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.
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.
This patch fixes the OFD ("file private") locks for architectures that
support non-LFS flock definition (__USE_FILE_OFFSET64 not defined). The
issue in this case is both F_OFD_{GETLK,SETLK,SETLKW} and
F_{SET,GET}L{W}K64 expects a flock64 argument and when using old
F_OFD_* flags with a non LFS flock argument the kernel might interpret
the underlying data wrongly. Kernel idea originally was to avoid using
such flags in non-LFS syscall, but since GLIBC uses fcntl with LFS
semantic as default it is possible to provide the functionality and
avoid the bogus struct kernel passing by adjusting the struct manually
for the required flags.
The idea follows other LFS interfaces that provide two symbols:
1. A new LFS fcntl64 is added on default ABI with the usual macros to
select it for FILE_OFFSET_BITS=64.
2. The Linux non-LFS fcntl use a stack allocated struct flock64 for
F_OFD_{GETLK,SETLK,SETLKW} copy the results on the user provided
struct.
3. Keep a compat symbol with old broken semantic for architectures
that do not define __OFF_T_MATCHES_OFF64_T.
So for architectures which defines __USE_FILE_OFFSET64, fcntl64 will
aliased to fcntl and no adjustment would be required. So to actually
use F_OFD_* with LFS support the source must be built with LFS support
(_FILE_OFFSET_BITS=64).
Also F_OFD_SETLKW command is handled a cancellation point, as for
F_SETLKW{64}.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[BZ #20251]
* NEWS: Mention fcntl64 addition.
* csu/check_fds.c: Replace __fcntl_nocancel by __fcntl64_nocancel.
* login/utmp_file.c: Likewise.
* sysdeps/posix/fdopendir.c: Likewise.
* sysdeps/posix/opendir.c: Likewise.
* sysdeps/unix/pt-fcntl.c: Likewise.
* include/fcntl.h (__libc_fcntl64, __fcntl64,
__fcntl64_nocancel_adjusted): New prototype.
(__fcntl_nocancel_adjusted): Remove prototype.
* io/Makefile (routines): Add fcntl64.
(CFLAGS-fcntl64.c): New rule.
* io/Versions [GLIBC_2.28] (fcntl64): New symbol.
[GLIBC_PRIVATE] (__libc_fcntl): Rename to __libc_fcntl64.
* io/fcntl.h (fcntl64): Add prototype and redirect if
__USE_FILE_OFFSET64 is defined.
* io/fcntl64.c: New file.
* manual/llio.text: Add a note for which commands fcntl acts a
cancellation point.
* nptl/Makefile (CFLAGS-fcntl64.c): New rule.
* sysdeps/mach/hurd/fcntl.c: Alias fcntl to fcntl64 symbols.
* sysdeps/mach/hurd/i386/libc.abilist [GLIBC_2.28] (fcntl, fcntl64):
New symbols.
* sysdeps/unix/sysv/linux/fcntl.c (__libc_fcntl): Fix F_GETLK64,
F_OFD_GETLK, F_SETLK64, F_SETLKW64, F_OFD_SETLK, and F_OFD_SETLKW for
non-LFS case.
* sysdeps/unix/sysv/linux/fcntl64.c: New file.
* sysdeps/unix/sysv/linux/fcntl_nocancel.c (__fcntl_nocancel): Rename
to __fcntl64_nocancel.
(__fcntl_nocancel_adjusted): Rename to __fcntl64_nocancel_adjusted.
* sysdeps/unix/sysv/linux/not-cancel.h (__fcntl_nocancel): Rename
to __fcntl64_nocancel.
* sysdeps/unix/sysv/linux/tst-ofdlocks.c: New file.
* sysdeps/unix/sysv/linux/tst-ofdlocks-compat.c: Likewise.
* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-ofdlocks.
(tests-internal): Add tst-ofdlocks-compat.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.28]
(fcntl64): New symbol.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.28] (fcntl,
fcntl64): Likewise.
* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilis: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
Move declare_mgen_finite_alias, declare_mgen_finite_alias_s and
declare_mgen_finite_alias_x to a shared place in order to reuse them in
other files that also declare _finite aliases.
* math/e_exp2_template.c (declare_mgen_finite_alias,
declare_mgen_finite_alias_s, declare_mgen_finite_alias_x): Move to...
* sysdeps/generic/math-type-macros.h (declare_mgen_finite_alias,
declare_mgen_finite_alias_s, declare_mgen_finite_alias_x): ... here.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
_Float128 is defined for certain compilers indirectly from
<libm-alias-double.h>, and <ieee754_float128.h> (included from
<math-nan-payload-float128.h>) needs this definition.
This patch continues the math_private.h cleanup by stopping
math_private.h from including math-barriers.h and making the users of
the barrier macros include the latter header directly. No attempt is
made to remove any math_private.h includes that are now unused, except
in strtod_l.c where that is done to avoid line number changes in
assertions, so that installed stripped shared libraries can be
compared before and after the patch. (I think the floating-point
environment support in math_private.h should also move out - some
architectures already have fenv_private.h as an architecture-internal
header included from their math_private.h - and after moving that out
might be a better time to identify unused math_private.h includes.)
Tested for x86_64 and x86, and tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by the patch.
* sysdeps/generic/math_private.h: Do not include
<math-barriers.h>.
* stdlib/strtod_l.c: Include <math-barriers.h> instead of
<math_private.h>.
* math/fromfp.h: Include <math-barriers.h>.
* math/math-narrow.h: Likewise.
* math/s_nextafter.c: Likewise.
* math/s_nexttowardf.c: Likewise.
* sysdeps/aarch64/fpu/s_llrint.c: Likewise.
* sysdeps/aarch64/fpu/s_llrintf.c: Likewise.
* sysdeps/aarch64/fpu/s_lrint.c: Likewise.
* sysdeps/aarch64/fpu/s_lrintf.c: Likewise.
* sysdeps/i386/fpu/s_nextafterl.c: Likewise.
* sysdeps/i386/fpu/s_nexttoward.c: Likewise.
* sysdeps/i386/fpu/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/dbl-64/e_atan2.c: Likewise.
* sysdeps/ieee754/dbl-64/e_atanh.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp2.c: Likewise.
* sysdeps/ieee754/dbl-64/e_j0.c: Likewise.
* sysdeps/ieee754/dbl-64/e_sqrt.c: Likewise.
* sysdeps/ieee754/dbl-64/s_expm1.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fma.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fmaf.c: Likewise.
* sysdeps/ieee754/dbl-64/s_log1p.c: Likewise.
* sysdeps/ieee754/dbl-64/s_nearbyint.c: Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c: Likewise.
* sysdeps/ieee754/flt-32/e_atanhf.c: Likewise.
* sysdeps/ieee754/flt-32/e_j0f.c: Likewise.
* sysdeps/ieee754/flt-32/s_expm1f.c: Likewise.
* sysdeps/ieee754/flt-32/s_log1pf.c: Likewise.
* sysdeps/ieee754/flt-32/s_nearbyintf.c: Likewise.
* sysdeps/ieee754/flt-32/s_nextafterf.c: Likewise.
* sysdeps/ieee754/k_standardl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_asinl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_expl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_powl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nearbyintl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nextafterl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttoward.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_asinl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c: Likewise.
* sysdeps/ieee754/ldbl-96/e_atanhl.c: Likewise.
* sysdeps/ieee754/ldbl-96/e_j0l.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fma.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Likewise.
* sysdeps/m68k/m680x0/fpu/s_nextafterl.c: Likewise.
This patch continues cleaning up math_private.h by moving the
math_opt_barrier and math_force_eval macros to a separate header
math-barriers.h.
At present, those macros are inside a "#ifndef math_opt_barrier" in
math_private.h to allow architectures to override them and then use
a separate math-barriers.h header, no such #ifndef or #include_next is
needed; architectures just have their own alternative version of
math-barriers.h when providing their own optimized versions that avoid
going through memory unnecessarily. The generic math-barriers.h has a
comment added to document these two macros.
In this patch, math_private.h is made to #include <math-barriers.h>,
so files using these macros do not need updating yet. That is because
of uses of math_force_eval in math_check_force_underflow and
math_check_force_underflow_nonneg, which are still defined in
math_private.h. Once those are moved out to a separate header, that
separate header can be made to include <math-barriers.h>, as can the
other files directly using these barrier macros, and then the include
of <math-barriers.h> from math_private.h can be removed.
Tested for x86_64 and x86. Also tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by this patch.
* sysdeps/generic/math-barriers.h: New file.
* sysdeps/generic/math_private.h [!math_opt_barrier]
(math_opt_barrier): Move to math-barriers.h.
[!math_opt_barrier] (math_force_eval): Likewise.
* sysdeps/aarch64/fpu/math-barriers.h: New file.
* sysdeps/aarch64/fpu/math_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
* sysdeps/alpha/fpu/math-barriers.h: New file.
* sysdeps/alpha/fpu/math_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
* sysdeps/x86/fpu/math-barriers.h: New file.
* sysdeps/i386/fpu/fenv_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
* sysdeps/m68k/m680x0/fpu/math_private.h: Move to....
