Kbuild updates for v4.16 (2nd)

Makefile changes:
 - enable unused-variable warning that was wrongly disabled for clang
 
 Kconfig changes:
 - warn blank 'help' and fix existing instances
 - fix 'choice' behavior to not write out invisible symbols
 - fix misc weirdness
 
 Coccinell changes:
 - fix false positive of free after managed memory alloc detection
 - improve performance of NULL dereference detection
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Merge tag 'kbuild-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild updates from Masahiro Yamada:
 "Makefile changes:
   - enable unused-variable warning that was wrongly disabled for clang

  Kconfig changes:
   - warn about blank 'help' and fix existing instances
   - fix 'choice' behavior to not write out invisible symbols
   - fix misc weirdness

  Coccinell changes:
   - fix false positive of free after managed memory alloc detection
   - improve performance of NULL dereference detection"

* tag 'kbuild-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits)
  kconfig: remove const qualifier from sym_expand_string_value()
  kconfig: add xrealloc() helper
  kconfig: send error messages to stderr
  kconfig: echo stdin to stdout if either is redirected
  kconfig: remove check_stdin()
  kconfig: remove 'config*' pattern from .gitignnore
  kconfig: show '?' prompt even if no help text is available
  kconfig: do not write choice values when their dependency becomes n
  coccinelle: deref_null: avoid useless computation
  coccinelle: devm_free: reduce false positives
  kbuild: clang: disable unused variable warnings only when constant
  kconfig: Warn if help text is blank
  nios2: kconfig: Remove blank help text
  arm: vt8500: kconfig: Remove blank help text
  MIPS: kconfig: Remove blank help text
  MIPS: BCM63XX: kconfig: Remove blank help text
  lib/Kconfig.debug: Remove blank help text
  Staging: rtl8192e: kconfig: Remove blank help text
  Staging: rtl8192u: kconfig: Remove blank help text
  mmc: kconfig: Remove blank help text
  ...

Makefile

@@ -729,7 +729,6 @@ endif
 
 ifeq ($(cc-name),clang)
 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
-KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
@@ -747,9 +746,9 @@ else
 # These warnings generated too much noise in a regular build.
 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
-KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 endif
 
+KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 ifdef CONFIG_FRAME_POINTER
 KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
 else

arch/arm/mach-vt8500/Kconfig

@@ -13,7 +13,6 @@ config ARCH_WM8505
  	depends on ARCH_MULTI_V5
  	select ARCH_VT8500
  	select CPU_ARM926T
- 	help
 
 config ARCH_WM8750
 	bool "WonderMedia WM8750"

arch/mips/Kconfig

@@ -2333,7 +2333,6 @@ config MIPS_VPE_LOADER_TOM
 config MIPS_VPE_APSP_API
 	bool "Enable support for AP/SP API (RTLX)"
 	depends on MIPS_VPE_LOADER
-	help
 
 config MIPS_VPE_APSP_API_CMP
 	bool

arch/mips/bcm63xx/boards/Kconfig

@@ -7,6 +7,5 @@ choice
 config BOARD_BCM963XX
        bool "Generic Broadcom 963xx boards"
 	select SSB
-       help
 
 endchoice

arch/nios2/Kconfig

@@ -152,7 +152,6 @@ menu "Advanced setup"
 
 config ADVANCED_OPTIONS
 	bool "Prompt for advanced kernel configuration options"
-	help
 
 comment "Default settings for advanced configuration options are used"
 	depends on !ADVANCED_OPTIONS

drivers/mmc/host/Kconfig

@@ -874,7 +874,6 @@ config MMC_CQHCI
 config MMC_TOSHIBA_PCI
 	tristate "Toshiba Type A SD/MMC Card Interface Driver"
 	depends on PCI
-	help
 
 config MMC_BCM2835
 	tristate "Broadcom BCM2835 SDHOST MMC Controller support"

drivers/staging/rtl8192e/rtl8192e/Kconfig

@@ -6,4 +6,3 @@ config RTL8192E
 	select WEXT_PRIV
 	select CRYPTO
 	select FW_LOADER
-	---help---

drivers/staging/rtl8192u/Kconfig

@@ -5,4 +5,3 @@ config RTL8192U
 	select WIRELESS_EXT
 	select WEXT_PRIV
 	select CRYPTO
-	---help---

