libbb: reduce the overhead of single parameter bb_error_msg() calls

Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by
Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower
overhead call to bb_perror_msg() when only a string was being printed
with no parameters. This saves space for some CPU architectures because
it avoids the overhead of a call to a variadic function. However there
has never been a simple version of bb_error_msg(), and since 2007 many
new calls to bb_perror_msg() have been added that only take a single
parameter and so could have been using bb_simple_perror_message().

This changeset introduces 'simple' versions of bb_info_msg(),
bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and
bb_herror_msg_and_die(), and replaces all calls that only take a
single parameter, or use something like ("%s", arg), with calls to the
corresponding 'simple' version.

Since it is likely that single parameter calls to the variadic functions
may be accidentally reintroduced in the future a new debugging config
option WARN_SIMPLE_MSG has been introduced. This uses some macro magic
which will cause any such calls to generate a warning, but this is
turned off by default to avoid use of the unpleasant macros in normal
circumstances.

This is a large changeset due to the number of calls that have been
replaced. The only files that contain changes other than simple
substitution of function calls are libbb.h, libbb/herror_msg.c,
libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c,
networking/udhcp/common.h and util-linux/mdev.c additonal macros have
been added for logging so that single parameter and multiple parameter
logging variants exist.

The amount of space saved varies considerably by architecture, and was
found to be as follows (for 'defconfig' using GCC 7.4):

Arm:     -92 bytes
MIPS:    -52 bytes
PPC:   -1836 bytes
x86_64: -938 bytes

Note that for the MIPS architecture only an exception had to be made
disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h)
because it made these files larger on MIPS.

Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

9 files changed, 13 insertions, 13 deletions

diff --git a/selinux/chcon.c b/selinux/chcon.c
index 5bf91710c..afe7f713d 100644
--- a/selinux/chcon.c
+++ b/selinux/chcon.c
@@ -107,7 +107,7 @@ static int FAST_FUNC change_filedir_context(
 
 	context_string = context_str(context);
 	if (!context_string) {
-		bb_error_msg("can't obtain security context in text expression");
+		bb_simple_error_msg("can't obtain security context in text expression");
 		goto skip;
 	}
 
@@ -194,7 +194,7 @@ int chcon_main(int argc UNUSED_PARAM, char **argv)
 		/* specified_context is never NULL -
 		 * "-1" in opt_complementary prevents this. */
 		if (!argv[0])
-			bb_error_msg_and_die("too few arguments");
+			bb_simple_error_msg_and_die("too few arguments");
 	}
 
 	for (i = 0; (fname = argv[i]) != NULL; i++) {
diff --git a/selinux/getenforce.c b/selinux/getenforce.c
index 0286dd0be..f082ba614 100644
--- a/selinux/getenforce.c
+++ b/selinux/getenforce.c
@@ -29,12 +29,12 @@ int getenforce_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 
 	rc = is_selinux_enabled();
 	if (rc < 0)
-		bb_error_msg_and_die("is_selinux_enabled() failed");
+		bb_simple_error_msg_and_die("is_selinux_enabled() failed");
 
 	if (rc == 1) {
 		rc = security_getenforce();
 		if (rc < 0)
-			bb_error_msg_and_die("getenforce() failed");
+			bb_simple_error_msg_and_die("getenforce() failed");
 
 		if (rc)
 			puts("Enforcing");
diff --git a/selinux/getsebool.c b/selinux/getsebool.c
index 6d7805c8d..36ddd45b9 100644
--- a/selinux/getsebool.c
+++ b/selinux/getsebool.c
@@ -40,7 +40,7 @@ int getsebool_main(int argc, char **argv)
 
 		rc = security_get_boolean_names(&names, &len);
 		if (rc)
-			bb_perror_msg_and_die("can't get boolean names");
+			bb_simple_perror_msg_and_die("can't get boolean names");
 
