arm64/kernel: kaslr: reduce module randomization range to 4 GB

[mirror_ubuntu-bionic-kernel.git] / include / linux / compiler.h

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 52e611ab9a6cf6fde23dae53784f01bfb06ce448..c062238f408c46dbdb465fa4b907a5894c49ef86 100644 (file)
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -21,7 +21,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 #define unlikely_notrace(x)    __builtin_expect(!!(x), 0)
 
 #define __branch_check__(x, expect, is_constant) ({                    \
-                       int ______r;                                    \
+                       long ______r;                                   \
                        static struct ftrace_likely_data                \
                                __attribute__((__aligned__(4)))         \
                                __attribute__((section("_ftrace_annotated_branch"))) \
@@ -86,6 +86,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 # define barrier_data(ptr) barrier()
 #endif
 
+/* workaround for GCC PR82365 if needed */
+#ifndef barrier_before_unreachable
+# define barrier_before_unreachable() do { } while (0)
+#endif
+
 /* Unreachable code */
 #ifdef CONFIG_STACK_VALIDATION
 /*
@@ -185,23 +190,21 @@ void __read_once_size(const volatile void *p, void *res, int size)
 
 #ifdef CONFIG_KASAN
 /*
- * This function is not 'inline' because __no_sanitize_address confilcts
+ * We can't declare function 'inline' because __no_sanitize_address confilcts
  * with inlining. Attempt to inline it may cause a build failure.
  *     https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
  * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
  */
-static __no_sanitize_address __maybe_unused
-void __read_once_size_nocheck(const volatile void *p, void *res, int size)
-{
-       __READ_ONCE_SIZE;
-}
+# define __no_kasan_or_inline __no_sanitize_address __maybe_unused
 #else
-static __always_inline
+# define __no_kasan_or_inline __always_inline
+#endif
+
+static __no_kasan_or_inline
 void __read_once_size_nocheck(const volatile void *p, void *res, int size)
 {
        __READ_ONCE_SIZE;
 }
-#endif
 
 static __always_inline void __write_once_size(volatile void *p, void *res, int size)
 {
@@ -240,6 +243,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
  * required ordering.
  */
 #include <asm/barrier.h>
+#include <linux/kasan-checks.h>
 
 #define __READ_ONCE(x, check)                                          \
 ({                                                                     \
@@ -259,6 +263,13 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
  */
 #define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0)
 
+static __no_kasan_or_inline
+unsigned long read_word_at_a_time(const void *addr)
+{
+       kasan_check_read(addr, 1);
+       return *(unsigned long *)addr;
+}
+
 #define WRITE_ONCE(x, val) \
 ({                                                     \
        union { typeof(x) __val; char __c[1]; } __u =   \
@@ -271,6 +282,10 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 
 #endif /* __ASSEMBLY__ */
 
+#ifndef __optimize
+# define __optimize(level)
+#endif
+
 /* Compile time object size, -1 for unknown */
 #ifndef __compiletime_object_size
 # define __compiletime_object_size(obj) -1
@@ -280,29 +295,14 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 #endif
 #ifndef __compiletime_error
 # define __compiletime_error(message)
-/*
- * Sparse complains of variable sized arrays due to the temporary variable in
- * __compiletime_assert. Unfortunately we can't just expand it out to make
- * sparse see a constant array size without breaking compiletime_assert on old
- * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
- */
-# ifndef __CHECKER__
-#  define __compiletime_error_fallback(condition) \
-       do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
-# endif
-#endif
-#ifndef __compiletime_error_fallback
-# define __compiletime_error_fallback(condition) do { } while (0)
 #endif
 
 #ifdef __OPTIMIZE__
 # define __compiletime_assert(condition, msg, prefix, suffix)          \
        do {                                                            \
-               bool __cond = !(condition);                             \
                extern void prefix ## suffix(void) __compiletime_error(msg); \
-               if (__cond)                                             \
+               if (!(condition))                                       \
                        prefix ## suffix();                             \
-               __compiletime_error_fallback(__cond);                   \
        } while (0)
 #else
 # define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)