As described in BZ#20558, bzero and bcopy declaration can only benefit
from fortified macros when decl came from string.h and when __USE_MISC
is defined (default behaviour).
This is due no standard includes those functions in string.h, so they
are only declared if __USE_MISC is defined (as pointed out in comment 4).
However fortification should be orthogona to other features test macros,
i.e, any function should be fortified if that function is declared.
To fix this behavior, the patch moved the bzero, bcopy, and
__explicit_bzero_chk to a common header (string/bits/strings_fortified.h)
and explicit fortified inclusion macros similar to string.h is added
on strings.h. This allows to get fortified declarions by only including
strings.h.
Checked on x86_64-linux-gnu and along on a bootstrap installation to check
if the fortified are correctly triggered with example from bug report.
[BZ #20558]
* string/bits/string3.h [__USE_MISC] (bcopy): Move to
strings_fortified.h.
[__USE_MISC] (bzero): Likewise.
[__USE_MISC] (explicit_bzero): Likewise.
* string/strings.h: Include strings_fortified.h.
* string/Makefile (headers): Add strings_fortified.h.
* string/bits/strings_fortified.h: New file.
* include/bits/strings_fortified.h: Likewise.
This change also removes the preprocessor-based function renaming.
It also applied to tests in resolv/, which ended up running against
the historic functions.
_endhtent was not part of the ABI because it is not listed in the
resolv/Versions file.
When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.
We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves. (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
TS 18661-1 defines roundeven functions that round a floating-point
number to the nearest integer, in that floating-point type, with ties
rounding to even (whereas the round functions round ties away from
zero). As with other such functions, they raise no exceptions apart
from "invalid" for signaling NaNs. There was a previous user request
for this functionality in glibc in
<https://sourceware.org/ml/libc-help/2015-02/msg00005.html>.
This patch implements these functions for glibc. The implementations
use integer bit-manipulation (or roundeven on the high and low parts,
in the IBM long double case). It's possible that there may be faster
approaches on some architectures (in particular, on AArch64 the frintn
instruction should do exactly what's required); I'll leave it to
architecture maintainers or others interested to implement such
architecture-specific versions if desired. (Where architectures have
instructions to round to nearest integer in the current rounding mode,
implementations saving and restoring the rounding mode - and dealing
with exceptions if those instructions generate "inexact" - are also
possible, though their performance depends on the cost of manipulating
exceptions / rounding mode state.)
Tested for x86_64, x86, mips64 and powerpc.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(roundeven): New declaration.
* math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (roundeven): New
macro.
* math/Versions (roundeven): New libm symbol at version
GLIBC_2.25.
(roundevenf): Likewise.
(roundevenl): Likewise.
* math/Makefile (libm-calls): Add s_roundevenF.
* math/libm-test.inc (roundeven_test_data): New array.
(roundeven_test): New function.
(main): Call roundeven_test.
* math/test-tgmath.c (NCALLS): Increase to 134.
(F(compile_test)): Call roundeven.
(F(roundeven)): New function.
* manual/arith.texi (Rounding Functions): Document roundeven,
roundevenf and roundevenl.
* manual/libm-err-tab.pl (@all_functions): Add roundeven.
* include/math.h (roundeven): Use libm_hidden_proto.
* sysdeps/ieee754/dbl-64/s_roundeven.c: New file.
* sysdeps/ieee754/dbl-64/wordsize-64/s_roundeven.c: Likewise.
* sysdeps/ieee754/flt-32/s_roundevenf.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_roundevenl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_roundevenl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_roundevenl.c: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add
roundeven.
(CFLAGS-nldbl-roundeven.c): New variable.
* sysdeps/ieee754/ldbl-opt/nldbl-roundeven.c: New file.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
explicit_bzero(s, n) is the same as memset(s, 0, n), except that the
compiler is not allowed to delete a call to explicit_bzero even if the
memory pointed to by 's' is dead after the call. Right now, this effect
is achieved externally by having explicit_bzero be a function whose
semantics are unknown to the compiler, and internally, with a no-op
asm statement that clobbers memory. This does mean that small
explicit_bzero operations cannot be expanded inline as small memset
operations can, but on the other hand, small memset operations do get
deleted by the compiler. Hopefully full compiler support for
explicit_bzero will happen relatively soon.
There are two new tests: test-explicit_bzero.c verifies the
visible semantics in the same way as the existing test-bzero.c,
and tst-xbzero-opt.c verifies the not-being-optimized-out property.
The latter is conceptually based on a test written by Matthew Dempsky
for the OpenBSD regression suite.
The crypt() implementation has an immediate use for this new feature.
We avoid having to add a GLIBC_PRIVATE alias for explicit_bzero
by running all of libcrypt's calls through the fortified variant,
__explicit_bzero_chk, which is in the impl namespace anyway. Currently
I'm not aware of anything in libc proper that needs this, but the
glue is all in place if it does become necessary. The legacy DES
implementation wasn't bothering to clear its buffers, so I added that,
mostly for consistency's sake.
* string/explicit_bzero.c: New routine.
* string/test-explicit_bzero.c, string/tst-xbzero-opt.c: New tests.
* string/Makefile (routines, strop-tests, tests): Add them.
* string/test-memset.c: Add ifdeffage for testing explicit_bzero.
* string/string.h [__USE_MISC]: Declare explicit_bzero.
* debug/explicit_bzero_chk.c: New routine.
* debug/Makefile (routines): Add it.
* debug/tst-chk1.c: Test fortification of explicit_bzero.
* string/bits/string3.h: Fortify explicit_bzero.
* manual/string.texi: Document explicit_bzero.
* NEWS: Mention addition of explicit_bzero.
* crypt/crypt-entry.c (__crypt_r): Clear key-dependent intermediate
data before returning, using explicit_bzero.
* crypt/md5-crypt.c (__md5_crypt_r): Likewise.
* crypt/sha256-crypt.c (__sha256_crypt_r): Likewise.
* crypt/sha512-crypt.c (__sha512_crypt_r): Likewise.
* include/string.h: Redirect internal uses of explicit_bzero
to __explicit_bzero_chk[_internal].
* string/Versions [GLIBC_2.25]: Add explicit_bzero.
* debug/Versions [GLIBC_2.25]: Add __explicit_bzero_chk.
* sysdeps/arm/nacl/libc.abilist
* sysdeps/unix/sysv/linux/aarch64/libc.abilist
* sysdeps/unix/sysv/linux/alpha/libc.abilist
* sysdeps/unix/sysv/linux/arm/libc.abilist
* sysdeps/unix/sysv/linux/hppa/libc.abilist
* sysdeps/unix/sysv/linux/i386/libc.abilist
* sysdeps/unix/sysv/linux/ia64/libc.abilist
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
* sysdeps/unix/sysv/linux/microblaze/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
* sysdeps/unix/sysv/linux/nios2/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
* sysdeps/unix/sysv/linux/sh/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist:
Add entries for explicit_bzero and __explicit_bzero_chk.
For many years, the only effect of these macros has been to make
unistd.h declare getlogin_r. _POSIX_C_SOURCE >= 199506L also causes
this function to be declared. However, people who don't carefully
read all the headers might be confused into thinking they need to
define _REENTRANT for any threaded code (as was indeed the case a long
time ago).
Therefore, remove __USE_REENTRANT, and make _REENTRANT and _THREAD_SAFE
into synonyms for _POSIX_C_SOURCE=199506L. This will only affect
programs that don't select a higher conformance level some other way.
