bitkeeper revision 1.331 (3f0d4822DGZPrG8hjrH_59XaPHWQGA)

Merge labyrinth.cl.cam.ac.uk:/auto/groups/xeno/users/rac61/xeno.bk
into labyrinth.cl.cam.ac.uk:/auto/groups/xeno/users/sos22/xeno.bk

1 files changed, 88 insertions, 91 deletions

diff --git a/tools/internal/xi_build.c b/tools/internal/xi_build.c
index 59c4340db2..805ab22a2a 100644
--- a/tools/internal/xi_build.c
+++ b/tools/internal/xi_build.c
@@ -24,6 +24,10 @@
 #define GUEST_SIG   "XenoGues"
 #define SIG_LEN    8
 
+/* Watch for precedence when using thses ones... */
+#define PROC_XENO_DOM0_CMD "/proc/" PROC_XENO_ROOT "/" PROC_CMD
+#define PROC_XENO_DOMAINS "/proc" PROC_XENO_ROOT "/" PROC_DOMAINS
+
 /*
  * NB. No ring-3 access in initial guestOS pagetables. Note that we allow
  * ring-3 privileges in the page directories, so that the guestOS may later
@@ -53,7 +57,8 @@ static void dom_mem_cleanup(dom_mem_t * dom_mem)
 	    
     fd = open("/proc/xeno/dom0_cmd", O_WRONLY);
     if(fd < 0){
-        perror(PERR_STRING);
+        perror("openning /proc/xeno/dom0_cmd");
+	return;
     }
     
     argbuf.vaddr = dom_mem->vaddr;
@@ -90,62 +95,46 @@ static int map_dom_mem(unsigned long pfn, int pages, int dom,
     
     if (dom_mem->vaddr == -1) {
         perror("mapping domain memory");
+	close(fd);
 	return -1;
     }
+    close(fd);
 
     return 0;
 }
 
-/* open kernel image and do some sanity checks */
-static int do_kernel_chcks(char *image, long dom_size, 
-                           unsigned long * load_addr, size_t * ksize)
+/* read the kernel header, extracting the image size and load address. */
+static int read_kernel_header(int fd, long dom_size, 
+			      unsigned long * load_addr, size_t * ksize)
 {
     char signature[8];
     char status[MAX_PATH];
     struct stat stat;
-    int fd;
-    int ret; 
     
-    fd = open(image, O_RDONLY);
-    if(fd < 0){
-        perror(PERR_STRING);
-        ret = -1;    
-        goto out;
-    }
-
     if(fstat(fd, &stat) < 0){
         perror(PERR_STRING);
-        ret = -1;
-        close(fd);
-        goto out;
+	return -1;
     }
 
     if(stat.st_size > (dom_size << 10)){
         sprintf(status, "Kernel image size %ld larger than requested "
                 "domain size %ld\n Terminated.\n", stat.st_size, dom_size);
         dberr(status);
-        ret = -1;
-        close(fd);
-        goto out;
+	return -1;
     }
     
     read(fd, signature, SIG_LEN);
     if(strncmp(signature, GUEST_SIG, SIG_LEN)){
         dberr("Kernel image does not contain required signature. "
               "Terminating.\n");
-        ret = -1;
-        close(fd);
-        goto out;
+	return -1;
     }
 
     read(fd, load_addr, sizeof(unsigned long));
 
     *ksize = stat.st_size - SIG_LEN - sizeof(unsigned long);
 
-    ret = fd;
-
- out:    
-    return ret;
+    return 0;
 }
 
 /* this is the main guestos setup function,
@@ -159,21 +148,24 @@ static int do_kernel_chcks(char *image, long dom_size,
 static dom_meminfo_t *setup_guestos(int dom, int kernel_fd, int initrd_fd,
                                     unsigned long virt_load_addr, size_t ksize, dom_mem_t *dom_mem)
 {
-    dom_meminfo_t *meminfo;
-    unsigned long *page_array;
-    page_update_request_t *pgt_updates;
-    dom_meminfo_t *ret = NULL;
+    dom_meminfo_t *meminfo = NULL;
+    unsigned long *page_array = NULL;
+    page_update_request_t *pgt_updates = NULL;
     int alloc_index, num_pt_pages;
     unsigned long l2tab;
     unsigned long l1tab = 0;
     unsigned long num_pgt_updates = 0;
     unsigned long count, pt_start;
     struct dom0_dopgupdates_args pgupdate_req;
-    char cmd_path[MAX_PATH];
     int cmd_fd;
+    int result;
 
     meminfo     = (dom_meminfo_t *)malloc(sizeof(dom_meminfo_t));
     page_array  = malloc(dom_mem->tot_pages * 4);
+    if (!meminfo || !page_array) {
+	dberr ("Could not allocate memory");
+	goto error_out;
+    }
     pgt_updates = (page_update_request_t *)dom_mem->vaddr;
     alloc_index = dom_mem->tot_pages - 1;
 
