+extern const vm_offset_t vm_min_kernel_address;
+extern const vm_offset_t vm_max_kernel_address;
+
+extern vm_offset_t vm_kernel_stext;
+extern vm_offset_t vm_kernel_etext;
+extern vm_offset_t vm_kernel_slid_base;
+extern vm_offset_t vm_kernel_slid_top;
+extern vm_offset_t vm_kernel_slide;
+extern vm_offset_t vm_kernel_addrperm;
+extern vm_offset_t vm_kext_base;
+extern vm_offset_t vm_kext_top;
+extern vm_offset_t vm_kernel_base;
+extern vm_offset_t vm_kernel_top;
+extern vm_offset_t vm_hib_base;
+
+#define VM_KERNEL_IS_SLID(_o) \
+ (((vm_offset_t)(_o) >= vm_kernel_slid_base) && \
+ ((vm_offset_t)(_o) < vm_kernel_slid_top))
+
+#define VM_KERNEL_SLIDE(_u) \
+ ((vm_offset_t)(_u) + vm_kernel_slide)
+
+/*
+ * The following macros are to be used when exposing kernel addresses to
+ * userspace via any of the various debug or info facilities that might exist
+ * (e.g. stackshot, proc_info syscall, etc.). It is important to understand
+ * the goal of each macro and choose the right one depending on what you are
+ * trying to do. Misuse of these macros can result in critical data leaks
+ * which in turn lead to all sorts of system vulnerabilities. It is invalid to
+ * call these macros on a non-kernel address (NULL is allowed).
+ *
+ * VM_KERNEL_UNSLIDE:
+ * Use this macro when you are exposing an address to userspace which is
+ * *guaranteed* to be a "static" kernel or kext address (i.e. coming from text
+ * or data sections). These are the addresses which get "slid" via ASLR on
+ * kernel or kext load, and it's precisely the slide value we are trying to
+ * protect from userspace.
+ *
+ * VM_KERNEL_ADDRHIDE:
+ * Use when exposing an address for internal purposes: debugging, tracing,
+ * etc. The address will be unslid if necessary. Other addresses will be
+ * hidden on customer builds, and unmodified on internal builds.
+ *
+ * VM_KERNEL_ADDRHASH:
+ * Use this macro when exposing a kernel address to userspace on customer
+ * builds. The address can be from the static kernel or kext regions, or the
+ * kernel heap. The address will be unslid or hashed as appropriate.
+ *
+ *
+ * ** SECURITY WARNING: The following macros can leak kernel secrets.
+ * Use *only* in performance *critical* code.
+ *
+ * VM_KERNEL_ADDRPERM:
+ * VM_KERNEL_UNSLIDE_OR_PERM:
+ * Use these macros when exposing a kernel address to userspace on customer
+ * builds. The address can be from the static kernel or kext regions, or the
+ * kernel heap. The address will be unslid or permuted as appropriate.
+ *
+ * Nesting of these macros should be considered invalid.
+ */
+
+__BEGIN_DECLS
+extern vm_offset_t vm_kernel_addrhash(vm_offset_t addr);
+__END_DECLS
+
+#define __DO_UNSLIDE(_v) ((vm_offset_t)(_v) - vm_kernel_slide)
+
+#if DEBUG || DEVELOPMENT
+# define VM_KERNEL_ADDRHIDE(_v) (VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_address_t)(_v))
+#else
+# define VM_KERNEL_ADDRHIDE(_v) (VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_address_t)0)
+#endif
+
+#define VM_KERNEL_ADDRHASH(_v) vm_kernel_addrhash((vm_offset_t)(_v))
+
+#define VM_KERNEL_UNSLIDE_OR_PERM(_v) ({ \
+ VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : \
+ VM_KERNEL_ADDRESS(_v) ? ((vm_offset_t)(_v) + vm_kernel_addrperm) : \
+ (vm_offset_t)(_v); \
+ })
+
+#define VM_KERNEL_UNSLIDE(_v) ({ \
+ VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_offset_t)0; \
+ })
+
+#define VM_KERNEL_ADDRPERM(_v) VM_KERNEL_UNSLIDE_OR_PERM(_v)
+
+#undef mach_vm_round_page
+#undef round_page
+#undef round_page_32
+#undef round_page_64
+
+static inline mach_vm_offset_t
+mach_vm_round_page(mach_vm_offset_t x)
+{
+ if (round_page_overflow(x, &x)) {
+ panic("overflow detected");
+ }
+ return x;
+}
+
+static inline vm_offset_t
+round_page(vm_offset_t x)
+{
+ if (round_page_overflow(x, &x)) {
+ panic("overflow detected");
+ }
+ return x;
+}
+
+static inline mach_vm_offset_t
+round_page_64(mach_vm_offset_t x)
+{
+ if (round_page_overflow(x, &x)) {
+ panic("overflow detected");
+ }
+ return x;
+}
+
+static inline uint32_t
+round_page_32(uint32_t x)
+{
+ if (round_page_overflow(x, &x)) {
+ panic("overflow detected");
+ }
+ return x;
+}
+
projects / apple / xnu.git / blobdiff