For instance, -std=c89 -D_REENTRANT will see a change in visible
declarations, but -std=c99 -D_POSIX_C_SOURCE=200809L -D_REENTRANT won't,
and -D_REENTRANT all by itself also won't, because _DEFAULT_SOURCE
implies _POSIX_C_SOURCE > 199506.
* include/features.h: Remove __USE_REENTRANT. Treat _REENTRANT
and _THREAD_SAFE the same as _POSIX_C_SOURCE=199506L, if a higher
POSIX conformance level has not been selected by other macros.
* NEWS, manual/creature.texi: Document this change.
* posix/unistd.h, posix/bits/unistd.h: Don't check __USE_REENTRANT.
* include/libc-symbols.h: Don't define _REENTRANT.
* scripts/check-installed-headers.sh: Don't undefine _REENTRANT.
This uses atomic operations to access lock elision metadata that is accessed
concurrently (ie, adapt_count fields). The size of the data is less than a
word but accessed only with atomic loads and stores; therefore, we add
support for shorter-size atomic load and stores too.
* include/atomic.h (__atomic_check_size_ls): New.
(atomic_load_relaxed, atomic_load_acquire, atomic_store_relaxed,
atomic_store_release): Use it.
* sysdeps/x86/elide.h (ACCESS_ONCE): Remove.
(elision_adapt, ELIDE_LOCK): Use atomics.
* sysdeps/unix/sysv/linux/x86/elision-lock.c (__lll_lock_elision): Use
atomics and improve code comments.
* sysdeps/unix/sysv/linux/x86/elision-trylock.c
(__lll_trylock_elision): Likewise.
This patch fixes some hurd bits from commit afcf3cd8eb that added the
__access_noerrno internal symbol. It basically removes the nonrequired
__hurd_fail_noerrno (since the 'err' argument is ignored) and fixes
a typo for EACCES.
However, as stated on maillist [1] this __access_noerrno may still be
unsafe to run during initialization of tunables on the Hurd. The
access_common calls __hurd_file_name_lookup, which calls
__hurd_file_name_lookup_retry, which can set errno.
[1] https://sourceware.org/ml/libc-alpha/2016-11/msg00646.html
Extending linknamespace tests to cover libcrypt showed that crypt
brings in references to snprintf, but is in XPG3 and XPG4 which don't
have snprintf. This patch fixes it to use __snprintf instead,
exporting __snprintf from libc.so at version GLIBC_PRIVATE and adding
libc_hidden_proto / libc_hidden_def accordingly.
Tested for x86_64 and x86, in conjunction with the testsuite changes
to enable linknamespace testing for libdl and libcrypt. Also tested
(compilation only) for powerpc to make sure there were no problem
interactions with the optional-long-double handling for snprintf.
[BZ #20829]
* stdio-common/Versions (__snprintf): Add to version
GLIBC_PRIVATE.
* include/stdio.h (__snprintf): Use libc_hidden_proto.
* stdio-common/snprintf.c (__snprintf): Use libc_hidden_def.
* crypt/sha256-crypt.c (__sha256_crypt_r): Use __snprintf instead
of snprintf.
* crypt/sha512-crypt.c (__sha512_crypt_r): Likewise.
Implement an internal version of __access called __access_noerrno that
avoids setting errno. This is useful to check accessibility of files
very early on in process startup i.e. before TLS setup. This allows
tunables to replace MALLOC_CHECK_ safely (i.e. check existence of
/etc/suid-debug to enable/disable MALLOC_CHECK) and at the same time
initialize very early so that it can override IFUNCs.
Checked on x86_64.
* hurd/hurd.h (__hurd_fail_noerrno): New function.
* include/unistd.h [IS_IN (rtld) || !defined SHARED]: Declare
__access_noerrno.
* io/access.c (__access_noerrno): New function.
* sysdeps/mach/hurd/access.c (hurd_fail_seterrno): New function.
(hurd_fail_seterrno): Likewise.
(access_common): Likewise.
(__access_noerrno): Likewise.
* sysdeps/nacl/access.c (__access_noerrno): Likewise.
* sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise.
* sysdeps/nacl/nacl-interfaces.h (NACL_CALL_NOERRNO): New
macro.
This commit adds a new DIAG_IGNORE_Os_NEEDS_COMMENT which is only
enabled when compiling with -Os. This allows developers working on
-Os enabled builds to mark false-positive warnings without impacting the
warnings emitted at -O2.
Then using the new DIAG_IGNORE_Os_NEEDS_COMMENT we fix 6 warnings
generated with GCC 5 to get -Os builds working again.
No code uses atomic_fetch_xor_release except for the upcoming
conditional variable rewrite. Therefore there is no user
visible bug here. The use of atomic_compare_and_exchange_bool_rel
is removed (since it doesn't exist anymore), and is replaced
by atomic_compare_exchange_weak_release.
We use weak_release because it provides better performance in
the loop (the weak semantic) and because the xor is release MO
(the release semantic). We don't reload expected in the loop
because atomic_compare_and_exchange_weak_release does this for
us as part of the CAS failure.
It is otherwise a fairly plain conversion that fixes building
the new condvar for 32-bit x86. Passes all regression tests
for x86.
This patch uses the libc_ifunc_hidden macro to create already existing ifunc functions
time and gettimeofday on intel. This way, the libc_hidden_def macro can be used
instead of the libc_ifunc_hidden_def one which was only used here. Thus the
macro is removed from libc-symbols.h.
On i386, the __GI_* symbols do not target the ifunc symbol and thus the
redirection construct has to be applied here.
ChangeLog:
* sysdeps/unix/sysv/linux/x86/gettimeofday.c (__gettimeofday):
Use libc_ifunc_hidden macro. Use libc_hidden_def instead of
libc_ifunc_hidden_def.
* sysdeps/unix/sysv/linux/x86/time.c (time): Likewise.
* sysdeps/unix/sysv/linux/i386/gettimeofday.c (__gettimeofday):
Redirect ifunced function in header for using it as type of ifunc'ed
function. Redefine libc_hidden_def to use fallback non ifunc'ed
function for __GI_* symbol.
* sysdeps/unix/sysv/linux/i386/time.c (time): Likewise.
* include/libc-symbols.h
(libc_ifunc_hidden_def, libc_ifunc_hidden_def1): Delete macro.
The current s390 ifunc resolver for vector optimized functions and the common
libc_ifunc macro in include/libc-symbols.h uses something like that to generate ifunc'ed functions:
extern void *__resolve___strlen(unsigned long int dl_hwcap) asm (strlen);
asm (".type strlen, %gnu_indirect_function");
This leads to false debug information:
objdump --dwarf=info libc.so:
...
<1><1e6424>: Abbrev Number: 43 (DW_TAG_subprogram)
<1e6425> DW_AT_external : 1
<1e6425> DW_AT_name : (indirect string, offset: 0x1146e): __resolve___strlen
<1e6429> DW_AT_decl_file : 1
<1e642a> DW_AT_decl_line : 23
<1e642b> DW_AT_linkage_name: (indirect string, offset: 0x1147a): strlen
<1e642f> DW_AT_prototyped : 1
<1e642f> DW_AT_type : <0x1e4ccd>
<1e6433> DW_AT_low_pc : 0x998e0
<1e643b> DW_AT_high_pc : 0x16
<1e6443> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<1e6445> DW_AT_GNU_all_call_sites: 1
<1e6445> DW_AT_sibling : <0x1e6459>
<2><1e6449>: Abbrev Number: 44 (DW_TAG_formal_parameter)
<1e644a> DW_AT_name : (indirect string, offset: 0x1845): dl_hwcap
<1e644e> DW_AT_decl_file : 1
<1e644f> DW_AT_decl_line : 23
<1e6450> DW_AT_type : <0x1e4c8d>
<1e6454> DW_AT_location : 0x122115 (location list)
...
