These machine-dependent inline string functions have never been on by
default, and even if they were a good idea at the time they were
introduced, they haven't really been touched in ten to fifteen years
and probably aren't a good idea on current-gen processors. Current
thinking is that this class of optimization is best left to the
compiler.
* bits/string.h, string/bits/string.h
* sysdeps/aarch64/bits/string.h
* sysdeps/m68k/m680x0/m68020/bits/string.h
* sysdeps/s390/bits/string.h, sysdeps/sparc/bits/string.h
* sysdeps/x86/bits/string.h: Delete file.
* string/string.h: Don't include bits/string.h.
* string/bits/string3.h: Rename to bits/string_fortified.h.
No need to undef various symbols that the removed headers
might have defined as macros.
* string/Makefile (headers): Remove bits/string.h, change
bits/string3.h to bits/string_fortified.h.
* string/string-inlines.c: Update commentary. Remove definitions
of various macros that nothing looks at anymore. Don't directly
include bits/string.h. Set _STRING_INLINE_unaligned here, based on
compiler-predefined macros.
* string/strncat.c: If STRNCAT is not defined, or STRNCAT_PRIMARY
_is_ defined, provide internal hidden alias __strncat.
* include/string.h: Declare internal hidden alias __strncat.
Only forward __stpcpy to __builtin_stpcpy if __NO_STRING_INLINES is
not defined.
* include/bits/string3.h: Rename to bits/string_fortified.h,
update to match above.
* sysdeps/i386/string-inlines.c: Define compat symbols for
everything formerly defined by sysdeps/x86/bits/string.h.
Make existing definitions into compat symbols as well.
Remove some no-longer-necessary messing around with macros.
* sysdeps/powerpc/powerpc32/power4/multiarch/mempcpy.c
* sysdeps/powerpc/powerpc64/multiarch/mempcpy.c
* sysdeps/powerpc/powerpc64/multiarch/stpcpy.c
* sysdeps/s390/multiarch/mempcpy.c
No need to define _HAVE_STRING_ARCH_mempcpy.
Do define __NO_STRING_INLINES and NO_MEMPCPY_STPCPY_REDIRECT.
* sysdeps/i386/i686/multiarch/strncat-c.c
* sysdeps/s390/multiarch/strncat-c.c
* sysdeps/x86_64/multiarch/strncat-c.c
Define STRNCAT_PRIMARY. Don't change definition of libc_hidden_def.
This patch removes some MIPS code in glibc that was conditional on old
GCC versions no longer supported for building glibc.
Tested with build-many-glibcs.py.
* sysdeps/mips/atomic-machine.h (R10K_BEQZ_INSN): Remove.
[__GNUC_PREREQ (4, 8) || __mips16]: Make code unconditional.
[!__GNUC_PREREQ (4, 8) && !__mips16]: Remove conditional code.
* sysdeps/mips/math-tests.h
[_MIPS_SIM != _ABIO32 && !__GNUC_PREREQ (4, 9)]: Remove
conditional code.
The wait3 function was removed in the 2001 edition of POSIX.
sys/wait.h wrongly declares it for the 2001 and 2008 editions of POSIX
when XSI features are enabled. This patch fixes the conditionals.
Tested for x86_64.
[BZ #21625]
* posix/sys/wait.h (strust rusage forward declaration): Change
[__USE_XOPEN_EXTENDED] conditional to [__USE_XOPEN_EXTENDED &&
!__USE_XOPEN2K].
(wait3): Likewise.
This patch makes configure require GCC 4.9 or later for building
glibc, and documents that requirement. Requiring GCC 4.9 or later
allows use of _Generic (as in tzcode). It would allow <stdatomic.h>
and _Atomic to be used as well if desired, although we need to avoid
any libatomic dependencies on any platforms. This patch is explicitly
the minimum to implement a new version requirement, with any
consequent cleanups of conditional code (not in installed headers or
files shared with gnulib etc.) to be done separately.
Tested for x86_64.
* configure.ac (libc_cv_compiler_ok): Require GCC 4.9 or later.
* configure: Regenerated.
* manual/install.texi (Tools for Compilation): Document
requirement for GCC 4.9 or later.
* INSTALL: Regenerated.
LD_LIBRARY_PATH can only be used to reorder system search paths, which
is not useful functionality.
This makes an exploitable unbounded alloca in _dl_init_paths unreachable
for AT_SECURE=1 programs.
This patch removes PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS
and PTRACE_SETFPREGS as these requests does not exist on s390 kernel.
