MIPS: OCTEON: make get_system_type() thread-safe

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commit 608308682a upstream.

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>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Aaro Koskinen 2014-07-22 14:51:08 +03:00 • committed by Greg Kroah-Hartman

parent d0fe2a761f

commit fd32ecad8e

1 changed files with 13 additions and 5 deletions

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arch/mips/cavium-octeon/setup.c

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