ld.so: Do not export free/calloc/malloc/realloc functions [BZ #25486]

Exporting functions and relying on symbol interposition from libc.so
makes the choice of implementation dependent on DT_NEEDED order, which
is not what some compiler drivers expect.

This commit replaces one magic mechanism (symbol interposition) with
another one (preprocessor-/compiler-based redirection).  This makes
the hand-over from the minimal malloc to the full malloc more
explicit.

Removing the ABI symbols is backwards-compatible because libc.so is
always in scope, and the dynamic loader will find the malloc-related
symbols there since commit f0b2132b35248c1f4a80f62a2c38cddcc802aa8c
("ld.so: Support moving versioned symbols between sonames
[BZ #24741]").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.data
index 2d5c66ae28..e2083c0ce6 100644
--- a/sysdeps/generic/localplt.data
+++ b/sysdeps/generic/localplt.data
@@ -7,12 +7,6 @@ libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
-# The main malloc is interposed into the dynamic linker, for
-# allocations after the initial link (when dlopen is used).
-ld.so: malloc
-ld.so: calloc
-ld.so: realloc
-ld.so: free
 # The TLS-enabled version of these functions is interposed from libc.so.
 ld.so: _dl_signal_error
 ld.so: _dl_catch_error