But the kernel has support for PTRACE_SINGLEBLOCK,
PTRACE_SECCOMP_GET_FILTER, PTRACE_PEEKUSR_AREA, PTRACE_POKEUSR_AREA,
PTRACE_GET_LAST_BREAK, PTRACE_ENABLE_TE, PTRACE_DISABLE_TE and
PTRACE_TE_ABORT_RAND. Thus those are defined now.
The current kernel s390 specific ptrace.h file also defines
PTRACE_PEEKTEXT_AREA, PTRACE_PEEKDATA_AREA, PTRACE_POKETEXT_AREA,
PTRACE_POKEDATA_AREA, PTRACE_PEEK_SYSTEM_CALL, PTRACE_POKE_SYSTEM_CALL
and PTRACE_PROT, but those requests are not supported.
Thus those defines are skipped in glibc ptrace.h.
There were old includes of ptrace.h in sysdeps/s390/fpu/fesetenv.c.
The ptrace feature isn't used there anymore, thus I removed the includes.
Before this patch, <glibc>/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
uses ptrace-request 12 for PTRACE_GETREGS,
but <kernel>/include/uapi/linux/ptrace.h uses 12 for PTRACE_SINGLEBLOCK.
The s390 kernel has never had support for PTRACE_GETREGS!
Thus glibc ptrace.h is adjusted to match kernel ptrace.h.
The new s390 specific test ensures, that PTRACE_SINGLEBLOCK defined
in glibc works as expected. If the kernel would interpret it as
PTRACE_GETREGS, then the testcase will not make any progress
and will time out.
ChangeLog:
[BZ #21539]
* NEWS: Mention s390 ptrace request changes.
* sysdeps/unix/sysv/linux/s390/sys/ptrace.h
(PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS,
PTRACE_SETFPREGS): Remove enum constant.
(PT_GETREGS, PT_SETREGS, PT_GETFPREGS, T_SETFPREGS):
Remove defines.
(PTRACE_SINGLEBLOCK): New enum constant.
(PT_STEPBLOCK): New define.
(PTRACE_PEEKUSR_AREA, PTRACE_POKEUSR_AREA,
PTRACE_GET_LAST_BREAK, PTRACE_ENABLE_TE, PTRACE_DISABLE_TE,
PTRACE_TE_ABORT_RAND): New enum constant and define.
* sysdeps/s390/fpu/fesetenv.c: Remove ptrace.h includes.
* sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c:
New file.
* sysdeps/unix/sysv/linux/s390/Makefile: Add test.
This patch fixes a namespace issue for one more field in the x86
sys/ucontext.h that I missed in my previous changes.
Tested for x86_64.
[BZ #21457]
* sysdeps/unix/sysv/linux/x86/sys/ucontext.h [__x86_64__] (struct
_libc_xmmreg): Use __ctx in defining field.
The siginterrupt function is XSI-shaded in POSIX. glibc wrongly
declares it in <signal.h> for non-XSI POSIX.1:2008. This patch fixes
the conditionals (moving it into the __USE_XOPEN_EXTENDED ||
__USE_MISC block as the minimum conservative change, although it's not
clear this obsolescent function should be declared by default).
Tested for x86_64.
[BZ #21597]
* signal/signal.h (siginterrupt): Make declaration conditional on
[__USE_XOPEN_EXTENDED || __USE_MISC].
In POSIX.1:2008, various signal stack symbols - sigaltstack, SS_*,
SIGSTKSZ, MINSIGSTKSZ - are all XSI-shaded. glibc wrongly makes them
visible for non-XSI POSIX. This patch fixes the conditionals, leaving
the symbols available for __USE_MISC as it seems likely some of them
are widely used and should be visible by default. (Note that stack_t
is *not* XSI-shaded and so the conditionals on that are correctly
unchanged.)
Tested for x86_64.
[BZ #21584]
* signal/signal.h: Make includes of <bits/sigstack.h> and
<bits/ss_flags.h> conditional on [__USE_XOPEN_EXTENDED ||
__USE_MISC].
(sigaltstack): Make declaration conditional on
[__USE_XOPEN_EXTENDED || __USE_MISC].
Some older standards (XPG4.2 through POSIX.1:2001, XSI only) require
sys/wait.h to include the definition of struct rusage. This is
missing in glibc.
