Fixing the bug of CGPT when primary entry table is invalid.

http://code.google.com/p/chromium-os/issues/detail?id=9279
This issue disclosed a bug of cgpt. The bug comes from the 'show' command always
reads the primary entry table when '-i partition' is specified. I added an
ANY_VALID constant for GetEntry to automatically select valid entry table.

Also fixed the bugs in cmd_boot.c and cmd_find.c. In cmd_add.c, stop user to
continue if any header/entry table is invalid.

Also fixed the bug that untrusted header size could cause segmentation failure.

Hungte, this is FYI. But welcome to do review.

BUG=chromium-os:9279
TEST=RUNTESTS=1 emerge-x86-generic vboot_reference
     Manually tested:
       cgpt show /tmp/test -i 1 -b
       cgpt show /tmp/test
       cgpt add /tmp/test -i 1 -l TEST
       cgpt find /tmp/test -l STATE
       cgpt boot /tmp/test -i 1

Change-Id: Iaba9c635754096a82b3ec74634af184362d4e264
Change-Id: I6f3e87e3998457676e3388d2a6ed36c0564796d8

Review URL: http://codereview.chromium.org/5115002

1 files changed, 5 insertions, 5 deletions

diff --git a/cgpt/cmd_show.c b/cgpt/cmd_show.c
index a9963b5b..920a30fe 100644
--- a/cgpt/cmd_show.c
+++ b/cgpt/cmd_show.c
@@ -274,7 +274,7 @@ int cmd_show(int argc, char *argv[]) {
     }
 
     uint32_t index = partition - 1;
-    GptEntry *entry = GetEntry(&drive.gpt, PRIMARY, index);
+    GptEntry *entry = GetEntry(&drive.gpt, ANY_VALID, index);
     char buf[256];                      // scratch buffer for string conversion
 
     if (single_item) {
@@ -299,13 +299,13 @@ int cmd_show(int argc, char *argv[]) {
         printf("%s\n", buf);
         break;
       case 'S':
-        printf("%d\n", GetSuccessful(&drive.gpt, PRIMARY, index));
+        printf("%d\n", GetSuccessful(&drive.gpt, ANY_VALID, index));
         break;
       case 'T':
-        printf("%d\n", GetTries(&drive.gpt, PRIMARY, index));
+        printf("%d\n", GetTries(&drive.gpt, ANY_VALID, index));
         break;
       case 'P':
-        printf("%d\n", GetPriority(&drive.gpt, PRIMARY, index));
+        printf("%d\n", GetPriority(&drive.gpt, ANY_VALID, index));
         break;
       case 'A':
         printf("0x%x\n", entry->attrs.fields.gpt_att);
@@ -322,7 +322,7 @@ int cmd_show(int argc, char *argv[]) {
     char type[GUID_STRLEN];
 
     for (i = 0; i < GetNumberOfEntries(&drive.gpt); ++i) {
-      entry = GetEntry(&drive.gpt, PRIMARY, i);
+      entry = GetEntry(&drive.gpt, ANY_VALID, i);
 
       if (IsZero(&entry->type))
         continue;