Update for glibc 2.34+ : __malloc_hook / ... deprecated and no longer usable

[vhaudiquet]

I use glibc 2.35 on my system, and i can't compile libSlimGuard, because of the symbols used in src/gnuwrapper.cpp.
These symbols (__malloc_hook, etc) are not found by my compiler, because they have been removed from glibc.

From glibc 2.34 log :

• The deprecated memory allocation hooks __malloc_hook, __realloc_hook,
  __memalign_hook and __free_hook are now removed from the API. Compatibility
  symbols are present to support legacy programs but new applications can no
  longer link to these symbols. These hooks no longer have any effect on glibc
  functionality. The malloc debugging DSO libc_malloc_debug.so currently
  supports hooks and can be preloaded to get this functionality back for older
  programs. However this is a transitional measure and may be removed in a
  future release of the GNU C Library. Users may port away from these hooks by
  writing and preloading their own malloc interposition library.

Just wanted to let you know

[jvoisin]

It indeed doesn't compile anymore on a recent libc:

$ git clone git@github.com:ssrg-vt/SlimGuard.git
Cloning into 'SlimGuard'...
remote: Enumerating objects: 477, done.
remote: Counting objects: 100% (81/81), done.
remote: Compressing objects: 100% (60/60), done.
remote: Total 477 (delta 44), reused 48 (delta 21), pack-reused 396
Receiving objects: 100% (477/477), 2.89 MiB | 3.94 MiB/s, done.
Resolving deltas: 100% (277/277), done.
$  make -C SlimGuard
gcc -Wall -pedantic -O3 -Wno-deprecated-declarations -I./include -DGUARDPAGE -DRELEASE_MEM -DUSE_CANARY -o libSlimGuard.so src/gnuwrapper.cpp src/slimguard.c src/slimguard-large.c src/slimguard-mmap.c src/sll.c -shared -fPIC 
src/gnuwrapper.cpp: In function ‘void my_init_hook()’:
src/gnuwrapper.cpp:55:23: error: ‘__malloc_hook’ was not declared in this scope; did you mean ‘my_malloc_hook’?
   55 |     old_malloc_hook = __malloc_hook;
      |                       ^~~~~~~~~~~~~
      |                       my_malloc_hook
src/gnuwrapper.cpp:56:21: error: ‘__free_hook’ was not declared in this scope; did you mean ‘my_free_hook’?
   56 |     old_free_hook = __free_hook;
      |                     ^~~~~~~~~~~
      |                     my_free_hook
src/gnuwrapper.cpp:57:24: error: ‘__realloc_hook’ was not declared in this scope; did you mean ‘my_realloc_hook’?
   57 |     old_realloc_hook = __realloc_hook;
      |                        ^~~~~~~~~~~~~~
      |                        my_realloc_hook
src/gnuwrapper.cpp:58:25: error: ‘__memalign_hook’ was not declared in this scope; did you mean ‘my_memalign_hook’?
   58 |     old_memalign_hook = __memalign_hook;
      |                         ^~~~~~~~~~~~~~~
      |                         my_memalign_hook
src/gnuwrapper.cpp: At global scope:
src/gnuwrapper.cpp:81:17: warning: ‘void* my_memalign_hook(size_t, size_t, const void*)’ defined but not used [-Wunused-function]
   81 |   static void * my_memalign_hook (size_t size, size_t alignment, const void *) {
      |                 ^~~~~~~~~~~~~~~~
src/gnuwrapper.cpp:77:17: warning: ‘void* my_realloc_hook(void*, size_t, const void*)’ defined but not used [-Wunused-function]
   77 |   static void * my_realloc_hook (void * ptr, size_t size, const void *) {
      |                 ^~~~~~~~~~~~~~~
src/gnuwrapper.cpp:73:15: warning: ‘void my_free_hook(void*, const void*)’ defined but not used [-Wunused-function]
   73 |   static void my_free_hook (void * ptr, const void *) {
      |               ^~~~~~~~~~~~
src/gnuwrapper.cpp:68:17: warning: ‘void* my_malloc_hook(size_t, const void*)’ defined but not used [-Wunused-function]
   68 |   static void * my_malloc_hook (size_t size, const void *) {
      |                 ^~~~~~~~~~~~~~
make: *** [Makefile:18: libSlimGuard.so] Error 1
[2]

$ apt show libc6 | head -n2
Package: libc6
Version: 2.34-3
$