@@ -264,42 +256,51 @@ static dom_meminfo_t *setup_guestos(int dom, int kernel_fd, int initrd_fd,
     meminfo->virt_startinfo_addr = virt_load_addr + nr_2_page(alloc_index - 1);
     meminfo->domain = dom;
 
+    free(page_array);
+
     /*
      * Send the page update requests down to the hypervisor.
      * NB. We must do this before loading the guest OS image!
      */
-    sprintf(cmd_path, "%s%s%s%s", "/proc/", PROC_XENO_ROOT, "/", PROC_CMD);
-    if ( (cmd_fd = open(cmd_path, O_WRONLY)) < 0 ) goto out;
+    if ( (cmd_fd = open(PROC_XENO_DOM0_CMD, O_WRONLY)) < 0 )
+    {
+	dberr ("Could not open " PROC_XENO_DOM0_CMD);
+	goto error_out;
+    }
+
     pgupdate_req.pgt_update_arr  = (unsigned long)dom_mem->vaddr;
     pgupdate_req.num_pgt_updates = num_pgt_updates;
-    if (ioctl(cmd_fd, IOCTL_DOM0_DOPGUPDATES, &pgupdate_req) < 0) goto out;
+    result = ioctl(cmd_fd, IOCTL_DOM0_DOPGUPDATES, &pgupdate_req);
     close(cmd_fd);
+    if (result < 0) {
+	dberr ("Could not build domain page tables.");
+	goto error_out;
+    }
 
     /* Load the guest OS image. */
     if( read(kernel_fd, (char *)dom_mem->vaddr, ksize) != ksize )
     {
         dberr("Error reading kernel image, could not"
-              " read the whole image. Terminating.\n");
-        goto out;
+              " read the whole image.");
+	goto error_out;
     }
 
-    if( initrd_fd )
+    if( initrd_fd >= 0)
     {
 	struct stat stat;
 	unsigned long isize;
 
 	if(fstat(initrd_fd, &stat) < 0){
             perror(PERR_STRING);
-            close(initrd_fd);
-            goto out;
+            goto error_out;
 	}
 	isize = stat.st_size;
 
 	if( read(initrd_fd, ((char *)dom_mem->vaddr)+ksize, isize) != isize )
         {
 	    dberr("Error reading initrd image, could not"
-		  " read the whole image. Terminating.\n");
-	    goto out;
+		  " read the whole image. Terminating.");
+	    goto error_out;
         }
 
 	meminfo->virt_mod_addr = virt_load_addr + ksize;
@@ -308,20 +309,23 @@ static dom_meminfo_t *setup_guestos(int dom, int kernel_fd, int initrd_fd,
     }
 
 
-    ret = meminfo;
- out:
+    return meminfo;
+
+ error_out:
+    if (meminfo)
+	free(meminfo);
+    if (page_array)
+	free(page_array);
 
-    return ret;
+    return NULL;
 }
 
 static int launch_domain(dom_meminfo_t  * meminfo)
 {
-    char cmd_path[MAX_PATH];
     dom0_op_t dop;
     int cmd_fd;
 
-    sprintf(cmd_path, "%s%s%s%s", "/proc/", PROC_XENO_ROOT, "/", PROC_CMD);
-    cmd_fd = open(cmd_path, O_WRONLY);
+    cmd_fd = open(PROC_XENO_DOM0_CMD, O_WRONLY);
     if(cmd_fd < 0){
         perror(PERR_STRING);
         return -1;
@@ -340,39 +344,37 @@ static int get_domain_info (int domain_id,
                             int *tot_pages)
 {
     FILE *f; 
-    char domains_path[MAX_PATH];
     char domains_line[256];
-    int rc = -1;
     int read_id;
 