* sysdeps/m68k/m680x0/fpu/math-barriers.h: ... here. Adjust
multiple-include guard for rename.
* sysdeps/powerpc/fpu/math-barriers.h: New file.
* sysdeps/powerpc/fpu/math_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
This patch continues cleaning up the math_private.h header, which
contains lots of different definitions many of which are only needed
by a limited subset of files using that header (and some of which are
overridden by architectures that only want to override selected parts
of the header), by moving the math_narrow_eval macro out to a separate
math-narrow-eval.h header, only included by those files that need it.
That header is placed in include/ (since it's used in stdlib/, not
just files built in math/, but no sysdeps variants are needed at
present).
Tested for x86_64, and with build-many-glibcs.py. (Installed stripped
shared libraries change because of line numbers in assertions in
strtod_l.c.)
* include/math-narrow-eval.h: New file. Contents moved from ....
* sysdeps/generic/math_private.h: ... here.
(math_narrow_eval): Remove macro. Moved to math-narrow-eval.h.
[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
* math/s_fdim_template.c: Include <math-narrow-eval.h>.
* stdlib/strtod_l.c: Likewise.
* sysdeps/i386/fpu/s_f32xaddf64.c: Likewise.
* sysdeps/i386/fpu/s_f32xsubf64.c: Likewise.
* sysdeps/i386/fpu/s_fdim.c: Likewise.
* sysdeps/ieee754/dbl-64/e_cosh.c: Likewise.
* sysdeps/ieee754/dbl-64/e_gamma_r.c: Likewise.
* sysdeps/ieee754/dbl-64/e_j1.c: Likewise.
* sysdeps/ieee754/dbl-64/e_jn.c: Likewise.
* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Likewise.
* sysdeps/ieee754/dbl-64/e_sinh.c: Likewise.
* sysdeps/ieee754/dbl-64/gamma_productf.c: Likewise.
* sysdeps/ieee754/dbl-64/k_rem_pio2.c: Likewise.
* sysdeps/ieee754/dbl-64/lgamma_neg.c: Likewise.
* sysdeps/ieee754/dbl-64/s_erf.c: Likewise.
* sysdeps/ieee754/dbl-64/s_llrint.c: Likewise.
* sysdeps/ieee754/dbl-64/s_lrint.c: Likewise.
* sysdeps/ieee754/flt-32/e_coshf.c: Likewise.
* sysdeps/ieee754/flt-32/e_exp2f.c: Likewise.
* sysdeps/ieee754/flt-32/e_expf.c: Likewise.
* sysdeps/ieee754/flt-32/e_gammaf_r.c: Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c: Likewise.
* sysdeps/ieee754/flt-32/e_jnf.c: Likewise.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Likewise.
* sysdeps/ieee754/flt-32/e_sinhf.c: Likewise.
* sysdeps/ieee754/flt-32/k_rem_pio2f.c: Likewise.
* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
* sysdeps/ieee754/flt-32/s_erff.c: Likewise.
* sysdeps/ieee754/flt-32/s_llrintf.c: Likewise.
* sysdeps/ieee754/flt-32/s_lrintf.c: Likewise.
* sysdeps/ieee754/ldbl-96/gamma_product.c: Likewise.
Do not relocate absolute symbols by the base address. Such symbols have
SHN_ABS as the section index and their value is not supposed to be
affected by relocation as per the ELF gABI[1]:
"SHN_ABS
The symbol has an absolute value that will not change because of
relocation."
The reason for our non-conformance here seems to be an old SysV linker
bug causing symbols like _DYNAMIC to be incorrectly emitted as absolute
symbols[2]. However in a previous discussion it was pointed that this
is seriously flawed by preventing the lone purpose of the existence of
absolute symbols from being used[3]:
"On the contrary, the only interpretation that makes sense to me is that
it will not change because of relocation at link time or at load time.
Absolute symbols, from the days of the earliest linking loaders, have
been used to represent addresses that are outside the address space of
the module (e.g., memory-mapped addresses or kernel gateway pages).
They've even been used to represent true symbolic constants (e.g.,
system entry point numbers, sizes, version numbers). There's no other
way to represent a true absolute symbol, while the meaning you seek is
easily represented by giving the symbol a non-negative st_shndx value."
and we ought to stop supporting our current broken interpretation.
Update processing for dladdr(3) and dladdr1(3) so that SHN_ABS symbols
are ignored, because under the corrected interpretation they do not
represent addresses within a mapped file and therefore are not supposed
to be considered.
References:
[1] "System V Application Binary Interface - DRAFT - 19 October 2010",
The SCO Group, Section "Symbol Table",
<http://www.sco.com/developers/gabi/2012-12-31/ch4.symtab.html>
[2] Alan Modra, "Absolute symbols"
<https://sourceware.org/ml/binutils/2012-05/msg00019.html>
[3] Cary Coutant, "Re: Absolute symbols"
<https://sourceware.org/ml/binutils/2012-05/msg00020.html>
[BZ #19818]
* sysdeps/generic/ldsodefs.h (SYMBOL_ADDRESS): Handle SHN_ABS
symbols.
* elf/dl-addr.c (determine_info): Ignore SHN_ABS symbols.
* elf/tst-absolute-sym.c: New file.
* elf/tst-absolute-sym-lib.c: New file.
* elf/tst-absolute-sym-lib.lds: New file.
* elf/Makefile (tests): Add `tst-absolute-sym'.
(modules-names): Add `tst-absolute-sym-lib'.
(LDLIBS-tst-absolute-sym-lib.so): New variable.
($(objpfx)tst-absolute-sym-lib.so): New dependency.
($(objpfx)tst-absolute-sym): New dependency.
Wrap symbol address run-time calculation into a macro and use it
throughout, replacing inline calculations.
There are a couple of variants, most of them different in a functionally
insignificant way. Most calculations are right following RESOLVE_MAP,
at which point either the map or the symbol returned can be checked for
validity as the macro sets either both or neither. In some places both
the symbol and the map has to be checked however.
My initial implementation therefore always checked both, however that
resulted in code larger by as much as 0.3%, as many places know from
elsewhere that no check is needed. I have decided the size growth was
unacceptable.
Having looked closer I realized that it's the map that is the culprit.
Therefore I have modified LOOKUP_VALUE_ADDRESS to accept an additional
boolean argument telling it to access the map without checking it for
validity. This in turn has brought quite nice results, with new code
actually being smaller for i686, and MIPS o32, n32 and little-endian n64
targets, unchanged in size for x86-64 and, unusually, marginally larger
for big-endian MIPS n64, as follows:
i686:
text data bss dec hex filename
152255 4052 192 156499 26353 ld-2.27.9000-base.so
152159 4052 192 156403 262f3 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/el:
text data bss dec hex filename
142906 4396 260 147562 2406a ld-2.27.9000-base.so
142890 4396 260 147546 2405a ld-2.27.9000-elf-symbol-value.so
MIPS/n32/el:
text data bss dec hex filename
142267 4404 260 146931 23df3 ld-2.27.9000-base.so
142171 4404 260 146835 23d93 ld-2.27.9000-elf-symbol-value.so
MIPS/n64/el:
text data bss dec hex filename
149835 7376 408 157619 267b3 ld-2.27.9000-base.so
149787 7376 408 157571 26783 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/eb:
text data bss dec hex filename
142870 4396 260 147526 24046 ld-2.27.9000-base.so
142854 4396 260 147510 24036 ld-2.27.9000-elf-symbol-value.so
MIPS/n32/eb:
text data bss dec hex filename
142019 4404 260 146683 23cfb ld-2.27.9000-base.so
141923 4404 260 146587 23c9b ld-2.27.9000-elf-symbol-value.so
MIPS/n64/eb:
text data bss dec hex filename
149763 7376 408 157547 2676b ld-2.27.9000-base.so
149779 7376 408 157563 2677b ld-2.27.9000-elf-symbol-value.so
x86-64:
text data bss dec hex filename
148462 6452 400 155314 25eb2 ld-2.27.9000-base.so
148462 6452 400 155314 25eb2 ld-2.27.9000-elf-symbol-value.so
[BZ #19818]
* sysdeps/generic/ldsodefs.h (LOOKUP_VALUE_ADDRESS): Add `set'
parameter.
(SYMBOL_ADDRESS): New macro.
[!ELF_FUNCTION_PTR_IS_SPECIAL] (DL_SYMBOL_ADDRESS): Use
SYMBOL_ADDRESS for symbol address calculation.
* elf/dl-runtime.c (_dl_fixup): Likewise.
(_dl_profile_fixup): Likewise.
* elf/dl-symaddr.c (_dl_symbol_address): Likewise.
* elf/rtld.c (dl_main): Likewise.
* sysdeps/aarch64/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/alpha/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/arm/dl-machine.h (elf_machine_rel): Likewise.
(elf_machine_rela): Likewise.
* sysdeps/hppa/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/hppa/dl-symaddr.c (_dl_symbol_address): Likewise.
* sysdeps/i386/dl-machine.h (elf_machine_rel): Likewise.
(elf_machine_rela): Likewise.
* sysdeps/ia64/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/m68k/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/microblaze/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/mips/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
Likewise.
(elf_machine_reloc): Likewise.
