[PATCH 10/12] dlfcn,elf: implement dlmem() [BZ #11767]

[Stas Sergeev <stsp2@yandex.ru>]

This patch adds the following function:
void *dlmem(const unsigned char *buffer, size_t size, int flags,
            struct dlmem_args *dlm_args);

It is the same as dlopen() but allows to dynamic-link solibs from
the memory buffer, rather than from a file as dlopen() does.

"buffer" arg is the pointer to the solib image in memory.
"size" is the solib image size. Must be smaller-or-equal to the
    actual buffer size.
"flags" is the same flags argument used in dlopen().
"dlm_args" is an optional argument that allows to specify the load
    namespace and a premap callback.

This implementation is trying a "zero-copy" technique first, but
it works only with linux kernels 5.13 and newer. So the memcpy()
fall-back is added as well.

This patch adds a test-case named tst-dlmem-fdlopen. It implements
a bsd-compatible fdlopen() on top of dlmem() and loads a test lib
with it. It then checks /proc/<pid>/maps to make sure the library
was mmap()ed rather then memcopied. Then it does the regular set
of solib tests.

The test-suite was run on x86_64/64 and showed no regressions.

Signed-off-by: Stas Sergeev <stsp2@yandex.ru>
---
 dlfcn/Makefile                                |  10 +-
 dlfcn/Versions                                |   3 +
 dlfcn/dlfcn.h                                 |  22 +++
 dlfcn/dlmem.c                                 |  86 +++++++++
 dlfcn/tst-dlmem-extfns.c                      | 175 ++++++++++++++++++
 elf/dl-load.c                                 | 173 +++++++++++++++++
 elf/dl-load.h                                 |   3 +
 elf/dl-main.h                                 |  12 ++
 elf/dl-object.c                               |   5 +-
 elf/dl-open.c                                 |  13 ++
 elf/rtld.c                                    |   1 +
 manual/dynlink.texi                           |   1 +
 sysdeps/generic/ldsodefs.h                    |   9 +
 sysdeps/mach/hurd/i386/libc.abilist           |   1 +
 sysdeps/unix/sysv/linux/aarch64/libc.abilist  |   1 +
 sysdeps/unix/sysv/linux/alpha/libc.abilist    |   1 +
 sysdeps/unix/sysv/linux/arc/libc.abilist      |   1 +
 sysdeps/unix/sysv/linux/arm/be/libc.abilist   |   1 +
 sysdeps/unix/sysv/linux/arm/le/libc.abilist   |   1 +
 sysdeps/unix/sysv/linux/csky/libc.abilist     |   1 +
 sysdeps/unix/sysv/linux/hppa/libc.abilist     |   1 +
 sysdeps/unix/sysv/linux/i386/libc.abilist     |   1 +
 sysdeps/unix/sysv/linux/ia64/libc.abilist     |   1 +
 .../sysv/linux/loongarch/lp64/libc.abilist    |   1 +
 .../sysv/linux/m68k/coldfire/libc.abilist     |   1 +
 .../unix/sysv/linux/m68k/m680x0/libc.abilist  |   1 +
 .../sysv/linux/microblaze/be/libc.abilist     |   1 +
 .../sysv/linux/microblaze/le/libc.abilist     |   1 +
 .../sysv/linux/mips/mips32/fpu/libc.abilist   |   1 +
 .../sysv/linux/mips/mips32/nofpu/libc.abilist |   1 +
 .../sysv/linux/mips/mips64/n32/libc.abilist   |   1 +
 .../sysv/linux/mips/mips64/n64/libc.abilist   |   1 +
 sysdeps/unix/sysv/linux/nios2/libc.abilist    |   1 +
 sysdeps/unix/sysv/linux/or1k/libc.abilist     |   1 +
 .../linux/powerpc/powerpc32/fpu/libc.abilist  |   1 +
 .../powerpc/powerpc32/nofpu/libc.abilist      |   1 +
 .../linux/powerpc/powerpc64/be/libc.abilist   |   1 +
 .../linux/powerpc/powerpc64/le/libc.abilist   |   1 +
 .../unix/sysv/linux/riscv/rv32/libc.abilist   |   1 +
 .../unix/sysv/linux/riscv/rv64/libc.abilist   |   1 +
 .../unix/sysv/linux/s390/s390-32/libc.abilist |   1 +
 .../unix/sysv/linux/s390/s390-64/libc.abilist |   1 +
 sysdeps/unix/sysv/linux/sh/be/libc.abilist    |   1 +
 sysdeps/unix/sysv/linux/sh/le/libc.abilist    |   1 +
 .../sysv/linux/sparc/sparc32/libc.abilist     |   1 +
 .../sysv/linux/sparc/sparc64/libc.abilist     |   1 +
 .../unix/sysv/linux/x86_64/64/libc.abilist    |   1 +
 .../unix/sysv/linux/x86_64/x32/libc.abilist   |   1 +
 48 files changed, 546 insertions(+), 2 deletions(-)
 create mode 100644 dlfcn/dlmem.c
 create mode 100644 dlfcn/tst-dlmem-extfns.c

