coresight: etm4x: Fix input validation for sysfs.

coresight: etm4x: Fix input validation for sysfs.

BugLink: https://bugs.launchpad.net/bugs/1857158
commit 2fe6899e36aa174abefd017887f9cfe0cb60c43a upstream.

A number of issues are fixed relating to sysfs input validation:-

1) bb_ctrl_store() - incorrect compare of bit select field to absolute
value. Reworked per ETMv4 specification.
2) seq_event_store() - incorrect mask value - register has two
event values.
3) cyc_threshold_store() - must mask with max before checking min
otherwise wrapped values can set illegal value below min.
4) res_ctrl_store() - update to mask off all res0 bits.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Fixes: a77de2637c9eb ("coresight: etm4x: moving sysFS entries to a dedicated file")
Cc: stable <stable@vger.kernel.org> # 4.9+
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20191104181251.26732-6-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>