setreuid.2: Small clarification to description of when saved set-user-ID is set

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
daemon.3: ATTRIBUTES: Note function that is thread-safe

The function daemon() is thread safe.

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
difftime.3: ATTRIBUTES: Note function that is thread-safe

The function difftime() is thread safe.

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
erf.3: ATTRIBUTES: Note functions that are thread-safe

The functions erf(), erff() and erfl() are thread safe.

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
erfc.3: ATTRIBUTES: Note functions that are thread-safe

The functions erfc(), erfcf() and erfcl() are thread safe.

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
erfc.3: wfix

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
futimes.3: ATTRIBUTES: Note functions that are thread-safe

The functions futimes() and lutimes() are thread safe.

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
perf_event_open.2: PERF_EVENT_IOC_PERIOD update

The PERF_EVENT_IOC_PERIOD ioctl was broken until 2.6.36,
and it turns out that the ARM architecture has some
differing behavior too.

Reported-by: Andreas Sandberg <andreas.sandberg@it.uu.se>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
perf_event_open.2: tfix

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>