(elf_machine_got_rel): Likewise.
* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
* sysdeps/nios2/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/riscv/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/s390/s390-32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/s390/s390-64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/sh/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/tile/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Three of the functions defined by internal-signals.h were not actually
fulfilling their contracts when the sysdeps/generic version of that
file was used. Also, the Linux version included several more headers
than the generic version, which is the root cause of a build failure
on Hurd (already addressed in another way, but I think it is proper to
make the headers match).
* sysdeps/generic/internal-signals.h: Include signal.h,
sigsetops.h, and stdbool.h.
(__libc_signal_block_all): Actually block all signals.
(__libc_signal_block_app): Likewise.
(__libc_signal_restore_set): Actually restore the signal mask.
This patch filters out the internal NPTL signals (SIGCANCEL/SIGTIMER and
SIGSETXID) from signal functions. GLIBC on Linux requires both signals to
proper implement pthread cancellation, posix timers, and set*id posix
thread synchronization.
And not filtering out the internal signal is troublesome:
- A conformant program on a architecture that does not filter out the
signals might inadvertently disable pthread asynchronous cancellation,
set*id synchronization or posix timers.
- It might also to security issues if SIGSETXID is masked and set*id
functions are called (some threads might have effective user or group
id different from the rest).
The changes are basically:
- Change __is_internal_signal to bool and used on all signal function
that has a signal number as input. Also for signal function which accepts
signals sets (sigset_t) it assumes that canonical function were used to
add/remove signals which lead to some input simplification.
- Fix tst-sigset.c to avoid check for SIGCANCEL/SIGTIMER and SIGSETXID.
It is rewritten to check each signal indidually and to check realtime
signals using canonical macros.
- Add generic __clear_internal_signals and __is_internal_signal
version since both symbols are used on generic implementations.
- Remove superflous sysdeps/nptl/sigfillset.c.
- Remove superflous SIGTIMER handling on Linux __is_internal_signal
since it is the same of SIGCANCEL.
- Remove dangling define and obvious comment on nptl/sigaction.c.
Checked on x86_64-linux-gnu.
[BZ #22391]
* nptl/sigaction.c (__sigaction): Use __is_internal_signal to
check for internal nptl signals.
* nptl/sigaction.c (__sigaction): Likewise.
* signal/sigaddset.c (sigaddset): Likewise.
* signal/sigdelset.c (sigdelset): Likewise.
* sysdeps/posix/signal.c (__bsd_signal): Likewise.
* sysdeps/posix/sigset.c (sigset): Call and check sigaddset return
value.
* signal/sigfillset.c (sigfillset): User __clear_internal_signals
to filter out internal nptl signals.
* signal/tst-sigset.c (do_test): Check ech signal indidually and
also check realtime signals using standard macros.
* sysdeps/generic/internal-signals.h (__clear_internal_signals,
__is_internal_signal, __libc_signal_block_all,
__libc_signal_block_app, __libc_signal_restore_set): New functions.
* sysdeps/nptl/sigfillset.c: Remove file.
* sysdeps/unix/sysv/linux/internal-signals.h (__is_internal_signal):
Change return to bool.
(__clear_internal_signals): Remove SIGTIMER clean since it is
equal to SIGCANEL on Linux.
* sysdeps/unix/sysv/linux/sigtimedwait.c (__sigtimedwait): Assume
signal set was constructed using standard functions.
Reported-by: Yury Norov <ynorov@caviumnetworks.com>
* sysdeps/generic/libc-start.h [!SHARED] (ARCH_SETUP_TLS): Define to
__libc_setup_tls.
* sysdeps/unix/sysv/linux/powerpc/libc-start.h [!SHARED]
(ARCH_SETUP_TLS): Likewise.
* sysdeps/mach/hurd/libc-start.h: New file copied from
sysdeps/generic/libc-start.h, but define ARCH_SETUP_TLS to empty.
* csu/libc-start.c [!SHARED] (LIBC_START_MAIN): Call ARCH_SETUP_TLS instead
of __libc_setup_tls.
* sysdeps/mach/hurd/i386/init-first.c [!SHARED] (init1): Call
__libc_setup_tls before initializing libpthread and running _hurd_init which
starts the signal thread.
* sysdeps/generic/thread_state.h (MACHINE_NEW_THREAD_STATE_FLAVOR):
Define macro.
* sysdeps/mach/thread_state.h (MACHINE_THREAD_STATE_FIX_NEW): New macro.
* sysdeps/mach/i386/thread_state.h
(MACHINE_NEW_THREAD_STATE_FLAVOR): New macro, defined to
i386_THREAD_STATE.
(MACHINE_THREAD_STATE_FLAVOR): Define to i386_REGS_SEGS_STATE instead of
i386_THREAD_STATE.
(MACHINE_THREAD_STATE_FIX_NEW): New macro, reads segments.
* sysdeps/mach/hurd/i386/trampoline.c (_hurd_setup_sighandler): Use
i386_REGS_SEGS_STATE instead of i386_THREAD_STATE.
* sysdeps/mach/hurd/i386/tls.h (TCB_ALIGNMENT, HURD_SEL_LDT): New
macros.
(_hurd_tls_fork): Add original thread parameter, Duplicate existing LDT
descriptor instead of creating a new one.
(_hurd_tls_new): New function, creates a new descriptor and updates tcb.
* mach/setup-thread.c: Include <ldsodefs.h>.
(__mach_setup_thread): Call _dl_allocate_tls, pass
MACHINE_NEW_THREAD_STATE_FLAVOR to __thread_set_state instead of
MACHINE_THREAD_STATE_FLAVOR, before getting
MACHINE_THREAD_STATE_FLAVOR, calling _hurd_tls_new, and setting
MACHINE_THREAD_STATE_FLAVOR with the result.
* hurd/hurdfault.c (_hurdsig_fault_init): Call
MACHINE_THREAD_STATE_FIX_NEW.
* sysdeps/mach/hurd/fork.c (__fork): Call _hurd_tls_fork for sigthread
too. Add original thread parameter.
Remove the now unused target specific__ieee754_sqrt(f/l) inlines.
Also remove inlines of sqrt which are for really old GCC versions.
Removing these is desirable, under the general principle of leaving
such inlining to the compiler rather than trying to do it in installed
headers, especially when only very old compilers are affected.
Note that removing inlines for __ieee754_sqrt disables inlining in the
sqrt wrapper functions. Given the sqrt function will typically only be
called for negative arguments, it doesn't matter whether the inlining
happens or not.
* sysdeps/aarch64/fpu/math_private.h (__ieee754_sqrt): Remove.
(__ieee754_sqrtf): Remove.
* sysdeps/alpha/fpu/math_private.h (__ieee754_sqrt): Remove.
(__ieee754_sqrtf): Remove.
* sysdeps/generic/math-type-macros.h (M_SQRT): Use sqrt.
* sysdeps/m68k/m680x0/fpu/mathimpl.h (__ieee754_sqrt): Remove.
* sysdeps/powerpc/fpu/math_private.h (__ieee754_sqrt): Remove.
(__ieee754_sqrtf): Remove.
* sysdeps/s390/fpu/bits/mathinline.h: Remove file.
* sysdeps/sparc/fpu/bits/mathinline.h (sqrt) Remove.
(sqrtf): Remove.
(sqrtl): Remove.
(__ieee754_sqrt): Remove.
(__ieee754_sqrtf): Remove.
(__ieee754_sqrtl): Remove.
* sysdeps/m68k/m680x0/fpu/mathimpl.h (__ieee754_sqrt): Remove.
* sysdeps/x86/fpu/math_private.h (__ieee754_sqrt): Remove.
* sysdeps/x86_64/fpu/math_private.h (__ieee754_sqrt): Remove.
(__ieee754_sqrtf): Remove.
(__ieee754_sqrtl): Remove.
This patch series cleans up the many uses of __ieee754_sqrt(f/l) in GLIBC.
The goal is to enable GCC to do the inlining, and if this fails call the
__ieee754_sqrt function. This is done by internally declaring sqrt with asm
redirects. The compat symbols and sqrt wrappers need to disable the redirect.
The redirect is also disabled if there are already redirects defined when
using -ffinite-math-only.
All math functions (but not math tests, non-library code and libnldbl) are
built with -fno-math-errno which means GCC will typically inline sqrt as a
single instruction. This means targets are no longer forced to add a special
inline for sqrt.
* include/math.h (sqrt): Declare with asm redirect.
(sqrtf): Likewise.
(sqrtl): Likewise.
(sqrtf128): Likewise.
* Makeconfig: Add -fno-math-errno for libc/libm, but build testsuite,
nonlib and libnldbl with -fmath-errno.
* math/w_sqrt_compat.c: Define NO_MATH_REDIRECT.
* math/w_sqrt_template.c: Likewise.
* math/w_sqrtf_compat.c: Likewise.
* math/w_sqrtl_compat.c: Likewise.
* sysdeps/i386/fpu/w_sqrt.c: Likewise.
* sysdeps/i386/fpu/w_sqrt_compat.c: Likewise.
* sysdeps/generic/math-type-macros-float128.h: Remove math.h and
complex.h.
This patch renames the nptl-signals.h header to internal-signals.h.
