posix-cpu-timers: Make set_process_cpu_timer() more robust
authorMax R. P. Grossmann <m@max.pm>
Mon, 8 Jan 2018 19:01:57 +0000 (20:01 +0100)
committerThomas Gleixner <tglx@linutronix.de>
Sun, 14 Jan 2018 19:50:59 +0000 (20:50 +0100)
commita9445e47d897054876b8f43e46dc5a3eca2b844d
treed41dc9179e6aea71584e6276b7dcf261d4d1ed49
parent103bb56a2831bfc7f2d442da9e47f89f37d34952
posix-cpu-timers: Make set_process_cpu_timer() more robust

Because the return value of cpu_timer_sample_group() is not checked,
compilers and static checkers can legitimately warn about a potential use
of the uninitialized variable 'now'. This is not a runtime issue as all call
sites hand in valid clock ids.

Also cpu_timer_sample_group() is invoked unconditionally even when the
result is not used because *oldval is NULL.

Make the invocation conditional and check the return value.

[ tglx: Massage changelog ]

Signed-off-by: Max R. P. Grossmann <m@max.pm>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/20180108190157.10048-1-m@max.pm
kernel/time/posix-cpu-timers.c