[PATCH] Disable warnings due to deprecated libselinux symbols used by nss and nscd

[Arjun Shankar <arjun.is@lostca.se>]

From: Arjun Shankar <arjun@redhat.com>

The SELinux API deprecated several symbols in its 3.1 release, including
security_context_t, matchpathcon, avc_init, and sidput, which are used in
makedb and nscd.  While the usage of these should eventually be replaced by
newer interfaces, this commit disables GCC warnings due to the use of the
above symbols.
---
Aurelien recently posted a patch with an identical result, but using #pragma:
https://sourceware.org/pipermail/libc-alpha/2020-July/116523.html

Just put this together so it can hopefully go in soon with both glibc-2.32
being close by and Fedora 33 awaiting this change, since glibc already fails
to build on Fedora rawhide.

Tested on x86_64 with libselinux-3.1 installed.
---
 nscd/selinux.c | 16 ++++++++++++++++
 nss/makedb.c   |  9 +++++++++
 2 files changed, 25 insertions(+)

diff --git a/nscd/selinux.c b/nscd/selinux.c
index a4ea8008e2..8802d34265 100644
--- a/nscd/selinux.c
+++ b/nscd/selinux.c
@@ -33,6 +33,7 @@
 #ifdef HAVE_LIBAUDIT
 # include <libaudit.h>
 #endif
+#include <libc-diag.h>
 
 #include "dbg_log.h"
 #include "selinux.h"
@@ -320,6 +321,12 @@ avc_free_lock (void *lock)
 }
 
 
+/* avc_init (along with several other symbols) was marked as deprecated by the
+   SELinux API starting from version 3.1.  We use it here, but should
+   eventually switch to the newer API.  */
+DIAG_PUSH_NEEDS_COMMENT
+DIAG_IGNORE_NEEDS_COMMENT (10, "-Wdeprecated-declarations");
+
 /* Initialize the user space access vector cache (AVC) for NSCD along with
    log/thread/lock callbacks.  */
 void
@@ -335,7 +342,14 @@ nscd_avc_init (void)
   audit_init ();
 #endif
 }
+DIAG_POP_NEEDS_COMMENT
+
 
+/* security_context_t and sidput (along with several other symbols) were marked
+   as deprecated by the SELinux API starting from version 3.1.  We use them
+   here, but should eventually switch to the newer API.  */
+DIAG_PUSH_NEEDS_COMMENT
+DIAG_IGNORE_NEEDS_COMMENT (10, "-Wdeprecated-declarations");
 
 /* Check the permission from the caller (via getpeercon) to nscd.
    Returns 0 if access is allowed, 1 if denied, and -1 on error.
@@ -411,6 +425,7 @@ nscd_request_avc_has_perm (int fd, request_type req)
   rc = avc_has_perm (ssid, tsid, sc_nscd, perm, &aeref, NULL) < 0;
 
 out:
+
   if (scon)
     freecon (scon);
   if (tcon)
@@ -422,6 +437,7 @@ out:
 
   return rc;
 }
+DIAG_POP_NEEDS_COMMENT
 
 
 /* Wrapper to get AVC statistics.  */
diff --git a/nss/makedb.c b/nss/makedb.c
index 8e389a1683..8e1e8ec9ad 100644
--- a/nss/makedb.c
+++ b/nss/makedb.c
@@ -38,6 +38,7 @@
 #include <sys/stat.h>
 #include <sys/uio.h>
 #include "nss_db/nss_db.h"
+#include <libc-diag.h>
 
 /* Get libc version number.  */
 #include "../version.h"
@@ -841,6 +842,13 @@ print_database (int fd)
 
 
 #ifdef HAVE_SELINUX
+
+/* security_context_t and matchpathcon (along with several other symbols) were
+   marked as deprecated by the SELinux API starting from version 3.1.  We use
+   them here, but should eventually switch to the newer API.  */
+DIAG_PUSH_NEEDS_COMMENT
+DIAG_IGNORE_NEEDS_COMMENT (10, "-Wdeprecated-declarations");
+
 static void
 set_file_creation_context (const char *outname, mode_t mode)
 {
@@ -870,6 +878,7 @@ set_file_creation_context (const char *outname, mode_t mode)
       freecon (ctx);
     }
 }
+DIAG_POP_NEEDS_COMMENT
 
 static void
 reset_file_creation_context (void)
-- 
2.26.2