On Linux the definitions and functions are not only NPTL related, but
used for other POSIX definitions as well (for instance SIGTIMER for
posix times, SIGSETXID for id functions, and signal block/restore
helpers) and since generic functions will be places and used in generic
implementation it makes more sense to decouple it from NPTL.
Checked on x86_64-linux-gnu.
* sysdeps/nptl/nptl-signals.h: Move to ...
* sysdeps/generic/internal-signals.h: ... here. Adjust internal
comments.
* sysdeps/unix/sysv/linux/internal-signals.h: Add include guards.
(__nptl_is_internal_signal): Rename to __is_internal_signal.
(__nptl_clear_internal_signals): Rename to __clear_internal_signals.
* sysdeps/unix/sysv/linux/raise.c: Adjust nptl-signal.h to
include-signals.h rename.
* nptl/pthreadP.h: Likewise.
* sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Call
__is_internal_signal instead of __nptl_is_internal_signal.
This patch mechanically removes all remaining uses, and the
definitions, of the following libio name aliases:
name replaced with
---- -------------
_IO_FILE FILE
_IO_fpos_t __fpos_t
_IO_fpos64_t __fpos64_t
_IO_size_t size_t
_IO_ssize_t ssize_t or __ssize_t
_IO_off_t off_t
_IO_off64_t off64_t
_IO_pid_t pid_t
_IO_uid_t uid_t
_IO_wint_t wint_t
_IO_va_list va_list or __gnuc_va_list
_IO_BUFSIZ BUFSIZ
_IO_cookie_io_functions_t cookie_io_functions_t
__io_read_fn cookie_read_function_t
__io_write_fn cookie_write_function_t
__io_seek_fn cookie_seek_function_t
__io_close_fn cookie_close_function_t
I used __fpos_t and __fpos64_t instead of fpos_t and fpos64_t because
the definitions of fpos_t and fpos64_t depend on the largefile mode.
I used __ssize_t and __gnuc_va_list in a handful of headers where
namespace cleanliness might be relevant even though they're
internal-use-only. In all other cases, I used the public-namespace
name.
There are a tiny handful of places where I left a use of 'struct _IO_FILE'
alone, because it was being used together with 'struct _IO_FILE_plus'
or 'struct _IO_FILE_complete' in the same arithmetic expression.
Because this patch was almost entirely done with search and replace, I
may have introduced indentation botches. I did proofread the diff,
but I may have missed something.
The ChangeLog below calls out all of the places where this was not a
pure search-and-replace change.
Installed stripped libraries and executables are unchanged by this patch,
except that some assertions in vfscanf.c change line numbers.
* libio/libio.h (_IO_FILE): Delete; all uses changed to FILE.
(_IO_fpos_t): Delete; all uses changed to __fpos_t.
(_IO_fpos64_t): Delete; all uses changed to __fpos64_t.
(_IO_size_t): Delete; all uses changed to size_t.
(_IO_ssize_t): Delete; all uses changed to ssize_t or __ssize_t.
(_IO_off_t): Delete; all uses changed to off_t.
(_IO_off64_t): Delete; all uses changed to off64_t.
(_IO_pid_t): Delete; all uses changed to pid_t.
(_IO_uid_t): Delete; all uses changed to uid_t.
(_IO_wint_t): Delete; all uses changed to wint_t.
(_IO_va_list): Delete; all uses changed to va_list or __gnuc_va_list.
(_IO_BUFSIZ): Delete; all uses changed to BUFSIZ.
(_IO_cookie_io_functions_t): Delete; all uses changed to
cookie_io_functions_t.
(__io_read_fn): Delete; all uses changed to cookie_read_function_t.
(__io_write_fn): Delete; all uses changed to cookie_write_function_t.
(__io_seek_fn): Delete; all uses changed to cookie_seek_function_t.
(__io_close_fn): Delete: all uses changed to cookie_close_function_t.
* libio/iofopncook.c: Remove unnecessary forward declarations.
* libio/iolibio.h: Correct outdated commentary.
* malloc/malloc.c (__malloc_stats): Remove unnecessary casts.
* stdio-common/fxprintf.c (__fxprintf_nocancel):
Remove unnecessary casts.
* stdio-common/getline.c: Use _IO_getdelim directly.
Don't redefine ssize_t.
* stdio-common/printf_fp.c, stdio_common/printf_fphex.c
* stdio-common/printf_size.c: Don't redefine size_t or FILE.
Remove outdated comments.
* stdio-common/vfscanf.c: Don't redefine va_list.
This looks like a post-exploitation hardening measure: If an attacker is
able to redirect execution flow, they could use that to load a DSO which
contains additional code (or perhaps make the stack executable).
However, the checks are not in the correct place to be effective: If
they are performed before the critical operation, an attacker with
sufficient control over execution flow could simply jump directly to
the code which performs the operation, bypassing the check. The check
would have to be executed unconditionally after the operation and
terminate the process in case a caller violation was detected.
Furthermore, in _dl_check_caller, there was a fallback reading global
writable data (GL(dl_rtld_map).l_map_start and
GL(dl_rtld_map).l_text_end), which could conceivably be targeted by an
attacker to disable the check, too.
Other critical functions (such as system) remain completely
unprotected, so the value of these additional checks does not appear
that large. Therefore this commit removes this functionality.
Remove the slow paths from pow. Like several other double precision math
functions, pow is exactly rounded. This is not required from math functions
and causes major overheads as it requires multiple fallbacks using higher
precision arithmetic if a result is close to 0.5ULP. Ridiculous slowdowns
of up to 100000x have been reported when the highest precision path triggers.
All GLIBC math tests pass on AArch64 and x64 (with ULP of pow set to 1).
The worst case error is ~0.506ULP. A simple test over a few hundred million
values shows pow is 10% faster on average. This fixes BZ #13932.
[BZ #13932]
* sysdeps/ieee754/dbl-64/uexp.h (err_1): Remove.
* benchtests/pow-inputs: Update comment for slow path cases.
* manual/probes.texi (slowpow_p10): Delete removed probe.
(slowpow_p10): Likewise.
* math/Makefile: Remove halfulp.c and slowpow.c.
* sysdeps/aarch64/libm-test-ulps: Set ULP of pow to 1.
* sysdeps/generic/math_private.h (__exp1): Remove error argument.
(__halfulp): Remove.
(__slowpow): Remove.
* sysdeps/i386/fpu/halfulp.c: Delete file.
* sysdeps/i386/fpu/slowpow.c: Likewise.
* sysdeps/ia64/fpu/halfulp.c: Likewise.
* sysdeps/ia64/fpu/slowpow.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp.c (__exp1): Remove error argument,
improve comments and add error analysis.
* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Add error analysis.
(power1): Remove function:
(log1): Remove error argument, add error analysis.
(my_log2): Remove function.
* sysdeps/ieee754/dbl-64/halfulp.c: Delete file.
* sysdeps/ieee754/dbl-64/slowpow.c: Likewise.
* sysdeps/m68k/m680x0/fpu/halfulp.c: Likewise.
* sysdeps/m68k/m680x0/fpu/slowpow.c: Likewise.
* sysdeps/powerpc/power4/fpu/Makefile: Remove CPPFLAGS-slowpow.c.
* sysdeps/x86_64/fpu/libm-test-ulps: Set ULP of pow to 1.
* sysdeps/x86_64/fpu/multiarch/Makefile: Remove slowpow-fma.c,
slowpow-fma4.c, halfulp-fma.c, halfulp-fma4.c.
* sysdeps/x86_64/fpu/multiarch/e_pow-fma.c (__slowpow): Remove define.
* sysdeps/x86_64/fpu/multiarch/e_pow-fma4.c (__slowpow): Likewise.
* sysdeps/x86_64/fpu/multiarch/halfulp-fma.c: Delete file.
* sysdeps/x86_64/fpu/multiarch/halfulp-fma4.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowpow-fma.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowpow-fma4.c: Likewise.
As noted in bug 17979 (and as I noted earlier in
<https://sourceware.org/ml/libc-alpha/2012-02/msg00647.html>), uchar.h
has gratuitously complicated code to determine the types for char16_t
and char32_t, and to reject including that header for pre-C11
compilers not defining __CHAR16_TYPE__ and __CHAR32_TYPE__. Since
those types are always required to match uint_least16_t and
uint_least32_t, which glibc knows how to define without reference to
such predefined macros, it's safe just to define those types the same
as the *least* types are defined in stdint.h, so allowing the header
to work with (for example) GCC 4.3.
This patch implements that. bits/types.h is made to define
__int_leastN_t and __uint_leastN_t so the logic for those types can
stay in a single place, and stdint.h is made to use those __*_t to
define the public *_t types. uchar.h is then made to use
__uint_least16_t and __uint_least32_t to define char16_t and char32_t,
so simplifying the logic there. A new test is added that verifies the
types chosen for char16_t and char32_t do indeed match the types the
compiler uses for u"" and U"" string literals.
Tested for x86_64. (I have not tested with any of the older compilers
for which this would actually make a difference to whether you can
include uchar.h.)
[BZ #17979]
* posix/bits/types.h (__int_least8_t): New typedef.
(__uint_least8_t): Likewise.
