1 files changed, 109 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mpx.h b/arch/x86/include/asm/mpx.h
new file mode 100644
index 000000000..61eb4b63c
--- /dev/null
+++ b/arch/x86/include/asm/mpx.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_MPX_H
+#define _ASM_X86_MPX_H
+
+#include <linux/types.h>
+#include <linux/mm_types.h>
+
+#include <asm/ptrace.h>
+#include <asm/insn.h>
+
+/*
+ * NULL is theoretically a valid place to put the bounds
+ * directory, so point this at an invalid address.
+ */
+#define MPX_INVALID_BOUNDS_DIR	((void __user *)-1)
+#define MPX_BNDCFG_ENABLE_FLAG	0x1
+#define MPX_BD_ENTRY_VALID_FLAG	0x1
+
+/*
+ * The upper 28 bits [47:20] of the virtual address in 64-bit
+ * are used to index into bounds directory (BD).
+ *
+ * The directory is 2G (2^31) in size, and with 8-byte entries
+ * it has 2^28 entries.
+ */
+#define MPX_BD_SIZE_BYTES_64	(1UL<<31)
+#define MPX_BD_ENTRY_BYTES_64	8
+#define MPX_BD_NR_ENTRIES_64	(MPX_BD_SIZE_BYTES_64/MPX_BD_ENTRY_BYTES_64)
+
+/*
+ * The 32-bit directory is 4MB (2^22) in size, and with 4-byte
+ * entries it has 2^20 entries.
+ */
+#define MPX_BD_SIZE_BYTES_32	(1UL<<22)
+#define MPX_BD_ENTRY_BYTES_32	4
+#define MPX_BD_NR_ENTRIES_32	(MPX_BD_SIZE_BYTES_32/MPX_BD_ENTRY_BYTES_32)
+
+/*
+ * A 64-bit table is 4MB total in size, and an entry is
+ * 4 64-bit pointers in size.
+ */
+#define MPX_BT_SIZE_BYTES_64	(1UL<<22)
+#define MPX_BT_ENTRY_BYTES_64	32
+#define MPX_BT_NR_ENTRIES_64	(MPX_BT_SIZE_BYTES_64/MPX_BT_ENTRY_BYTES_64)
+
+/*
+ * A 32-bit table is 16kB total in size, and an entry is
+ * 4 32-bit pointers in size.
+ */
+#define MPX_BT_SIZE_BYTES_32	(1UL<<14)
+#define MPX_BT_ENTRY_BYTES_32	16
+#define MPX_BT_NR_ENTRIES_32	(MPX_BT_SIZE_BYTES_32/MPX_BT_ENTRY_BYTES_32)
+
+#define MPX_BNDSTA_TAIL		2
+#define MPX_BNDCFG_TAIL		12
+#define MPX_BNDSTA_ADDR_MASK	(~((1UL<<MPX_BNDSTA_TAIL)-1))
+#define MPX_BNDCFG_ADDR_MASK	(~((1UL<<MPX_BNDCFG_TAIL)-1))
+#define MPX_BNDSTA_ERROR_CODE	0x3
+
+#ifdef CONFIG_X86_INTEL_MPX
+siginfo_t *mpx_generate_siginfo(struct pt_regs *regs);
+int mpx_handle_bd_fault(void);
+static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
+{
+	return (mm->context.bd_addr != MPX_INVALID_BOUNDS_DIR);
+}
+static inline void mpx_mm_init(struct mm_struct *mm)
+{
+	/*
+	 * NULL is theoretically a valid place to put the bounds
+	 * directory, so point this at an invalid address.
+	 */
+	mm->context.bd_addr = MPX_INVALID_BOUNDS_DIR;
+}
+void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
+		      unsigned long start, unsigned long end);
+
+unsigned long mpx_unmapped_area_check(unsigned long addr, unsigned long len,
+		unsigned long flags);
+#else
+static inline siginfo_t *mpx_generate_siginfo(struct pt_regs *regs)
+{
+	return NULL;
+}
+static inline int mpx_handle_bd_fault(void)
+{
+	return -EINVAL;
+}
+static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
+{
+	return 0;
+}
+static inline void mpx_mm_init(struct mm_struct *mm)
+{
+}
+static inline void mpx_notify_unmap(struct mm_struct *mm,
+				    struct vm_area_struct *vma,
+				    unsigned long start, unsigned long end)
+{
+}
+
+static inline unsigned long mpx_unmapped_area_check(unsigned long addr,
+		unsigned long len, unsigned long flags)
+{
+	return addr;
+}
+#endif /* CONFIG_X86_INTEL_MPX */
+
+#endif /* _ASM_X86_MPX_H */