personality.h: Make the personality code optional

Some platforms don't have personality.h in their C library, this change
adds buildtime detection for the header and turns off the personality setting
code in those cases.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

configure.ac

@@ -221,7 +221,7 @@ AM_CONDITIONAL([IS_BIONIC], [test "x$is_bionic" = "xyes"])
 AC_CHECK_DECLS([PR_CAPBSET_DROP], [], [], [#include <sys/prctl.h>])
 
 # Check for some headers
-AC_CHECK_HEADERS([sys/signalfd.h pty.h sys/capability.h])
+AC_CHECK_HEADERS([sys/signalfd.h pty.h sys/capability.h sys/personality.h])
 
 # Check for some functions
 AC_CHECK_FUNCS([openpty])

src/lxc/conf.c

@@ -48,7 +48,6 @@
 #include <sys/mount.h>
 #include <sys/mman.h>
 #include <sys/prctl.h>
-#include <sys/personality.h>
 
 #include <arpa/inet.h>
 #include <fcntl.h>
@@ -74,6 +73,10 @@
 #include <sys/capability.h>
 #endif
 
+#if HAVE_SYS_PERSONALITY_H
+#include <sys/personality.h>
+#endif
+
 #include "lxcseccomp.h"
 
 lxc_log_define(lxc_conf, lxc);
@@ -1198,6 +1201,7 @@ out:
 
 static int setup_personality(int persona)
 {
+	#if HAVE_SYS_PERSONALITY_H
 	if (persona == -1)
 		return 0;
 
@@ -1207,6 +1211,7 @@ static int setup_personality(int persona)
 	}
 
 	INFO("set personality to '0x%x'", persona);
+	#endif
 
 	return 0;
 }

src/lxc/confile.c

@@ -31,12 +31,12 @@
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/utsname.h>
-#include <sys/personality.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <net/if.h>
 
 #include "parse.h"
+#include "config.h"
 #include "confile.h"
 #include "utils.h"
 
@@ -44,6 +44,10 @@
 #include <lxc/conf.h>
 #include "network.h"
 
+#if HAVE_SYS_PERSONALITY_H
+#include <sys/personality.h>
+#endif
+
 lxc_log_define(lxc_confile, lxc);
 
 static int config_personality(const char *, const char *, struct lxc_conf *);
@@ -1301,6 +1305,7 @@ int lxc_config_define_load(struct lxc_list *defines, struct lxc_conf *conf)
 
 signed long lxc_config_parse_arch(const char *arch)
 {
+	#if HAVE_SYS_PERSONALITY_H
 	struct per_name {
 		char *name;
 		unsigned long per;
@@ -1318,6 +1323,7 @@ signed long lxc_config_parse_arch(const char *arch)
 		if (!strcmp(pername[i].name, arch))
 		    return pername[i].per;
 	}
+	#endif
 
 	return -1;
 }
@@ -1333,18 +1339,22 @@ static int lxc_get_conf_int(struct lxc_conf *c, char *retv, int inlen, int v)
 
 static int lxc_get_arch_entry(struct lxc_conf *c, char *retv, int inlen)
 {
-	int len, fulllen = 0;
+	int fulllen = 0;
 
 	if (!retv)
 		inlen = 0;
 	else
 		memset(retv, 0, inlen);
 
+	#if HAVE_SYS_PERSONALITY_H
+	int len = 0;
+
 	switch(c->personality) {
 	case PER_LINUX32: strprint(retv, inlen, "x86"); break;
 	case PER_LINUX: strprint(retv, inlen, "x86_64"); break;
 	default: break;
 	}
+	#endif
 
 	return fulllen;
 }
@@ -1664,11 +1674,13 @@ void write_config(FILE *fout, struct lxc_conf *c)
 		fprintf(fout, "lxc.pts = %d\n", c->pts);
 	if (c->ttydir)
 		fprintf(fout, "lxc.devttydir = %s\n", c->ttydir);
+	#if HAVE_SYS_PERSONALITY_H
 	switch(c->personality) {
 	case PER_LINUX32: fprintf(fout, "lxc.arch = x86\n"); break;
 	case PER_LINUX: fprintf(fout, "lxc.arch = x86_64\n"); break;
 	default: break;
 	}
+	#endif
 #if HAVE_APPARMOR
 	if (c->aa_profile)
 		fprintf(fout, "lxc.aa_profile = %s\n", c->aa_profile);

src/lxc/lxc_attach.c

@@ -29,19 +29,23 @@
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <sys/personality.h>
 
 #include "attach.h"
 #include "commands.h"
 #include "arguments.h"
 #include "caps.h"
 #include "cgroup.h"
+#include "config.h"
 #include "confile.h"
 #include "start.h"
 #include "sync.h"
 #include "log.h"
 #include "namespace.h"
 
+#if HAVE_SYS_PERSONALITY_H
+#include <sys/personality.h>
+#endif
+
 lxc_log_define(lxc_attach_ui, lxc);
 
 static const struct option my_longopts[] = {
@@ -273,6 +277,7 @@ int main(int argc, char *argv[])
 			}
 		}
 
+		#if HAVE_SYS_PERSONALITY_H
 		if (new_personality < 0)
 			new_personality = init_ctx->personality;
 
@@ -281,6 +286,7 @@ int main(int argc, char *argv[])
 			      strerror(errno));
 			return -1;
 		}
+		#endif
 
 		if (!elevated_privileges && lxc_attach_drop_privs(init_ctx)) {
 			ERROR("could not drop privileges");