drivers/video/fbdev/Kconfig

@@ -1156,7 +1156,6 @@ config FB_I810_I2C
 	bool "Enable DDC Support"
 	depends on FB_I810 && FB_I810_GTF
 	select FB_DDC
-	help
 
 config FB_LE80578
 	tristate "Intel LE80578 (Vermilion) support"

lib/Kconfig.debug

@@ -351,7 +351,6 @@ config SECTION_MISMATCH_WARN_ONLY
 #
 config ARCH_WANT_FRAME_POINTERS
 	bool
-	help
 
 config FRAME_POINTER
 	bool "Compile the kernel with frame pointers"

scripts/coccinelle/free/devm_free.cocci

@@ -56,9 +56,62 @@ expression x;
  x = devm_ioport_map(...)
 )
 
+@safe depends on context || org || report exists@
+expression x;
+position p;
+@@
+
+(
+ x = kmalloc(...)
+|
+ x = kvasprintf(...)
+|
+ x = kasprintf(...)
+|
+ x = kzalloc(...)
+|
+ x = kmalloc_array(...)
+|
+ x = kcalloc(...)
+|
+ x = kstrdup(...)
+|
+ x = kmemdup(...)
+|
+ x = get_free_pages(...)
+|
+ x = request_irq(...)
+|
+ x = ioremap(...)
+|
+ x = ioremap_nocache(...)
+|
+ x = ioport_map(...)
+)
+...
+(
+ kfree@p(x)
+|
+ kzfree@p(x)
+|
+ __krealloc@p(x, ...)
+|
+ krealloc@p(x, ...)
+|
+ free_pages@p(x, ...)
+|
+ free_page@p(x)
+|
+ free_irq@p(x)
+|
+ iounmap@p(x)
+|
+ ioport_unmap@p(x)
+)
+
 @pb@
 expression r.x;
-position p;
+position p != safe.p;
 @@
 
 (

scripts/coccinelle/null/deref_null.cocci

@@ -212,7 +212,7 @@ else S3
 // The following three rules are duplicates of ifm, pr1 and pr2 respectively.
 // It is need because the previous rule as already made a "change".
 
-@ifm1@
+@ifm1 depends on context && !org && !report@
 expression *E;
 statement S1,S2;
 position p1;
@@ -220,7 +220,7 @@ position p1;
 
 if@p1 ((E == NULL && ...) || ...) S1 else S2
 
-@pr11 expression@
+@pr11 depends on context && !org && !report expression@
 expression *ifm1.E;
 identifier f;
 position p1;
@@ -228,7 +228,7 @@ position p1;
 
  (E != NULL && ...) ? <+...E->f@p1...+> : ...
 
-@pr12 expression@
+@pr12 depends on context && !org && !report expression@
 expression *ifm1.E;
 identifier f;
 position p2;

scripts/kconfig/.gitignore

@@ -1,7 +1,6 @@
 #
 # Generated files
 #
-config*
 *.lex.c
 *.tab.c
 *.tab.h

scripts/kconfig/conf.c

@@ -39,7 +39,6 @@ static enum input_mode input_mode = oldaskconfig;
 
 static int indent = 1;
 static int tty_stdio;
-static int valid_stdin = 1;
 static int sync_kconfig;
 static int conf_cnt;
 static char line[PATH_MAX];
@@ -72,21 +71,14 @@ static void strip(char *str)
 		*p-- = 0;
 }
 
-static void check_stdin(void)
-{
-	if (!valid_stdin) {
-		printf(_("aborted!\n\n"));
-		printf(_("Console input/output is redirected. "));
-		printf(_("Run 'make oldconfig' to update configuration.\n\n"));
-		exit(1);
-	}
-}
-
 /* Helper function to facilitate fgets() by Jean Sacren. */
 static void xfgets(char *str, int size, FILE *in)
 {
 	if (!fgets(str, size, in))
 		fprintf(stderr, "\nError in reading or end of file.\n");
+
+	if (!tty_stdio)
+		printf("%s", str);
 }
 