The debuginfo for the ifunc-resolver function contains the DW_AT_linkage_name
field, which names the real function name "strlen". If you perform an inferior
function call to strlen in lldb, then it fails due to something like that:
"error: no matching function for call to 'strlen'
candidate function not viable: no known conversion from 'const char [6]'
to 'unsigned long' for 1st argument"
The unsigned long is the dl_hwcap argument of the resolver function.
The strlen function itself has no debufinfo.
The s390 ifunc resolver for memset & co uses something like that:
asm (".globl FUNC"
".type FUNC, @gnu_indirect_function"
".set FUNC, __resolve_FUNC");
This way the debuginfo for the ifunc-resolver function does not conain the
DW_AT_linkage_name field and the real function has no debuginfo, too.
Using this strategy for the vector optimized functions leads to some troubles
for functions like strnlen. Here we have __strnlen and a weak alias strnlen.
The __strnlen function is the ifunc function, which is realized with the asm-
statement above. The weak_alias-macro can't be used here due to undefined symbol:
gcc ../sysdeps/s390/multiarch/strnlen.c -c ...
In file included from <command-line>:0:0:
../sysdeps/s390/multiarch/strnlen.c:28:24: error: ‘strnlen’ aliased to undefined symbol ‘__strnlen’
weak_alias (__strnlen, strnlen)
^
./../include/libc-symbols.h:111:26: note: in definition of macro ‘_weak_alias’
extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
^
../sysdeps/s390/multiarch/strnlen.c:28:1: note: in expansion of macro ‘weak_alias’
weak_alias (__strnlen, strnlen)
^
make[2]: *** [build/string/strnlen.o] Error 1
As the __strnlen function is defined with asm-statements the function name
__strnlen isn't known by gcc. But the weak alias can also be done with an
asm statement to resolve this issue:
__asm__ (".weak strnlen\n\t"
".set strnlen,__strnlen\n");
In order to use the weak_alias macro, gcc needs to know the ifunc function. The
minimum gcc to build glibc is currently 4.7, which supports attribute((ifunc)).
See https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html.
It is only supported if gcc is configured with --enable-gnu-indirect-function
or gcc supports it by default for at least intel and s390x architecture.
This patch uses the old behaviour if gcc support is not available.
Usage of attribute ifunc is something like that:
__typeof (FUNC) FUNC __attribute__ ((ifunc ("__resolve_FUNC")));
Then gcc produces the same .globl, .type, .set assembler instructions like above.
And the debuginfo does not contain the DW_AT_linkage_name field and there is no
debuginfo for the real function, too.
But in order to get it work, there is also some extra work to do.
Currently, the glibc internal symbol on s390x e.g. __GI___strnlen is not the
ifunc symbol, but the fallback __strnlen_c symbol. Thus I have to omit the
libc_hidden_def macro in strnlen.c (here is the ifunc function __strnlen)
because it is already handled in strnlen-c.c (here is __strnlen_c).
Due to libc_hidden_proto (__strnlen) in string.h, compiling fails:
gcc ../sysdeps/s390/multiarch/strnlen.c -c ...
In file included from <command-line>:0:0:
../sysdeps/s390/multiarch/strnlen.c:53:24: error: ‘strnlen’ aliased to undefined symbol ‘__strnlen’
weak_alias (__strnlen, strnlen)
^
./../include/libc-symbols.h:111:26: note: in definition of macro ‘_weak_alias’
extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
^
../sysdeps/s390/multiarch/strnlen.c:53:1: note: in expansion of macro ‘weak_alias’
weak_alias (__strnlen, strnlen)
^
make[2]: *** [build/string/strnlen.os] Error 1
I have to redirect the prototypes for __strnlen in string.h and create a copy
of the prototype for using as ifunc function:
__typeof (__redirect___strnlen) __strnlen __attribute__ ((ifunc ("__resolve_strnlen")));
weak_alias (__strnlen, strnlen)
This way there is no trouble with the internal __GI_* symbols.
Glibc builds fine with this construct and the debuginfo is "correct".
For functions without a __GI_* symbol like memccpy this redirection is not needed.
This patch adjusts the common libc_ifunc and libm_ifunc macro to use gcc
attribute ifunc. Due to this change, the macro users where the __GI_* symbol
does not target the ifunc symbol have to be prepared with the redirection
construct.
Furthermore a configure check to test gcc support is added. If it is not supported,
the old behaviour is used.
This patch also prepares the libc_ifunc macro to be useable in s390-ifunc-macro.
The s390 ifunc-resolver-functions do have an hwcaps parameter and not all
resolvers need the same initialization code. The next patch in this series
changes the s390 ifunc macros to use this common one.
ChangeLog:
* include/libc-symbols.h (__ifunc_resolver):
New macro is used by __ifunc* macros.
(__ifunc): New macro uses gcc attribute ifunc or inline assembly
depending on HAVE_GCC_IFUNC.
(libc_ifunc, libm_ifunc): Use __ifunc as base macro.
(libc_ifunc_redirected, libc_ifunc_hidden, libm_ifunc_init): New macro.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_finite.c:
Redirect ifunced function in header for using as type for ifunc function.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_finitef.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isinf.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isinff.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memcmp.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memcpy.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memmove.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/mempcpy.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memset.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/rawmemchr.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strchr.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strlen.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strncmp.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strnlen.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_finite.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_finitef.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isinf.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isinff.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/memcmp.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/mempcpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/rawmemchr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/stpncpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strcat.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strchr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strcmp.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strcpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strncmp.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strncpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strnlen.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strrchr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strstr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/wcschr.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf.c:
Add libc_hidden_def() and use libc_ifunc_hidden() macro
instead of libc_ifunc() macro.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnanf.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/stpcpy.c: Likewise.
As described in
<https://sourceware.org/ml/libc-alpha/2016-10/msg00047.html>, there is
an include ordering issue with the integer width macros in glibc's
<limits.h>, where definitions conditional on LONG_MAX do not work as
intended because when the headers are installed, this part of glibc's
<limits.h> is processed before the part of GCC's <limits.h> that will
define LONG_MAX. This patch changes the definitions just to use
__WORDSIZE for the expansion of LONG_WIDTH and ULONG_WIDTH rather than
making those definitions conditional on LONG_MAX.
Tested for x86_64 and x86.
* include/limits.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (LONG_WIDTH):
Define to __WORDSIZE, not conditional on [LONG_MAX ==
0x7fffffffL].
[__GLIBC_USE (IEC_60559_BFP_EXT)] (ULONG_WIDTH): Likewise.
This adds a test to ensure that the problems fixed in the last several
patches do not recur. Each directory checks the headers that it
installs for two properties: first, each header must be compilable in
isolation, as both C and C++, under a representative combination of
language and library conformance levels; second, there is a blacklist
of identifiers that may not appear in any installed header, currently
consisting of the legacy BSD typedefs. (There is an exemption for the
headers that define those typedefs, and for the RPC headers. It may be
necessary to make this more sophisticated if we add more stuff to the
blacklist in the future.)
In order for this test to work correctly, every wrapper header
that actually defines something must guard those definitions with
#ifndef _ISOMAC. This is the existing mechanism used by the conform/
tests to tell wrapper headers not to define anything that the public
header wouldn't, and not to use anything from libc-symbols.h. conform/
only cares for headers that we need to check for standards conformance,
whereas this test applies to *every* header. (Headers in include/ that
are either installed directly, or are internal-use-only and do *not*
correspond to any installed header, are not affected.)
* scripts/check-installed-headers.sh: New script.
