Merge dd6eb962de into 4fe9018b6f

- memset is disabled for now as it causes hangs
- underlying functions were copied from isoalloc, licensed Apache-2.0
	- credit Chris Rohlf for memcpy/memset
	- credit David Carlier for memmove

Signed-off-by: Tavi <tavi@divested.dev>

README.md

@@ -279,7 +279,7 @@ The following boolean configuration options are available:
 * `CONFIG_BLOCK_OPS_CHECK_SIZE`: `true` or `false` (default) to ensure length
   parameter of the memcpy/memmove/memset block operations are within
   approximate bounds to minimize buffer overflows. Note, memset override is
-  currently disabled due to improper behavior.
+  currently disabled due to being broken.
 
 The following integer configuration options are available:
 

h_malloc.c

@@ -528,7 +528,7 @@ static void set_canary(UNUSED const struct slab_metadata *metadata, UNUSED void
     }
 #endif
 
-    memcpy((char *)p + size - canary_size, &metadata->canary_value, canary_size);
+    h_memcpy_real((char *)p + size - canary_size, &metadata->canary_value, canary_size);
 #endif
 }
 
@@ -541,7 +541,7 @@ static void check_canary(UNUSED const struct slab_metadata *metadata, UNUSED con
 #endif
 
     u64 canary_value;
-    memcpy(&canary_value, (const char *)p + size - canary_size, canary_size);
+    h_memcpy_real(&canary_value, (const char *)p + size - canary_size, canary_size);
 
 #ifdef HAS_ARM_MTE
     if (unlikely(canary_value == 0)) {
@@ -831,7 +831,7 @@ static inline void deallocate_small(void *p, const size_t *expected_size) {
 #endif
 
         if (ZERO_ON_FREE && !skip_zero) {
-            memset(p, 0, size - canary_size);
+            h_memset_real(p, 0, size - canary_size);
         }
     }
 
@@ -1502,7 +1502,7 @@ EXPORT void *h_calloc(size_t nmemb, size_t size) {
     total_size = adjust_size_for_canary(total_size);
     void *p = alloc(total_size);
     if (!ZERO_ON_FREE && likely(p != NULL) && total_size && total_size <= max_slab_size_class) {
-        memset(p, 0, total_size - canary_size);
+        h_memset_real(p, 0, total_size - canary_size);
     }
 #ifdef HAS_ARM_MTE
     // use an assert instead of adding a conditional to memset() above (freed memory is always
@@ -1624,7 +1624,7 @@ EXPORT void *h_realloc(void *old, size_t size) {
                 mutex_unlock(&ra->lock);
 
                 if (memory_remap_fixed(old, old_size, new, size)) {
-                    memcpy(new, old, copy_size);
+                    h_memcpy_real(new, old, copy_size);
                     deallocate_pages(old, old_size, old_guard_size);
                 } else {
                     memory_unmap((char *)old - old_guard_size, old_guard_size);
@@ -1646,7 +1646,7 @@ EXPORT void *h_realloc(void *old, size_t size) {
     if (copy_size > 0 && copy_size <= max_slab_size_class) {
         copy_size -= canary_size;
     }
-    memcpy(new, old_orig, copy_size);
+    h_memcpy_real(new, old_orig, copy_size);
     if (old_size <= max_slab_size_class) {
         deallocate_small(old, NULL);
     } else {
@@ -1874,8 +1874,8 @@ EXPORT size_t h_malloc_object_size_fast(const void *p) {
     return SIZE_MAX;
 }
 
-#if CONFIG_BLOCK_OPS_CHECK_SIZE
 inline void *h_memcpy_real(void *dst, const void *src, size_t len) {
+#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE)
     char *p_dst = (char *)dst;
     char const *p_src = (char const *)src;
 
@@ -1884,27 +1884,16 @@ inline void *h_memcpy_real(void *dst, const void *src, size_t len) {
     }
 
     return dst;
-}
-
-EXPORT void *h_memcpy(void *dst, const void *src, size_t len) {
-    if (len > malloc_object_size_fast(src)) {
-        fatal_error("memcpy read overflow");
-    }
-    if (len > malloc_object_size_fast(dst)) {
-        fatal_error("memcpy buffer overflow");
-    }
-
-    return h_memcpy_real(dst, src, len);
+#else
+    return memcpy(dst, src, len);
+#endif
 }
 
 inline void *h_memmove_real(void *dst, const void *src, size_t len) {
+#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE)
     char *p_dst = (char *)dst;
     char const *p_src = (char const *)src;
 
-    if(dst == src) {
-        return dst;
-    }
-
     if(p_src < p_dst) {
         p_dst += len;
         p_src += len;
@@ -1912,24 +1901,17 @@ inline void *h_memmove_real(void *dst, const void *src, size_t len) {
             *--p_dst = *--p_src;
         }
     } else {
-        dst = h_memcpy(dst, src, len);
+        dst = h_memcpy_real(dst, src, len);
     }
 
     return dst;
-}
-
-EXPORT void *h_memmove(void *dst, const void *src, size_t len) {
-    if (len > malloc_object_size_fast(src)) {
-        fatal_error("memmove read overflow");
-    }
-    if (len > malloc_object_size_fast(dst)) {
-        fatal_error("memmove buffer overflow");
-    }
-
-    return h_memmove_real(dst, src, len);
+#else
+    return memmove(dst, src, len);
+#endif
 }
 