(__int_least16_t): Likewise.
(__uint_least16_t): Likewise.
(__int_least32_t): Likewise.
(__uint_least32_t): Likewise.
(__int_least64_t): Likewise.
(__uint_least64_t): Likewise.
* sysdeps/generic/stdint.h (int_least8_t): Define using
__int_least8_t.
(int_least16_t): Define using __int_least16_t.
(int_least32_t): Define using __int_least32_t.
(int_least64_t): Define using __int_least64_t.
(uint_least8_t): Define using __uint_least8_t.
(uint_least16_t): Define using __uint_least16_t.
(uint_least32_t): Define using __uint_least32_t.
(uint_least64_t): Define using __uint_least64_t.
* wcsmbs/uchar.h: Include <bits/types.h>.
(char16_t): Define using __uint_least16_t conditional only on
[!__USE_ISOCXX11].
(char32_t): Define using __uint_least32_t conditional only on
[!__USE_ISOCXX11].
* wcsmbs/test-char-types.c: New file.
* wcsmbs/Makefile (tests): Add test-char-types.
Nearly everything in _G_config.h is either junk or more appropriately
defined elsewhere:
* _G_fpos_t, _G_fpos64_t, and _G_BUFSIZ are already completely unused.
* All remaining uses of _G_va_list have been changed to __gnuc_va_list.
* The definition of _G_HAVE_ST_BLKSIZE/_IO_HAVE_ST_BLKSIZE has
been inlined into its sole use.
* The complete definition of _G_iconv_t has been moved to libio.h and
renamed _IO_iconv_t (all actual users used that name).
* _G_IO_IO_FILE_VERSION is vestigial; some code cares whether
_IO_stdin_used exists, but nothing looks at its value. I've
preserved the value as a hardwired constant in csu/init.c.
This means csu/init.c no longer needs to include anything.
* Many of the headers included by _G_config.h were already being
included directly by either either libio.h or stdio.h; the
remaining ones were moved to libio.h.
* _G_HAVE_MREMAP is still relevant, because mremap genuinely is a
Linux extension; it's not in POSIX and as far as I can tell it's
not available on the Hurd either. I also preserved _G_HAVE_MMAP,
since it's conceivable someone would want to port glibc to a
MMU-less, mmap-less environment in the future. Both are now always
defined to 1/0 as is the current convention, instead of the older
1/undef convention. These are the only symbols still defined in
_G_config.h.
* The actual inclusion of _G_config.h moves from libio.h to libioP.h,
as this is where a potential override of _G_HAVE_MMAP happens.
* The #ifdef logic in libioP.h controlling _IO_JUMPS_OFFSET has been
simplified.
After this patch, the only surviving _G_ symbols are the struct tag
names _G_fpos_t and _G_fpos64_t, which are preserved for the sake of
C++ mangled names in applications, and _G_HAVE_MMAP and _G_HAVE_MREMAP,
which do not seem worth renaming.
Installed stripped libraries are unchanged by this patch.
* bits/_G_config.h: Move back to sysdeps/generic/_G_config.h.
Delete all contents except for definitions of _G_HAVE_MMAP and
_G_HAVE_MREMAP. Add commentary explaining those two symbols.
* sysdeps/unix/sysv/linux/bits/_G_config.h: Move back to
sysdeps/unix/sysv/linux/_G_config.h. Make same content
change as above.
* libio/libio.h: Don't include bits/_G_config.h here.
Include stddef.h with __need_wchar_t defined. Include
bits/types/__mbstate_t.h, bits/types/wint_t.h, and gconv.h.
Define _IO_iconv_t here, directly.
Don't define _IO_HAVE_ST_BLKSIZE.
* libio/libioP.h: Include _G_config.h here. Move include of
shlib-compat.h up with rest of includes. Simplify conditionals
controlling definition of _IO_JUMPS_OFFSET.
* csu/init.c: Remove always-true #if around entire file.
Don't include stdio.h. Set _IO_stdin_used to hardwired
constant 0x20001, and update commentary.
* include/stdio.h, sysdeps/ieee754/ldbl-opt/nldbl-compat.h:
Replace all uses of _G_va_list with __gnuc_va_list.
* libio/filedoalloc.c: Use #if defined _STATBUF_ST_BLKSIZE
instead of #if _IO_HAVE_ST_BLKSIZE.
* libio/fileops.c: Test _G_HAVE_MREMAP with #if, not #ifdef.
* libio/iofdopen.c, libio/iofopen.c: Test _G_HAVE_MMAP with #if,
not #ifdef.
The general rule in glibc is that it's better for a macro to be always
defined, and tested with #if, than for it to be tested with #ifdef,
because the latter is prone to typos in the macro name as well as to
the header with the macro accidentally not being included in a file
testing it. (Testing with an "if" statement is even better, in those
cases where it's possible to do things that way, as it then means both
cases in the code get checked for syntax in glibc builds with either
value of the condition.)
math_private.h has several different groups of macros, meaning that
architectures wanting to override some of them need to define those
then include the generic version, which then defines macros if not
already defined. It's hard to avoid that arrangement completely, but
various cases can be improved by splitting out macros or groups of
macros into separate files.
This patch splits out the LDBL_CLASSIFY_COMPAT macro into a separate
ldbl-classify-compat.h header. This macro is tested with #ifdef; this
patch changes it to testing with #if, with a default definition to 0
in the generic header and then architecture-specific headers defining
it to 1.
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by the patch.
* sysdeps/generic/ldbl-classify-compat.h: New file.
* sysdeps/arm/ldbl-classify-compat.h: Likewise.
* sysdeps/m68k/coldfire/ldbl-classify-compat.h: Likewise.
* sysdeps/microblaze/ldbl-classify-compat.h: Likewise.
* sysdeps/mips/ldbl-classify-compat.h: Likewise.
* sysdeps/nios2/ldbl-classify-compat.h: Likewise.
* sysdeps/sh/ldbl-classify-compat.h: Likewise.
* sysdeps/ieee754/dbl-64/s_finite.c: Include
<ldbl-classify-compat.h>.
[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
* sysdeps/ieee754/dbl-64/s_isinf.c: Include
<ldbl-classify-compat.h>.
[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
* sysdeps/ieee754/dbl-64/s_isnan.c: Include
<ldbl-classify-compat.h>.
[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
* sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c: Include
<ldbl-classify-compat.h>.
[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
* sysdeps/ieee754/dbl-64/wordsize-64/s_isinf.c: Include
<ldbl-classify-compat.h>.
[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
* sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c: Include
<ldbl-classify-compat.h>.
[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
* sysdeps/arm/math_private.h (LDBL_CLASSIFY_COMPAT): Remove macro.
* sysdeps/mips/math_private.h (LDBL_CLASSIFY_COMPAT): Likewise.
* sysdeps/m68k/coldfire/math_private.h: Remove file.
* sysdeps/microblaze/math_private.h: Likewise.
* sysdeps/nios2/math_private.h: Likewise.
* sysdeps/sh/math_private.h: Likewise.
Continuing the process of improving and cleaning up the handling of
configurations lacking support for floating-point exceptions and
rounding modes, this patch adds trivial inline definitions of
feholdexcept and __feholdexcept to the set of inlines for such
configurations in math_private.h. These inlines were missing from the
tile version used as a basis for the previous inlines, despite a few
such function calls ending up in libm.so.
Tested with build-many-glibcs.py. As expected, installed stripped
shared libraries are unchanged for architectures supporting exceptions
and rounding modes, but changed for architectures lacking such
support.
* sysdeps/generic/math_private.h
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (feholdexcept):
New inline function.
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (__feholdexcept):
Likewise.
The tile version of math_private.h defines some inline functions for
fenv.h functions, to optimize away internal calls to these functions
that do nothing given no support for floating-point exceptions and
rounding modes. (Some functions may have error cases for invalid
arguments, but those aren't applicable to the internal calls from
within glibc.) Other configurations lacking support for exceptions
and rounding modes lack such inline functions. This patch moves them
to the generic math_private.h, appropriately conditioned, so that all
such configurations can benefit from the.
include/fenv.h is made to check whether there are any non-default
rounding modes; that needs to be done there, rather than later,
because get-rounding-mode.h defines values for otherwise unsupported
FE_* rounding modes. It also gives an error for FE_TONEAREST
undefined, a case that already did not work for building the glibc
testsuite; the convention has by now been established that all
architectures need to provide a version of bits/fenv.h that at least
defines FE_TONEAREST.
Tested with build-many-glibcs.py. As expected, installed stripped
shared libraries are unchanged for tile and for architectures
supporting exceptions and rounding modes, but changed for non-tile
architectures not supporting exceptions and rounding modes that
previously lacked this optimization (e.g. Nios II libm.so is about 1kB
smaller).
The optimization is not in fact complete (does not cover feholdexcept
/ __feholdexcept, so a few calls to those remain unnecessarily within
libm even after this patch), but that can be dealt with separately.
* include/fenv.h [!_ISOMAC && !FE_TONEAREST]: Give #error.
[!_ISOMAC] (FE_HAVE_ROUNDING_MODES): New macro.
* sysdeps/generic/math_private.h
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (fegetenv): New
inline function.