* Rules: In each directory that defines header files to be installed,
run check-installed-headers.sh on them as a special test.
* Makefile: Likewise for the headers installed at top level.
* include/aliases.h, include/alloca.h, include/argz.h
* include/arpa/nameser.h, include/arpa/nameser_compat.h
* include/elf.h, include/envz.h, include/err.h
* include/execinfo.h, include/fpu_control.h, include/getopt.h
* include/gshadow.h, include/ifaddrs.h, include/libintl.h
* include/link.h, include/malloc.h, include/mcheck.h
* include/mntent.h, include/netinet/ether.h
* include/nss.h, include/obstack.h, include/printf.h
* include/pty.h, include/resolv.h, include/rpc/auth.h
* include/rpc/auth_des.h, include/rpc/auth_unix.h
* include/rpc/clnt.h, include/rpc/des_crypt.h
* include/rpc/key_prot.h, include/rpc/netdb.h
* include/rpc/pmap_clnt.h, include/rpc/pmap_prot.h
* include/rpc/pmap_rmt.h, include/rpc/rpc.h
* include/rpc/rpc_msg.h, include/rpc/svc.h
* include/rpc/svc_auth.h, include/rpc/xdr.h
* include/rpcsvc/nis_callback.h, include/rpcsvc/nislib.h
* include/rpcsvc/yp.h, include/rpcsvc/ypclnt.h
* include/rpcsvc/ypupd.h, include/shadow.h
* include/stdio_ext.h, include/sys/epoll.h
* include/sys/file.h, include/sys/gmon.h, include/sys/ioctl.h
* include/sys/prctl.h, include/sys/profil.h
* include/sys/statfs.h, include/sys/sysctl.h
* include/sys/sysinfo.h, include/ttyent.h, include/utmp.h
* sysdeps/arm/nacl/include/bits/setjmp.h
* sysdeps/mips/include/sys/asm.h
* sysdeps/unix/sysv/linux/include/sys/sysinfo.h
* sysdeps/unix/sysv/linux/include/sys/timex.h
* sysdeps/x86/fpu/include/bits/fenv.h:
Add #ifndef _ISOMAC guard around internal declarations.
Add multiple-inclusion guard if not already present.
Many headers are expected to expose a subset of the type definitions
in time.h. time.h has a whole bunch of messy logic for conditionally
defining some its types and structs, but, as best I can tell, this
has never worked 100%. In particular, __need_timespec is ineffective
if _TIME_H has already been defined, which means that if you compile
#include <time.h>
#include <sched.h>
with e.g. -fsyntax-only -std=c89 -Wall -Wsystem-headers, you will get
In file included from test.c:2:0:
/usr/include/sched.h:74:57: warning: "struct timespec" declared inside
parameter list will not be visible outside of this definition or declaration
extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __THROW;
^~~~~~~~
And if you want to _use_ sched_rr_get_interval in a TU compiled that
way, you're hosed.
This patch replaces all of that with small bits/types/TYPE.h headers
as introduced earlier. time.h and bits/time.h are now *much* simpler,
and a lot of other headers are slightly simpler.
* time/time.h, bits/time.h, sysdeps/unix/sysv/linux/bits/time.h:
Remove all logic conditional on __need macros. Move all the
conditionally defined types to their own headers...
* time/bits/types/clock_t.h: Define clock_t here.
* time/bits/types/clockid_t.h: Define clockid_t here.
* time/bits/types/struct_itimerspec.h: Define struct itimerspec here.
* time/bits/types/struct_timespec.h: Define struct timespec here.
* time/bits/types/struct_timeval.h: Define struct timeval here.
* time/bits/types/struct_tm.h: Define struct tm here.
* time/bits/types/time_t.h: Define time_t here.
* time/bits/types/timer_t.h: Define timer_t here.
* time/Makefile: Install the new headers.
* bits/resource.h, io/fcntl.h, io/sys/poll.h, io/sys/stat.h
* io/utime.h, misc/sys/select.h, posix/sched.h, posix/sys/times.h
* posix/sys/types.h, resolv/netdb.h, rt/aio.h, rt/mqueue.h
* signal/signal.h, pthread/semaphore.h, sysdeps/nptl/pthread.h
* sysdeps/unix/sysv/linux/alpha/bits/resource.h
* sysdeps/unix/sysv/linux/alpha/sys/acct.h
* sysdeps/unix/sysv/linux/bits/resource.h
* sysdeps/unix/sysv/linux/bits/timex.h
* sysdeps/unix/sysv/linux/mips/bits/resource.h
* sysdeps/unix/sysv/linux/net/ppp_defs.h
* sysdeps/unix/sysv/linux/sparc/bits/resource.h
* sysdeps/unix/sysv/linux/sys/acct.h
* sysdeps/unix/sysv/linux/sys/timerfd.h
* sysvipc/sys/msg.h, sysvipc/sys/sem.h, sysvipc/sys/shm.h
* time/sys/time.h, time/sys/timeb.h
Use the new bits/types headers.
* include/time.h: Remove __need logic.
* include/bits/time.h
* include/bits/types/clock_t.h, include/bits/types/clockid_t.h
* include/bits/types/time_t.h, include/bits/types/timer_t.h
* include/bits/types/struct_itimerspec.h
* include/bits/types/struct_timespec.h
* include/bits/types/struct_timeval.h
* include/bits/types/struct_tm.h:
New wrapper headers.
Several network-related structures are defined conditionally under
__USE_MISC, but unconditionally used by other headers. The path of
least resistance is usually to condition the uses on __USE_MISC as
well.
* sysdeps/mach/hurd/net/if_ppp.h
* sysdeps/unix/sysv/linux/net/if_ppp.h:
Only define struct ifpppstatsreq and struct ifpppcstatsreq
if __USE_MISC is defined, to ensure struct ifreq is declared.
* inet/netinet/ether.h: Condition all function prototypes
on __USE_MISC, to ensure struct ether_addr is declared.
sys/socket.h defines struct osockaddr only under __USE_MISC, whereas
protocols/talkd.h requires it unconditionally. Here it doesn't make
sense to condition the entire body of protocols/talkd.h on __USE_MISC.
Rather than complicate sys/socket.h with a __need macro or duplicate
the definition, I am introducing a new concept: tiny headers named
bits/types/TYPE.h that define TYPE and nothing else. This can, I hope,
ultimately replace *all* the __need macros. The guard macro for such
headers will be __TYPE_defined, just in case application or third-party
library code is looking at them.
* socket/bits/types/struct_osockaddr.h: New header.
* include/bits/types/struct_osockaddr.h: New wrapper.
* socket/Makefile: Install the new header.
* socket/sys/socket.h, inet/protocols/talkd.h:
Refer to bits/types/struct_osockaddr.h for the definition of
struct osockaddr.
The types u_char, u_short, u_int, u_long, ushort, uint, ulong, u_int8_t,
u_int16_t, u_int32_t, u_int64_t, quad_t, and u_quad_t are BSDisms that
have never been standardized. While glibc should continue to *provide*
these types for compatibility's sake, its public headers should not
use them.
