{
return !*fn.path;
}
+
+#ifdef DEBUG
+static FILE *debug_fp = NULL;
+static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
+static int debug_got_console = 0;
+
+void dputs(char *buf)
+{
+ DWORD dw;
+
+ if (!debug_got_console) {
+ if (AllocConsole()) {
+ debug_got_console = 1;
+ debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
+ }
+ }
+ if (!debug_fp) {
+ debug_fp = fopen("debug.log", "w");
+ }
+
+ if (debug_hdl != INVALID_HANDLE_VALUE) {
+ WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
+ }
+ fputs(buf, debug_fp);
+ fflush(debug_fp);
+}
+#endif
+
+#ifdef MINEFIELD
+/*
+ * Minefield - a Windows equivalent for Electric Fence
+ */
+
+#define PAGESIZE 4096
+
+/*
+ * Design:
+ *
+ * We start by reserving as much virtual address space as Windows
+ * will sensibly (or not sensibly) let us have. We flag it all as
+ * invalid memory.
+ *
+ * Any allocation attempt is satisfied by committing one or more
+ * pages, with an uncommitted page on either side. The returned
+ * memory region is jammed up against the _end_ of the pages.
+ *
+ * Freeing anything causes instantaneous decommitment of the pages
+ * involved, so stale pointers are caught as soon as possible.
+ */
+
+static int minefield_initialised = 0;
+static void *minefield_region = NULL;
+static long minefield_size = 0;
+static long minefield_npages = 0;
+static long minefield_curpos = 0;
+static unsigned short *minefield_admin = NULL;
+static void *minefield_pages = NULL;
+
+static void minefield_admin_hide(int hide)
+{
+ int access = hide ? PAGE_NOACCESS : PAGE_READWRITE;
+ VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL);
+}
+
+static void minefield_init(void)
+{
+ int size;
+ int admin_size;
+ int i;
+
+ for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) {
+ minefield_region = VirtualAlloc(NULL, size,
+ MEM_RESERVE, PAGE_NOACCESS);
+ if (minefield_region)
+ break;
+ }
+ minefield_size = size;
+
+ /*
+ * Firstly, allocate a section of that to be the admin block.
+ * We'll need a two-byte field for each page.
+ */
+ minefield_admin = minefield_region;
+ minefield_npages = minefield_size / PAGESIZE;
+ admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1);
+ minefield_npages = (minefield_size - admin_size) / PAGESIZE;
+ minefield_pages = (char *) minefield_region + admin_size;
+
+ /*
+ * Commit the admin region.
+ */
+ VirtualAlloc(minefield_admin, minefield_npages * 2,
+ MEM_COMMIT, PAGE_READWRITE);
+
+ /*
+ * Mark all pages as unused (0xFFFF).
+ */
+ for (i = 0; i < minefield_npages; i++)
+ minefield_admin[i] = 0xFFFF;
+
+ /*
+ * Hide the admin region.
+ */
+ minefield_admin_hide(1);
+
+ minefield_initialised = 1;
+}
+
+static void minefield_bomb(void)
+{
+ div(1, *(int *) minefield_pages);
+}
+
+static void *minefield_alloc(int size)
+{
+ int npages;
+ int pos, lim, region_end, region_start;
+ int start;
+ int i;
+
+ npages = (size + PAGESIZE - 1) / PAGESIZE;
+
+ minefield_admin_hide(0);
+
+ /*
+ * Search from current position until we find a contiguous
+ * bunch of npages+2 unused pages.
+ */
+ pos = minefield_curpos;
+ lim = minefield_npages;
+ while (1) {
+ /* Skip over used pages. */
+ while (pos < lim && minefield_admin[pos] != 0xFFFF)
+ pos++;
+ /* Count unused pages. */
+ start = pos;
+ while (pos < lim && pos - start < npages + 2 &&
+ minefield_admin[pos] == 0xFFFF)
+ pos++;
+ if (pos - start == npages + 2)
+ break;
+ /* If we've reached the limit, reset the limit or stop. */
+ if (pos >= lim) {
+ if (lim == minefield_npages) {
+ /* go round and start again at zero */
+ lim = minefield_curpos;
+ pos = 0;
+ } else {
+ minefield_admin_hide(1);
+ return NULL;
+ }
+ }
+ }
+
+ minefield_curpos = pos - 1;
+
+ /*
+ * We have npages+2 unused pages starting at start. We leave
+ * the first and last of these alone and use the rest.
+ */
+ region_end = (start + npages + 1) * PAGESIZE;
+ region_start = region_end - size;
+ /* FIXME: could align here if we wanted */
+
+ /*
+ * Update the admin region.
+ */
+ for (i = start + 2; i < start + npages + 1; i++)
+ minefield_admin[i] = 0xFFFE; /* used but no region starts here */
+ minefield_admin[start + 1] = region_start % PAGESIZE;
+
+ minefield_admin_hide(1);
+
+ VirtualAlloc((char *) minefield_pages + region_start, size,
+ MEM_COMMIT, PAGE_READWRITE);
+ return (char *) minefield_pages + region_start;
+}
+
+static void minefield_free(void *ptr)
+{
+ int region_start, i, j;
+
+ minefield_admin_hide(0);
+
+ region_start = (char *) ptr - (char *) minefield_pages;
+ i = region_start / PAGESIZE;
+ if (i < 0 || i >= minefield_npages ||
+ minefield_admin[i] != region_start % PAGESIZE)
+ minefield_bomb();
+ for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) {
+ minefield_admin[j] = 0xFFFF;
+ }
+
+ VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT);
+
+ minefield_admin_hide(1);
+}
+
+static int minefield_get_size(void *ptr)
+{
+ int region_start, i, j;
+
+ minefield_admin_hide(0);
+
+ region_start = (char *) ptr - (char *) minefield_pages;
+ i = region_start / PAGESIZE;
+ if (i < 0 || i >= minefield_npages ||
+ minefield_admin[i] != region_start % PAGESIZE)
+ minefield_bomb();
+ for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++);
+
+ minefield_admin_hide(1);
+
+ return j * PAGESIZE - region_start;
+}
+
+void *minefield_c_malloc(size_t size)
+{
+ if (!minefield_initialised)
+ minefield_init();
+ return minefield_alloc(size);
+}
+
+void minefield_c_free(void *p)
+{
+ if (!minefield_initialised)
+ minefield_init();
+ minefield_free(p);
+}
+
+/*
+ * realloc _always_ moves the chunk, for rapid detection of code
+ * that assumes it won't.
+ */
+void *minefield_c_realloc(void *p, size_t size)
+{
+ size_t oldsize;
+ void *q;
+ if (!minefield_initialised)
+ minefield_init();
+ q = minefield_alloc(size);
+ oldsize = minefield_get_size(p);
+ memcpy(q, p, (oldsize < size ? oldsize : size));
+ minefield_free(p);
+ return q;
+}
+
+#endif /* MINEFIELD */
projects / u / mdw / putty / blobdiff