diff --git a/dlfcn/Makefile b/dlfcn/Makefile
index 1fa7fea1ef..55e5f5fcdf 100644
--- a/dlfcn/Makefile
+++ b/dlfcn/Makefile
@@ -28,6 +28,7 @@ routines = \
   dlclose \
   dlerror \
   dlinfo \
+  dlmem \
   dlmopen \
   dlopen \
   dlsym \
@@ -51,7 +52,8 @@ endif
 ifeq (yes,$(build-shared))
 tests = glrefmain failtest tst-dladdr default errmsg1 tstcxaatexit \
 	bug-dlopen1 bug-dlsym1 tst-dlinfo bug-atexit1 bug-atexit2 \
-	bug-atexit3 tstatexit bug-dl-leaf tst-rec-dlopen
+	bug-atexit3 tstatexit bug-dl-leaf tst-rec-dlopen tst-dlmem-extfns
+CPPFLAGS-tst-dlmem-extfns.c += -DBUILDDIR=\"$(objpfx)\"
 endif
 modules-names = glreflib1 glreflib2 glreflib3 failtestmod defaultmod1 \
 		defaultmod2 errmsg1mod modatexit modcxaatexit \
@@ -102,6 +104,12 @@ $(objpfx)glrefmain.out: $(objpfx)glrefmain \
 $(objpfx)failtest.out: $(objpfx)failtestmod.so
 
 $(objpfx)tst-dladdr.out: $(objpfx)glreflib1.so
+# Create fancy container file with solib within.
+$(objpfx)glreflib1.img: $(objpfx)glreflib1.so
+	dd if=/dev/urandom bs=512 count=1 >$@
+	cat $^ >>$@
+	dd if=/dev/urandom bs=512 count=1 >>$@
+$(objpfx)tst-dlmem-extfns.out: $(objpfx)glreflib1.so $(objpfx)glreflib1.img
 
 $(objpfx)tst-dlinfo.out: $(objpfx)glreflib3.so
 LDFLAGS-glreflib3.so = -Wl,-rpath,:
diff --git a/dlfcn/Versions b/dlfcn/Versions
index cc34eb824d..b427c9c3a3 100644
--- a/dlfcn/Versions
+++ b/dlfcn/Versions
@@ -28,6 +28,9 @@ libc {
     dlsym;
     dlvsym;
   }
+  GLIBC_2.38 {
+    dlmem;
+  }
   GLIBC_PRIVATE {
     __libc_dlerror_result;
     _dlerror_run;
diff --git a/dlfcn/dlfcn.h b/dlfcn/dlfcn.h
index c5d192597d..fe5e5a7d09 100644
--- a/dlfcn/dlfcn.h
+++ b/dlfcn/dlfcn.h
@@ -68,6 +68,28 @@ extern void *dlsym (void *__restrict __handle,
 /* Like `dlopen', but request object to be allocated in a new namespace.  */
 extern void *dlmopen (Lmid_t __nsid, const char *__file, int __mode) __THROWNL;
 