 static int conf_askvalue(struct symbol *sym, const char *def)
@@ -113,13 +105,10 @@ static int conf_askvalue(struct symbol *sym, const char *def)
 			printf("%s\n", def);
 			return 0;
 		}
-		check_stdin();
 		/* fall through */
 	case oldaskconfig:
 		fflush(stdout);
 		xfgets(line, sizeof(line), stdin);
-		if (!tty_stdio)
-			printf("\n");
 		return 1;
 	default:
 		break;
@@ -199,9 +188,7 @@ static int conf_sym(struct menu *menu)
 			printf("/m");
 		if (oldval != yes && sym_tristate_within_range(sym, yes))
 			printf("/y");
-		if (menu_has_help(menu))
+		printf("/?] ");
-			printf("/?");
-		printf("] ");
 		if (!conf_askvalue(sym, sym_get_string_value(sym)))
 			return 0;
 		strip(line);
@@ -303,10 +290,7 @@ static int conf_choice(struct menu *menu)
 			printf("[1]: 1\n");
 			goto conf_childs;
 		}
-		printf("[1-%d", cnt);
+		printf("[1-%d?]: ", cnt);
-		if (menu_has_help(menu))
-			printf("?");
-		printf("]: ");
 		switch (input_mode) {
 		case oldconfig:
 		case silentoldconfig:
@@ -315,7 +299,6 @@ static int conf_choice(struct menu *menu)
 				printf("%d\n", cnt);
 				break;
 			}
-			check_stdin();
 			/* fall through */
 		case oldaskconfig:
 			fflush(stdout);
@@ -508,7 +491,7 @@ int main(int ac, char **av)
 	bindtextdomain(PACKAGE, LOCALEDIR);
 	textdomain(PACKAGE);
 
-	tty_stdio = isatty(0) && isatty(1) && isatty(2);
+	tty_stdio = isatty(0) && isatty(1);
 
 	while ((opt = getopt_long(ac, av, "s", long_opts, NULL)) != -1) {
 		if (opt == 's') {
@@ -565,7 +548,7 @@ int main(int ac, char **av)
 		}
 	}
 	if (ac == optind) {
-		printf(_("%s: Kconfig file missing\n"), av[0]);
+		fprintf(stderr, _("%s: Kconfig file missing\n"), av[0]);
 		conf_usage(progname);
 		exit(1);
 	}
@@ -590,9 +573,11 @@ int main(int ac, char **av)
 		if (!defconfig_file)
 			defconfig_file = conf_get_default_confname();
 		if (conf_read(defconfig_file)) {
-			printf(_("***\n"
+			fprintf(stderr,
-				"*** Can't find default configuration \"%s\"!\n"
+				_("***\n"
-				"***\n"), defconfig_file);
+				  "*** Can't find default configuration \"%s\"!\n"
+				  "***\n"),
+				defconfig_file);
 			exit(1);
 		}
 		break;
@@ -650,7 +635,6 @@ int main(int ac, char **av)
 				return 1;
 			}
 		}
-		valid_stdin = tty_stdio;
 	}
 
 	switch (input_mode) {

scripts/kconfig/confdata.c

@@ -201,7 +201,7 @@ static int add_byte(int c, char **lineptr, size_t slen, size_t *n)
 	if (new_size > *n) {
 		new_size += LINE_GROWTH - 1;
 		new_size *= 2;
-		nline = realloc(*lineptr, new_size);
+		nline = xrealloc(*lineptr, new_size);
 		if (!nline)
 			return -1;
 

scripts/kconfig/expr.c

@@ -94,7 +94,7 @@ struct expr *expr_copy(const struct expr *org)
 		e->right.expr = expr_copy(org->right.expr);
 		break;
 	default:
-		printf("can't copy type %d\n", e->type);
+		fprintf(stderr, "can't copy type %d\n", e->type);
 		free(e);
 		e = NULL;
 		break;
@@ -127,7 +127,7 @@ void expr_free(struct expr *e)
 		expr_free(e->right.expr);
 		break;
 	default:
-		printf("how to free type %d?\n", e->type);
+		fprintf(stderr, "how to free type %d?\n", e->type);
 		break;
 	}
 	free(e);

scripts/kconfig/lkc.h

@@ -114,6 +114,7 @@ struct file *file_lookup(const char *name);
 int file_write_dep(const char *name);
 void *xmalloc(size_t size);
 void *xcalloc(size_t nmemb, size_t size);
+void *xrealloc(void *p, size_t size);
 
