kconfig: recursive checks drop file/lineno

This prevents segfault when getting filename and lineno in recursive
checks.

If the following snippet is found in Kconfig:

[Test code 1]

config FOO
        bool
        depends on BAR
        select BAR

... without BAR defined; then there is a segfault.

  Kconfig:34:error: recursive dependency detected!
  Kconfig:34:	symbol FOO depends on BAR
  make[4]: *** [scripts/kconfig/Makefile:85: allnoconfig] Segmentation fault

This is because of the following. BAR is a fake entry created by
sym_lookup() with prop being NULL. In the recursive check, there is a
NULL check for prop to fall back to stack->sym->prop if stack->prop is
NULL. However, in this case, stack->sym points to the fake BAR entry
created by sym_lookup(), so prop is still NULL. prop was then referenced
without additional NULL checks, causing segfault.

As the previous email thread suggests, the file and lineno for select is
also wrong:

[Test code 2]

config FOO
       bool

config BAR
       bool

config FOO
       bool "FOO"
       depends on BAR
       select BAR

  $ make defconfig
  *** Default configuration is based on 'x86_64_defconfig'
  Kconfig:1:error: recursive dependency detected!
  Kconfig:1: symbol FOO depends on BAR
  Kconfig:4: symbol BAR is selected by FOO
  [...]

Kconfig:4 should be Kconfig:10.

This patch deletes the wrong and segfault-prone filename/lineno
inference completely. With this patch, Test code 1 yields:

error: recursive dependency detected!
	symbol FOO depends on BAR
	symbol BAR is selected by FOO

Signed-off-by: HONG Yifan <elsk@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 6c6f238c4f7bbf0a2bd42fdfbae79736341e0c00..71502abd3b12d97bfbe90046b09c2c1b26faf227 100644 (file)
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -1074,10 +1074,9 @@ static void sym_check_print_recursive(struct symbol *last_sym)
 {
        struct dep_stack *stack;
        struct symbol *sym, *next_sym;
-       struct menu *menu = NULL;
        struct menu *choice;
-       struct property *prop;
        struct dep_stack cv_stack;
+       enum prop_type type;
 
        choice = sym_get_choice_menu(last_sym);
        if (choice) {
@@ -1096,53 +1095,36 @@ static void sym_check_print_recursive(struct symbol *last_sym)
        for (; stack; stack = stack->next) {
                sym = stack->sym;
                next_sym = stack->next ? stack->next->sym : last_sym;
-               prop = stack->prop;
-               if (prop == NULL)
-                       prop = stack->sym->prop;
-
-               /* for choice values find the menu entry (used below) */
-               if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
-                       for (prop = sym->prop; prop; prop = prop->next) {
-                               menu = prop->menu;
-                               if (prop->menu)
-                                       break;
-                       }
-               }
+               type = stack->prop ? stack->prop->type : P_UNKNOWN;
+
                if (stack->sym == last_sym)
-                       fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
-                               prop->filename, prop->lineno);
+                       fprintf(stderr, "error: recursive dependency detected!\n");
 
                if (sym_is_choice(next_sym)) {
                        choice = list_first_entry(&next_sym->menus, struct menu, link);
 
