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authorJean-Philippe Brucker <jean-philippe.brucker@arm.com>2019-04-08 18:17:18 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-21 18:50:14 +0200
commit6728b5409e1f35ec371a9eac21ca13fe86fa6056 (patch)
tree7efdd11f96a22971245eb163c3ad9348a71c931a
parent45514ea4f2298e8bab3597c33ed24d5bbb0abf09 (diff)
arm64: Clear OSDLR_EL1 on CPU boot
commit 6fda41bf12615ee7c3ddac88155099b1a8cf8d00 upstream. Some firmwares may reboot CPUs with OS Double Lock set. Make sure that it is unlocked, in order to use debug exceptions. Cc: <stable@vger.kernel.org> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/arm64/kernel/debug-monitors.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index c7ef99904934..edb63bf2ac1c 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -133,6 +133,7 @@ NOKPROBE_SYMBOL(disable_debug_monitors);
*/
static int clear_os_lock(unsigned int cpu)
{
+ write_sysreg(0, osdlr_el1);
write_sysreg(0, oslar_el1);
isb();
return 0;