The meat of this change was mechanically generated by the following
shell command:
perl -pi~ -e '
s/\b(__)?u_char\b/unsigned char/g;
s/\b(__)?u_?short\b/unsigned short/g;
s/\b(__)?u_?int\b/unsigned int/g;
s/\b(__)?u_?long\b/unsigned long/g;
s/\b(__)?u_int8_t\b/uint8_t/g;
s/\b(__)?u_int16_t\b/uint16_t/g;
s/\b(__)?u_int32_t\b/uint32_t/g;
s/\b(__)?u_int64_t\b/uint64_t/g;
s/\b(__)?u_quad_t\b/uint64_t/g;
s/\b(__)?quad_t\b/uint64_t/g;
' $(grep -lE -e '\<((__)?(quad_t|u(short|int|long|_(char|short|int([0-9]+_t)?|long|quad_t))))\>' \
$(grep -LE '\<(_(SYS|BITS)_TYPES_H|rpc/(rpc|rpc_msg|types|xdr)\.h)\>' \
$(find . \( -false $(sed 's/^/-o -name /' all-installed-headers) \
\) -printf '%P\n' | sort -u)))
where 'all-installed-headers' was a list of the basenames of all installed
header files, manually extracted from the Makefiles. Non-installed
wrapper headers in include/ are also adjusted, for consistency.
I then manually fixed up indentation and line-wrapping.
sys/types.h and bits/types.h are excluded because they must continue
to define the u_* types (under __USE_MISC) for compatibility with
applications. They do not use these types themselves.
All headers that (transitively) include rpc/types.h are also excluded,
for three reasons. First, the u_* types are defined by rpc/types.h,
unconditionally (not just under __USE_MISC) so they are logically part
of the SunRPC API. Second, many of those headers appear to be
machine-generated. Third, it's my understanding that we are getting
rid of as much of SunRPC as possible in the near future.
(The one file under sunrpc/ that's touched, sunrpc/rpc/rpc_des.h, does
*not* include rpc/types.h. This may itself be a bug.)
After changing from u_intNN_t to uintNN_t, a number of headers now
need to include stdint.h to pick up those types. It might be more
hygenic, namespace-wise, to use __uintNN_t instead, but none of these
headers are bound by ISO or POSIX to do so, and it's unlikely that
anyone using them will be bothered. (The two files that were using
__-prefixed versions of the u_types, sysdeps/mach/hurd/net/route.h and
sysdeps/unix/sysv/linux/net/route.h, both already also contained uses of
the unprefixed versions.)
Some of these files directly included features.h and/or sys/cdefs.h,
which I removed, as the style generally seems to be to let sys/types.h
do that for us. (This does not change the set of definitions exposed
by any header; sys/types.h unconditionally includes both features.h
and sys/cdefs.h.)
One file included asm/types.h unnecessarily.
* bits/in.h, gmon/sys/gmon.h, inet/netinet/igmp.h
* inet/protocols/routed.h, inet/protocols/talkd.h
* inet/protocols/timed.h, io/fts.h, nptl_db/thread_db.h
* resolv/arpa/nameser.h, resolv/resolv.h, sunrpc/rpc/rpc_des.h
* sysdeps/generic/netinet/if_ether.h
* sysdeps/generic/netinet/in_systm.h
* sysdeps/generic/netinet/ip.h, sysdeps/generic/netinet/tcp.h
* sysdeps/gnu/netinet/ip_icmp.h, sysdeps/gnu/netinet/tcp.h
* sysdeps/gnu/netinet/udp.h, sysdeps/mach/hurd/net/ethernet.h
* sysdeps/mach/hurd/net/if_arp.h
* sysdeps/mach/hurd/net/if_ppp.h
* sysdeps/mach/hurd/net/route.h, sysdeps/mach/sys/reboot.h
* sysdeps/unix/sysv/linux/bits/in.h
* sysdeps/unix/sysv/linux/net/ethernet.h
* sysdeps/unix/sysv/linux/net/if_arp.h
* sysdeps/unix/sysv/linux/net/if_ppp.h
* sysdeps/unix/sysv/linux/net/if_shaper.h
* sysdeps/unix/sysv/linux/net/route.h
* sysdeps/unix/sysv/linux/netinet/if_ether.h
* sysdeps/unix/sysv/linux/netinet/if_fddi.h
* sysdeps/unix/sysv/linux/netinet/if_tr.h
* sysdeps/unix/sysv/linux/netipx/ipx.h
* sysdeps/unix/sysv/linux/sys/acct.h
* include/arpa/nameser.h, include/resolv.h:
Change all uses of u_char to unsigned char,
u_short and ushort to unsigned short, u_int and uint to unsigned int,
u_long and ulong to unsigned long, u_int8_t to uint8_t,
u_int16_t to uint16_t, u_int32_t to uint32_t, quad_t to int64_t,
and u_int64_t and u_quad_t to uint64_t.
* mach/sys/reboot.h: Remove two casts of integer literals
to the types they already have.
* bits/in.h: Correct error in description of IP_MULTICAST_LOOP.
* sysdeps/unix/sysv/linux/bits/in.h: Likewise.
* sysdeps/unix/sysv/linux/netinet/if_ether.h: Change a comment
from referring to 'unsigned char' to 'uint8_t' for consistency with
the macro definition below.
* gmon/sys/gmon.h, inet/netinet/igmp.h, inet/protocols/talkd.h
* io/fts.h, resolv/arpa/nameser.h, resolv/resolv.h
* sunrpc/rpc/rpc_des.h, sysdeps/generic/netinet/ip.h
* sysdeps/gnu/netinet/tcp.h, sysdeps/gnu/netinet/udp.h
* sysdeps/mach/hurd/net/if_ppp.h, sysdeps/unix/sysv/linux/net/if_ppp.h
* sysdeps/unix/sysv/linux/sys/acct.h
* include/arpa/nameser.h, include/resolv.h:
Fix indentation disrupted by mechanical edits.
* inet/protocols/talkd.h, resolv/arpa/nameser.h
* sysdeps/generic/netinet/in_systm.h
* sysdeps/gnu/netinet/ip_icmp.h, sysdeps/gnu/netinet/tcp.h
* sysdeps/gnu/netinet/udp.h
* sysdeps/unix/sysv/linux/net/ethernet.h
* sysdeps/unix/sysv/linux/net/if_arp.h
* sysdeps/unix/sysv/linux/net/if_ppp.h
* sysdeps/unix/sysv/linux/net/if_shaper.h
* sysdeps/unix/sysv/linux/netinet/if_fddi.h
* sysdeps/unix/sysv/linux/netinet/if_tr.h
* sysdeps/unix/sysv/linux/netipx/ipx.h
* sysdeps/unix/sysv/linux/sys/acct.h
Include stdint.h for uintNN_t definitions.
Don't include sys/cdefs.h, features.h, or asm/types.h directly.
TS 18661-1 defines macros for the width of integer types, intended for
use with the fromfp functions to convert from floating-point types to
integer types of any width, in any rounding mode and with control over
whether "inexact" is raised. Such macros are, of course, more
generally useful than just with those functions.
Those macros are added to <limits.h> and <stdint.h>. This patch adds
the <limits.h> macros to glibc's header, with the <stdint.h> ones
intended to be added in a separate patch (which would add to the NEWS
entry created by this patch). I've also added these macros to GCC's
headers for GCC 7, but definitions in glibc's <limits.h> are still
useful for older GCC, for non-GNU compilers and for when it's
_GNU_SOURCE rather than __STDC_WANT_IEC_60559_BFP_EXT__ that implies
the macros should be defined since the GCC header only considers
__STDC_WANT_IEC_60559_BFP_EXT__ (and for glibc systems, the
definitions in GCC's <stdint.h> will only be used with
-ffreestanding).
Tested for x86_64 and x86.
* include/limits.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (CHAR_WIDTH): New macro.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (SCHAR_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (UCHAR_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (SHRT_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (USHRT_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (INT_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (UINT_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (LONG_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (ULONG_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (LLONG_WIDTH): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (ULLONG_WIDTH): Likewise.
* manual/lang.texi (Width of Type): Document these macros.
