From 9d0d266046571f4b3e733c7eb9cf7c959f37fbdd Mon Sep 17 00:00:00 2001 From: HONG Yifan Date: Wed, 17 Jul 2024 01:50:41 +0000 Subject: [PATCH] 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 Signed-off-by: Masahiro Yamada --- scripts/kconfig/symbol.c | 40 +++++-------------- .../tests/err_recursive_dep/expected_stderr | 36 ++++++++--------- 2 files changed, 29 insertions(+), 47 deletions(-) diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c index 6c6f238c4f7b..71502abd3b12 100644 --- 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; + 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->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 : "", 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 : "", - 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 : "", - 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 05d4ced70320..fc2e860af082 100644 --- 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"