This patch adds the required definition. struct rusage is moved to a
new header bits/types/struct_rusage.h to avoid bringing in the whole
of sys/resource.h (although the standards in question do allow the
whole of sys/resource.h to be brought in). In the five
bits/resource.h headers, the only variation between the definitions of
struct rusage is that the sysdeps/unix/sysv/linux version is prepared
for x32 (by having anonymous unions with __syscall_slong_t fields) and
the others are not. Thus, this version is suitable for use
generically (everything other than x32 simply has __syscall_slong_t
the same as long int, so there are no API or ABI changes involved, and
anonymous unions are already a required language feature for glibc
headers elsewhere), and this patch uses it as a base for the single
implementation of bits/types/struct_rusage.h.
Tested for x86_64, and with build-many-glibcs.py.
[BZ #21575]
* resource/bits/types/struct_rusage.h: New file.
* include/bits/types/struct_rusage.h: Likewise.
* bits/resource.h (struct rusage): Include
<bits/types/struct_rusage.h> instead of defining here.
* sysdeps/unix/sysv/linux/bits/resource.h (struct rusage):
Likewise.
* sysdeps/unix/sysv/linux/alpha/bits/resource.h (struct rusage):
Likewise.
* sysdeps/unix/sysv/linux/mips/bits/resource.h (struct rusage):
Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/resource.h (struct rusage):
Likewise.
* resource/Makefile (headers): Add bits/types/struct_rusage.h.
* posix/sys/wait.h [__USE_XOPEN_EXTENDED && !__USE_XOPEN2K8]:
Include <bits/types/struct_rusage.h>
Awk 3.1.x does not support multi-dimensional arrays, so fix up to make
sure that gen-tunables.awk works on it.
* scripts/gen-tunables.awk: Avoid multi-dimensional arrays.
Building glibc with gcc configured with --enable-default-pie failed on s390
due to assembler messages:
../sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S:44:
Error: junk at end of line, first unrecognized character is `@'
HIDDEN_JUMPTARGET was expanded to exit@PLT@GOTOFF.
If SHARED is not defined, HIDDEN_JUMPTARGET is defined to JUMPTARGET
in sysdeps/s390/s390-32/sysdep.h. There it expanded to exit@PLT
in non SHARED case as PIC is defined if gcc is configured with
--enable-default-pie. Thus I've changed the "ifdef PIC" to "ifdef SHARED"
as we do not want PLTs in the static obj files. I've also changed this
in sysdeps/s390/s390-64/sysdep.h.
I've also adjusted sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S.
If glibc is configured with --disable-hidden-plt, then NO_HIDDEN is defined.
In SHARED case HIDDEN_JUMPTARGET would be expanded to exit@PLT@GOTOFF
instead of __GI_exit@GOTOFF.
Now we jump to:
- __GI_exit if SHARED is defined
- exit@PLT if SHARED and NO_HIDDEN is defined
- exit if both are not defined.
On s390 31bit we have to setup GOT pointer in r12 if we use a PLT stub.
Therefore I use SYSCALL_PIC_SETUP from sysdep.h and added the missing semicolons.
ChangeLog:
[BZ #21537]
* sysdeps/s390/s390-32/sysdep.h (JUMPTARGET, SYSCALL_PIC_SETUP):
Check SHARED instead of PIC.
(SYSCALL_PIC_SETUP): Add missing semicolons.
* sysdeps/s390/s390-64/sysdep.h (JUMPTARGET, SYSCALL_PIC_SETUP):
Check SHARED instead of PIC.
* sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S
(__makecontext_ret): Adjust code to jump to exit.
Since kernel 2.6.0 all Linux version accept the system call number
in register 1 for svc 0. There is no need to have special handling
that uses EX for system calls < 256. This will simplify and speed
up that code.
A microbenchmark doing "syscall(__NR_getpid);" in a loops gets faster
by ~12%.
* sysdeps/unix/sysv/linux/s390/s390-32/syscall.S: Simplify
code by always using SVC 0 instead of EX.
* sysdeps/unix/sysv/linux/s390/s390-64/syscall.S: Likewise.
Since _dl_out_of_memory is static in elf/dl-error-skeleton.c:
static const char _dl_out_of_memory[] = "out of memory";
remove _dl_out_of_memory from elf/Versions.
* elf/Versions (ld): Remove _dl_out_of_memory.
This patch updates files coming from tzcode to the versions in tzcode
2017b. A couple of changes to other glibc code are needed.
time/tzset.c was using the SECSPERDAY macro from tzfile.h, which no
longer defines that macro, so a local definition is added to tzset.c.
