The DBGVCR, used for configuring vector catch debug events, is UNKNOWN out of reset on ARMv7. When enabling monitor mode, this must be zeroed to avoid UNPREDICTABLE behaviour.
This patch adds the zeroing code to the debug reset path. Cc: stable <[email protected]> Reported-by: Stepan Moskovchenko <[email protected]> Signed-off-by: Will Deacon <[email protected]> KernelVersion: 2.6.39-rc1 --- arch/arm/kernel/hw_breakpoint.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 8dbc126..87acc25 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -868,6 +868,13 @@ static void reset_ctrl_regs(void *info) */ asm volatile("mcr p14, 0, %0, c1, c0, 4" : : "r" (0)); isb(); + + /* + * Clear any configured vector-catch events before + * enabling monitor mode. + */ + asm volatile("mcr p14, 0, %0, c0, c7, 0" : : "r" (0)); + isb(); } if (enable_monitor_mode()) -- 1.7.0.4 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
