GNU_PROPERTY_X86_FEATURE_1_IBT:
a. If legacy interwork is allowed, then mark all pages in executable
PT_LOAD segments in legacy code page bitmap. Failure of legacy code
page bitmap allocation causes an error.
b. If legacy interwork isn't allowed, it causes an error.
GNU_PROPERTY_X86_FEATURE_1_SHSTK is added to GNU program property to
indicate that all executable sections are compatible with SHSTK where
return address popped from shadow stack always matches return address
popped from normal stack. Linker sets GNU_PROPERTY_X86_FEATURE_1_SHSTK
on output only if it is set on all relocatable inputs.
On a SHSTK capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on the executable.
2. When loading an executable with an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_SHSTK isn't set on the executable
or any shared objects loaded via the DT_NEEDED tag, disable SHSTK.
b. Otherwise lock SHSTK.
3. After SHSTK is enabled, it is an error to load a shared object
without GNU_PROPERTY_X86_FEATURE_1_SHSTK.
To enable CET support in glibc, --enable-cet is required to configure
glibc. When CET is enabled, both compiler and assembler must support
CET. Otherwise, it is a configure-time error.
To support CET run-time control,
1. _dl_x86_feature_1 is added to the writable ld.so namespace to indicate
if IBT or SHSTK are enabled at run-time. It should be initialized by
init_cpu_features.
2. For dynamic executables:
a. A l_cet field is added to struct link_map to indicate if IBT or
SHSTK is enabled in an ELF module. _dl_process_pt_note or
_rtld_process_pt_note is called to process PT_NOTE segment for
GNU program property and set l_cet.
b. _dl_open_check is added to check IBT and SHSTK compatibilty when
dlopening a shared object.
3. Replace i386 _dl_runtime_resolve and _dl_runtime_profile with
_dl_runtime_resolve_shstk and _dl_runtime_profile_shstk, respectively if
SHSTK is enabled.
CET run-time control can be changed via GLIBC_TUNABLES with
$ export GLIBC_TUNABLES=glibc.tune.x86_shstk=[permissive|on|off]
$ export GLIBC_TUNABLES=glibc.tune.x86_ibt=[permissive|on|off]
1. permissive: SHSTK is disabled when dlopening a legacy ELF module.
2. on: IBT or SHSTK are always enabled, regardless if there are IBT or
SHSTK bits in GNU program property.
3. off: IBT or SHSTK are always disabled, regardless if there are IBT or
SHSTK bits in GNU program property.
<cet.h> from CET-enabled GCC is automatically included by assembly codes
to add GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK
to GNU program property. _CET_ENDBR is added at the entrance of all
assembly functions whose address may be taken. _CET_NOTRACK is used to
insert NOTRACK prefix with indirect jump table to support IBT. It is
defined as notrack when _CET_NOTRACK is defined in <cet.h>.
[BZ #21598]
* configure.ac: Add --enable-cet.
* configure: Regenerated.
* elf/Makefille (all-built-dso): Add a comment.
* elf/dl-load.c (filebuf): Moved before "dynamic-link.h".
Include <dl-prop.h>.
(_dl_map_object_from_fd): Call _dl_process_pt_note on PT_NOTE
segment.
* elf/dl-open.c: Include <dl-prop.h>.
(dl_open_worker): Call _dl_open_check.
* elf/rtld.c: Include <dl-prop.h>.
(dl_main): Call _rtld_process_pt_note on PT_NOTE segment. Call
_rtld_main_check.
* sysdeps/generic/dl-prop.h: New file.
* sysdeps/i386/dl-cet.c: Likewise.
* sysdeps/unix/sysv/linux/x86/cpu-features.c: Likewise.
* sysdeps/unix/sysv/linux/x86/dl-cet.h: Likewise.
* sysdeps/x86/cet-tunables.h: Likewise.
* sysdeps/x86/check-cet.awk: Likewise.
* sysdeps/x86/configure: Likewise.
* sysdeps/x86/configure.ac: Likewise.
* sysdeps/x86/dl-cet.c: Likewise.
* sysdeps/x86/dl-procruntime.c: Likewise.
* sysdeps/x86/dl-prop.h: Likewise.
* sysdeps/x86/libc-start.h: Likewise.
* sysdeps/x86/link_map.h: Likewise.
* sysdeps/i386/dl-trampoline.S (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
(_dl_runtime_resolve_shstk): New.
(_dl_runtime_profile_shstk): Likewise.
* sysdeps/linux/x86/Makefile (sysdep-dl-routines): Add dl-cet
if CET is enabled.
(CFLAGS-.o): Add -fcf-protection if CET is enabled.
(CFLAGS-.os): Likewise.
(CFLAGS-.op): Likewise.
(CFLAGS-.oS): Likewise.
(asm-CPPFLAGS): Add -fcf-protection -include cet.h if CET
is enabled.
(tests-special): Add $(objpfx)check-cet.out.
(cet-built-dso): New.
