The patch below does not apply to the 3.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 33d9a530d4a87c5d645cfc82f23108ca8d89aa78 Mon Sep 17 00:00:00 2001 From: Aaro Koskinen <[email protected]> Date: Tue, 22 Jul 2014 14:51:08 +0300 Subject: [PATCH] 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 <[email protected]> Cc: [email protected] Reviewed-by: Markos Chandras <[email protected]> Patchwork: http://patchwork.linux-mips.org/patch/7437/ Signed-off-by: James Hogan <[email protected]> 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) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