Because timezone/private.h now defines the _ macro whenever
HAVE_GETTEXT is true, even if it was previously defined, it is also
necessary to avoid a conflict with the definition in
include/libintl.h. Defining _ISOMAC is the obvious way to avoid such
internal definitions being visible, together with defining TZ_DOMAIN
so that zic and zdump continue to get the messages from the libc
domain as desired. However, zic and zdump rely on PKGVERSION and
REPORT_BUGS_TO from config.h, which is not included by default with
_ISOMAC, so -include config.h needs adding to the options for these
programs as well. Together those changes allow unmodified tzcode
2017b sources to work in glibc.
Tested for x86_64.
* timezone/private.h: Update from tzcode 2017b.
* timezone/tzfile.h: Likewise.
* timezone/tzselect.ksh: Likewise.
* timezone/zdump.c: Likewise.
* timezone/zic.c: Likewise.
* timezone/Makefile (tz-cflags): Add -D_ISOMAC
-DTZ_DOMAIN='"libc"' -include $(common-objpfx)config.h.
* time/tzset.c (SECSPERDAY): New macro.
The Summary is now generated from @standards, and syntax-checking is
performed. If invalid @standards syntax is detected, summary.pl will
fail, reporting all errors. Failure and error reporting is disabled
for now, however, since much of the manual is still incomplete
wrt. header and standards annotations.
Note that the sorting order of the Summary has changed; summary.pl
respects the locale, like summary.awk did, but the use of LC_ALL=C is
introduced in the Makefile. Other notable deviations are improved
detection of the annotated elements' names, which are used for
sorting, and improved detection of the @node used to reference into
the manual. The most noticeable difference in the rendered Summary is
that entries may now contain multiple lines, one for each header and
standard combination.
summary.pl accepts a `--help' option, which details the expected
syntax of @standards. If errors are reported, the user is directed to
this feature for further information.
* manual/Makefile: Generate summary.texi with summary.pl.
Force use of the C locale. Update Perl dependency comment.
* manual/header.texi: Update reference to summary.awk.
* manual/macros.texi: Refer authors to `summary.pl --help'.
* manual/summary.awk: Remove file.
* manual/summary.pl: New file. Generate summary.texi, and
check for @standards-related syntax errors.
* manual/argp.texi: Convert header and standards @comments to
@standards.
* manual/arith.texi: Likewise.
* manual/charset.texi: Likewise.
* manual/conf.texi: Likewise.
* manual/creature.texi: Likewise.
* manual/crypt.texi: Likewise.
* manual/ctype.texi: Likewise.
* manual/debug.texi: Likewise.
* manual/errno.texi: Likewise.
* manual/filesys.texi: Likewise.
* manual/getopt.texi: Likewise.
* manual/job.texi: Likewise.
* manual/lang.texi: Likewise.
* manual/llio.texi: Likewise.
* manual/locale.texi: Likewise.
* manual/math.texi: Likewise.
* manual/memory.texi: Likewise.
* manual/message.texi: Likewise.
* manual/pattern.texi: Likewise.
* manual/pipe.texi: Likewise.
* manual/process.texi: Likewise.
* manual/resource.texi: Likewise.
* manual/search.texi: Likewise.
* manual/setjmp.texi: Likewise.
* manual/signal.texi: Likewise.
* manual/socket.texi: Likewise.
* manual/startup.texi: Likewise.
* manual/stdio.texi: Likewise.
* manual/string.texi: Likewise.
* manual/sysinfo.texi: Likewise.
* manual/syslog.texi: Likewise.
* manual/terminal.texi: Likewise.
* manual/threads.texi: Likewise.
* manual/time.texi: Likewise.
* manual/users.texi: Likewise.
Header and standards annotations are slated for standardization,
including being rendered in the description of functions, variables,
etc. (elements), and eventually required. This commit adds @standards
dummy macros so we can convert all existing annotations to the new
framework while maintaining the rendered status quo.
There needs to be a way to disambiguate annotations in lists of @*x
elements, where a common description is shared but some elements may
have different headers or standards. The @standardsx macro fills this
role by accepting an additional parameter: the name of the annotated
element.
* manual/macros.texi (@standards): New macro. Provide
placeholder for header and standards annotations.
(@standardsx): New macro. Likewise, for lists of @*x
elements.
This patch consolidates Linux sync_file_range at default
sysdeps/unix/sysv/linux/sync_file_range.c implementation. It also
moves the rules flags from generic io/Makefile to Linux one due the
fact it is a Linux-only symbol.
Checked on i686-linux-gnu and x86_64-linux-gnu.
