Merge branch 'linux-2.6' into merge

[linux-2.6-omap-h63xx.git] / arch / um / os-Linux / sys-i386 / task_size.c

diff --git a/arch/um/os-Linux/sys-i386/task_size.c b/arch/um/os-Linux/sys-i386/task_size.c
index ccb49b0aff598d673659d12a8e7249feb485fdee..be04c1e183bfec5d3ccafb26bc4456c5f901c9d6 100644 (file)
--- a/arch/um/os-Linux/sys-i386/task_size.c
+++ b/arch/um/os-Linux/sys-i386/task_size.c
@@ -63,7 +63,7 @@ static int page_ok(unsigned long page)
        return ok;
 }
 
-unsigned long os_get_task_size(void)
+unsigned long os_get_top_address(void)
 {
        struct sigaction sa, old;
        unsigned long bottom = 0;
@@ -76,9 +76,9 @@ unsigned long os_get_task_size(void)
         * hosts, but shouldn't hurt otherwise.
         */
        unsigned long top = 0xffffd000 >> UM_KERN_PAGE_SHIFT;
-       unsigned long test;
+       unsigned long test, original;
 
-       printf("Locating the top of the address space ... ");
+       printf("Locating the bottom of the address space ... ");
        fflush(stdout);
 
        /*
@@ -89,16 +89,31 @@ unsigned long os_get_task_size(void)
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_NODEFER;
        if (sigaction(SIGSEGV, &sa, &old)) {
-               perror("os_get_task_size");
+               perror("os_get_top_address");
                exit(1);
        }
 
-       if (!page_ok(bottom)) {
-               fprintf(stderr, "Address 0x%x no good?\n",
-                       bottom << UM_KERN_PAGE_SHIFT);
+       /* Manually scan the address space, bottom-up, until we find
+        * the first valid page (or run out of them).
+        */
+       for (bottom = 0; bottom < top; bottom++) {
+               if (page_ok(bottom))
+                       break;
+       }
+
+       /* If we've got this far, we ran out of pages. */
+       if (bottom == top) {
+               fprintf(stderr, "Unable to determine bottom of address "
+                       "space.\n");
                exit(1);
        }
 
+       printf("0x%x\n", bottom << UM_KERN_PAGE_SHIFT);
+       printf("Locating the top of the address space ... ");
+       fflush(stdout);
+
+       original = bottom;
+
        /* This could happen with a 4G/4G split */
        if (page_ok(top))
                goto out;
@@ -114,7 +129,7 @@ unsigned long os_get_task_size(void)
 out:
        /* Restore the old SIGSEGV handling */
        if (sigaction(SIGSEGV, &old, NULL)) {
-               perror("os_get_task_size");
+               perror("os_get_top_address");
                exit(1);
        }
        top <<= UM_KERN_PAGE_SHIFT;