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Message-ID: <20240717015042.339931-1-elsk@google.com>
Date: Wed, 17 Jul 2024 01:50:41 +0000
From: HONG Yifan <elsk@...gle.com>
To: Masahiro Yamada <masahiroy@...nel.org>
Cc: HONG Yifan <elsk@...gle.com>, kernel-team@...roid.com, linux-kbuild@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH v4] 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
Link: https://lore.kernel.org/linux-kbuild/20240627231919.2461945-1-elsk@google.com/T/
Link: https://lore.kernel.org/linux-kbuild/20240620211112.500465-1-elsk@google.com/
Link: https://lore.kernel.org/linux-kbuild/20240618185609.4096399-1-elsk@google.com/
Signed-off-by: HONG Yifan <elsk@...gle.com>
--
v4: Rebased & addressed comments from masahiroy@...nel.org. Simplify
code by dropping `prop` variable.
v3: Rebase on top of
https://lore.kernel.org/linux-kbuild/20240626182212.3758235-1-masahiroy@kernel.org/T/#t
& resolve merge conflicts. Fix
scripts/kconfig/tests/err_recursive_dep/expected_stderr
v2: Delete all filenames/lineno completely as suggested by
masahiroy@...nel.org
---
scripts/kconfig/symbol.c | 42 ++++++-------------
.../tests/err_recursive_dep/expected_stderr | 36 ++++++++--------
2 files changed, 30 insertions(+), 48 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;
-
- /* 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 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"
--
2.45.2.993.g49e7a77208-goog
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