* io/Makefile (CFLAGS-sync_file_range.c): Remove rule.
* sysdeps/unix/sysv/linux/Makefile (CFLAGS-sync_file_range.c): New
rule.
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list: Remove
sync_file_range.
This patch adds an option to test to add small command line option
through CMDLINE_OPTSTRING define. For instance:
#define CMDLINE_OPTSTRING "vd"
static void
cmdline_process_function (int c)
{
switch (c):
'v':
/* process '-v' option. */
break;
'd':
/* process '-d' option. */
break;
}
#define CMDLINE_PROCESS cmdline_process_function
It will add both '-v' and '-d' along with already default long options.
* support/support_test_main.c (support_test_main): Use optstring
member for option string in getopt_long.
* support/test-driver.c: Add comment about CMDLINE_OPTSTRING.
(CMDLINE_OPTSTRING): New define.
* support/test-driver.h (test_config): Add optstring member.
Implement strcspn/strpbrk/strspn IFUNC selectors in C
All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register. For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized. Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for strcspn/strpbrk/strspn functions within libc.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
strcspn-sse2, strpbrk-sse2 and strspn-sse2.
* sysdeps/x86_64/strcspn.S (STRPBRK_P): Removed.
Check USE_AS_STRPBRK instead of STRPBRK_P.
* sysdeps/x86_64/strpbrk.S (USE_AS_STRPBRK): New.
* sysdeps/x86_64/multiarch/ifunc-sse4_2.h: New file.
* sysdeps/x86_64/multiarch/strcspn-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/strcspn.c: Likewise.
* sysdeps/x86_64/multiarch/strpbrk-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/strpbrk.c: Likewise.
* sysdeps/x86_64/multiarch/strspn-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/strspn.c: Likewise.
* sysdeps/x86_64/multiarch/strcspn.S: Removed.
* sysdeps/x86_64/multiarch/strpbrk.S: Likewise.
* sysdeps/x86_64/multiarch/strspn.S: Likewise.
* sysdeps/x86_64/multiarch/strpbrk-c.c: Remove "#ifdef SHARED"
and "#endif".
Implement strcat family IFUNC selectors in C.
All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register. For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized. Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for strcat family functions within libc.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
strcat-sse2.
* sysdeps/x86_64/multiarch/strcat-sse2.S: New file.
* sysdeps/x86_64/multiarch/strcat.c: Likewise.
* sysdeps/x86_64/multiarch/strncat.c: Likewise.
* sysdeps/x86_64/multiarch/strcat.S: Removed.
* sysdeps/x86_64/multiarch/strncat.S: Likewise.
Implement memcmp family IFUNC selectors in C.
All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register. For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized. Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for memcmp family functions within libc.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
memcmp-sse2.
* sysdeps/x86_64/multiarch/ifunc-memcmp.h: New file.
* sysdeps/x86_64/multiarch/memcmp-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/memcmp.c: Likewise.
* sysdeps/x86_64/multiarch/wmemcmp.c: Likewise.
* sysdeps/x86_64/multiarch/memcmp.S: Removed.
* sysdeps/x86_64/multiarch/wmemcmp.S: Likewise.
Implement memset family IFUNC selectors in C.
All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register. For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized. Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for memset functions within libc.
2017-06-07 H.J. Lu <hongjiu.lu@intel.com>
Erich Elsen <eriche@google.com>
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
memset-sse2-unaligned-erms, and memset_chk-nonshared.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add test for __memset_chk_erms.
Update comments.
* sysdeps/x86_64/multiarch/ifunc-memset.h: New file.
* sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Likewise.
* sysdeps/x86_64/multiarch/memset.c: Likewise.
* sysdeps/x86_64/multiarch/memset_chk-nonshared.S: Likewise.
* sysdeps/x86_64/multiarch/memset_chk.c: Likewise.
* sysdeps/x86_64/multiarch/memset.S: Removed.
* sysdeps/x86_64/multiarch/memset_chk.S: Likewise.
* sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
(__memset_chk_erms): New function.
All of the major architectures are adopting tunables as a way to add
tuning to the library, from hwcap_mask for aarch64 to HLE for s390 and
ifunc and cache geometry for x86. Given this adoption and the fact
that we don't want additional tuning knobs to be added outside of
tunables, it makes sense to enable tunables by default using this
trivial patch.
Smoke tested on x86 to ensure that tunables code was built without
specifying it as a configure flag. I have kept it as --enabled and
not changed it to --disable since we want to still keep the option of
different kinds of front-ends for tunables.
