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authorAaro Koskinen <aaro.koskinen@nsn.com>2014-07-22 14:51:08 +0300
committerRalf Baechle <ralf@linux-mips.org>2014-08-19 18:24:42 +0200
commit608308682addfdc7b8e2aee88f0e028331d88e4d (patch)
treedbf68401067b7d6582d55705afb23ab374c57329 /arch/mips/cavium-octeon
parent6521d9a436a62e83ce57d6be6e5484e1098c1380 (diff)
downloadlinux-608308682addfdc7b8e2aee88f0e028331d88e4d.tar.bz2
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>
Diffstat (limited to 'arch/mips/cavium-octeon')
-rw-r--r--arch/mips/cavium-octeon/setup.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index dba7cf7656c7..38f4c32e2816 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -457,6 +457,18 @@ static void octeon_halt(void)
octeon_kill_core(NULL);
}
+static char __read_mostly octeon_system_type[80];
+
+static int __init init_octeon_system_type(void)
+{
+ snprintf(octeon_system_type, sizeof(octeon_system_type), "%s (%s)",
+ cvmx_board_type_to_string(octeon_bootinfo->board_type),
+ octeon_model_get_string(read_c0_prid()));
+
+ return 0;
+}
+early_initcall(init_octeon_system_type);
+
/**
* Return a string representing the system type
*
@@ -464,11 +476,7 @@ static void octeon_halt(void)
*/
const char *octeon_board_type_string(void)
{
- static char name[80];
- sprintf(name, "%s (%s)",
- cvmx_board_type_to_string(octeon_bootinfo->board_type),
- octeon_model_get_string(read_c0_prid()));
- return name;
+ return octeon_system_type;
}
const char *get_system_type(void)