 inline void *h_memset_real(void *dst, int value, size_t len) {
+#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE)
     char *p_dst = (char *)dst;
 
     while(len--) {
@@ -1937,13 +1919,45 @@ inline void *h_memset_real(void *dst, int value, size_t len) {
     }
 
     return dst;
+#else
+    return memset(dst, value, len);
+#endif
+}
+
+#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE)
+EXPORT void *h_memcpy(void *dst, const void *src, size_t len) {
+    if(dst == src || len == 0) {
+        return dst;
+    }
+    if (len > malloc_object_size(src)) {
+        fatal_error("memcpy read overflow");
+    }
+    if (len > malloc_object_size(dst)) {
+        fatal_error("memcpy buffer overflow");
+    }
+    return h_memcpy_real(dst, src, len);
+}
+
+EXPORT void *h_memmove(void *dst, const void *src, size_t len) {
+    if(dst == src || len == 0) {
+        return dst;
+    }
+    if (len > malloc_object_size(src)) {
+        fatal_error("memmove read overflow");
+    }
+    if (len > malloc_object_size(dst)) {
+        fatal_error("memmove buffer overflow");
+    }
+    return h_memmove_real(dst, src, len);
 }
 
 EXPORT void *h_memset(void *dst, int value, size_t len) {
-    if (len > malloc_object_size_fast(dst)) {
+    if(len == 0) {
+        return dst;
+    }
+    if (len > malloc_object_size(dst)) {
         fatal_error("memset buffer overflow");
     }
-
     return h_memset_real(dst, value, len);
 }
 #endif

include/h_malloc.h

@@ -15,7 +15,7 @@ extern "C" {
 #define h_realloc realloc
 #define h_aligned_alloc aligned_alloc
 #define h_free free
-#if CONFIG_BLOCK_OPS_CHECK_SIZE
+#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE)
 #define h_memcpy memcpy
 #define h_memmove memmove
 //#define h_memset memset
@@ -59,12 +59,12 @@ __attribute__((alloc_size(2))) void *h_realloc(void *ptr, size_t size);
 __attribute__((malloc)) __attribute__((alloc_size(2))) __attribute__((alloc_align(1)))
 void *h_aligned_alloc(size_t alignment, size_t size);
 void h_free(void *ptr);
-#if CONFIG_BLOCK_OPS_CHECK_SIZE
 void *h_memcpy_real(void *dst, const void *src, size_t len);
-void *h_memcpy(void *dst, const void *src, size_t len);
 void *h_memmove_real(void *dst, const void *src, size_t len);
-void *h_memmove(void *dst, const void *src, size_t len);
 void *h_memset_real(void *dst, int value, size_t len);
+#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE)
+void *h_memcpy(void *dst, const void *src, size_t len);
+void *h_memmove(void *dst, const void *src, size_t len);
 void *h_memset(void *dst, int value, size_t len);
 #endif
 

test/memcpy_buffer_overflow.c

@@ -9,7 +9,7 @@ OPTNONE int main(void) {
     if (!firstbuffer && !secondbuffer) {
         return 1;
     }
-    memset(secondbuffer, 'a', 16);
+    memset(secondbuffer, 'a', 32);
     memcpy(firstbuffer, secondbuffer, 32);
     return 1;
 }

test/memcpy_valid_mismatched.c

@@ -4,12 +4,12 @@
 #include "test_util.h"
 
 OPTNONE int main(void) {
-    char *firstbuffer = malloc(16);
-    char *secondbuffer = malloc(8);
+    char *firstbuffer = malloc(32);
+    char *secondbuffer = malloc(16);
     if (!firstbuffer && !secondbuffer) {
         return 1;
     }
-    memset(secondbuffer, 'a', 8);
-    memcpy(firstbuffer, secondbuffer, 8);
+    memset(secondbuffer, 'a', 16);
+    memcpy(firstbuffer, secondbuffer, 16);
     return 0;
 }

test/memmove_buffer_overflow.c

@@ -9,7 +9,7 @@ OPTNONE int main(void) {
     if (!firstbuffer && !secondbuffer) {
         return 1;
     }
-    memset(secondbuffer, 'a', 16);
+    memset(secondbuffer, 'a', 32);
     memmove(firstbuffer, secondbuffer, 32);
     return 1;
 }

test/memmove_valid_mismatched.c

@@ -4,12 +4,12 @@
 #include "test_util.h"
 
 OPTNONE int main(void) {
-    char *firstbuffer = malloc(16);
-    char *secondbuffer = malloc(8);
+    char *firstbuffer = malloc(32);
+    char *secondbuffer = malloc(16);
     if (!firstbuffer && !secondbuffer) {
         return 1;
     }
-    memset(secondbuffer, 'a', 8);
-    memmove(firstbuffer, secondbuffer, 8);
+    memset(secondbuffer, 'a', 16);
+    memmove(firstbuffer, secondbuffer, 16);
     return 0;
 }

test/memset_valid_mismatched.c

@@ -4,10 +4,10 @@
 #include "test_util.h"
 
 OPTNONE int main(void) {
-    char *buffer = malloc(16);
+    char *buffer = malloc(32);
     if (!buffer) {
         return 1;
     }
-    memset(buffer, 'a', 8);
+    memset(buffer, 'a', 16);
     return 0;
 }