* configure.ac(--enable-tunables): Enable by default.
* configure: Regenerate.
* NEWS: Mention change.
* manual/install.texi (enable-tunables): Adjust documentation.
* INSTALL: Regenerate.
Current allocate_stack logic for create stacks is to first mmap all
the required memory with the desirable memory and then mprotect the
guard area with PROT_NONE if required. Although it works as expected,
it pessimizes the allocation because it requires the kernel to actually
increase commit charge (it counts against the available physical/swap
memory available for the system).
The only issue is to actually check this change since side-effects are
really Linux specific and to actually account them it would require a
kernel specific tests to parse the system wide information. On the kernel
I checked /proc/self/statm does not show any meaningful difference for
vmm and/or rss before and after thread creation. I could only see
really meaningful information checking on system wide /proc/meminfo
between thread creation: MemFree, MemAvailable, and Committed_AS shows
large difference without the patch. I think trying to use these
kind of information on a testcase is fragile.
The BZ#18988 reports shows that the commit pages are easily seen with
mlockall (MCL_FUTURE) (with lock all pages that become mapped in the
process) however a more straighfoward testcase shows that pthread_create
could be faster using this patch:
--
static const int inner_count = 256;
static const int outer_count = 128;
static
void *thread1(void *arg)
{
return NULL;
}
static
void *sleeper(void *arg)
{
pthread_t ts[inner_count];
for (int i = 0; i < inner_count; i++)
pthread_create (&ts[i], &a, thread1, NULL);
for (int i = 0; i < inner_count; i++)
pthread_join (ts[i], NULL);
return NULL;
}
int main(void)
{
pthread_attr_init(&a);
pthread_attr_setguardsize(&a, 1<<20);
pthread_attr_setstacksize(&a, 1134592);
pthread_t ts[outer_count];
for (int i = 0; i < outer_count; i++)
pthread_create(&ts[i], &a, sleeper, NULL);
for (int i = 0; i < outer_count; i++)
pthread_join(ts[i], NULL);
assert(r == 0);
}
return 0;
}
--
On x86_64 (4.4.0-45-generic, gcc 5.4.0) running the small benchtests
I see:
$ time ./test
real 0m3.647s
user 0m0.080s
sys 0m11.836s
While with the patch I see:
$ time ./test
real 0m0.696s
user 0m0.040s
sys 0m1.152s
So I added a pthread_create benchtest (thread_create) which check
the thread creation latency. As for the simple benchtests, I saw
improvements in thread creation on all architectures I tested the
change.
Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
arm-linux-gnueabihf, powerpc64le-linux-gnu, sparc64-linux-gnu,
and sparcv9-linux-gnu.
[BZ #18988]
* benchtests/thread_create-inputs: New file.
* benchtests/thread_create-source.c: Likewise.
* support/xpthread_attr_setguardsize.c: Likewise.
* support/Makefile (libsupport-routines): Add
xpthread_attr_setguardsize object.
* support/xthread.h: Add xpthread_attr_setguardsize prototype.
* benchtests/Makefile (bench-pthread): Add thread_create.
* nptl/allocatestack.c (allocate_stack): Call mmap with PROT_NONE and
then mprotect the required area.
Implement memmove family IFUNC selectors in C.
All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register. For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized. Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for memmove family functions within libc.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
memmove-sse2-unaligned-erms, memcpy_chk-nonshared,
mempcpy_chk-nonshared and memmove_chk-nonshared.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add tests for __memmove_chk_erms,
__memcpy_chk_erms and __mempcpy_chk_erms. Update comments.
* sysdeps/x86_64/multiarch/ifunc-memmove.h: New file.
* sysdeps/x86_64/multiarch/memcpy.c: Likewise.
* sysdeps/x86_64/multiarch/memcpy_chk-nonshared.S: Likewise.
* sysdeps/x86_64/multiarch/memcpy_chk.c: Likewise.
* sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S: Likewise.
* sysdeps/x86_64/multiarch/memmove.c: Likewise.
* sysdeps/x86_64/multiarch/memmove_chk-nonshared.S: Likewise.
* sysdeps/x86_64/multiarch/memmove_chk.c: Likewise.
* sysdeps/x86_64/multiarch/mempcpy.c: Likewise.
* sysdeps/x86_64/multiarch/mempcpy_chk-nonshared.S: Likewise.
* sysdeps/x86_64/multiarch/mempcpy_chk.c: Likewise.
* sysdeps/x86_64/multiarch/memcpy.S: Removed.
