fopen should set the FD_CLOEXEC flag if requested evenif the kernel does
not support an aotmic operation.
freopen should reuse the file descriptor for the stream. This is
especially important for calls to change the standard streams (stin,
stdout, stderr).
When dynamically loading a library along with several dependencies, calls to
_dl_add_to_slotinfo and _dl_update_slotinfo can become intermixed. As a
consequence, _dl_update_slotinfo will update the generation counter of the dtv
although not all of the slots belonging to that generation have been added.
Subsequent calls to _dl_add_to_slotinfo will add more slots to the same
generation, for which no storage will be allocated, as the dtv generation
checks will claim no work is necessary. This will lead to uninitialized dtv
entries and will likely cause a SIGSEGV when thread local variables are
accessed.
If iconv is called more than once in a row for adding bytes to the sequence
while still remain under the minimum size of a character and if STORE_REST
is defined, we didn't consume any input. Fix that.
Together with a previous patch which introduced the initgroups
entry in nsswitch.conf this patch allows more customization of
the lookups for initgroups/getgrouplist. Nothing changes if
the groups entry in nsswitch.conf is used. If the initgroups entry
is used instead the code now doesn't automatically continue looking
for more entries aftedr a successful lookup. Instead the normal
rules are followed which do specify that by default no more
service is consulted. This can be overwritten with
[SUCCESS=continue]
appropriately placed in the line.
The getcwd syscall (so far?) can only handle path up to one page
in size. There is no limit about directory hierarchy depth, though,
and the POSIX getcwd is supposed to handle this. In that case fall
back to the generic getcwd.
Additionally, optimize the generic getcwd to use openat when possible
to change the asymptotic performance from O(N^2) to O(n).