* stdlib/tst-width.c: New file.
* stdlib/Makefile (tests): Add tst-width.
Existing interposed mallocs do not define the glibc-internal
fork callbacks (and they should not), so statically interposed
mallocs lead to link failures because the strong reference from
fork pulls in glibc's malloc, resulting in multiple definitions
of malloc-related symbols.
This patch implements support for the
__STDC_WANT_IEC_60559_FUNCS_EXT__ feature test macro, following the
__GLIBC_USE approach used for other ISO C feature test macros.
Currently this only affects the exp10 functions (which glibc has had
for a long time).
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_FUNCS_EXT): New
macro.
* include/features.h (__STDC_WANT_IEC_60559_FUNCS_EXT__):
Document.
* manual/creature.texi (__STDC_WANT_IEC_60559_FUNCS_EXT__):
Document macro.
* manual/math.texi (exp10): Document as ISO from TS 18661-4:2015.
(exp10f): Likewise.
(exp10l): Likewise.
* math/bits/mathcalls.h (exp10): Declare if
[__GLIBC_USE (IEC_60559_FUNCS_EXT)], not [__USE_GNU].
Presently sys/sysmacros.h is entirely defined in sysdeps. This would
mean that the deprecation logic coming up in the next patch would have
to be written twice (in generic/ and unix/sysv/linux/). To avoid that,
hoist all but the unavoidably system-dependent logic to misc/, leaving a
bits/ header behind. This also promotes the Linux-specific encoding of
dev_t, which accommodates 32-bit major and minor numbers in a 64-bit dev_t,
to generic, as glibc's dev_t is always 64 bits wide.
The former Linux implementation used inline functions to avoid evaluating
arguments more than once. After this change, all platforms use inline
functions, which means that three new symbols are added to the generic ABI.
(These symbols are in the user namespace, which is how they have always
been on Linux. They begin with "gnu_dev_", so collisions with user code
are pretty unlikely.)
New ports henceforth need only provide a bits/sysmacros.h defining
internal macros __SYSMACROS_{DECLARE,DEFINE}_{MAJOR,MINOR,MAKEDEV}.
This is only necessary if the kernel encoding is incompatible with
the now-generic encoding (for instance, it would be necessary for
FreeBSD).
While I was at it, I added a basic round-trip test for these functions.
* sysdeps/generic/sys/sysmacros.h: Delete file.
* sysdeps/unix/sysv/linux/makedev.c: Delete file.
* sysdeps/unix/sysv/linux/sys/sysmacros.h: Move file ...
* bits/sysmacros.h: ... here; this encoding is now the generic
encoding. Now defines only the following macros:
__SYSMACROS_DECLARE_MAJOR, __SYSMACROS_DEFINE_MAJOR,
__SYSMACROS_DECLARE_MINOR, __SYSMACROS_DEFINE_MINOR,
__SYSMACROS_DECLARE_MAKEDEV, __SYSMACROS_DEFINE_MAKEDEV.
* misc/sys/sysmacros.h, misc/makedev.c: New files that use
bits/sysmacros.h and the above new macros to generate the
public implementations of major, minor, and makedev.
* misc/tst-makedev.c: New test.
* include/sys/sysmacros.h: New wrapper.
* misc/Makefile (headers): Add sys/sysmacros.h, bits/sysmacros.h.
(routines): Add makedev.
(tests): Add tst-makedev.
* misc/Versions [GLIBC_2.25]: Add gnu_dev_major, gnu_dev_minor,
gnu_dev_makedev.
* posix/Makefile (headers): Remove sys/sysmacros.h.
* sysdeps/unix/sysv/linux/Makefile (sysdep_routines): Remove makedev.
* sysdeps/arm/nacl/libc.abilist: Add GLIBC_2.25,
gnu_dev_major, gnu_dev_makedev, gnu_dev_minor.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist
* sysdeps/unix/sysv/linux/alpha/libc.abilist
* sysdeps/unix/sysv/linux/arm/libc.abilist
* sysdeps/unix/sysv/linux/hppa/libc.abilist
* sysdeps/unix/sysv/linux/i386/libc.abilist
* sysdeps/unix/sysv/linux/ia64/libc.abilist
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
* sysdeps/unix/sysv/linux/microblaze/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
* sysdeps/unix/sysv/linux/nios2/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
* sysdeps/unix/sysv/linux/sh/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist:
Add GLIBC_2.25.
There are three new macros added to features.h and sys/cdefs.h:
* __glibc_clang_prereq: just like __GNUC_PREREQ, but for clang.
* __glibc_clang_has_extension: wraps clang's intrinsic __has_extension.
Writing "#if defined __clang__ && __has_extension (...)" doesn't work,
because compilers other than clang will object to the unknown macro
__has_extension even though they don't need to evaluate it.
Instead, write "#if __glibc_clang_has_extension (...)".
* __attribute_deprecated_msg__(msg): like __attribute_deprecated__, but
if possible, prints a message.
The first two are used to define the third. The third will be used
in subsequent patches.
* include/features.h (__glibc_clang_prereq): New macro.
* misc/sys/cdefs.h (__glibc_clang_has_extension)
(__attribute_deprecated_msg__): New macros.
This patch implements support for the __STDC_WANT_IEC_60559_BFP_EXT__
feature test macro from ISO/IEC 18661-1:2014, following the
__GLIBC_USE approach now used for __STDC_WANT_LIB_EXT2__. For this
macro, the relevant consideration is whether it is defined or
undefined when an affected header is included (not what its value is
if defined, and not whether it's defined or undefined when any other
unaffected system header is included).
Currently this macro only affects the issignaling macro and the nextup
and nextdown functions (so they can be enabled by defining this macro,
not just by defining _GNU_SOURCE as previously). Any further features
from this TS added in future would also be conditioned on this macro.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_BFP_EXT): New
macro.
* include/features.h (__STDC_WANT_IEC_60559_BFP_EXT__): Document.
* manual/arith.texi (issignaling): Document as ISO from TS
18661-1:2014.
(nextup): Likewise.
(nextupf): Likewise.
(nextupl): Likewise.
(nextdown): Likewise.
(nextdownf): Likewise.
(nextdownl): Likewise.
* manual/creature.texi (__STDC_WANT_IEC_60559_BFP_EXT__): Document
macro.
* math/math.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
(issignaling): Define if [__GLIBC_USE (IEC_60559_BFP_EXT)], not
[__USE_GNU].
* math/bits/mathcalls.h (nextdown): Declare if
[__GLIBC_USE (IEC_60559_BFP_EXT)], not [__USE_GNU].
(nextup): Likewise.
(__issignaling): Likewise.
This patch implements support for the __STDC_WANT_LIB_EXT2__ feature
test macro from ISO/IEC TR 24731-2:2010, thereby implementing one
possible approach for supporting ISO C feature test macros.
Recall that, as described in
<https://sourceware.org/ml/libc-alpha/2016-05/msg00486.html>, these
macros work based on the definition when affected headers are
included, so cannot be handled once when the first system header is
included because that might not be one of the headers the particular
macro in question affects.
<https://sourceware.org/ml/libc-alpha/2016-05/msg00680.html> expresses
views on possible approaches for implementation and
<https://sourceware.org/ml/libc-alpha/2016-06/msg00039.html> follows
up on that.
This patch arranges things so that the relevant condition is
__GLIBC_USE (LIB_EXT2), following one of the suggestions given.
Headers using these macros include <bits/libc-header-start.h>, which
in turn includes <features.h>. Headers must define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION before including
<bits/libc-header-start.h>, to discourage inclusion outside glibc as
requested. __USE_GNU conditions on affected functions are changed to
__GLIBC_USE (LIB_EXT2), while it's added as an additional alternative
on the conditions for functions already enabled for some POSIX
versions.