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (__fegetenv):
Likewise.
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (fesetenv):
Likewise.
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (__fesetenv):
Likewise.
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (feupdateenv):
Likewise.
[!FE_HAVE_ROUNDING_MODES && FE_ALL_EXCEPT == 0] (__feupdateenv):
Likewise.
[!FE_HAVE_ROUNDING_MODES] (fegetround): Likewise.
[!FE_HAVE_ROUNDING_MODES] (__fegetround): Likewise.
[!FE_HAVE_ROUNDING_MODES] (fesetround): Likewise.
[!FE_HAVE_ROUNDING_MODES] (__fesetround): Likewise.
* sysdeps/tile/math_private.h (fegetenv): Remove inline function.
(__fegetenv): Likewise.
(fesetenv): Likewise.
(__fesetenv): Likewise.
(feupdateenv): Likewise.
(__feupdateenv): Likewise.
(fegetround): Likewise.
(__fegetround): Likewise.
(fesetround): Likewise.
(__fesetround): Likewise.
Various configurations lacking support for floating-point exceptions
and rounding modes have a math_private.h that overrides certain
functions and macros, internal and external, to avoid references to
FE_* constants that are undefined in those configurations. For
example, there are unconditional feraiseexcept (FE_INVALID) calls in
generic libm code, and these macro definitions duly define
feraiseexcept to ignore its argument to avoid an error from FE_INVALID
being undefined.
In fact it is easy to tell in an architecture-independent way whether
this is needed, by testing whether FE_ALL_EXCEPT == 0. Thus, this
patch puts such a test, and feraiseexcept and __feraiseexcept macros,
in the generic math_private.h, so reducing the duplication between
architecture versions of this header. The feclearexcept macro present
in several versions of this header, and fetestexcept in the tile
version, are not needed; they would have been needed before there were
proper soft-fp fma implementations (when generic versions, that depend
on FE_TOWARDZERO and FE_INEXACT, were being used for configurations
not supporting those features), but aren't needed any more, and so are
removed.
The tile version of this header has several inline functions for
fenv.h functions to optimize calls to them away in such configurations
where they do nothing useful, and all these header versions also have
definitions of some of the libc_fe* internal macros. I intend to make
those generic in subsequent patches.
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch.
* sysdeps/generic/math_private.h [FE_ALL_EXCEPT == 0]
(feraiseexcept): New macro.
[FE_ALL_EXCEPT == 0] (__feraiseexcept): Likewise.
* sysdeps/m68k/coldfire/nofpu/math_private.h (feraiseexcept):
Remove macro.
(__feraiseexcept): Likewise.
(feclearexcept): Likewise.
* sysdeps/microblaze/math_private.h (feraiseexcept): Likewise.
(__feraiseexcept): Likewise.
(feclearexcept): Likewise.
* sysdeps/nios2/math_private.h (feraiseexcept): Likewise.
(__feraiseexcept): Likewise.
(feclearexcept): Likewise.
* sysdeps/tile/math_private.h (feraiseexcept): Likewise.
(__feraiseexcept): Likewise.
(feclearexcept): Likewise.
(fetestexcept): Likewise.
* hurd/hurd.h (__hurd_fail): Always declare function, and provide inline
version only if __USE_EXTERN_INLINES is defined.
* hurd/hurd/fd.h (_hurd_fd_error_signal, _hurd_fd_error, __hurd_dfail,
__hurd_sockfail): Likewise.
(_hurd_fd_get): Always declare functions, and provide inline versions
only if __USE_EXTERN_INLINES and _LIBC are defined and IS_IN(libc).
* hurd/hurd/port.h (_hurd_port_init, _hurd_port_locked_get,
_hurd_port_get, _hurd_port_free, _hurd_port_locked_set,
_hurd_port_set): Always declare functions, and provide inline versions
only if __USE_EXTERN_INLINES and _LIBC are defined and
IS_IN(libc).
* hurd/hurd/signal.h (_hurd_self_sigstate, _hurd_critical_section_lock,
_hurd_critical_section_unlock): Likewise.
* hurd/hurd/threadvar.h (__hurd_threadvar_location_from_sp,
* __hurd_threadvar_location): Likewise.
* hurd/hurd/userlink.h (_hurd_userlink_link, _hurd_userlink_unlink,
_hurd_userlink_clear): Likewise.
* mach/lock-intern.h (__spin_lock_init, __spin_lock, __mutex_lock,
__mutex_unlock, __mutex_trylock): Always declare functions, and provide
inline versions only if __USE_EXTERN_INLINES and _LIBC are defined.
* mach/mach/mig_support.h (__mig_strncpy): Likewise.
* sysdeps/generic/machine-lock.h (__spin_unlock, __spin_try_lock,
__spin_lock_locked): Likewise.
* sysdeps/mach/i386/machine-lock.h (__spin_unlock, __spin_try_lock,
__spin_lock_locked): Likewise.
* mach/spin-lock.c (__USE_EXTERN_INLINES): Define to 1.
* hurd/Versions (libc: GLIBC_2.27): Add _hurd_fd_error_signal,
_hurd_fd_error, __hurd_dfail, __hurd_sockfail, _hurd_port_locked_set,
__hurd_threadvar_location_from_sp, __hurd_threadvar_location,
_hurd_userlink_link, _hurd_userlink_unlink, _hurd_userlink_clear.
The RISC-V port defines ELF flags that enforce compatibility between
various objects. This adds the shared support necessary for these
flags.
2018-01-25 Palmer Dabbelt <palmer@sifive.com>
* elf/cache.c (print_entry): Add FLAG_RISCV_FLOAT_ABI_SOFT and
FLAG_RISCV_FLOAT_ABI_DOUBLE.
* elf/elf.h (EF_RISCV_RVC): New define.
(EF_RISCV_FLOAT_ABI): Likewise.
(EF_RISCV_FLOAT_ABI_SOFT): Likewise.
(EF_RISCV_FLOAT_ABI_SINGLE): Likewise.
(EF_RISCV_FLOAT_ABI_DOUBLE): Likewise.
(EF_RISCV_FLOAT_ABI_QUAD): Likewise.
* sysdeps/generic/ldconfig.h (FLAG_RISCV_FLOAT_ABI_SOFT): New
define.
(FLAG_RISCV_FLOAT_ABI_DOUBLE): Likewise.
For soft-float powerpc, the math/test-nearbyint-except-2 test fails
because nearbyintl traps when traps on "inexact" are enabled on entry
(and an "inexact" exception is generated internally, though cleared
for the final return).
The problem is the default implementation of
libc_feholdsetround_noex_ctx, which does not disable exception traps.
There is some ambiguity about whether the *noex* interfaces are
required to do so or only permitted to do so. But given that we
support fe* interfaces to enable and disable traps (on architectures
with that functionality), functions that must not raise an exception
(must not leave the flag set on exit if not set on entry) should also
not trap on it when traps on that exception are enabled. So it is
appropriate to define these interfaces to have the feholdexcept effect
of disabling exception traps; this patch updates the default
implementation and comments accordingly.
At least some architecture versions already disable traps; there are
few uses of the *noex* interfaces at all, and while it's possible
there are bugs on any architecture versions failing to disable traps
that appear in the exp2 and remainder implementations, there are
currently no tests, other than this one for nearbyintl (where only the
ldbl-128ibm implementation uses SET_RESTORE_ROUND_NOEX), that would
fail as a result of such a bug. (Hard-float powerpc does disable
traps here, hence the nearbyintl failure not appearing there.)
Tested for powerpc (soft-float). This brings that configuration to
clean math/ test results, provided you build with GCC 8 to get the fix
for GCC bug 64811.
[BZ #22702]
* sysdeps/generic/math_private.h (libc_feresetround_noex): Update
comment to say exceptions are discarded.
(libc_feholdsetround_noex_ctx): Use __feholdexcept instead of
__fegetenv.
(SET_RESTORE_ROUND_NOEX): Update comment to say non-stop mode must
be enabled.
is_path argument is no longer used and could be safely removed.
* elf/dl-dst.h (DL_DST_COUNT): Remove is_path argument, all callers
updated.
* elf/dl-load.c (is_dst, _dl_dst_count, _dl_dst_substitute,
expand_dynamic_string_token): Likewise.
* sysdeps/generic/ldsodefs.h (_dl_dst_count, _dl_dst_substitute): Remove
is_path argument.
libio.h was originally the header for a set of supported GNU
extensions, but they have not been maintained as such in many years,
they are now standing in the way of improvements to stdio, and we
don't think there are any remaining external users. _G_config.h was
never intended for public use, but predates the bits convention.
Move both of these headers into the bits directory and provide stubs
at top level which issue deprecation warnings.
The contents of (bits/)libio.h and (bits/)_G_config.h are still
exposed to external software via stdio.h; changing that requires more
complex surgery than I have time to attempt right now.
* libio/libio.h, libio/_G_config.h: New stub headers which issue a
deprecation warning and then include <bits/libio.h>, <bits/_G_config.h>
respectively.
* libio/libio.h: Rename the original version of this file to
libio/bits/libio.h. Error out if not included by stdio.h or the
stub libio.h.