+/* Callback for dlmem. */
+typedef void *
+(dlmem_premap_t) (void *mappref, size_t maplength, size_t mapalign,
+	          void *cookie);
+
+struct dlmem_args {
+  /* Optional name to associate with the loaded object. */
+  const char *soname;
+  /* Namespace where to load the object. */
+  Lmid_t nsid;
+  /* dlmem-specific flags. */
+  unsigned int flags;
+  /* Optional premap callback. */
+  dlmem_premap_t *premap;
+  /* Optional argument for premap callback. */
+  void *cookie;
+};
+
+/* Like `dlmopen', but loads shared object from memory buffer.  */
+extern void *dlmem (const unsigned char *buffer, size_t size, int mode,
+		    struct dlmem_args *dlm_args);
+
 /* Find the run-time address in the shared object HANDLE refers to
    of the symbol called NAME with VERSION.  */
 extern void *dlvsym (void *__restrict __handle,
diff --git a/dlfcn/dlmem.c b/dlfcn/dlmem.c
new file mode 100644
index 0000000000..d59eb99ec1
--- /dev/null
+++ b/dlfcn/dlmem.c
@@ -0,0 +1,86 @@
+/* Load a shared object from memory.
+   Copyright (C) 1995-2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <dlfcn.h>
+#include <libintl.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <ldsodefs.h>
+#include <shlib-compat.h>
+
+struct _dlmem_args
+{
+  /* The arguments for dlmem_doit.  */
+  const unsigned char *buffer;
+  size_t size;
+  int mode;
+  struct dlmem_args *args;
+  /* The return value of dlmem_doit.  */
+  void *new;
+  /* Address of the caller.  */
+  const void *caller;
+};
+
+static void
+dlmem_doit (void *a)
+{
+  struct _dlmem_args *args = (struct _dlmem_args *) a;
+
+  if (args->mode & ~(RTLD_BINDING_MASK | RTLD_NOLOAD | RTLD_DEEPBIND
+		     | RTLD_GLOBAL | RTLD_LOCAL | RTLD_NODELETE
+		     | __RTLD_SPROF))
+    _dl_signal_error (EINVAL, NULL, NULL, _("invalid mode parameter"));
+  if ((uintptr_t) args->buffer & (GLRO(dl_pagesize) - 1))
+    _dl_signal_error (EINVAL, NULL, NULL, _("buffer not aligned"));
+
+  args->new = GLRO(dl_mem) (args->buffer, args->size,
+			    args->mode | __RTLD_DLOPEN,
+			    args->args,
+			    args->caller,
+			    __libc_argc, __libc_argv, __environ);
+}
+
+
+static void *
+dlmem_implementation (const unsigned char *buffer, size_t size, int mode,
+		      struct dlmem_args *dlm_args, void *dl_caller)
+{
+  struct _dlmem_args args;
+  args.buffer = buffer;
+  args.size = size;
+  args.mode = mode;
+  args.args = dlm_args;
+  args.caller = dl_caller;
+
+  return _dlerror_run (dlmem_doit, &args) ? NULL : args.new;
+}
+
+void *
+___dlmem (const unsigned char *buffer, size_t size, int mode,
+	  struct dlmem_args *dlm_args)
+{
+  return dlmem_implementation (buffer, size, mode, dlm_args,
+				 RETURN_ADDRESS (0));
+}
+
+#ifdef SHARED
+versioned_symbol (libc, ___dlmem, dlmem, GLIBC_2_38);
+#else /* !SHARED */
+weak_alias (___dlmem, dlmem)
+static_link_warning (dlmem)
+#endif /* !SHARED */
diff --git a/dlfcn/tst-dlmem-extfns.c b/dlfcn/tst-dlmem-extfns.c
new file mode 100644
index 0000000000..3b98a6e859
--- /dev/null
+++ b/dlfcn/tst-dlmem-extfns.c
@@ -0,0 +1,175 @@
+/* Test for external functions (fdlopen, dlopen_with_offset4) on top of dlmem.
+   Copyright (C) 2000-2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <dlfcn.h>
+#include <link.h>
+#include <errno.h>
+#include <error.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <support/check.h>
+
+/* Load the shared library from an open fd. */
+static void *
+fdlopen (int fd, int flags)
+{
+  off_t len;
+  void *addr;
+  void *handle;
+
+  len = lseek (fd, 0, SEEK_END);
+  lseek (fd, 0, SEEK_SET);
+  addr = mmap (NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
+  if (addr == MAP_FAILED)
+    return NULL;
+  handle = dlmem (addr, len, flags, NULL);
+  munmap (addr, len);
+  return handle;
+}
+
+/* Load the shared library from a container file.
+   file   - file name.
+   offset - solib offset within a container file.
+            Highly recommended to be page-aligned.
+   length - solib file length (not a container file length).
+   flags  - dlopen() flags. */