It would be possible to convert existing __USE_* conditionals to
__GLIBC_USE (with the relevant __GLIBC_USE_* being defined in
<features.h> where __USE_* are presently defined), and so make them
typo-proof (given -Wundef -Werror in glibc builds) because __GLIBC_USE
is used with #if not #ifdef / #if defined.
No attempt is made to enforce the rule about diagnosing different
definitions of __STDC_WANT_LIB_EXT2__ when affected headers are
included; such a diagnostic is incompatible with multiple-include
guards on the affected headers, unless compiler extensions are added
to support it.
As previously noted, glibc does not implement all features from TR
24731-2:2010: the functions aswprintf vaswprintf getwdelim getwline
are not in glibc, although they would be appropriate to add if someone
wished to do so. But I think it makes sense to support the feature
test macro if *any* of the controlled features are present in glibc.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/libc-header-start.h: New file.
* Makefile (headers): Add bits/libc-header-start.h.
* include/features.h (__STDC_WANT_LIB_EXT2__): Document.
(__GLIBC_USE): New macro.
* libio/stdio.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
(fmemopen): Declare also if [__GLIBC_USE (LIB_EXT2)].
(open_memstream): Likewise.
(vasprintf): Declare if [__GLIBC_USE (LIB_EXT2)], not [__USE_GNU].
(__asprintf): Likewise.
(asprintf): Likewise.
(__getdelim): Declare also if [__GLIBC_USE (LIB_EXT2)].
(getdelim): Likewise.
(getline): Likewise.
* string/string.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
(strdup): Declare also if [__GLIBC_USE (LIB_EXT2)]
(strndup): Likewise.
* wcsmbs/wchar.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
(open_wmemstream): Declare also if [__GLIBC_USE (LIB_EXT2)].
* manual/creature.texi (__STDC_WANT_LIB_EXT2__): Document macro.
atomic_compare_and_exchange_bool_rel and
catomic_compare_and_exchange_bool_rel are removed and replaced with the
new C11-like atomic_compare_exchange_weak_release. The concurrent code
in nscd/cache.c has not been reviewed yet, so this patch does not add
detailed comments.
* nscd/cache.c (cache_add): Use new C11-like atomic operation instead
of atomic_compare_and_exchange_bool_rel.
* nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full): Likewise.
* include/atomic.h (atomic_compare_and_exchange_bool_rel,
catomic_compare_and_exchange_bool_rel): Remove.
* sysdeps/aarch64/atomic-machine.h
(atomic_compare_and_exchange_bool_rel): Likewise.
* sysdeps/alpha/atomic-machine.h
(atomic_compare_and_exchange_bool_rel): Likewise.
* sysdeps/arm/atomic-machine.h
(atomic_compare_and_exchange_bool_rel): Likewise.
* sysdeps/mips/atomic-machine.h
(atomic_compare_and_exchange_bool_rel): Likewise.
* sysdeps/tile/atomic-machine.h
(atomic_compare_and_exchange_bool_rel): Likewise.
__malloc_initialize_hook is interposed by application code, so
the usual approach to define a compatibility symbol does not work.
This commit adds a new mechanism based on #pragma GCC poison in
<stdc-predef.h>.
When trying to compile regression tests that use
C++ and the threads header you get this failure:
In file included from /usr/include/c++/5.3.1/cwchar:44:0,
from /usr/include/c++/5.3.1/bits/postypes.h:40,
from /usr/include/c++/5.3.1/bits/char_traits.h:40,
from /usr/include/c++/5.3.1/string:40,
from /usr/include/c++/5.3.1/stdexcept:39,
from /usr/include/c++/5.3.1/array:38,
from /usr/include/c++/5.3.1/tuple:39,
from /usr/include/c++/5.3.1/functional:55,
from /usr/include/c++/5.3.1/thread:39,
from tst-thread-quick_exit.cc:19:
../include/wchar.h:105:23: error: invalid conversion from ‘wchar_t*
(*)(wchar_t*, wchar_t, size_t) throw () {aka wchar_t* (*)(wchar_t*,
wchar_t, long unsigned int) throw ()}’ to ‘int’ [-fpermissive]
extern typeof (wmemset) __wmemset;
^
../include/wchar.h:105:25: error: expected ‘,’ or ‘;’ before ‘__wmemset’
extern typeof (wmemset) __wmemset;
^
The simplest fix for C++ is to avoid the use of
typeof and just declare the prototype as expected.
No regressions on x86_64. Committed as obvious.
The include/wchar.h header is only for internal
build uses and therefore is not ever seen by any
external users and needs no bug #.
https://sourceware.org/glibc/wiki/Proposals/GroupMerging
== Justification ==
It is common today for users to rely on centrally-managed user stores for
handling their user accounts. However, much software existing today does
not have an innate understanding of such accounts. Instead, they commonly
rely on membership in known groups for managing access-control (for
example the "wheel" group on Fedora and RHEL systems or the "adm" group
on Debian-derived systems). In the present incarnation of nsswitch, the
only way to have such groups managed by a remote user store such as
FreeIPA or Active Directory would be to manually remove the groups from
/etc/group on the clients so that nsswitch would then move past nss_files
and into the SSSD, nss-ldap or other remote user database.
== Solution ==
With this patch, a new action is introduced for nsswitch:
NSS_ACTION_MERGE. To take advantage of it, one will add [SUCCESS=merge]
between two database entries in the nsswitch.conf file. When a group is
located in the first of the two group entries, processing will continue
on to the next one. If the group is also found in the next entry (and the
group name and GID are an exact match), the member list of the second
entry will be added to the group object to be returned.
== Implementation ==
After each DL_LOOKUP_FN() returns, the next action is checked. If the
function returned NSS_STATUS_SUCCESS and the next action is
NSS_ACTION_MERGE, a copy of the result buffer is saved for the next pass
through the loop. If on this next pass through the loop the database
returns another instance of a group matching both the group name and GID,
the member list is added to the previous list and it is returned as a
single object. If the following database does not contain the same group,
then the original is copied back into the destination buffer.
This patch implements merge functionality only for the group database.
For other databases, there is a default implementation that will return
the EINVAL errno if a merge is requested. The merge functionality can be
implemented for other databases at a later time if such is needed. Each
database must provide a unique implementation of the deep-copy and merge
functions.
If [SUCCESS=merge] is present in nsswitch.conf for a glibc version that
does not support it, glibc will process results up until that operation,
at which time it will return results if it has found them or else will
simply return an error. In practical terms, this ends up behaving like
the remainder of the nsswitch.conf line does not exist.
== Iterators ==
This feature does not modify the iterator functionality from its current
behavior. If getgrnam() or getgrgid() is called, glibc will iterate
through all entries in the `group` line in nsswitch.conf and display the
list of members without attempting to merge them. This is consistent with
the behavior of nss_files where if two separate lines are specified for
the same group in /etc/groups, getgrnam()/getgrgid() will display both.
Clients are already expected to handle this gracefully.
== No Premature Optimizations ==
The following is a list of places that might be eligible for
optimization, but were not overengineered for this initial contribution:
* Any situation where a merge may occur will result in one malloc() of
the same size as the input buffer.
* Any situation where a merge does occur will result in a second
malloc() to hold the list of pointers to member name strings.
* The list of members is simply concatenated together and is not tested
for uniqueness (which is identical to the behavior for nss_files,
which will simply return identical values if they both exist on the
line in the file. This could potentially be optimized to reduce space
usage in the buffer, but it is both complex and computationally
expensive to do so.