 struct gstr {
 	size_t len;

scripts/kconfig/lkc_proto.h

@@ -31,7 +31,7 @@ extern struct symbol * symbol_hash[SYMBOL_HASHSIZE];
 
 struct symbol * sym_lookup(const char *name, int flags);
 struct symbol * sym_find(const char *name);
-const char * sym_expand_string_value(const char *in);
+char *sym_expand_string_value(const char *in);
 const char * sym_escape_string_value(const char *in);
 struct symbol ** sym_re_search(const char *pattern);
 const char * sym_type_name(enum symbol_type type);

scripts/kconfig/nconf.gui.c

@@ -6,6 +6,7 @@
  *
  */
 #include "nconf.h"
+#include "lkc.h"
 
 /* a list of all the different widgets we use */
 attributes_t attributes[ATTR_MAX+1] = {0};
@@ -374,7 +375,7 @@ int dialog_inputbox(WINDOW *main_window,
 
 	if (strlen(init)+1 > *result_len) {
 		*result_len = strlen(init)+1;
-		*resultp = result = realloc(result, *result_len);
+		*resultp = result = xrealloc(result, *result_len);
 	}
 
 	/* find the widest line of msg: */

scripts/kconfig/symbol.c

@@ -371,11 +371,13 @@ void sym_calc_value(struct symbol *sym)
 		sym->curr.tri = no;
 		return;
 	}
-	if (!sym_is_choice_value(sym))
+	sym->flags &= ~SYMBOL_WRITE;
-		sym->flags &= ~SYMBOL_WRITE;
 
 	sym_calc_visibility(sym);
 
+	if (sym->visible != no)
+		sym->flags |= SYMBOL_WRITE;
+
 	/* set default if recursively called */
 	sym->curr = newval;
 
@@ -390,7 +392,6 @@ void sym_calc_value(struct symbol *sym)
 				/* if the symbol is visible use the user value
 				 * if available, otherwise try the default value
 				 */
-				sym->flags |= SYMBOL_WRITE;
 				if (sym_has_value(sym)) {
 					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 							      sym->visible);
@@ -433,12 +434,9 @@ void sym_calc_value(struct symbol *sym)
 	case S_STRING:
 	case S_HEX:
 	case S_INT:
-		if (sym->visible != no) {
+		if (sym->visible != no && sym_has_value(sym)) {
-			sym->flags |= SYMBOL_WRITE;
+			newval.val = sym->def[S_DEF_USER].val;
-			if (sym_has_value(sym)) {
+			break;
-				newval.val = sym->def[S_DEF_USER].val;
-				break;
-			}
 		}
 		prop = sym_get_default_prop(sym);
 		if (prop) {
@@ -901,7 +899,7 @@ struct symbol *sym_find(const char *name)
  * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
  * the empty string.
  */
-const char *sym_expand_string_value(const char *in)
+char *sym_expand_string_value(const char *in)
 {
 	const char *src;
 	char *res;
@@ -938,7 +936,7 @@ const char *sym_expand_string_value(const char *in)
 		newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
 		if (newlen > reslen) {
 			reslen = newlen;
-			res = realloc(res, reslen);
+			res = xrealloc(res, reslen);
 		}
 
 		strcat(res, symval);
@@ -1223,7 +1221,7 @@ static struct symbol *sym_check_expr_deps(struct expr *e)
 	default:
 		break;
 	}
-	printf("Oops! How to check %d?\n", e->type);
+	fprintf(stderr, "Oops! How to check %d?\n", e->type);
 	return NULL;
 }
 

scripts/kconfig/util.c

@@ -14,11 +14,11 @@
 struct file *file_lookup(const char *name)
 {
 	struct file *file;
-	const char *file_name = sym_expand_string_value(name);
+	char *file_name = sym_expand_string_value(name);
 