+void *dlopen_with_offset4 (const char *file, off_t offset, size_t length,
+                           int flags)
+{
+    void *addr;
+    void *handle;
+    int fd;
+    off_t pad_size = (offset & (getpagesize () - 1));
+    off_t aligned_offset = offset - pad_size;
+    size_t map_length = length + pad_size;
+
+    fd = open (file, O_RDONLY);
+    if (fd == -1)
+        return NULL;
+    addr = mmap (NULL, map_length, PROT_READ, MAP_PRIVATE, fd, aligned_offset);
+    close(fd);
+    if (addr == MAP_FAILED)
+        return NULL;
+    if (pad_size)
+      {
+        /* We need to fix alignment by hands. :-(
+           And for that we need a shared mapping. */
+        void *addr2 = mmap (NULL, length, PROT_READ | PROT_WRITE,
+                            MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+        if (addr2 == MAP_FAILED)
+          {
+            munmap (addr, map_length);
+            return NULL;
+          }
+        memcpy (addr2, addr + pad_size, length);
+        munmap (addr, map_length);
+        addr = addr2;
+        map_length = length;
+      }
+    handle = dlmem (addr, length, flags, NULL);
+    munmap (addr, map_length);
+    return handle;
+}
+
+
+#define TEST_FUNCTION do_test
+extern int do_test (void);
+
+int
+do_test (void)
+{
+  char cmd[256];
+  void *handle;
+  int (*sym) (void); /* We load ref1 from glreflib1.c.  */
+  Dl_info info;
+  int rc;
+  int fd;
+  struct stat sb;
+  const unsigned char *unaligned_buf = (const unsigned char *) 1;
+
+  /* First check the reaction to unaligned buf. */
+  handle = dlmem (unaligned_buf, 4096, RTLD_NOW, NULL);
+  TEST_VERIFY (handle == NULL);
+  /* errno is set by dlerror() so needs to print something. */
+  printf ("unaligned buf gives %s\n", dlerror ());
+  TEST_COMPARE (errno, EINVAL);
+
+  fd = open (BUILDDIR "glreflib1.so", O_RDONLY);
+  if (fd == -1)
+    error (EXIT_FAILURE, 0, "cannot open: glreflib1.so");
+  fstat (fd, &sb);
+  handle = fdlopen (fd, RTLD_NOW);
+  close (fd);
+  if (handle == NULL)
+    {
+      printf ("fdlopen failed, %s\n", dlerror ());
+      exit (EXIT_FAILURE);
+    }
+
+  /* Check that the lib is properly mmap()ed, rather than memcpy()ed.
+     This may fail on linux kernels <5.13. */
+  snprintf (cmd, sizeof(cmd), "grep glreflib1.so /proc/%i/maps", getpid());
+  rc = system (cmd);
+  TEST_COMPARE (rc, 0);
+
+  sym = dlsym (handle, "ref1");
+  if (sym == NULL)
+    error (EXIT_FAILURE, 0, "dlsym failed");
+
+  dlclose (handle);
+
+  /* Try to load the solib from container, with the worst, unaligned case. */
+  handle = dlopen_with_offset4 (BUILDDIR "glreflib1.img", 512, sb.st_size,
+                                RTLD_NOW);
+
+  sym = dlsym (handle, "ref1");
+  if (sym == NULL)
+    error (EXIT_FAILURE, 0, "dlsym failed");
+
+  memset (&info, 0, sizeof (info));
+  rc = dladdr (sym, &info);
+  if (rc == 0)
+    error (EXIT_FAILURE, 0, "dladdr failed");
+
+  printf ("info.dli_fname = %p (\"%s\")\n", info.dli_fname, info.dli_fname);
+  printf ("info.dli_fbase = %p\n", info.dli_fbase);
+  printf ("info.dli_sname = %p (\"%s\")\n", info.dli_sname, info.dli_sname);
+  printf ("info.dli_saddr = %p\n", info.dli_saddr);
+
+  if (info.dli_fname == NULL)
+    error (EXIT_FAILURE, 0, "dli_fname is NULL");
+  if (info.dli_fbase == NULL)
+    error (EXIT_FAILURE, 0, "dli_fbase is NULL");
+  if (info.dli_sname == NULL)
+    error (EXIT_FAILURE, 0, "dli_sname is NULL");
+  if (info.dli_saddr == NULL)
+    error (EXIT_FAILURE, 0, "dli_saddr is NULL");
+
+  /* Handle can be closed only after checking info, as some info fields
+     point to memory that is freed by dlclose(). */
+  dlclose (handle);
+  return 0;
+}
+
+
+#include <support/test-driver.c>
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 6708210da7..fd81a9103e 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -75,6 +75,7 @@ struct filebuf
 #include <dl-machine-reject-phdr.h>
 #include <dl-sysdep-open.h>
 #include <dl-prop.h>
+#include <dl-main.h>
 #include <not-cancel.h>
 