* sysdeps/x86_64/multiarch/memcpy_chk.S: Likewise.
* sysdeps/x86_64/multiarch/memmove.S: Likewise.
* sysdeps/x86_64/multiarch/memmove_chk.S: Likewise.
* sysdeps/x86_64/multiarch/mempcpy.S: Likewise.
* sysdeps/x86_64/multiarch/mempcpy_chk.S: Likewise.
* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
(__mempcpy_chk_erms): New function.
(__memmove_chk_erms): Likewise.
(__memcpy_chk_erms): New alias.
Since commit d957c4d3fa (i386: Compile
rtld-*.os with -mno-sse -mno-mmx -mfpmath=387), vector intrinsics can
no longer be used in ld.so, even if the compiled code never makes it
into the final ld.so link. This commit adds the missing IS_IN (libc)
guard to the SSE 4.2 strcspn implementation, so that it can be used from
ld.so in the future.
This is fairly complicated, not because the users of __need_Emath and
__need_error_t have complicated requirements, but because the core
changes had a lot of fallout.
__need_error_t exists for gnulib compatibility in argz.h and argp.h.
error_t itself is a Hurdism, an enum containing all the E-constants,
so you can do 'p (error_t) errno' in gdb and get a symbolic value.
argz.h and argp.h use it for function return values, and they want to
fall back to 'int' when that's not available. There is no reason why
these nonstandard headers cannot just go ahead and include all of
errno.h; so we do that.
__need_Emath is defined only by .S files; what they _really_ need is
for errno.h to avoid declaring anything other than the E-constants
(e.g. 'extern int __errno_location(void);' is a syntax error in
assembly language). This is replaced with a check for __ASSEMBLER__ in
errno.h, plus a carefully documented requirement for bits/errno.h not
to define anything other than macros. That in turn has the
consequence that bits/errno.h must not define errno - fortunately, all
live ports use the same definition of errno, so I've moved it to
errno.h. The Hurd bits/errno.h must also take care not to define
error_t when __ASSEMBLER__ is defined, which involves repeating all of
the definitions twice, but it's a generated file so that's okay.
* stdlib/errno.h: Remove __need_Emath and __need_error_t logic.
Reorganize file. Declare errno here. When __ASSEMBLER__ is
defined, don't declare anything other than the E-constants.
* include/errno.h: Change conditional for exposing internal
declarations to (not _ISOMAC and not __ASSEMBLER__).
* bits/errno.h: Remove logic for __need_Emath. Document
requirements for a port-specific bits/errno.h.
* sysdeps/unix/sysv/linux/bits/errno.h
* sysdeps/unix/sysv/linux/alpha/bits/errno.h
* sysdeps/unix/sysv/linux/hppa/bits/errno.h
* sysdeps/unix/sysv/linux/mips/bits/errno.h
* sysdeps/unix/sysv/linux/sparc/bits/errno.h:
Add multiple-include guard and check against improper inclusion.
Remove __need_Emath logic. Don't declare errno here. Ensure all
constants are defined as simple integer literals. Consistent
formatting.
* sysdeps/mach/hurd/errnos.awk: Likewise. Only define error_t and
enum __error_t_codes if __ASSEMBLER__ is not defined.
* sysdeps/mach/hurd/bits/errno.h: Regenerate.
* argp/argp.h, string/argz.h: Don't define __need_error_t before
including errno.h.
* sysdeps/i386/i686/fpu/multiarch/s_cosf-sse2.S
* sysdeps/i386/i686/fpu/multiarch/s_sincosf-sse2.S
* sysdeps/i386/i686/fpu/multiarch/s_sinf-sse2.S
* sysdeps/x86_64/fpu/s_cosf.S
* sysdeps/x86_64/fpu/s_sincosf.S
* sysdeps/x86_64/fpu/s_sinf.S:
Just include errno.h; don't define __need_Emath or include
bits/errno.h directly.
__need_FOPEN_MAX wasn't being used anywhere. __need_IOV_MAX was more
complicated; the basic deal is that sys/uio.h wants to define a
constant named UIO_MAXIOV and bits/xopen_lim.h wants to define a
constant named IOV_MAX, with the same meaning. For no apparent reason
this was being handled via bits/stdio_lim.h -- stdio.h is NOT supposed
to define IOV_MAX -- and some mess in Makerules. Also, bits/uio.h on
Linux was being used as a dumping ground for extension functions.
