vppinfra: asan: fix overflow support

[vpp.git] / src / vppinfra / sanitizer.h

diff --git a/src/vppinfra/sanitizer.h b/src/vppinfra/sanitizer.h
index db4daea..658d828 100644 (file)
--- a/src/vppinfra/sanitizer.h
+++ b/src/vppinfra/sanitizer.h
@@ -5,25 +5,92 @@
 
 #include <sanitizer/asan_interface.h>
 #include <vppinfra/clib.h>
+#include <vppinfra/error_bootstrap.h>
+
+typedef struct
+{
+  size_t shadow_scale;
+  size_t shadow_offset;
+} clib_sanitizer_main_t;
+
+extern clib_sanitizer_main_t sanitizer_main;
 
 #define CLIB_NOSANITIZE_ADDR    __attribute__((no_sanitize_address))
 #define CLIB_MEM_POISON(a, s)   ASAN_POISON_MEMORY_REGION((a), (s))
 #define CLIB_MEM_UNPOISON(a, s) ASAN_UNPOISON_MEMORY_REGION((a), (s))
 
-#define CLIB_MEM_OVERFLOW(f, src, n) \
-  ({ \
-   typeof (f) clib_mem_overflow_ret__; \
-   const void *clib_mem_overflow_src__ = (src); \
-   size_t clib_mem_overflow_n__ = (n); \
-   const void *clib_mem_overflow_start__ = __asan_region_is_poisoned((void *)clib_mem_overflow_src__, clib_mem_overflow_n__); \
-   clib_mem_overflow_n__ -= (size_t)(clib_mem_overflow_start__ - clib_mem_overflow_src__); \
-   if (clib_mem_overflow_start__) \
-     CLIB_MEM_UNPOISON(clib_mem_overflow_start__, clib_mem_overflow_n__); \
-   clib_mem_overflow_ret__ = f; \
-   if (clib_mem_overflow_start__) \
-     CLIB_MEM_POISON(clib_mem_overflow_start__, clib_mem_overflow_n__); \
-   clib_mem_overflow_ret__; \
-   })
+#define CLIB_MEM_OVERFLOW_MAX 64
+
+static_always_inline void
+sanitizer_unpoison__ (u64 *restrict *shadow_ptr, size_t *shadow_len,
+                     const void *ptr, size_t len)
+{
+  size_t scale, off;
+
+  if (PREDICT_FALSE (~0 == sanitizer_main.shadow_scale))
+    __asan_get_shadow_mapping (&sanitizer_main.shadow_scale,
+                              &sanitizer_main.shadow_offset);
+
+  scale = sanitizer_main.shadow_scale;
+  off = sanitizer_main.shadow_offset;
+
+  /* compute the shadow address and length */
+  *shadow_len = len >> scale;
+  ASSERT (*shadow_len <= CLIB_MEM_OVERFLOW_MAX);
+  *shadow_ptr = (void *) (((clib_address_t) ptr >> scale) + off);
+}
+
+static_always_inline CLIB_NOSANITIZE_ADDR void
+sanitizer_unpoison_push__ (u64 *restrict shadow, const void *ptr, size_t len)
+{
+  u64 *restrict shadow_ptr;
+  size_t shadow_len;
+  int i;
+
+  sanitizer_unpoison__ (&shadow_ptr, &shadow_len, ptr, len);
+
+  /* save the shadow area */
+  for (i = 0; i < shadow_len; i++)
+    shadow[i] = shadow_ptr[i];
+
+  /* unpoison */
+  for (i = 0; i < shadow_len; i++)
+    shadow_ptr[i] = 0;
+}
+
+static_always_inline CLIB_NOSANITIZE_ADDR void
+sanitizer_unpoison_pop__ (const u64 *restrict shadow, const void *ptr,
+                         size_t len)
+{
+  u64 *restrict shadow_ptr;
+  size_t shadow_len;
+  int i;
+
+  sanitizer_unpoison__ (&shadow_ptr, &shadow_len, ptr, len);
+
+  /* restore the shadow area */
+  for (i = 0; i < shadow_len; i++)
+    {
+      ASSERT (0 == shadow_ptr[i]);
+      shadow_ptr[i] = shadow[i];
+    }
+}
+
+#define CLIB_MEM_OVERFLOW(f, src, n)                                          \
+  ({                                                                          \
+    typeof (f) clib_mem_overflow_ret__;                                       \
+    const void *clib_mem_overflow_src__ = (src);                              \
+    size_t clib_mem_overflow_n__ = (n);                                       \
+    u64 clib_mem_overflow_shadow__[CLIB_MEM_OVERFLOW_MAX];                    \
+    sanitizer_unpoison_push__ (clib_mem_overflow_shadow__,                    \
+                              clib_mem_overflow_src__,                       \
+                              clib_mem_overflow_n__);                        \
+    clib_mem_overflow_ret__ = f;                                              \
+    sanitizer_unpoison_pop__ (clib_mem_overflow_shadow__,                     \
+                             clib_mem_overflow_src__,                        \
+                             clib_mem_overflow_n__);                         \
+    clib_mem_overflow_ret__;                                                  \
+  })
 
 #define CLIB_MEM_OVERFLOW_LOAD(f, src) \
   ({ \