libio: Implement internal function __libc_readline_unlocked

This is a variant of fgets which fails with ERANGE if the
buffer is too small, and the buffer length is given as an
argument of type size_t.

This function will be useful for implementing NSS file reading
operations.  Compared to a direct implementation using the public API,
it avoids an lseek system call in case the line terminator can be
found in the internal read buffer.

1 files changed, 4 insertions, 0 deletions

diff --git a/libio/Versions b/libio/Versions
index 7712334..acb896a 100644
--- a/libio/Versions
+++ b/libio/Versions
@@ -158,5 +158,9 @@ libc {
 
     # Used by NPTL
     _IO_enable_locks;
+
+    __fseeko64;
+    __ftello64;
+    __libc_readline_unlocked;
   }
 }