* include/libio.h: Move to include/bits. Forward to libio/bits/libio.h.
* sysdeps/generic/_G_config.h: Move to top-level bits/. Error out
if not included by bits/libio.h or the stub _G_config.h.
* sysdeps/unix/sysv/linux/_G_config.h: Move to
sysdeps/unix/sysv/linux/bits. Error out if not included by
bits/libio.h or the stub _G_config.h.
* libio/stdio.h: Include bits/libio.h, not libio.h.
* libio/Makefile: Install bits/libio.h and bits/_G_config.h as
well as libio.h and _G_config.h.
* csu/init.c, libio/fmemopen.c, libio/iolibio.h, libio/oldfmemopen.c
* libio/strfile.h, stdio-common/vfscanf.c
* sysdeps/pthread/flockfile.c, sysdeps/pthread/funlockfile.c
Include stdio.h, not _G_config.h nor libio.h.
* libio/iofgetpos.c: Also rename fgetpos64 out of the way.
* libio/iofsetpos.c: Also rename fsetpos64 out of the way.
* scripts/check-installed-headers.sh: Skip libio.h and _G_config.h.
These changes will be active for all platforms that don't provide
their own exp() routines. They will also be active for ieee754
versions of ccos, ccosh, cosh, csin, csinh, sinh, exp10, gamma, and
erf.
Typical performance gains is typically around 5x when measured on
Sparc s7 for common values between exp(1) and exp(40).
Using the glibc perf tests on sparc,
sparc (nsec) x86 (nsec)
old new old new
max 17629 395 5173 144
min 399 54 15 13
mean 5317 200 1349 23
The extreme max times for the old (ieee754) exp are due to the
multiprecision computation in the old algorithm when the true value is
very near 0.5 ulp away from an value representable in double
precision. The new algorithm does not take special measures for those
cases. The current glibc exp perf tests overrepresent those values.
Informal testing suggests approximately one in 200 cases might
invoke the high cost computation. The performance advantage of the new
algorithm for other values is still large but not as large as indicated
by the chart above.
Glibc correctness tests for exp() and expf() were run. Within the
test suite 3 input values were found to cause 1 bit differences (ulp)
when "FE_TONEAREST" rounding mode is set. No differences in exp() were
seen for the tested values for the other rounding modes.
Typical example:
exp(-0x1.760cd2p+0) (-1.46113312244415283203125)
new code: 2.31973271630014299393707e-01 0x1.db14cd799387ap-3
old code: 2.31973271630014271638132e-01 0x1.db14cd7993879p-3
exp = 2.31973271630014285508337 (high precision)
Old delta: off by 0.49 ulp
New delta: off by 0.51 ulp
In addition, because ieee754_exp() is used by other routines, cexp()
showed test results with very small imaginary input values where the
imaginary portion of the result was off by 3 ulp when in upward
rounding mode, but not in the other rounding modes. For x86, tgamma
showed a few values where the ulp increased to 6 (max ulp for tgamma
is 5). Sparc tgamma did not show these failures. I presume the tgamma
differences are due to compiler optimization differences within the
gamma function.The gamma function is known to be difficult to compute
accurately.
* sysdeps/ieee754/dbl-64/e_exp.c: Include <math-svid-compat.h> and
<errno.h>. Include "eexp.tbl".
(half): New constant.
(one): Likewise.
(__ieee754_exp): Rewrite.
(__slowexp): Remove prototype.
* sysdeps/ieee754/dbl-64/eexp.tbl: New file.
* sysdeps/ieee754/dbl-64/slowexp.c: Remove file.
* sysdeps/i386/fpu/slowexp.c: Likewise.
* sysdeps/ia64/fpu/slowexp.c: Likewise.
* sysdeps/m68k/m680x0/fpu/slowexp.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowexp-avx.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowexp-fma.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowexp-fma4.c: Likewise.
* sysdeps/generic/math_private.h (__slowexp): Remove prototype.
* sysdeps/ieee754/dbl-64/e_pow.c: Remove mention of slowexp.c in
comment.
* sysdeps/powerpc/power4/fpu/Makefile [$(subdir) = math]
(CPPFLAGS-slowexp.c): Remove variable.
* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):
Remove slowexp-fma, slowexp-fma4 and slowexp-avx.
(CFLAGS-slowexp-fma.c): Remove variable.
(CFLAGS-slowexp-fma4.c): Likewise.
(CFLAGS-slowexp-avx.c): Likewise.
* sysdeps/x86_64/fpu/multiarch/e_exp-avx.c (__slowexp): Do not
define as macro.
* sysdeps/x86_64/fpu/multiarch/e_exp-fma.c (__slowexp): Likewise.
* sysdeps/x86_64/fpu/multiarch/e_exp-fma4.c (__slowexp): Likewise.
* math/Makefile (type-double-routines): Remove slowexp.
* manual/probes.texi (slowexp_p6): Remove.
(slowexp_p32): Likewise.
GLRO (_rtld_global_ro) is read-only after initialization and can
therefore not be patched at run time, unlike the hook table addresses
and their contents, so this is a desirable hardening feature.
The hooks are only needed if ld.so has not been initialized, and this
happens only after static dlopen (dlmopen uses a single ld.so object
across all namespaces).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Static PIE extends address space layout randomization to static
executables. It provides additional security hardening benefits at
the cost of some memory and performance.
Dynamic linker, ld.so, is a standalone program which can be loaded at
any address. This patch adds a configure option, --enable-static-pie,
to embed the part of ld.so in static executable to create static position
independent executable (static PIE). A static PIE is similar to static
executable, but can be loaded at any address without help from a dynamic
linker. When --enable-static-pie is used to configure glibc, libc.a is
built as PIE and all static executables, including tests, are built as
static PIE. The resulting libc.a can be used together with GCC 8 or
above to build static PIE with the compiler option, -static-pie. But
GCC 8 isn't required to build glibc with --enable-static-pie. Only GCC
with PIE support is needed. When an older GCC is used to build glibc
with --enable-static-pie, proper input files are passed to linker to
create static executables as static PIE, together with "-z text" to
prevent dynamic relocations in read-only segments, which are not allowed
in static PIE.
The following changes are made for static PIE:
1. Add a new function, _dl_relocate_static_pie, to:
a. Get the run-time load address.
b. Read the dynamic section.
c. Perform dynamic relocations.
Dynamic linker also performs these steps. But static PIE doesn't load
any shared objects.
2. Call _dl_relocate_static_pie at entrance of LIBC_START_MAIN in
libc.a. crt1.o, which is used to create dynamic and non-PIE static
executables, is updated to include a dummy _dl_relocate_static_pie.
rcrt1.o is added to create static PIE, which will link in the real
_dl_relocate_static_pie. grcrt1.o is also added to create static PIE
with -pg. GCC 8 has been updated to support rcrt1.o and grcrt1.o for
static PIE.
Static PIE can work on all architectures which support PIE, provided:
1. Target must support accessing of local functions without dynamic
relocations, which is needed in start.S to call __libc_start_main with
function addresses of __libc_csu_init, __libc_csu_fini and main. All
functions in static PIE are local functions. If PIE start.S can't reach
main () defined in a shared object, the code sequence:
pass address of local_main to __libc_start_main
...
local_main:
tail call to main via PLT
can be used.
2. start.S is updated to check PIC instead SHARED for PIC code path and
avoid dynamic relocation, when PIC is defined and SHARED isn't defined,
to support static PIE.
3. All assembly codes are updated check PIC instead SHARED for PIC code
path to avoid dynamic relocations in read-only sections.
4. All assembly codes are updated check SHARED instead PIC for static
symbol name.
5. elf_machine_load_address in dl-machine.h are updated to support static
PIE.
6. __brk works without TLS nor dynamic relocations in read-only section
so that it can be used by __libc_setup_tls to initializes TLS in static
PIE.
NB: When glibc is built with GCC defaulted to PIE, libc.a is compiled
with -fPIE, regardless if --enable-static-pie is used to configure glibc.
When glibc is configured with --enable-static-pie, libc.a is compiled
with -fPIE, regardless whether GCC defaults to PIE or not. The same
libc.a can be used to build both static executable and static PIE.
There is no need for separate PIE copy of libc.a.
On x86-64, the normal static sln:
text data bss dec hex filename
625425 8284 5456 639165 9c0bd elf/sln
the static PIE sln:
text data bss dec hex filename
657626 20636 5392 683654 a6e86 elf/sln
The code size is increased by 5% and the binary size is increased by 7%.
Linker requirements to build glibc with --enable-static-pie:
1. Linker supports --no-dynamic-linker to remove PT_INTERP segment from
static PIE.
2. Linker can create working static PIE. The x86-64 linker needs the
fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=21782
The i386 linker needs to be able to convert "movl main@GOT(%ebx), %eax"
to "leal main@GOTOFF(%ebx), %eax" if main is defined locally.
Binutils 2.29 or above are OK for i686 and x86-64. But linker status for
other targets need to be verified.
3. Linker should resolve undefined weak symbols to 0 in static PIE:
https://sourceware.org/bugzilla/show_bug.cgi?id=22269
4. Many ELF backend linkers incorrectly check bfd_link_pic for TLS
relocations, which should check bfd_link_executable instead:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
Tested on aarch64, i686 and x86-64.