 #include <endian.h>
@@ -2351,6 +2352,178 @@ _dl_map_object (struct link_map *loader, const char *name,
   return __dl_map_object (loader, name, NULL, type, trace_mode, mode, nsid);
 }
 
+static void *
+do_memremap (void *addr, size_t length, int prot, int flags,
+             void *arg, off_t offset)
+{
+  const struct dlmem_fbuf *fb = arg;
+  size_t to_copy = 0;
+
+  assert (flags & MAP_FIXED);
+  if (offset < fb->len)
+    {
+      to_copy = length;
+      if (offset + to_copy > fb->len)
+        to_copy = fb->len - offset;
+#ifdef MREMAP_DONTUNMAP
+      void *addr2 = __mremap ((void *) (fb->buf + offset), to_copy, to_copy,
+                              MREMAP_MAYMOVE | MREMAP_FIXED | MREMAP_DONTUNMAP,
+                              addr);
+      /* MREMAP_DONTUNMAP introduced in linux-5.7, but only works for
+         file-based maps since commit a460938 went in 5.13.
+         So have a fall-back. */
+      if (addr2 == MAP_FAILED)
+        memcpy (addr, fb->buf + offset, to_copy);
+#else
+      /* MREMAP_DONTUNMAP is not always available. This is a fall-back. */
+      memcpy (addr, fb->buf + offset, to_copy);
+#endif
+    }
+  /* memset the rest. */
+  if (length > to_copy)
+    memset (addr + to_copy, 0, length - to_copy);
+  if (__mprotect (addr, length, prot) == -1)
+    return MAP_FAILED;
+  return addr;
+}
+
+static void *
+do_dlmem_premap (void *mappref, size_t maplength, size_t mapalign,
+		 void *cookie)
+{
+  struct dlmem_fbuf *fb = cookie;
+  void *ret = MAP_FAILED;
+
+  if (fb->dlm_args && fb->dlm_args->premap)
+    ret = fb->dlm_args->premap (mappref, maplength, mapalign,
+                                fb->dlm_args->cookie);
+  if (ret == MAP_FAILED)
+    ret = (void *) _dl_map_segment ((ElfW(Addr)) mappref, maplength,
+                                    mapalign);
+  return ret;
+}
+
+static ssize_t
+do_pread_memcpy (void *arg, void *buf, size_t count, off_t offset)
+{
+  struct dlmem_fbuf *fb = arg;
+  if (offset >= fb->len)
+    return -1;
+  if (offset + count > fb->len)
+    count = fb->len - offset;
+  if (count)
+    memcpy (buf, fb->buf + offset, count);
+  return count;
+}
+
+static struct link_map *
+___dl_map_object_from_mem (struct link_map *loader, const char *name,
+			   void *private, int type, int trace_mode,
+			   int mode, Lmid_t nsid, struct filebuf *fbp)
+{
+  struct link_map *l;
+  int err;
+  char *realname;
+  /* Initialize to keep the compiler happy.  */
+  const char *errstring = NULL;
+  int errval = 0;
+  struct r_debug *r = _dl_debug_update (nsid);
+  bool make_consistent = false;
+  struct r_file_id id = {};
+
+  assert (nsid >= 0);
+  assert (nsid < GL(dl_nns));
+
+  if (name && *name)
+    {
+      /* Look for this name among those already loaded.  */
+      l = _dl_check_loaded (name, nsid);
+      if (l)
