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-rw-r--r--arch/x86/include/asm/vsyscall.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h
index ab60a71a8dcb98..472f0263dbc612 100644
--- a/arch/x86/include/asm/vsyscall.h
+++ b/arch/x86/include/asm/vsyscall.h
@@ -4,6 +4,7 @@
#include <linux/seqlock.h>
#include <uapi/asm/vsyscall.h>
+#include <asm/page_types.h>
#ifdef CONFIG_X86_VSYSCALL_EMULATION
extern void map_vsyscall(void);
@@ -24,4 +25,13 @@ static inline bool emulate_vsyscall(unsigned long error_code,
}
#endif
+/*
+ * The (legacy) vsyscall page is the long page in the kernel portion
+ * of the address space that has user-accessible permissions.
+ */
+static inline bool is_vsyscall_vaddr(unsigned long vaddr)
+{
+ return unlikely((vaddr & PAGE_MASK) == VSYSCALL_ADDR);
+}
+
#endif /* _ASM_X86_VSYSCALL_H */