Re: [PATCH] MIPS: OCTEON: make get_system_type() thread-safe

Markos Chandras
2014-07-22T12:32:04Z

On 07/22/2014 12:51 PM, Aaro Koskinen wrote:
> 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
> ---
> arch/mips/cavium-octeon/setup.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>

It looks reasonable to me.

Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>

--
markos