+        return l;
+    }
+
+  /* Will be true if we found a DSO which is of the other ELF class.  */
+  bool found_other_class = false;
+
+  err = do_open_verify (name, private, fbp,
+                        loader ?: GL(dl_ns)[nsid]._ns_loaded,
+                        &found_other_class, false, do_pread_memcpy);
+  if (err)
+    return NULL;
+
+  /* In case the LOADER information has only been provided to get to
+     the appropriate RUNPATH/RPATH information we do not need it
+     anymore.  */
+  if (mode & __RTLD_CALLMAP)
+    loader = NULL;
+
+  if (mode & RTLD_NOLOAD)
+    {
+      /* We are not supposed to load the object unless it is already
+	 loaded.  So return now.  */
+      return NULL;
+    }
+
+  /* Print debugging message.  */
+  if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
+    _dl_debug_printf ("dlmem [%lu];  generating link map\n", nsid);
+
+  /* _dl_new_object() treats "" separately and doesn't free it. */
+  realname = *name ? __strdup (name) : (char *) "";
+  /* Enter the new object in the list of loaded objects.  */
+  l = _dl_new_object (realname, name, type, loader, mode, nsid);
+  if (__glibc_unlikely (l == NULL))
+    {
+      errstring = N_("cannot create shared object descriptor");
+      goto lose_errno;
+    }
+
+  void *stack_end = __libc_stack_end;
+  if (_dl_map_object_1 (l, private, fbp, mode, loader, &stack_end, &errval,
+                        &errstring, do_memremap, do_dlmem_premap))
+    goto lose;
+
+  _dl_map_object_2 (l, mode, id, NULL, nsid);
+  return l;
+
+lose_errno:
+  errval = errno;
+lose:
+  if (l != NULL && l->l_map_start != 0)
+    _dl_unmap_segments (l);
+  if (l != NULL && l->l_origin != (char *) -1l)
+    free ((char *) l->l_origin);
+  if (l != NULL && !l->l_libname->dont_free)
+    free (l->l_libname);
+  if (l != NULL && l->l_phdr_allocated)
+    free ((void *) l->l_phdr);
+  free (l);
+
+  if (make_consistent && r != NULL)
+    {
+      r->r_state = RT_CONSISTENT;
+      _dl_debug_state ();
+      LIBC_PROBE (map_failed, 2, nsid, r);
+    }
+
+  _dl_signal_error (errval, NULL, NULL, errstring);
+  return NULL;
+}
+
+struct link_map *
+__dl_map_object_from_mem (struct link_map *loader, const char *name,
+			  void *private, int type, int trace_mode,
+			  int mode, Lmid_t nsid)
+{
+  struct link_map *ret;
+  struct filebuf fb = {};
+
+  ret = ___dl_map_object_from_mem (loader, name, private, type, trace_mode,
+                                  mode, nsid, &fb);
+  filebuf_done (&fb);
+  return ret;
+}
+
 struct add_path_state
 {
   bool counting;
diff --git a/elf/dl-load.h b/elf/dl-load.h
index e777da5838..09b2878260 100644
--- a/elf/dl-load.h
+++ b/elf/dl-load.h
@@ -106,6 +106,9 @@ _dl_postprocess_loadcmd (struct link_map *l, const ElfW(Ehdr) *header,
                                       - c->mapoff);
 }
 