-    sprintf (domains_path, "%s%s%s%s", "/proc/", PROC_XENO_ROOT, "/", PROC_DOMAINS
-        );
-
-    f = fopen (domains_path, "r");
-    if (f == NULL) goto out;
+    f = fopen (PROC_XENO_DOMAINS, "r");
+    if (f == NULL) return -1;
 
     read_id = -1;
     while (fgets (domains_line, 256, f) != 0)
     { 
         int trans;
+	read_id = -1;
         trans = sscanf (domains_line, "%d %*d %*d %*d %*d %*d %x %d %*s", &read_id
                         , pg_head, tot_pages);
-        if (trans == 3) {
-            if (read_id == domain_id) {
-                rc = 0;
-                break;
-            }
+	if (trans != 3) {
+	    dberr ("format of " PROC_XENO_DOMAINS " changed -- wrong kernel version?");
+	    read_id = -1;
+	    break;
+	}
+
+        if (read_id == domain_id) {
+	    break;
         }
     }
 
+    fclose (f);
+
     if (read_id == -1) {
         errno = ESRCH;
     }
 
-    fclose (f);
-
- out:
-    return rc;
+    return 0;
 }
 
 
@@ -383,15 +385,15 @@ int main(int argc, char **argv)
     dom_meminfo_t * meminfo;
     size_t ksize;
     unsigned long load_addr;
-    int kernel_fd, initrd_fd = 0;
+    int kernel_fd, initrd_fd = -1;
     int count;
     int cmd_len;
-    int rc = -1;
     int args_start = 4;
     char initrd_name[1024];
     int domain_id;
     int pg_head;
     int tot_pages;
+    int rc;
 
     /**** this argument parsing code is really _gross_. rewrite me! ****/
 
@@ -406,21 +408,26 @@ int main(int argc, char **argv)
     if ( get_domain_info (domain_id, &pg_head, &tot_pages) != 0 ) 
     {
         perror ("Could not find domain information");
-        rc = -1;
-        goto out;
+	return -1;
     }
 	     
-    kernel_fd = do_kernel_chcks(argv[2], 
-                                tot_pages << (PAGE_SHIFT - 10), 
-                                &load_addr, &ksize);
-    if ( kernel_fd < 0 )
+    kernel_fd = open(argv[2], O_RDONLY);
+    if (kernel_fd < 0) {
+        perror ("Could not open kernel image");
+	return -1;
+    }
+
+    rc = read_kernel_header(kernel_fd,
+			    tot_pages << (PAGE_SHIFT - 10), 
+			    &load_addr, &ksize);
+    if ( rc < 0 )
 	return -1;
     
 
     /* map domain's memory */
     if ( map_dom_mem(pg_head, tot_pages,
                      domain_id, &dom_os_image) )
-        goto out;
+	return -1;
 
     if( (argc > args_start) && 
         (strncmp("initrd=", argv[args_start], 7) == 0) )
@@ -433,22 +440,23 @@ int main(int argc, char **argv)
 	initrd_fd = open(initrd_name, O_RDONLY);
 	if(initrd_fd < 0){
             perror(PERR_STRING);
-            goto out;
+	    return -1;
 	}
     }
 
     /* the following code does the actual domain building */
     meminfo = setup_guestos(domain_id, kernel_fd, initrd_fd, load_addr, 
 			    ksize, &dom_os_image); 
-    
+    if (!meminfo)
+	return -1;
+
+    if (initrd_fd >= 0)
+	close(initrd_fd);
+    close(kernel_fd);
+
     /* and unmap the new domain's memory image since we no longer need it */
     dom_mem_cleanup(&dom_os_image);
 
-    if(!meminfo) { 
-	printf("Domain Builder: debug: meminfo NULL\n");
-        goto out;
-    }
-
     meminfo->virt_load_addr = load_addr;
     meminfo->num_vifs = atoi(argv[3]);
     meminfo->cmd_line[0] = '\0';
@@ -463,19 +471,8 @@ int main(int argc, char **argv)
         cmd_len += strlen(argv[count] + 1);
     }
 
-    /*    sprintf(status, 
-          "About to launch new domain %d with folowing parameters:\n"
-          " * page table base: %lx \n * load address: %lx \n"
-          " * shared info address: %lx \n * start info address: %lx \n"
-          " * number of vifs: %d \n * cmd line: %s \n", meminfo->domain, 
-          meminfo->l2_pgt_addr, meminfo->virt_load_addr, 
-          meminfo->virt_shinfo_addr, meminfo->virt_startinfo_addr, 
-          meminfo->num_vifs, meminfo->cmd_line);
-          dbstatus(status);*/
-    
     /* and launch the domain */
     rc = launch_domain(meminfo); 
     
- out:
-    return rc;
+    return 0;
 }