https://bugs.gentoo.org/888912
https://github.com/elogind/elogind/commit/ab72a46f3104f44a32ef7bec7439aa9d3b5f0fdc

Rebased version to apply to 246.10 by concord@.

From ab72a46f3104f44a32ef7bec7439aa9d3b5f0fdc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Fri, 9 Oct 2020 16:48:03 +0200
Subject: [PATCH] basic/selinux: work around mallinfo deprecation

Latest glibc has deprecated mallinfo(), so it might become unavailable at some point
in the future. There is malloc_info(), but it returns XML, ffs. I think the information
that we get from mallinfo() is quite useful, so let's use mallinfo() if available, and
not otherwise.
--- a/meson.build
+++ b/meson.build
@@ -617,6 +617,7 @@ foreach ident : [
                                  #include <unistd.h>
                                  #include <signal.h>
                                  #include <sys/wait.h>'''],
+        ['mallinfo',          '''#include <malloc.h>'''],
 ]
 
         have = cc.has_function(ident[0], prefix : ident[1], args : '-D_GNU_SOURCE')
--- a/src/basic/macro.h
+++ b/src/basic/macro.h
@@ -93,6 +93,10 @@
 #endif
 
 /* Temporarily disable some warnings */
+#define DISABLE_WARNING_DEPRECATED_DECLARATIONS                         \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
+
 #define DISABLE_WARNING_FORMAT_NONLITERAL                               \
         _Pragma("GCC diagnostic push");                                 \
         _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
--- a/src/basic/selinux-util.c
+++ b/src/basic/selinux-util.c
@@ -72,12 +72,21 @@ void mac_selinux_retest(void) {
 #endif
 }
 
+#if HAVE_MALLINFO
+static struct mallinfo mallinfo_nowarn(void) {
+        /* glibc has deprecated mallinfo(), but the replacement malloc_info() returns an XML blob ;=[ */
+DISABLE_WARNING_DEPRECATED_DECLARATIONS
+        return mallinfo();
+REENABLE_WARNING
+}
+#else
+#	warning "mallinfo() is missing, add mallinfo2() support instead."
+#endif
+
 int mac_selinux_init(void) {
 #if HAVE_SELINUX
         usec_t before_timestamp, after_timestamp;
-        struct mallinfo before_mallinfo, after_mallinfo;
         char timespan[FORMAT_TIMESPAN_MAX];
-        int l;
 
         selinux_set_callback(SELINUX_CB_POLICYLOAD, (union selinux_callback) mac_selinux_reload);
 
@@ -87,7 +96,9 @@ int mac_selinux_init(void) {
         if (!mac_selinux_use())
                 return 0;
 
-        before_mallinfo = mallinfo();
+#if HAVE_MALLINFO
+        struct mallinfo before_mallinfo = mallinfo_nowarn();
+#endif
         before_timestamp = now(CLOCK_MONOTONIC);
 
         label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0);
@@ -95,14 +107,17 @@ int mac_selinux_init(void) {
                 return log_enforcing_errno(errno, "Failed to initialize SELinux labeling handle: %m");
 
         after_timestamp = now(CLOCK_MONOTONIC);
-        after_mallinfo = mallinfo();
-
-        l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0;
+#if HAVE_MALLINFO
+        struct mallinfo after_mallinfo = mallinfo_nowarn();
+        int l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0;
 
         log_debug("Successfully loaded SELinux database in %s, size on heap is %iK.",
                   format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp, 0),
-                  (l+1023)/1024);
-
+                  DIV_ROUND_UP(l, 1024));
+#else
+        log_debug("Successfully loaded SELinux database in %s.",
+                  format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp, 0));
+#endif
 #endif
         return 0;
 }
-- 
2.40.1