(+$(cet-built-dso:=.note)): Likewise.
(common-generated): Add $(cet-built-dso:$(common-objpfx)%=%.note).
($(objpfx)check-cet.out): New.
(generated): Add check-cet.out.
* sysdeps/x86/cpu-features.c: Include <dl-cet.h> and
<cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New prototype.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
(init_cpu_features): Call get_cet_status to check CET status
and update dl_x86_feature_1 with CET status. Call
TUNABLE_CALLBACK (set_x86_ibt) and TUNABLE_CALLBACK
(set_x86_shstk). Disable and lock CET in libc.a.
* sysdeps/x86/cpu-tunables.c: Include <cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New function.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
* sysdeps/x86/sysdep.h (_CET_NOTRACK): New.
(_CET_ENDBR): Define if not defined.
(ENTRY): Add _CET_ENDBR.
* sysdeps/x86/dl-tunables.list (glibc.tune): Add x86_ibt and
x86_shstk.
* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
Save and restore shadow stack pointer in setjmp and longjmp to support
shadow stack in Intel CET. Use feature_1 in tcbhead_t to check if
shadow stack is enabled before saving and restoring shadow stack pointer.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/i386/__longjmp.S: Include <jmp_buf-ssp.h>.
(__longjmp): Restore shadow stack pointer if shadow stack is
enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
isn't defined for __longjmp_cancel.
* sysdeps/i386/bsd-_setjmp.S: Include <jmp_buf-ssp.h>.
(_setjmp): Save shadow stack pointer if shadow stack is enabled
and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/i386/bsd-setjmp.S: Include <jmp_buf-ssp.h>.
(setjmp): Save shadow stack pointer if shadow stack is enabled
and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/i386/setjmp.S: Include <jmp_buf-ssp.h>.
(__sigsetjmp): Save shadow stack pointer if shadow stack is
enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Include
<jmp_buf-ssp.h>.
(____longjmp_chk): Restore shadow stack pointer if shadow stack
is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/unix/sysv/linux/x86/Makefile (gen-as-const-headers):
Remove jmp_buf-ssp.sym.
* sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Include
<jmp_buf-ssp.h>.
(____longjmp_chk): Restore shadow stack pointer if shadow stack
is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/x86/Makefile (gen-as-const-headers): Add
jmp_buf-ssp.sym.
* sysdeps/x86/jmp_buf-ssp.sym: New dummy file.
* sysdeps/x86_64/__longjmp.S: Include <jmp_buf-ssp.h>.
(__longjmp): Restore shadow stack pointer if shadow stack is
enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
isn't defined for __longjmp_cancel.
* sysdeps/x86_64/setjmp.S: Include <jmp_buf-ssp.h>.
(__sigsetjmp): Save shadow stack pointer if shadow stack is
enabled and SHADOW_STACK_POINTER_OFFSET is defined.
feature_1 has X86_FEATURE_1_IBT and X86_FEATURE_1_SHSTK bits for CET
run-time control.
CET_ENABLED, IBT_ENABLED and SHSTK_ENABLED are defined to 1 or 0 to
indicate that if CET, IBT and SHSTK are enabled.
<tls-setup.h> is added to set up thread-local data.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
[BZ #22563]
* nptl/pthread_create.c: Include <tls-setup.h>.
(__pthread_create_2_1): Call tls_setup_tcbhead.
* sysdeps/generic/tls-setup.h: New file.
* sysdeps/x86/nptl/tls-setup.h: Likewise.
* sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
* sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET):
Likewise.
* sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1
to feature_1.
* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
* sysdeps/x86/sysdep.h (X86_FEATURE_1_IBT): New.
(X86_FEATURE_1_SHSTK): Likewise.
(CET_ENABLED): Likewise.
(IBT_ENABLED): Likewise.
(SHSTK_ENABLED): Likewise.
From Zen onwards this will be enabled. It was disabled for the
Excavator case and will remain disabled.
Reviewd-by: Carlos O'Donell <carlos@redhat.com>
Although the REP MOVSB implementations of memmove, memcpy and mempcpy
aren't used by the current processors, this patch adds Prefer_FSRM
check in ifunc-memmove.h so that they can be used in the future.
* sysdeps/x86/cpu-features.h (bit_arch_Prefer_FSRM): New.
(index_arch_Prefer_FSRM): Likewise.
* sysdeps/x86/cpu-tunables.c (TUNABLE_CALLBACK (set_hwcaps)):
Also check Prefer_FSRM.
* sysdeps/x86_64/multiarch/ifunc-memmove.h (IFUNC_SELECTOR):
Also return OPTIMIZE (erms) for Prefer_FSRM.
The newer Intel processors support Fast Short REP MOVSB which has a
feature bit in CPUID. This patch adds the Fast Short REP MOVSB (FSRM)
bit to x86 cpu-features.
* sysdeps/x86/cpu-features.h (bit_cpu_FSRM): New.
(index_cpu_FSRM): Likewise.
(reg_FSRM): Likewise.
