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-rw-r--r--arch/arm64/mm/fault.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 1fdbb3704698..c7c0471e384f 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -30,9 +30,11 @@
#include <linux/highmem.h>
#include <linux/perf_event.h>
+#include <asm/cpufeature.h>
#include <asm/exception.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
+#include <asm/sysreg.h>
#include <asm/system_misc.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
@@ -225,6 +227,13 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
}
/*
+ * PAN bit set implies the fault happened in kernel space, but not
+ * in the arch's user access functions.
+ */
+ if (IS_ENABLED(CONFIG_ARM64_PAN) && (regs->pstate & PSR_PAN_BIT))
+ goto no_context;
+
+ /*
* As per x86, we may deadlock here. However, since the kernel only
* validly references user space from well defined areas of the code,
* we can bug out early if this is from code which shouldn't.
@@ -531,3 +540,10 @@ asmlinkage int __exception do_debug_exception(unsigned long addr,
return 0;
}
+
+#ifdef CONFIG_ARM64_PAN
+void cpu_enable_pan(void)
+{
+ config_sctlr_el1(SCTLR_EL1_SPAN, 0);
+}
+#endif /* CONFIG_ARM64_PAN */