== Testing ==
I performed testing by running the getent utility against my newly-built
glibc and configuring /etc/nsswitch.conf with the following entry:
group: group: files [SUCCESS=merge] sss
In /etc/group I included the line:
wheel❌10:sgallagh
I then configured my local SSSD using the id_provider=local to respond
with:
wheel:*:10:localuser,localuser2
I then ran `getent group wheel` against the newly-built glibc in
multiple situations and received the expected output as described
above:
* When SSSD was running.
* When SSSD was configured in nsswitch.conf but the daemon was not
running.
* When SSSD was configured in nsswitch.conf but nss_sss.so.2 was not
installed on the system.
* When the order of 'sss' and 'files' was reversed.
* All of the above with the [SUCCESS=merge] removed (to ensure no
regressions).
* All of the above with `getent group 10`.
* All of the above with `getent group` with and without
`enumerate=true` set in SSSD.
* All of the above with and without nscd enabled on the system.
The overloading approach in the W* macros was incompatible with
integer expressions of a type different from int. Applications
using union wait and these macros will have to migrate to the
POSIX-specified int status type.
bits/xopen_lim.h (included by limits.h if __USE_XOPEN) defines
NL_NMAX, but this constant was removed in the 2008 edition of POSIX so
should not be defined in that case. This patch duly disables that
define for __USE_XOPEN2K8. It remains enabled for __USE_GNU to avoid
affecting sysconf (_SC_NL_NMAX), the implementation of which uses
"#ifdef NL_NMAX".
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
[BZ #19929]
* include/bits/xopen_lim.h (NL_NMAX): Do not define if
[__USE_XOPEN2K8 && !__USE_GNU].
* conform/Makefile (test-xfail-XOPEN2K8/limits.h/conform): Remove
variable.
* sysdeps/generic/dl-fcntl.h: New file, adds attribute_hidden to __open
and __fcntl.
* sysdeps/mach/hurd/dl-fcntl.h: New file, adds attribute_hidden to
__fcntl only.
* include/fcntl.h [IS_IN (rtld)]: Include <dl-fcntl.h> instead of
adding attribute_hidden to __open and __fcntl.
The GNU libc testsuite fails to build on powerpc/ppc64/ppc64le with the
following error:
../sysdeps/powerpc/test-get_hwcap.c:26:22: fatal error: sys/auxv.h: No such file or director
This is because test-get_hwcap.c includes <sys/auxv.h>, but we don't
provide a wrapper in include/sys. This patch adds one.
Changelog:
* include/sys/auxv.h: New file.
This patch implements a new posix_spawn{p} implementation for Linux. The main
difference is it uses the clone syscall directly with CLONE_VM and CLONE_VFORK
flags and a direct allocated stack. The new stack and start function solves
most the vfork limitation (possible parent clobber due stack spilling). The
remaning issue are related to signal handling:
1. That no signal handlers must run in child context, to avoid corrupt
parent's state.
2. Child must synchronize with parent to enforce stack deallocation and
to possible return execv issues.
The first one is solved by blocking all signals in child, even NPTL-internal
ones (SIGCANCEL and SIGSETXID). The second issue is done by a stack allocation
in parent and a synchronization with using a pipe or waitpid (in case or error).
The pipe has the advantage of allowing the child signal an exec error (checked
with new tst-spawn2 test).
There is an inherent race condition in pipe2 usage for architectures that do not
support the syscall directly. In such cases the a pipe plus fctnl is used
instead and it may lead to file descriptor leak in parent (as decribed by fcntl
documentation).
The child process stack is allocate with a mmap with MAP_STACK flag using
default architecture stack size. Although it is slower than use a stack buffer
from parent, it allows some slack for the compatibility code to run scripts
with no shebang (which may use a buffer with size depending of argument list
count).
Performance should be similar to the vfork default posix implementation and
way faster than fork path (vfork on mostly linux ports are basically
clone with CLONE_VM plus CLONE_VFORK). The only difference is the syscalls
required for the stack allocation/deallocation.
It fixes BZ#10354, BZ#14750, and BZ#18433.
Tested on i386, x86_64, powerpc64le, and aarch64.
[BZ #14750]
[BZ #10354]
[BZ #18433]
* include/sched.h (__clone): Add hidden prototype.
(__clone2): Likewise.
* include/unistd.h (__dup): Likewise.
* posix/Makefile (tests): Add tst-spawn2.
* posix/tst-spawn2.c: New file.
* sysdeps/posix/dup.c (__dup): Add hidden definition.
* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/alpha/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/arm/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/hppa/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/i386/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/ia64/clone2.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/m68k/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/microblaze/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/mips/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/nios2/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone):
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/sh/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/tile/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/x86_64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/nptl-signals.h
(____nptl_is_internal_signal): New function.
* sysdeps/unix/sysv/linux/spawni.c: New file.
As discussed in
https://sourceware.org/ml/libc-alpha/2015-10/msg00403.html
the setting of _STRING_ARCH_unaligned currently controls the external
GLIBC ABI as well as selecting the use of unaligned accesses withing
GLIBC.
Since _STRING_ARCH_unaligned was recently changed for AArch64, this
would potentially break the ABI in GLIBC 2.23, so split the uses and add
_STRING_INLINE_unaligned to select the string ABI. This setting must be
fixed for each target, while _STRING_ARCH_unaligned may be changed from
release to release. _STRING_ARCH_unaligned is used unconditionally in
glibc. But <bits/string.h>, which defines _STRING_ARCH_unaligned, isn't
included with -Os. Since _STRING_ARCH_unaligned is internal to glibc and
may change between glibc releases, it should be made private to glibc.
_STRING_ARCH_unaligned should defined in the new string_private.h heade
file which is included unconditionally from internal <string.h> for glibc
build.
[BZ #19462]
* bits/string.h (_STRING_ARCH_unaligned): Renamed to ...
(_STRING_INLINE_unaligned): This.
* include/string.h: Include <string_private.h>.
* string/bits/string2.h: Replace _STRING_ARCH_unaligned with
_STRING_INLINE_unaligned.
* sysdeps/aarch64/bits/string.h (_STRING_ARCH_unaligned): Removed.
(_STRING_INLINE_unaligned): New.
* sysdeps/aarch64/string_private.h: New file.
* sysdeps/generic/string_private.h: Likewise.
* sysdeps/m68k/m680x0/m68020/string_private.h: Likewise.
* sysdeps/s390/string_private.h: Likewise.
* sysdeps/x86/string_private.h: Likewise.
* sysdeps/m68k/m680x0/m68020/bits/string.h
(_STRING_ARCH_unaligned): Renamed to ...
(_STRING_INLINE_unaligned): This.
* sysdeps/s390/bits/string.h (_STRING_ARCH_unaligned): Renamed
to ...
(_STRING_INLINE_unaligned): This.
* sysdeps/sparc/bits/string.h (_STRING_ARCH_unaligned): Renamed
to ...
(_STRING_INLINE_unaligned): This.
* sysdeps/x86/bits/string.h (_STRING_ARCH_unaligned): Renamed
to ...
(_STRING_INLINE_unaligned): This.
Since internal unistd functions are only used internally in ld.so and
libc.so, they can be made hidden. __close, __getcwd, __getpid,
__libc_read and __libc_write can't be hidden in ld.so on Hurd since they
will be preempted by the ones in libc.so after bootstrap.
[BZ #19122]
* include/unistd.h [IS_IN (rtld)]: Include <dl-unistd.h>.
* sysdeps/generic/dl-unistd.h: New file.
* sysdeps/mach/hurd/dl-unistd.h: Likewise.
