uml: don't kill pid 0

[karo-tx-linux.git] / arch / um / kernel / skas / mmu.c

diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index e8dc8540d444cc76a5554585005e7be128519384..78b3e9f69d57d6a81d9ac446e9f6edc16586e5fe 100644 (file)
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -164,8 +164,20 @@ void destroy_context(struct mm_struct *mm)
 
        if (proc_mm)
                os_close_file(mmu->id.u.mm_fd);
-       else
+       else {
+               /*
+                * If init_new_context wasn't called, this will be
+                * zero, resulting in a kill(0), which will result in the
+                * whole UML suddenly dying.  Also, cover negative and
+                * 1 cases, since they shouldn't happen either.
+                */
+               if (mmu->id.u.pid < 2) {
+                       printk(KERN_ERR "corrupt mm_context - pid = %d\n",
+                              mmu->id.u.pid);
+                       return;
+               }
                os_kill_ptraced_process(mmu->id.u.pid, 1);
+       }
 
        if (skas_needs_stub)
                free_page(mmu->id.stack);