Commit Graph

2 Commits

Author SHA1 Message Date
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Adhemerval Zanella
72e84d1db2 Linux: Use 32-bit vDSO for clock_gettime, gettimeofday, time (BZ# 28071)
The previous approach defeats the vDSO optimization on older kernels
because a failing clock_gettime64 system call is performed on every
function call.  It also results in a clobbered errno value, exposing
an OpenJDK bug (JDK-8270244).

This patch fixes by open-code INLINE_VSYSCALL macro and replace all
INLINE_SYSCALL_CALL with INTERNAL_SYSCALL_CALLS.  Now for
__clock_gettime64x, the 64-bit vDSO is used and the 32-bit vDSO is
tried before falling back to 64-bit syscalls.

The previous code preferred 64-bit syscall for the case where the kernel
provides 64-bit time_t syscalls *and* also a 32-bit vDSO (in this case
the *64-bit* syscall should be preferable over the vDSO).  All
architectures that provides 32-bit vDSO (i386, mips, powerpc, s390)
modulo sparc; but I am not sure if some kernels versions do provide
only 32-bit vDSO while still providing 64-bit time_t syscall.
Regardless, for such cases the 64-bit time_t syscall is used if the
vDSO returns overflowed 32-bit time_t.

Tested on i686-linux-gnu (with a time64 and non-time64 kernel),
x86_64-linux-gnu.  Built with build-many-glibcs.py.

Co-authored-by: Florian Weimer <fweimer@redhat.com>
2021-07-12 17:37:56 -03:00