(pthread_getattr_np): Make sure stack info returned for main thread does not overlap with any other VMA.

1 files changed, 9 insertions, 6 deletions

diff --git a/nptl/pthread_getattr_np.c b/nptl/pthread_getattr_np.c
index f66e97fa68..0e1082079a 100644
--- a/nptl/pthread_getattr_np.c
+++ b/nptl/pthread_getattr_np.c
@@ -98,6 +98,7 @@ pthread_getattr_np (thread_id, attr)
 
 	  char *line = NULL;
 	  size_t linelen = 0;
+	  uintptr_t last_to = 0;
 
 	  while (! feof_unlocked (fp))
 	    {
@@ -106,23 +107,25 @@ pthread_getattr_np (thread_id, attr)
 
 	      uintptr_t from;
 	      uintptr_t to;
-	      if (sscanf (line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) == 2
-		  && from <= (uintptr_t) __libc_stack_end
+	      if (sscanf (line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) != 2)
+		continue;
+	      if (from <= (uintptr_t) __libc_stack_end
 		  && (uintptr_t) __libc_stack_end < to)
 		{
 		  /* Found the entry.  Now we have the info we need.  */
 		  iattr->stacksize = rl.rlim_cur;
 		  iattr->stackaddr = (void *) to;
 
-		  /* The limit might be too high.  This is a bogus
-		     situation but try to avoid making it worse.  */
-		  if ((size_t) iattr->stacksize > (size_t) iattr->stackaddr)
-		    iattr->stacksize = (size_t) iattr->stackaddr;
+		  /* The limit might be too high.  */
+		  if ((size_t) iattr->stacksize
+		      > (size_t) iattr->stackaddr - last_to)
+		    iattr->stacksize = (size_t) iattr->stackaddr - last_to;
 
 		  /* We succeed and no need to look further.  */
 		  ret = 0;
 		  break;
 		}
+	      last_to = to;
 	    }
 
 	  fclose (fp);