Merge tag 'v4.4.3'

[firefly-linux-kernel-4.4.55.git] / kernel / sys.c

diff --git a/kernel/sys.c b/kernel/sys.c
index 11333311cf1c5da8aab5c1eaceaaaee671468676..b5a8e844a96887e2d4253536a5a45dd2a0ca296e 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1855,11 +1855,13 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data
                user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
        }
 
-       if (prctl_map.exe_fd != (u32)-1)
+       if (prctl_map.exe_fd != (u32)-1) {
                error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
-       down_read(&mm->mmap_sem);
-       if (error)
-               goto out;
+               if (error)
+                       return error;
+       }
+
+       down_write(&mm->mmap_sem);
 
        /*
         * We don't validate if these members are pointing to
@@ -1896,10 +1898,8 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data
        if (prctl_map.auxv_size)
                memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
 
-       error = 0;
-out:
-       up_read(&mm->mmap_sem);
-       return error;
+       up_write(&mm->mmap_sem);
+       return 0;
 }
 #endif /* CONFIG_CHECKPOINT_RESTORE */
 
@@ -1965,7 +1965,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
 
        error = -EINVAL;
 
-       down_read(&mm->mmap_sem);
+       down_write(&mm->mmap_sem);
        vma = find_vma(mm, addr);
 
        prctl_map.start_code    = mm->start_code;
@@ -2058,7 +2058,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
 
        error = 0;
 out:
-       up_read(&mm->mmap_sem);
+       up_write(&mm->mmap_sem);
        return error;
 }