So now we have bits/uio_lim.h, which defines __IOV_MAX.
bits/xopen_lim.h and sys/uio.h use that to define their respective
constants. We also now have bits/uio-ext.h, which is the official
Proper Home for extensions to sys/uio.h. bits/uio.h is removed, and
stdio_lim.h doesn't define IOV_MAX at all.
* bits/uio_lim.h, sysdeps/unix/sysv/linux/bits/uio_lim.h
* bits/uio-ext.h, sysdeps/unix/sysv/linux/bits/uio-ext.h: New file.
* bits/uio.h, sysdeps/unix/sysv/linux/bits/uio.h: Delete file.
* include/bits/xopen_lim.h: Use bits/uio_lim.h to get the value
for IOV_MAX.
* misc/Makefile: Install bits/uio-ext.h and bits/uio_lim.h.
Don't install bits/uio.h.
* misc/sys/uio.h: Don't include bits/uio.h. Do include
bits/types/struct_iovec.h and bits/uio_lim.h. Set UIO_MAXIOV
based on __IOV_MAX. Under __USE_GNU, also include bits/uio-ext.h.
* stdio-common/stdio_lim.h.in: Remove logic for __need_FOPEN_MAX
and __need_IOV_MAX. Don't define IOV_MAX at all.
* Makerules (stdio_lim.h): Remove logic for setting IOV_MAX.
* sysdeps/unix/sysv/linux/bits/fcntl-linux.h:
Include bits/types/struct_iovec.h, not bits/uio.h.
Use __ssize_t, not ssize_t, in function prototypes.
Don't use hard TAB for double space after period in comments.
ELFv2 functions with localentry:0 are those with a single entry point,
ie. global entry == local entry, that have no requirement on r2 or
r12 and guarantee r2 is unchanged on return. Such an external
function can be called via the PLT without saving r2 or restoring it
on return, avoiding a common load-hit-store for small functions.
This patch implements the ld.so changes necessary for this
optimization. ld.so needs to check that an optimized plt call
sequence is in fact calling a function implemented with localentry:0,
end emit a fatal error otherwise.
The elf/testobj6.c change is to stop "error while loading shared
libraries: expected localentry:0 `preload'" when running
elf/preloadtest, which we'd get otherwise.
* elf/elf.h (PPC64_OPT_LOCALENTRY): Define.
* sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Add
refsym and sym parameters. Adjust callers.
* sysdeps/aarch64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/hppa/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/m68k/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/microblaze/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/mips/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/nios2/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_fixup_plt):
Likewise.
* sysdeps/s390/s390-32/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/s390/s390-64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sh/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/tile/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.c (_dl_error_localentry): New.
(_dl_reloc_overflow): Increase buffser size. Formatting.
* sysdeps/powerpc/powerpc64/dl-machine.h (ppc64_local_entry_offset):
Delete reloc param, add refsym and sym. Check optimized plt
call stubs for localentry:0 functions. Adjust callers.
(elf_machine_fixup_plt, elf_machine_plt_conflict): Add refsym
and sym parameters. Adjust callers.
(_dl_reloc_overflow): Move attribute.
(_dl_error_localentry): Declare.
* elf/dl-runtime.c (_dl_fixup): Save original sym. Pass
refsym and sym to elf_machine_fixup_plt.
* elf/testobj6.c (preload): Call printf.
Makes __stpncpy_power8 call __memset_power8 directly rather than via an
IFUNC. Fixes a missing _mcount, and removes some redundant NOPS. The
*_is_local defines are also used in a followup patch.
* sysdeps/powerpc/powerpc64/multiarch/strncpy-power7.S: Define
MEMSET_is_local.
* sysdeps/powerpc/powerpc64/multiarch/strncpy-power8.S: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/stpncpy-power8.S: Likewise.
Define MEMSET.
* sysdeps/powerpc/powerpc64/multiarch/strstr-power7.S: Define
STRLEN_is_local, STRNLEN_is_local, and STRCHR_is_local.
* sysdeps/powerpc/powerpc64/power7/strstr.S: Likewise. Don't add
nop after local calls.
* sysdeps/powerpc/powerpc64/power7/strncpy.S: Define MEMSET_is_local.
Don't add nop after local call.
* sysdeps/powerpc/powerpc64/power8/strncpy.S: Likewise. Add missing
CALL_MCOUNT.
Zack Weinberg
Rical Jasan
Joseph Myers
Florian Weimer
Stefan Liebler
Siddhesh Poyarekar
Adhemerval Zanella
Christian Borntraeger
H.J. Lu
Alan Modra