+static void *
+do_mmap (void *addr, size_t length, int prot, int flags,
+         void *arg, off_t offset);
 
 /* This is a subroutine of _dl_map_object_from_fd.  It is responsible
    for filling in several fields in *L: l_map_start, l_map_end, l_addr,
diff --git a/elf/dl-main.h b/elf/dl-main.h
index 344a87d5e8..e60fafaeb6 100644
--- a/elf/dl-main.h
+++ b/elf/dl-main.h
@@ -104,6 +104,13 @@ struct dl_main_state
   bool version_info;
 };
 
+struct dlmem_fbuf
+{
+  ssize_t len;
+  const unsigned char *buf;
+  struct dlmem_args *dlm_args;
+};
+
 /* Open the shared object NAME and map in its segments.
    LOADER's DT_RPATH is used in searching for NAME.
    If the object is already opened, returns its existing map.  */
@@ -112,6 +119,11 @@ __dl_map_object (struct link_map *loader,
                  const char *name, void *private,
                  int type, int trace_mode, int mode,
                  Lmid_t nsid) attribute_hidden;
+extern struct link_map *
+__dl_map_object_from_mem (struct link_map *loader,
+			  const char *name, void *private,
+			  int type, int trace_mode, int mode,
+			  Lmid_t nsid) attribute_hidden;
 
 /* Helper function to invoke _dl_init_paths with the right arguments
    from *STATE.  */
diff --git a/elf/dl-object.c b/elf/dl-object.c
index f1f2ec956c..ab926cd4bf 100644
--- a/elf/dl-object.c
+++ b/elf/dl-object.c
@@ -122,7 +122,10 @@ _dl_new_object (char *realname, const char *libname, int type,
 #endif
     new->l_name = realname;
   else
-    new->l_name = (char *) newname->name + libname_len - 1;
+    /* When realname="", it is not allocated and points to the constant
+       string. Constness is dropped by an explicit cast. :(
+       So strdup() it here. */
+    new->l_name = __strdup ("");
 
   new->l_type = type;
   /* If we set the bit now since we know it is never used we avoid
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 9055b95f17..bcae45d714 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -957,6 +957,19 @@ _dl_open (const char *file, int mode, const void *caller_dlopen, Lmid_t nsid,
                      __dl_map_object);
 }
 
+void *
+_dl_mem (const unsigned char *buffer, size_t size, int mode,
+	 struct dlmem_args *dlm_args, const void *caller_dlopen,
+	 int argc, char *argv[], char *env[])
+{
+  struct dlmem_fbuf fb = { .buf = buffer, .len = size, .dlm_args = dlm_args };
+  Lmid_t nsid = dlm_args ? dlm_args->nsid : LM_ID_BASE;
+  const char *file = (dlm_args && dlm_args->soname) ? dlm_args->soname : "";
+
+  return do_dl_open (file, &fb, mode, caller_dlopen, nsid, argc, argv, env,
+                     __dl_map_object_from_mem);
+}
+
 void
 _dl_show_scope (struct link_map *l, int from)
 {
diff --git a/elf/rtld.c b/elf/rtld.c
index c1e383b055..30c3190593 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -367,6 +367,7 @@ struct rtld_global_ro _rtld_global_ro attribute_relro =
     ._dl_mcount = _dl_mcount,
     ._dl_lookup_symbol_x = _dl_lookup_symbol_x,
     ._dl_open = _dl_open,
+    ._dl_mem = _dl_mem,
     ._dl_close = _dl_close,
     ._dl_catch_error = _dl_catch_error,
     ._dl_error_free = _dl_error_free,
diff --git a/manual/dynlink.texi b/manual/dynlink.texi
index 6a4a50d3f0..21bc6c067c 100644
--- a/manual/dynlink.texi
+++ b/manual/dynlink.texi
@@ -209,6 +209,7 @@ This function is a GNU extension.
 @c dladdr1
 @c dlclose
 @c dlerror
+@c dlmem
 @c dlmopen
 @c dlopen
 @c dlsym
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index e1ab272a79..fae485fe1f 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -664,6 +664,9 @@ struct rtld_global_ro
 				   struct link_map *);
   void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
 		     Lmid_t nsid, int argc, char *argv[], char *env[]);
+  void *(*_dl_mem) (const unsigned char *buffer, size_t size, int mode,
+		    struct dlmem_args *dlm_args, const void *caller_dlopen,
+		    int argc, char *argv[], char *env[]);
   void (*_dl_close) (void *map);
   /* libdl in a secondary namespace (after dlopen) must use
      _dl_catch_error from the main namespace, so it has to be
@@ -1235,6 +1238,12 @@ extern void *_dl_open (const char *name, int mode, const void *caller,
 		       Lmid_t nsid, int argc, char *argv[], char *env[])
      attribute_hidden;
 
