kernel_optimize_test/arch/arm64
Will Deacon 9c413e25d9 arm64: debug: clear mdscr_el1 instead of taking the OS lock
During boot, we take the debug OS lock before interrupts are enabled.
This is required to prevent clearing of PSTATE.D on the interrupt entry
path, which could result in spurious debug exceptions before we've got
round to resetting things like the hardware breakpoints registers to a
sane state.

A problem with this approach is that taking the OS lock prevents an
external JTAG debugger from debugging the system, which is especially
irritating during boot, where JTAG debugging can be most useful.

This patch clears mdscr_el1 rather than taking the lock, clearing the
MDE and KDE bits and preventing self-hosted hardware debug exceptions
from occurring.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@vger.kernel.org
2013-05-13 11:44:56 +01:00
..
boot
configs
include
kernel arm64: debug: clear mdscr_el1 instead of taking the OS lock 2013-05-13 11:44:56 +01:00
lib
mm arm64: debug: clear mdscr_el1 instead of taking the OS lock 2013-05-13 11:44:56 +01:00
Kconfig
Kconfig.debug
Makefile