From 892be3b3d7a459808ee47709d0f4e7f65566a6e5 Mon Sep 17 00:00:00 2001
From: Stefan Kangas <stefankangas@gmail.com>
Date: Tue, 10 Dec 2024 11:07:01 +0100
Subject: [PATCH] Remove check for working malloc_set_state

This check was added to 'malloc_initialize_hook' in order to "insulate
Emacs better from configuration screwups" (commit b4788b9394f3).  With
unexec gone, we no longer use 'malloc_set_state', and thus don't need
this check.

Note that this patch removes the last uses of the deprecated glibc
functions 'malloc_set_state' and 'malloc_get_state' from our code.

* src/alloc.c (malloc_initialize_hook) [DOUG_LEA_MALLOC]:
Remove check for working 'malloc_set_state'.
(alloc_unexec_pre) [DOUG_LEA_MALLOC]: Delete unused function.
(alloc_unexec_post) [DOUG_LEA_MALLOC]: Delete function.
(malloc_state_ptr) [DOUG_LEA_MALLOC]: Delete variable.
* configure.ac (emacs_cv_var_doug_lea_malloc): Don't check for
malloc_set_state and malloc_get_state.
---
 configure.ac |  5 ++---
 src/alloc.c  | 29 -----------------------------
 2 files changed, 2 insertions(+), 32 deletions(-)

diff --git a/configure.ac b/configure.ac
index b320c4978d6..86e2e0a9f78 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3206,8 +3206,7 @@ AC_CACHE_CHECK(
        [AC_LANG_PROGRAM(
 	  [[#include <malloc.h>
 	    static void hook (void) {}]],
-	  [[malloc_set_state (malloc_get_state ());
-	    __after_morecore_hook = hook;
+          [[__after_morecore_hook = hook;
 	    __malloc_initialize_hook = hook;]])],
        [emacs_cv_var_doug_lea_malloc=yes])
    fi])
@@ -3255,7 +3254,7 @@ if test "$doug_lea_malloc" = "yes"; then
   fi
   AC_DEFINE([DOUG_LEA_MALLOC], [1],
     [Define to 1 if the system memory allocator is Doug Lea style,
-     with malloc hooks and malloc_set_state.])
+     with malloc hooks.])
 
   ## Use mmap directly for allocating larger buffers.
   ## FIXME this comes from src/s/{gnu,gnu-linux}.h:
diff --git a/src/alloc.c b/src/alloc.c
index e557e82883c..1e0e5f58e84 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -209,10 +209,6 @@ enum { MALLOC_ALIGNMENT = max (2 * sizeof (size_t), alignof (long double)) };
 
 # define MMAP_MAX_AREAS 100000000
 
-/* A pointer to the memory allocated that copies that static data
-   inside glibc's malloc.  */
-static void *malloc_state_ptr;
-
 /* Restore the dumped malloc state.  Because malloc can be invoked
    even before main (e.g. by the dynamic linker), the dumped malloc
    state must be restored as early as possible using this special hook.  */
@@ -247,10 +243,6 @@ malloc_initialize_hook (void)
 		  break;
 		}
 	}
-
-      if (malloc_set_state (malloc_state_ptr) != 0)
-	emacs_abort ();
-      alloc_unexec_post ();
     }
 }
 
@@ -266,27 +258,6 @@ voidfuncptr __MALLOC_HOOK_VOLATILE __malloc_initialize_hook EXTERNALLY_VISIBLE
 #endif
 
 #if defined DOUG_LEA_MALLOC
-
-/* Allocator-related actions to do just before and after unexec.  */
-
-void
-alloc_unexec_pre (void)
-{
-# ifdef DOUG_LEA_MALLOC
-  malloc_state_ptr = malloc_get_state ();
-  if (!malloc_state_ptr)
-    fatal ("malloc_get_state: %s", strerror (errno));
-# endif
-}
-
-void
-alloc_unexec_post (void)
-{
-# ifdef DOUG_LEA_MALLOC
-  free (malloc_state_ptr);
-# endif
-}
-
 # ifdef GNU_LINUX
 
 /* The address where the heap starts.  */