Using GCC 7 and binutils master branch, build-many-glibcs.py with
--enable-static-pie with all patches for static PIE applied have the
following build successes:
PASS: glibcs-aarch64_be-linux-gnu build
PASS: glibcs-aarch64-linux-gnu build
PASS: glibcs-armeb-linux-gnueabi-be8 build
PASS: glibcs-armeb-linux-gnueabi build
PASS: glibcs-armeb-linux-gnueabihf-be8 build
PASS: glibcs-armeb-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabi build
PASS: glibcs-arm-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabihf-v7a build
PASS: glibcs-arm-linux-gnueabihf-v7a-disable-multi-arch build
PASS: glibcs-m68k-linux-gnu build
PASS: glibcs-microblazeel-linux-gnu build
PASS: glibcs-microblaze-linux-gnu build
PASS: glibcs-mips64el-linux-gnu-n32 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n32-soft build
PASS: glibcs-mips64el-linux-gnu-n64 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n64-soft build
PASS: glibcs-mips64-linux-gnu-n32 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n32-soft build
PASS: glibcs-mips64-linux-gnu-n64 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n64-soft build
PASS: glibcs-mipsel-linux-gnu build
PASS: glibcs-mipsel-linux-gnu-nan2008 build
PASS: glibcs-mipsel-linux-gnu-nan2008-soft build
PASS: glibcs-mipsel-linux-gnu-soft build
PASS: glibcs-mips-linux-gnu build
PASS: glibcs-mips-linux-gnu-nan2008 build
PASS: glibcs-mips-linux-gnu-nan2008-soft build
PASS: glibcs-mips-linux-gnu-soft build
PASS: glibcs-nios2-linux-gnu build
PASS: glibcs-powerpc64le-linux-gnu build
PASS: glibcs-powerpc64-linux-gnu build
PASS: glibcs-tilegxbe-linux-gnu-32 build
PASS: glibcs-tilegxbe-linux-gnu build
PASS: glibcs-tilegx-linux-gnu-32 build
PASS: glibcs-tilegx-linux-gnu build
PASS: glibcs-tilepro-linux-gnu build
and the following build failures:
FAIL: glibcs-alpha-linux-gnu build
elf/sln is failed to link due to:
assertion fail bfd/elf64-alpha.c:4125
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-hppa-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault]
https://sourceware.org/bugzilla/show_bug.cgi?id=22537
FAIL: glibcs-ia64-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault]
FAIL: glibcs-powerpc-linux-gnu build
FAIL: glibcs-powerpc-linux-gnu-soft build
FAIL: glibcs-powerpc-linux-gnuspe build
FAIL: glibcs-powerpc-linux-gnuspe-e500v1 build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22264
FAIL: glibcs-powerpc-linux-gnu-power4 build
elf/sln is failed to link due to:
findlocale.c:96:(.text+0x22c): @local call to ifunc memchr
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-s390-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped
assertion fail bfd/elflink.c:14299
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-sh3eb-linux-gnu build
FAIL: glibcs-sh3-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu-soft build
FAIL: glibcs-sh4-linux-gnu build
FAIL: glibcs-sh4-linux-gnu-soft build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
Also TLS code sequence in SH assembly syscalls in glibc doesn't match TLS
code sequence expected by ld:
https://sourceware.org/bugzilla/show_bug.cgi?id=22270
FAIL: glibcs-sparc64-linux-gnu build
FAIL: glibcs-sparcv9-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu-32 build
FAIL: glibcs-tilegx-linux-gnu build
FAIL: glibcs-tilegx-linux-gnu-32 build
FAIL: glibcs-tilepro-linux-gnu build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
[BZ #19574]
* INSTALL: Regenerated.
* Makeconfig (real-static-start-installed-name): New.
(pic-default): Updated for --enable-static-pie.
(pie-default): New for --enable-static-pie.
(default-pie-ldflag): Likewise.
(+link-static-before-libc): Replace $(DEFAULT-LDFLAGS-$(@F))
with $(if $($(@F)-no-pie),$(no-pie-ldflag),$(default-pie-ldflag)).
Replace $(static-start-installed-name) with
$(real-static-start-installed-name).
(+prectorT): Updated for --enable-static-pie.
(+postctorT): Likewise.
(CFLAGS-.o): Add $(pie-default).
(CFLAGS-.op): Likewise.
* NEWS: Mention --enable-static-pie.
* config.h.in (ENABLE_STATIC_PIE): New.
* configure.ac (--enable-static-pie): New configure option.
(have-no-dynamic-linker): New LIBC_CONFIG_VAR.
(have-static-pie): Likewise.
Enable static PIE if linker supports --no-dynamic-linker.
(ENABLE_STATIC_PIE): New AC_DEFINE.
(enable-static-pie): New LIBC_CONFIG_VAR.
* configure: Regenerated.
* csu/Makefile (omit-deps): Add r$(start-installed-name) and
gr$(start-installed-name) for --enable-static-pie.
(extra-objs): Likewise.
(install-lib): Likewise.
(extra-objs): Add static-reloc.o and static-reloc.os
($(objpfx)$(start-installed-name)): Also depend on
$(objpfx)static-reloc.o.
($(objpfx)r$(start-installed-name)): New.
($(objpfx)g$(start-installed-name)): Also depend on
$(objpfx)static-reloc.os.
($(objpfx)gr$(start-installed-name)): New.
* csu/libc-start.c (LIBC_START_MAIN): Call _dl_relocate_static_pie
in libc.a.
* csu/libc-tls.c (__libc_setup_tls): Add main_map->l_addr to
initimage.
* csu/static-reloc.c: New file.
* elf/Makefile (routines): Add dl-reloc-static-pie.
(elide-routines.os): Likewise.
(DEFAULT-LDFLAGS-tst-tls1-static-non-pie): Removed.
(tst-tls1-static-non-pie-no-pie): New.
* elf/dl-reloc-static-pie.c: New file.
* elf/dl-support.c (_dl_get_dl_main_map): New function.
* elf/dynamic-link.h (ELF_DURING_STARTUP): Also check
STATIC_PIE_BOOTSTRAP.
* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
* gmon/Makefile (tests): Add tst-gmon-static-pie.
(tests-static): Likewise.
(DEFAULT-LDFLAGS-tst-gmon-static): Removed.
(tst-gmon-static-no-pie): New.
(CFLAGS-tst-gmon-static-pie.c): Likewise.
(CRT-tst-gmon-static-pie): Likewise.
(tst-gmon-static-pie-ENV): Likewise.
(tests-special): Likewise.
($(objpfx)tst-gmon-static-pie.out): Likewise.
(clean-tst-gmon-static-pie-data): Likewise.
($(objpfx)tst-gmon-static-pie-gprof.out): Likewise.
* gmon/tst-gmon-static-pie.c: New file.
* manual/install.texi: Document --enable-static-pie.
* sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New.
(_dl_get_dl_main_map): Likewise.
* sysdeps/i386/configure.ac: Check if linker supports static PIE.
* sysdeps/x86_64/configure.ac: Likewise.
* sysdeps/i386/configure: Regenerated.
* sysdeps/x86_64/configure: Likewise.
* sysdeps/mips/Makefile (ASFLAGS-.o): Add $(pie-default).
(ASFLAGS-.op): Likewise.
This patch makes the libm_alias_float macro support creating _Float32
aliases, in preparation for enabling glibc support for that type.
Tested for x86_64; also tested with build-many-glibcs.py in
conjunction with other _Float32 changes.
* sysdeps/generic/libm-alias-float.h: Include <bits/floatn.h>.
[__HAVE_FLOAT32 && !__HAVE_DISTINCT_FLOAT32]
(libm_alias_float_other_r): Create f32 alias.
(libm_alias_float_r): Use semicolon before call to
libm_alias_float_other_r.
This patch makes the libm_alias_double macros support creating
_Float64 and _Float32x aliases, in preparation for enabling glibc
support for those types.
Tested for x86_64; also tested with build-many-glibcs.py in
conjunction with other _Float64 / _Float32x changes.
* sysdeps/generic/libm-alias-double.h: Include <bits/floatn.h>.
(libm_alias_double_other_r_f64): New macro.
(libm_alias_double_other_r_f32x): Likewise.
(libm_alias_double_other_r): Use libm_alias_double_other_r_f64 and
libm_alias_double_other_r_f32x.
(libm_alias_double_r): Use semicolon before call to
libm_alias_double_other_r.
* sysdeps/ieee754/ldbl-opt/libm-alias-double.h: Include
<bits/floatn.h>.
(libm_alias_double_other_r_f64): New macro.
(libm_alias_double_other_r_f32x): Likewise.
(libm_alias_double_other_r): Use libm_alias_double_other_r_f64 and
libm_alias_double_other_r_f32x.
H.J. Lu
Adhemerval Zanella
Florian Weimer
Tulio Magno Quites Machado Filho
Joseph Myers
Maciej W. Rozycki
Zack Weinberg
Samuel Thibault
Wilco Dijkstra
Szabolcs Nagy
Palmer Dabbelt
Dmitry V. Levin
Patrick McGehearty