-                       fprintf(stderr, "%s:%d:\tsymbol %s is part of choice block at %s:%d\n",
-                               menu->filename, menu->lineno,
+                       fprintf(stderr, "\tsymbol %s is part of choice block at %s:%d\n",
                                sym->name ? sym->name : "<choice>",
                                choice->filename, choice->lineno);
                } else if (stack->expr == &sym->dir_dep.expr) {
-                       fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
-                               prop->filename, prop->lineno,
+                       fprintf(stderr, "\tsymbol %s depends on %s\n",
                                sym->name ? sym->name : "<choice>",
                                next_sym->name);
                } else if (stack->expr == &sym->rev_dep.expr) {
-                       fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
-                               prop->filename, prop->lineno,
+                       fprintf(stderr, "\tsymbol %s is selected by %s\n",
                                sym->name, next_sym->name);
                } else if (stack->expr == &sym->implied.expr) {
-                       fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
-                               prop->filename, prop->lineno,
+                       fprintf(stderr, "\tsymbol %s is implied by %s\n",
                                sym->name, next_sym->name);
                } else if (stack->expr) {
-                       fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
-                               prop->filename, prop->lineno,
+                       fprintf(stderr, "\tsymbol %s %s value contains %s\n",
                                sym->name ? sym->name : "<choice>",
-                               prop_get_type_name(prop->type),
+                               prop_get_type_name(type),
                                next_sym->name);
                } else {
-                       fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
-                               prop->filename, prop->lineno,
+                       fprintf(stderr, "\tsymbol %s %s is visible depending on %s\n",
                                sym->name ? sym->name : "<choice>",
-                               prop_get_type_name(prop->type),
+                               prop_get_type_name(type),
                                next_sym->name);
                }
        }

diff --git a/scripts/kconfig/tests/err_recursive_dep/expected_stderr b/scripts/kconfig/tests/err_recursive_dep/expected_stderr
index 05d4ced703206f8d10ed0d34f78a4957bb53b678..fc2e860af082cb1fdf6cba63b2350a08add3ff93 100644 (file)
--- a/scripts/kconfig/tests/err_recursive_dep/expected_stderr
+++ b/scripts/kconfig/tests/err_recursive_dep/expected_stderr
@@ -1,38 +1,38 @@
-Kconfig:5:error: recursive dependency detected!
-Kconfig:5:     symbol A depends on A
+error: recursive dependency detected!
+       symbol A depends on A
 For a resolution refer to Documentation/kbuild/kconfig-language.rst
 subsection "Kconfig recursive dependency limitations"
 
-Kconfig:11:error: recursive dependency detected!
-Kconfig:11:    symbol B is selected by B
+error: recursive dependency detected!
+       symbol B is selected by B
 For a resolution refer to Documentation/kbuild/kconfig-language.rst
 subsection "Kconfig recursive dependency limitations"
 
-Kconfig:17:error: recursive dependency detected!
-Kconfig:17:    symbol C1 depends on C2
-Kconfig:21:    symbol C2 depends on C1
+error: recursive dependency detected!
+       symbol C1 depends on C2
+       symbol C2 depends on C1
 For a resolution refer to Documentation/kbuild/kconfig-language.rst
 subsection "Kconfig recursive dependency limitations"
 
-Kconfig:27:error: recursive dependency detected!
-Kconfig:27:    symbol D1 depends on D2
-Kconfig:32:    symbol D2 is selected by D1
+error: recursive dependency detected!
+       symbol D1 depends on D2
+       symbol D2 is selected by D1
 For a resolution refer to Documentation/kbuild/kconfig-language.rst
 subsection "Kconfig recursive dependency limitations"
 
-Kconfig:37:error: recursive dependency detected!
-Kconfig:37:    symbol E1 depends on E2
-Kconfig:42:    symbol E2 is implied by E1
+error: recursive dependency detected!
+       symbol E1 depends on E2
+       symbol E2 is implied by E1
 For a resolution refer to Documentation/kbuild/kconfig-language.rst
 subsection "Kconfig recursive dependency limitations"
 
-Kconfig:49:error: recursive dependency detected!
-Kconfig:49:    symbol F1 default value contains F2
-Kconfig:51:    symbol F2 depends on F1
+error: recursive dependency detected!
+       symbol F1 default value contains F2
+       symbol F2 depends on F1
 For a resolution refer to Documentation/kbuild/kconfig-language.rst
 subsection "Kconfig recursive dependency limitations"
 
-Kconfig:60:error: recursive dependency detected!
-Kconfig:60:    symbol G depends on G
+error: recursive dependency detected!
+       symbol G depends on G
 For a resolution refer to Documentation/kbuild/kconfig-language.rst
 subsection "Kconfig recursive dependency limitations"