From 6fda41bf12615ee7c3ddac88155099b1a8cf8d00 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Mon, 8 Apr 2019 18:17:18 +0100 Subject: [PATCH] arm64: Clear OSDLR_EL1 on CPU boot Some firmwares may reboot CPUs with OS Double Lock set. Make sure that it is unlocked, in order to use debug exceptions. Cc: Signed-off-by: Jean-Philippe Brucker Signed-off-by: Will Deacon --- arch/arm64/kernel/debug-monitors.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index 800486cc..555b6bd 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -135,6 +135,7 @@ 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; -- 2.7.4