MIPS: OCTEON: make get_system_type() thread-safe
get_system_type() is not thread-safe on OCTEON. It uses static data, also more dangerous issue is that it's calling cvmx_fuse_read_byte() every time without any synchronization. Currently it's possible to get processes stuck looping forever in kernel simply by launching multiple readers of /proc/cpuinfo: (while true; do cat /proc/cpuinfo > /dev/null; done) & (while true; do cat /proc/cpuinfo > /dev/null; done) & ... Fix by initializing the system type string only once during the early boot. Signed-off-by: Aaro Koskinen <aaro.koskinen@nsn.com> Cc: stable@vger.kernel.org Reviewed-by: Markos Chandras <markos.chandras@imgtec.com> Patchwork: http://patchwork.linux-mips.org/patch/7437/Signed-off-by: James Hogan <james.hogan@imgtec.com>
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