+/* Open shared object from memory buffer. */
+extern void *_dl_mem (const unsigned char *buffer, size_t size, int mode,
+		      struct dlmem_args *dlm_args, const void *caller,
+		      int argc, char *argv[], char *env[])
+     attribute_hidden;
+
 /* Free or queue for freeing scope OLD.  If other threads might be
    in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
    old scope, OLD can't be freed until no thread is using it.  */
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index ed0c4789eb..1880004336 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -2326,6 +2326,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 0e2d9c3045..c4d31cabed 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2665,3 +2665,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index f1bec1978d..93b37a1e1d 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2774,6 +2774,7 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
index aa874b88d0..9fec2308c3 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2426,3 +2426,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index afbd57da6f..bd0f04e58a 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -546,6 +546,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
 GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index e7364cd3fe..dccc49c8d6 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -543,6 +543,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
 GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index 913fa59215..0df8524ac0 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2702,3 +2702,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 43af3a9811..fa4680e97a 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2651,6 +2651,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index af72f8fab0..bfb1bde49d 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2835,6 +2835,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 48cbb0fa50..e53505abe0 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2600,6 +2600,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
index c15884bb0b..9f56cbdcab 100644
--- a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
@@ -2186,3 +2186,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 3738db81df..d5443b1198 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -547,6 +547,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0x98
 GLIBC_2.4 _IO_2_1_stdin_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index ed13627752..640c8b8c4a 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2778,6 +2778,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index 8357738621..79b400efc6 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2751,3 +2751,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 58c5da583d..38b4098950 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2748,3 +2748,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index d3741945cd..9a4f909a25 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2743,6 +2743,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 5319fdc204..c8b9f85fdb 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2741,6 +2741,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index 1743ea6eb9..0887b67394 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2749,6 +2749,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index 9b1f53c6ac..1c3a6f4bee 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2651,6 +2651,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index ae1c6ca1b5..31b23859a4 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2790,3 +2790,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/or1k/libc.abilist b/sysdeps/unix/sysv/linux/or1k/libc.abilist
index a7c572c947..59f4aa7766 100644
--- a/sysdeps/unix/sysv/linux/or1k/libc.abilist
+++ b/sysdeps/unix/sysv/linux/or1k/libc.abilist
@@ -2172,3 +2172,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 074fa031a7..d715d0ae97 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2817,6 +2817,7 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index dfcb4bd2d5..3addcf3d17 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2850,6 +2850,7 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index 63bbccf3f9..5365978277 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2571,6 +2571,7 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index ab85fd61ef..f0af576192 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2885,3 +2885,4 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index b716f5c763..941fd40ea8 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2428,3 +2428,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index 774e777b65..74f58439ad 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2628,3 +2628,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index 8625135c48..cf3a10aa76 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2815,6 +2815,7 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index d00c7eb262..2ad97f87b2 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2608,6 +2608,7 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
index b63037241d..7c81b94953 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2658,6 +2658,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index d80055617d..0493d6b456 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2655,6 +2655,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 5be55c11d2..6fd09f6499 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2810,6 +2810,7 @@ GLIBC_2.38 __nldbl___isoc23_vsscanf F
 GLIBC_2.38 __nldbl___isoc23_vswscanf F
 GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index 475fdaae15..24dbc4801f 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2623,6 +2623,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index 6cfb928bc8..522ca8e8aa 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2574,6 +2574,7 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index c735097172..42b170c805 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2680,3 +2680,4 @@ GLIBC_2.38 __isoc23_wcstoull F
 GLIBC_2.38 __isoc23_wcstoull_l F
 GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
+GLIBC_2.38 dlmem F
-- 
2.37.2