Memory: refactor hex_dump to use buffer with DEBUG output

lib/mem.c

@@ -51,27 +51,29 @@ static void init_mutex() {
 static void* allocated_head = NULL;
 static size_t allocated_count = 0;
 
-static void hex_dump(const void* mem, size_t len) {
+static void hex_dump_buf(const void* mem, size_t len, char* buf, size_t buf_size) {
     const uint8_t* data = (const uint8_t*)mem;
-    for (size_t i = 0; i < len; i += 16) {
-        printf("%08zx: ", i);
+    size_t off = 0;
+    for (size_t i = 0; i < len && i < 256; i += 16) {
+        if (off >= buf_size - 80) break;
+        off += snprintf(buf + off, buf_size - off, "%08zx: ", i);
         for (size_t j = 0; j < 16; j++) {
             if (i + j < len) {
-                printf("%02x ", data[i + j]);
+                off += snprintf(buf + off, buf_size - off, "%02x ", data[i + j]);
             } else {
-                printf("   ");
+                off += snprintf(buf + off, buf_size - off, "   ");
             }
         }
-        printf("  ");
+        off += snprintf(buf + off, buf_size - off, " ");
         for (size_t j = 0; j < 16; j++) {
             if (i + j < len) {
                 uint8_t c = data[i + j];
-                printf("%c", (c >= 32 && c <= 126) ? c : '.');
+                off += snprintf(buf + off, buf_size - off, "%c", (c >= 32 && c <= 126) ? c : '.');
             } else {
-                printf(" ");
+                off += snprintf(buf + off, buf_size - off, " ");
             }
         }
-        printf("\n");
+        off += snprintf(buf + off, buf_size - off, "\n");
     }
 }
 
@@ -115,7 +117,9 @@ void u_check(void* ptr, const char* text, const char* location) {
         printf("%s: %s: Allocated at: %s\n", location, text, alloc_loc);
         printf("%s: %s: Memory block size (user): %u bytes, total allocated: %u bytes\n", location, text, size, total);
         printf("%s: %s: Full memory dump at base %p:\n", location, text, base);
-        hex_dump(base, total);
+        char dump_buf[4096];
+        hex_dump_buf(base, total, dump_buf, sizeof(dump_buf));
+        DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "%s", dump_buf);
         exit(EXIT_FAILURE);
     }
 }
@@ -227,7 +231,9 @@ void u_report_unfreed_blocks(void) {
         u_check(user_ptr, "unfreed_check", "u_report_unfreed_blocks");
         DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, " - Allocated at: %s, size: %u bytes\n", alloc_loc, size);
         DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "   Full memory dump at %p:\n", user_ptr);
-        hex_dump(user_ptr, size);
+        char dump_buf[4096];
+        hex_dump_buf(user_ptr, size, dump_buf, sizeof(dump_buf));
+        DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "%s", dump_buf);
         curr = *(void**)((uint8_t*)curr + NEXT_OFFSET);
     }
 }