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Consolidate generic gettimeofday implementation to use clock_gettime.
Linux ports that still provide gettimeofday through vDSO are not
changed.
Remove sysdeps/unix/clock_gettime.c, which implemented clock_gettime
using gettimeofday; new OS ports must provide a real implementation of
clock_gettime.
Rename sysdeps/mach/gettimeofday.c to sysdeps/mach/clock_gettime.c and
convert into an implementation of clock_gettime. It only supports
CLOCK_REALTIME; Mach does not appear to have any support for monotonic
clocks. It uses __host_get_time, which provides at best microsecond
resolution. Hurd is currently using sysdeps/posix/clock_getres.c for
clock_getres; its output for CLOCK_REALTIME is based on
sysconf (_SC_CLK_TCK), and I do not know whether that gives the
correct result.
Unlike settimeofday, there are no known uses of gettimeofday's
vestigial "get time zone" feature that are not bugs. (The per-process
timezone support in localtime and friends is unrelated, and the
programs that set the kernel's offset between the hardware clock and
UTC do not need to read it back.) Therefore, this feature is dummied
out. Henceforth, if gettimeofday's "struct timezone" argument is not
NULL, it will write zeroes to both fields. Any program that is
actually looking at this data will thus think it is running in UTC,
which is probably more correct than whatever it was doing before.
[__]gettimeofday no longer has any internal callers, so we can now
remove its internal prototype and PLT bypass aliases. The
__gettimeofday@GLIBC_2.0 export remains, in case it is used by any
third-party code.
It also allows to simplify the arch-specific implementation on x86 and
powerpc to remove the hack to disable the internal route to non iFUNC
variant for internal symbol.
This patch also fixes a missing optimization on aarch64, powerpc, and
x86 where the code used on static build do not use the vDSO.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Co-authored-by: Zack Weinberg <zackw@panix.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
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Linux/Alpha has two versions of several system call wrappers that take
or return data of type "struct timeval" (possibly nested inside a
larger structure). The GLIBC_2.0 version is a compat symbol that
calls __NR_osf_foo or __NR_old_foo and uses a struct timeval with a
32-bit tv_sec field. The GLIBC_2.1 version is used for current code,
calls __NR_foo, and uses a struct timeval with a 64-bit tv_sec field.
This patch changes all of the compat symbols of this type to be
wrappers around their GLIBC_2.1 counterparts; the compatibility system
calls will no longer be used. It serves as a proposal for part of how
we do the transition to 64-bit time_t on systems that currently use
32-bit time_t:
* The patched glibc will NOT use system calls that involve 32-bit
time_t to implement its compatibility symbols. This will make both
our lives and the kernel maintainers' lives easier. The primary
argument I've seen against it is that the kernel could warn about
uses of the old system calls, helping people find old binaries that
need to be recompiled. I think there are several other ways we
could accomplish this, e.g. scripts to scan the filesystem for
binaries with references to the old symbol versions, or issuing
diagnostics ourselves.
* The compat symbols do NOT report failure after the Y2038 deadline.
An earlier revision of this patch had them return -1 and set errno
to EOVERFLOW, but Adhemerval pointed out that many of them have
already performed side effects at the point where we discover the
overflow, so that would break more than it fixes. Also, we don't
want people to be _checking_ for EOVERFLOW from these functions; we
want them to recompile with 64-bit time_t. So it's not actually
useful for them to report failure to the calling code.
* What they do do, when they encounter overflow, is saturate the
overflowed "struct timeval"(s): tv_sec is set to INT32_MAX and
tv_nsec is set to 999999. That means time stops advancing for
programs with 32-bit time_t when they reach the deadline. That's
obviously going to break stuff, but I think wrapping around is
probably going to break _more_ stuff. I'd be interested to hear
arguments against, if anyone has one.
The new header file tv32-compat.h is currently Alpha-specific but I
mean for it to be reused to aid in writing wrappers for all affected
architectures. I only put it in sysdeps/unix/sysv/linux/alpha for now
because I haven't checked whether the various "foo32" structures it
defines agree with the ABI for ports other than Linux/Alpha.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:
sed -ri '
s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
$(find $(git ls-files) -prune -type f \
! -name '*.po' \
! -name 'ChangeLog*' \
! -path COPYING ! -path COPYING.LIB \
! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
! -path manual/texinfo.tex ! -path scripts/config.guess \
! -path scripts/config.sub ! -path scripts/install-sh \
! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
! -path INSTALL ! -path locale/programs/charmap-kw.h \
! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
! '(' -name configure \
-execdir test -f configure.ac -o -f configure.in ';' ')' \
! '(' -name preconfigure \
-execdir test -f preconfigure.ac ';' ')' \
-print)
and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:
chmod a+x sysdeps/unix/sysv/linux/riscv/configure
# Omit irrelevant whitespace and comment-only changes,
# perhaps from a slightly-different Autoconf version.
git checkout -f \
sysdeps/csky/configure \
sysdeps/hppa/configure \
sysdeps/riscv/configure \
sysdeps/unix/sysv/linux/csky/configure
# Omit changes that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
git checkout -f \
sysdeps/powerpc/powerpc64/ppc-mcount.S \
sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
# Omit change that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
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* All files with FSF copyright notices: Update copyright dates
using scripts/update-copyrights.
* locale/programs/charmap-kw.h: Regenerated.
* locale/programs/locfile-kw.h: Likewise.
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* All files with FSF copyright notices: Update copyright dates
using scripts/update-copyrights.
* locale/programs/charmap-kw.h: Regenerated.
* locale/programs/locfile-kw.h: Likewise.
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This patch removes the architecture specific gettimeofday implementation
to use the vDSO symbol and consolidate it on a common Linux one.
Similar to clock_gettime and clock_getres vDSO implementation, each port
that supports gettimeofday through vDSO should just implement INLINE_VSYSCALL
to access the symbol and define HAVE_{GETTIME,GETRES}_VSYSCAL as 1.
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