Release address space to the OS at gencgc_release_granularity

[sbcl.git] / src / runtime / save.c

diff --git a/src/runtime/save.c b/src/runtime/save.c
index 20d72d7..b3addc9 100644 (file)
--- a/src/runtime/save.c
+++ b/src/runtime/save.c
@@ -56,13 +56,18 @@ write_runtime_options(FILE *file, struct runtime_options *options)
         optarray[3] = options->thread_control_stack_size;
     }
 
-    fwrite(optarray, sizeof(size_t), RUNTIME_OPTIONS_WORDS, file);
+    if (RUNTIME_OPTIONS_WORDS !=
+        fwrite(optarray, sizeof(size_t), RUNTIME_OPTIONS_WORDS, file)) {
+        perror("Error writing runtime options to file");
+    }
 }
 
 static void
 write_lispobj(lispobj obj, FILE *file)
 {
-    fwrite(&obj, sizeof(lispobj), 1, file);
+    if (1 != fwrite(&obj, sizeof(lispobj), 1, file)) {
+        perror("Error writing to file");
+    }
 }
 
 static long
@@ -307,15 +312,22 @@ save_to_filehandle(FILE *file, char *filename, lispobj init_function,
             &~(os_vm_page_size-1);
         unsigned long *data = calloc(size, 1);
         if (data) {
+            unsigned long word;
             long offset;
             int i;
             for (i = 0; i < last_free_page; i++) {
-                data[i] = page_table[i].region_start_offset;
+                /* Thanks to alignment requirements, the two low bits
+                 * are always zero, so we can use them to store the
+                 * allocation type -- region is always closed, so only
+                 * the two low bits of allocation flags matter. */
+                word = page_table[i].region_start_offset;
+                gc_assert((word & 0x03) == 0);
+                data[i] = word | (0x03 & page_table[i].allocated);
             }
             write_lispobj(PAGE_TABLE_CORE_ENTRY_TYPE_CODE, file);
             write_lispobj(4, file);
             write_lispobj(size, file);
-            offset = write_bytes(file, (char *) data, size, core_start_pos);
+            offset = write_bytes(file, (char *)data, size, core_start_pos);
             write_lispobj(offset, file);
         }
     }
@@ -354,9 +366,13 @@ save_to_filehandle(FILE *file, char *filename, lispobj init_function,
     write_runtime_options(file,
                           (save_runtime_options ? runtime_options : NULL));
 
-    fwrite(&core_start_pos, sizeof(os_vm_offset_t), 1, file);
-    write_lispobj(CORE_MAGIC, file);
-    fclose(file);
+    if (1 != fwrite(&core_start_pos, sizeof(os_vm_offset_t), 1, file)) {
+        perror("Error writing core starting position to file");
+        fclose(file);
+    } else {
+        write_lispobj(CORE_MAGIC, file);
+        fclose(file);
+    }
 
 #ifndef LISP_FEATURE_WIN32
     if (make_executable)
@@ -367,6 +383,25 @@ save_to_filehandle(FILE *file, char *filename, lispobj init_function,
     exit(0);
 }
 
+/* Check if the build_id for the current runtime is present in a
+ * buffer. */
+int
+check_runtime_build_id(void *buf, size_t size)
+{
+    size_t idlen;
+    char *pos;
+
+    idlen = strlen(build_id) - 1;
+    while ((pos = memchr(buf, build_id[0], size)) != NULL) {
+        size -= (pos + 1) - (char *)buf;
+        buf = (pos + 1);
+        if (idlen <= size && memcmp(buf, build_id + 1, idlen) == 0)
+            return 1;
+    }
+
+    return 0;
+}
+
 /* Slurp the executable portion of the runtime into a malloced buffer
  * and return it.  Places the size in bytes of the runtime into
  * 'size_out'.  Returns NULL if the runtime cannot be loaded from
@@ -398,6 +433,12 @@ load_runtime(char *runtime_path, size_t *size_out)
         goto lose;
     }
 
+    if (!check_runtime_build_id(buf, size)) {
+        fprintf(stderr, "Failed to locate current build_id in runtime: %s\n",
+            runtime_path);
+        goto lose;
+    }
+
     fclose(input);
     *size_out = size;
     return buf;
@@ -416,13 +457,20 @@ save_runtime_to_filehandle(FILE *output, void *runtime, size_t runtime_size)
     size_t padding;
     void *padbytes;
 
-    fwrite(runtime, 1, runtime_size, output);
+    if (runtime_size != fwrite(runtime, 1, runtime_size, output)) {
+        perror("Error saving runtime");
+        return 0;
+    }
 
     padding = (os_vm_page_size - (runtime_size % os_vm_page_size)) & ~os_vm_page_size;
     if (padding > 0) {
         padbytes = successful_malloc(padding);
         memset(padbytes, 0, padding);
-        fwrite(padbytes, 1, padding, output);
+        if (padding != fwrite(padbytes, 1, padding, output)) {
+            perror("Error saving runtime");
+            free(padbytes);
+            return 0;
+        }
         free(padbytes);
     }
 
@@ -437,15 +485,19 @@ prepare_to_save(char *filename, boolean prepend_runtime, void **runtime_bytes,
     char *runtime_path;
 
     if (prepend_runtime) {
-        runtime_path = os_get_runtime_executable_path();
+        runtime_path = os_get_runtime_executable_path(0);
 
-        if (runtime_path == NULL) {
+        if (runtime_path == NULL && saved_runtime_path == NULL) {
             fprintf(stderr, "Unable to get default runtime path.\n");
             return NULL;
         }
 
-        *runtime_bytes = load_runtime(runtime_path, runtime_size);
-        free(runtime_path);
+        if (runtime_path == NULL)
+            *runtime_bytes = load_runtime(saved_runtime_path, runtime_size);
+        else {
+            *runtime_bytes = load_runtime(runtime_path, runtime_size);
+            free(runtime_path);
+        }
 
         if (*runtime_bytes == NULL)
             return 0;