 		if (!len) {
 			puts("No booleans");
diff --git a/selinux/load_policy.c b/selinux/load_policy.c
index b7930839c..eac6ba6c1 100644
--- a/selinux/load_policy.c
+++ b/selinux/load_policy.c
@@ -31,7 +31,7 @@ int load_policy_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 
 	rc = selinux_mkload_policy(1);
 	if (rc < 0) {
-		bb_perror_msg_and_die("can't load policy");
+		bb_simple_perror_msg_and_die("can't load policy");
 	}
 
 	return 0;
diff --git a/selinux/runcon.c b/selinux/runcon.c
index a5a394427..bc4fa23e0 100644
--- a/selinux/runcon.c
+++ b/selinux/runcon.c
@@ -65,7 +65,7 @@ static context_t runcon_compute_new_context(char *user, char *role, char *type,
 	security_context_t cur_context;
 
 	if (getcon(&cur_context))
-		bb_error_msg_and_die("can't get current context");
+		bb_simple_error_msg_and_die("can't get current context");
 
 	if (compute_trans) {
 		security_context_t file_context, new_context;
@@ -75,7 +75,7 @@ static context_t runcon_compute_new_context(char *user, char *role, char *type,
 					command);
 		if (security_compute_create(cur_context, file_context,
 					SECCLASS_PROCESS, &new_context))
-			bb_error_msg_and_die("unable to compute a new context");
+			bb_simple_error_msg_and_die("unable to compute a new context");
 		cur_context = new_context;
 	}
 
@@ -137,7 +137,7 @@ int runcon_main(int argc UNUSED_PARAM, char **argv)
 	if (!(opts & OPTS_CONTEXT_COMPONENT)) {
 		context = *argv++;
 		if (!argv[0])
-			bb_error_msg_and_die("no command given");
+			bb_simple_error_msg_and_die("no command given");
 	}
 
 	if (context) {
diff --git a/selinux/sestatus.c b/selinux/sestatus.c
index 6954aca70..098a4d189 100644
--- a/selinux/sestatus.c
+++ b/selinux/sestatus.c
@@ -216,5 +216,5 @@ int sestatus_main(int argc UNUSED_PARAM, char **argv)
 	return 0;
 
   error:
-	bb_perror_msg_and_die("libselinux returns unknown state");
+	bb_simple_perror_msg_and_die("libselinux returns unknown state");
 }
diff --git a/selinux/setenforce.c b/selinux/setenforce.c
index c28de6ec5..996034f8e 100644
--- a/selinux/setenforce.c
+++ b/selinux/setenforce.c
@@ -49,7 +49,7 @@ int setenforce_main(int argc UNUSED_PARAM, char **argv)
 			continue;
 		rc = security_setenforce(i & 1);
 		if (rc < 0)
-			bb_perror_msg_and_die("setenforce() failed");
+			bb_simple_perror_msg_and_die("setenforce() failed");
 		return 0;
 	}
 
diff --git a/selinux/setfiles.c b/selinux/setfiles.c
index 740eaf8fb..55bfb4d02 100644
--- a/selinux/setfiles.c
+++ b/selinux/setfiles.c
@@ -182,7 +182,7 @@ static void inc_err(void)
 {
 	nerr++;
 	if (nerr > 9 && !FLAG_d_debug) {
-		bb_error_msg_and_die("exiting after 10 errors");
+		bb_simple_error_msg_and_die("exiting after 10 errors");
 	}
 }
 
diff --git a/selinux/setsebool.c b/selinux/setsebool.c
index 579118172..2af23acd7 100644
--- a/selinux/setsebool.c
+++ b/selinux/setsebool.c
@@ -46,7 +46,7 @@ int setsebool_main(int argc, char **argv)
 	}
 
 	if (security_set_boolean(argv[1], value) < 0)
-		bb_error_msg_and_die("can't set boolean");
+		bb_simple_error_msg_and_die("can't set boolean");
 
 	return 0;
 }