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Diffstat (limited to 'arch/arm64/mm/fault.c')
-rw-r--r--arch/arm64/mm/fault.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 53d9159662fe..0f8788374815 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -29,7 +29,9 @@
#include <linux/sched.h>
#include <linux/highmem.h>
#include <linux/perf_event.h>
+#include <linux/preempt.h>
+#include <asm/bug.h>
#include <asm/cpufeature.h>
#include <asm/exception.h>
#include <asm/debug-monitors.h>
@@ -670,9 +672,17 @@ asmlinkage int __exception do_debug_exception(unsigned long addr,
NOKPROBE_SYMBOL(do_debug_exception);
#ifdef CONFIG_ARM64_PAN
-void cpu_enable_pan(void *__unused)
+int cpu_enable_pan(void *__unused)
{
+ /*
+ * We modify PSTATE. This won't work from irq context as the PSTATE
+ * is discarded once we return from the exception.
+ */
+ WARN_ON_ONCE(in_interrupt());
+
config_sctlr_el1(SCTLR_EL1_SPAN, 0);
+ asm(SET_PSTATE_PAN(1));
+ return 0;
}
#endif /* CONFIG_ARM64_PAN */
@@ -683,8 +693,9 @@ void cpu_enable_pan(void *__unused)
* We need to enable the feature at runtime (instead of adding it to
* PSR_MODE_EL1h) as the feature may not be implemented by the cpu.
*/
-void cpu_enable_uao(void *__unused)
+int cpu_enable_uao(void *__unused)
{
asm(SET_PSTATE_UAO(1));
+ return 0;
}
#endif /* CONFIG_ARM64_UAO */