aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv/linux/i386/gettimeofday.c
AgeCommit message (Collapse)Author
2019-10-30Use clock_gettime to implement gettimeofday.Adhemerval Zanella
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>
2019-09-07Prefer https to http for gnu.org and fsf.org URLsPaul Eggert
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
2019-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
* 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.
2018-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
* 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.
2017-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
2016-10-07i386, x86: Use libc_ifunc macro for time, gettimeofday.Stefan Liebler
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.
2016-01-04Update copyright dates with scripts/update-copyrights.Joseph Myers
2015-06-09x86: Remove vsyscall usageAdhemerval Zanella
This patch removes the vsyscall usage for x86_64 port. As indicated by kernel code comments [1], vsyscalls are a legacy ABI and its concept is problematic: - It interferes with ASLR. - It's awkward to write code that lives in kernel addresses but is callable by userspace at fixed addresses. - The whole concept is impossible for 32-bit compat userspace. - UML cannot easily virtualize a vsyscall. The VDSO is a better approach for such functionality. Tested on i686, x86_64, and x32. * sysdeps/unix/sysv/linux/i386/gettimeofday.c (__gettimeofday_syscall): Remove vsyscall fallback. * sysdeps/unix/sysv/linux/i386/time.c (__time_syscall): Likewise. * sysdeps/unix/sysv/linux/x86/gettimeofday.c (__gettimeofday_syscall): Add syscall fallback function. (gettimeofday_ifunc): Use __gettimeofday_syscall as fallback mechanism if vDSO is not present. * sysdeps/unix/sysv/linux/x86/time.c (__time_syscall): Add syscall fallback function. (time_ifunc): Use __time_syscall as fallback mechanism if vDSO is not present. * sysdeps/unix/sysv/linux/x86_64/gettimeofday.c: Remove file. * sysdeps/unix/sysv/linux/x86_64/time.c: Likewise. [1] arch/x86/kernel/vsyscall_64.c
2015-01-12Add x86 32 bit vDSO time function supportAdhemerval Zanella
Linux 3.15 adds support for clock_gettime, gettimeofday, and time vDSO (commit id 37c975545ec63320789962bf307f000f08fabd48). This patch adds GLIBC supports to use such symbol when they are avaiable. Along with x86 vDSO support, this patch cleanup x86_64 code by moving all common code to x86 common folder. Only init-first.c is different between implementations.