 	for (file = file_list; file; file = file->next) {
 		if (!strcmp(name, file->name)) {
-			free((void *)file_name);
+			free(file_name);
 			return file;
 		}
 	}
@@ -104,7 +104,7 @@ void str_append(struct gstr *gs, const char *s)
 	if (s) {
 		l = strlen(gs->s) + strlen(s) + 1;
 		if (l > gs->len) {
-			gs->s   = realloc(gs->s, l);
+			gs->s = xrealloc(gs->s, l);
 			gs->len = l;
 		}
 		strcat(gs->s, s);
@@ -145,3 +145,12 @@ void *xcalloc(size_t nmemb, size_t size)
 	fprintf(stderr, "Out of memory.\n");
 	exit(1);
 }
+
+void *xrealloc(void *p, size_t size)
+{
+	p = realloc(p, size);
+	if (p)
+		return p;
+	fprintf(stderr, "Out of memory.\n");
+	exit(1);
+}

scripts/kconfig/zconf.l

@@ -52,7 +52,7 @@ static void append_string(const char *str, int size)
 	if (new_size > text_asize) {
 		new_size += START_STRSIZE - 1;
 		new_size &= -START_STRSIZE;
-		text = realloc(text, new_size);
+		text = xrealloc(text, new_size);
 		text_asize = new_size;
 	}
 	memcpy(text + text_size, str, size);
@@ -184,7 +184,9 @@ n	[A-Za-z0-9_-]
 			append_string(yytext, 1);
 	}
 	\n	{
-		printf("%s:%d:warning: multi-line strings not supported\n", zconf_curname(), zconf_lineno());
+		fprintf(stderr,
+			"%s:%d:warning: multi-line strings not supported\n",
+			zconf_curname(), zconf_lineno());
 		current_file->lineno++;
 		BEGIN(INITIAL);
 		return T_EOL;
@@ -294,7 +296,7 @@ void zconf_initscan(const char *name)
 {
 	yyin = zconf_fopen(name);
 	if (!yyin) {
-		printf("can't find file %s\n", name);
+		fprintf(stderr, "can't find file %s\n", name);
 		exit(1);
 	}
 
@@ -315,8 +317,8 @@ void zconf_nextfile(const char *name)
 	current_buf->state = YY_CURRENT_BUFFER;
 	yyin = zconf_fopen(file->name);
 	if (!yyin) {
-		printf("%s:%d: can't open file \"%s\"\n",
+		fprintf(stderr, "%s:%d: can't open file \"%s\"\n",
-		    zconf_curname(), zconf_lineno(), file->name);
+			zconf_curname(), zconf_lineno(), file->name);
 		exit(1);
 	}
 	yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
@@ -325,20 +327,21 @@ void zconf_nextfile(const char *name)
 
 	for (iter = current_file->parent; iter; iter = iter->parent ) {
 		if (!strcmp(current_file->name,iter->name) ) {
-			printf("%s:%d: recursive inclusion detected. "
+			fprintf(stderr,
-			       "Inclusion path:\n  current file : '%s'\n",
+				"%s:%d: recursive inclusion detected. "
-			       zconf_curname(), zconf_lineno(),
+				"Inclusion path:\n  current file : '%s'\n",
-			       zconf_curname());
+				zconf_curname(), zconf_lineno(),
+				zconf_curname());
 			iter = current_file->parent;
 			while (iter && \
 			       strcmp(iter->name,current_file->name)) {
-				printf("  included from: '%s:%d'\n",
+				fprintf(stderr, "  included from: '%s:%d'\n",
-				       iter->name, iter->lineno-1);
+					iter->name, iter->lineno-1);
 				iter = iter->parent;
 			}
 			if (iter)
-				printf("  included from: '%s:%d'\n",
+				fprintf(stderr, "  included from: '%s:%d'\n",
-				       iter->name, iter->lineno+1);
+					iter->name, iter->lineno+1);
 			exit(1);
 		}
 	}

scripts/kconfig/zconf.y

@@ -436,6 +436,12 @@ help: help_start T_HELPTEXT
 		zconfprint("warning: '%s' defined with more than one help text -- only the last one will be used",
 			   current_entry->sym->name ?: "<choice>");
 	}
+
+	/* Is the help text empty or all whitespace? */
+	if ($2[strspn($2, " \f\n\r\t\v")] == '\0')
+		zconfprint("warning: '%s' defined with blank help text",
+			   current_entry->sym->name ?: "<choice>");
+
 	current_entry->help = $2;
 };