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
  ...

23 files changed, 121 insertions, 77 deletions

diff --git a/Makefile b/Makefile
index d192dd826cce..cd9145c0878d 100644
--- a/Makefile
+++ b/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
diff --git a/arch/arm/mach-vt8500/Kconfig b/arch/arm/mach-vt8500/Kconfig
index 1156a585dafc..8841199058ea 100644
--- a/arch/arm/mach-vt8500/Kconfig
+++ b/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"
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 449397c60b56..8128c3b68d6b 100644
--- a/arch/mips/Kconfig
+++ b/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
diff --git a/arch/mips/bcm63xx/boards/Kconfig b/arch/mips/bcm63xx/boards/Kconfig
index 6ff0a7481081..f60d96610ace 100644
--- a/arch/mips/bcm63xx/boards/Kconfig
+++ b/arch/mips/bcm63xx/boards/Kconfig
@@ -7,6 +7,5 @@ choice
 config BOARD_BCM963XX
        bool "Generic Broadcom 963xx boards"
         select SSB
-       help
 
 endchoice
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 60fae03dac79..3d4ec88f1db1 100644
--- a/arch/nios2/Kconfig
+++ b/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
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 0eae619419d9..620c2d90a646 100644
--- a/drivers/mmc/host/Kconfig
+++ b/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"
diff --git a/drivers/staging/rtl8192e/rtl8192e/Kconfig b/drivers/staging/rtl8192e/rtl8192e/Kconfig
index 282e293da18f..7ac42a590e21 100644
--- a/drivers/staging/rtl8192e/rtl8192e/Kconfig
+++ b/drivers/staging/rtl8192e/rtl8192e/Kconfig
@@ -6,4 +6,3 @@ config RTL8192E
         select WEXT_PRIV
         select CRYPTO
         select FW_LOADER
-        ---help---
diff --git a/drivers/staging/rtl8192u/Kconfig b/drivers/staging/rtl8192u/Kconfig
index 3ee9d0d00fb6..97df6507a485 100644
--- a/drivers/staging/rtl8192u/Kconfig
+++ b/drivers/staging/rtl8192u/Kconfig
@@ -5,4 +5,3 @@ config RTL8192U
         select WIRELESS_EXT
         select WEXT_PRIV
         select CRYPTO
-        ---help---
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 6962b4583fd7..11e699f1062b 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/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"
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b66c264d4194..6088408ef26c 100644
--- a/lib/Kconfig.debug
+++ b/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"
diff --git a/scripts/coccinelle/free/devm_free.cocci b/scripts/coccinelle/free/devm_free.cocci
index c990d2c7ee16..b2a2cf8bf81f 100644
--- a/scripts/coccinelle/free/devm_free.cocci
+++ b/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;
 @@
 
 (
diff --git a/scripts/coccinelle/null/deref_null.cocci b/scripts/coccinelle/null/deref_null.cocci
index f192d6035d02..b16ccb7663a7 100644
--- a/scripts/coccinelle/null/deref_null.cocci
+++ b/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;
diff --git a/scripts/kconfig/.gitignore b/scripts/kconfig/.gitignore
index 51f1c877b543..a76856e559c0 100644
--- a/scripts/kconfig/.gitignore
+++ b/scripts/kconfig/.gitignore
@@ -1,7 +1,6 @@
 #
 # Generated files
 #
-config*
 *.lex.c
 *.tab.c
 *.tab.h
diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 307bc3f7b945..822dc51923d6 100644
--- a/scripts/kconfig/conf.c
+++ b/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);
-                if (menu_has_help(menu))
-                        printf("?");
-                printf("]: ");
+                printf("[1-%d?]: ", cnt);
                 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"
-                                "*** Can't find default configuration \"%s\"!\n"
-                                "***\n"), defconfig_file);
+                        fprintf(stderr,
+                                _("***\n"
+                                  "*** 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) {
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index f7927391de30..5c12dc91ef34 100644
--- a/scripts/kconfig/confdata.c
+++ b/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;
 
diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
index 2ba332b3fed7..d45381986ac7 100644
--- a/scripts/kconfig/expr.c
+++ b/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);
diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index 16cb62b92650..4e23febbe4b2 100644
--- a/scripts/kconfig/lkc.h
+++ b/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;
diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index 5d86e2dfae59..9dc8abfb1dc3 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/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);
diff --git a/scripts/kconfig/nconf.gui.c b/scripts/kconfig/nconf.gui.c
index a64b1c31253e..88874acfda36 100644
--- a/scripts/kconfig/nconf.gui.c
+++ b/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: */
diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index c9123ed2b791..cca9663be5dd 100644
--- a/scripts/kconfig/symbol.c
+++ b/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) {
-                        sym->flags |= SYMBOL_WRITE;
-                        if (sym_has_value(sym)) {
-                                newval.val = sym->def[S_DEF_USER].val;
-                                break;
-                        }
+                if (sym->visible != no && sym_has_value(sym)) {
+                        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;
 }
 
diff --git a/scripts/kconfig/util.c b/scripts/kconfig/util.c
index 0e76042473cc..b98a79e30e04 100644
--- a/scripts/kconfig/util.c
+++ b/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);
+}
diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index 07e074dc68a1..02de6fe302a9 100644
--- a/scripts/kconfig/zconf.l
+++ b/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",
-                    zconf_curname(), zconf_lineno(), file->name);
+                fprintf(stderr, "%s:%d: can't open file \"%s\"\n",
+                        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. "
-                               "Inclusion path:\n  current file : '%s'\n",
-                               zconf_curname(), zconf_lineno(),
-                               zconf_curname());
+                        fprintf(stderr,
+                                "%s:%d: recursive inclusion detected. "
+                                "Inclusion path:\n  current file : '%s'\n",
+                                zconf_curname(), zconf_lineno(),
+                                zconf_curname());
                         iter = current_file->parent;
                         while (iter && \
                                strcmp(iter->name,current_file->name)) {
-                                printf("  included from: '%s:%d'\n",
-                                       iter->name, iter->lineno-1);
+                                fprintf(stderr, "  included from: '%s:%d'\n",
+                                        iter->name, iter->lineno-1);
                                 iter = iter->parent;
                         }
                         if (iter)
-                                printf("  included from: '%s:%d'\n",
-                                       iter->name, iter->lineno+1);
+                                fprintf(stderr, "  included from: '%s:%d'\n",
+                                        iter->name, iter->lineno+1);
                         exit(1);
                 }
         }
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
index 21ce883e5d9e..4be98050b961 100644
--- a/scripts/kconfig/zconf.y
+++ b/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;
 };