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kconfig: recursive checks drop file/lineno

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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>
This commit is contained in:
HONG Yifan 2024-07-17 01:50:41 +00:00 committed by Masahiro Yamada
parent 301c10908e
commit 9d0d266046
2 changed files with 29 additions and 47 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

40
scripts/kconfig/symbol.c
View file

@ -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;
type = stack->prop ? stack->prop->type : P_UNKNOWN;
/* 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;
}
}
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);
}
}

36
scripts/kconfig/tests/err_recursive_dep/expected_stderr
View file

@ -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"