kernel/linux.git/scripts/kconfig/symbol.c, branch v5.10.257

kconfig: fix comparison to constant symbols, 'm', 'n'

2024-06-16T11:32:29+00:00

[ Upstream commit aabdc960a283ba78086b0bf66ee74326f49e218e ] Currently, comparisons to 'm' or 'n' result in incorrect output. [Test Code] config MODULES def_bool y modules config A def_tristate m config B def_bool A > n CONFIG_B is unset, while CONFIG_B=y is expected. The reason for the issue is because Kconfig compares the tristate values as strings. Currently, the .type fields in the constant symbol definitions, symbol_{yes,mod,no} are unspecified, i.e., S_UNKNOWN. When expr_calc_value() evaluates 'A > n', it checks the types of 'A' and 'n' to determine how to compare them. The left-hand side, 'A', is a tristate symbol with a value of 'm', which corresponds to a numeric value of 1. (Internally, 'y', 'm', and 'n' are represented as 2, 1, and 0, respectively.) The right-hand side, 'n', has an unknown type, so it is treated as the string "n" during the comparison. expr_calc_value() compares two values numerically only when both can have numeric values. Otherwise, they are compared as strings. symbol numeric value ASCII code ------------------------------------- y 2 0x79 m 1 0x6d n 0 0x6e 'm' is greater than 'n' if compared numerically (since 1 is greater than 0), but smaller than 'n' if compared as strings (since the ASCII code 0x6d is smaller than 0x6e). Specifying .type=S_TRISTATE for symbol_{yes,mod,no} fixes the above test code. Doing so, however, would cause a regression to the following test code. [Test Code 2] config MODULES def_bool n modules config A def_tristate n config B def_bool A = m You would get CONFIG_B=y, while CONFIG_B should not be set. The reason is because sym_get_string_value() turns 'm' into 'n' when the module feature is disabled. Consequently, expr_calc_value() evaluates 'A = n' instead of 'A = m'. This oddity has been hidden because the type of 'm' was previously S_UNKNOWN instead of S_TRISTATE. sym_get_string_value() should not tweak the string because the tristate value has already been correctly calculated. There is no reason to return the string "n" where its tristate value is mod. Fixes: 31847b67bec0 ("kconfig: allow use of relations other than (in)equality") Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

kconfig: fix memory leak from range properties

2023-12-13T17:26:56+00:00

[ Upstream commit ae1eff0349f2e908fc083630e8441ea6dc434dc0 ] Currently, sym_validate_range() duplicates the range string using xstrdup(), which is overwritten by a subsequent sym_calc_value() call. It results in a memory leak. Instead, only the pointer should be copied. Below is a test case, with a summary from Valgrind. [Test Kconfig] config FOO int "foo" range 10 20 [Test .config] CONFIG_FOO=0 [Before] LEAK SUMMARY: definitely lost: 3 bytes in 1 blocks indirectly lost: 0 bytes in 0 blocks possibly lost: 0 bytes in 0 blocks still reachable: 17,465 bytes in 21 blocks suppressed: 0 bytes in 0 blocks [After] LEAK SUMMARY: definitely lost: 0 bytes in 0 blocks indirectly lost: 0 bytes in 0 blocks possibly lost: 0 bytes in 0 blocks still reachable: 17,462 bytes in 20 blocks suppressed: 0 bytes in 0 blocks Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

kconfig: add 'static' to some file-local data

2020-08-14T04:30:04+00:00

Fix some warnings from sparce like follows: warning: symbol '...' was not declared. Should it be static? Signed-off-by: Masahiro Yamada

kconfig: do not use OR-assignment for zero-cleared structure

2020-05-12T04:28:30+00:00

The simple assignment is enough because memset() three lines above has zero-cleared the structure. Signed-off-by: Masahiro Yamada

kconfig: make 'imply' obey the direct dependency

2020-03-13T01:05:34+00:00

The 'imply' statement may create unmet direct dependency when the implied symbol depends on m. [Test Code] config FOO tristate "foo" imply BAZ config BAZ tristate "baz" depends on BAR config BAR def_tristate m config MODULES def_bool y option modules If you set FOO=y, BAZ is also promoted to y, which results in the following .config file: CONFIG_FOO=y CONFIG_BAZ=y CONFIG_BAR=m CONFIG_MODULES=y This does not meet the dependency 'BAZ depends on BAR'. Unlike 'select', what is worse, Kconfig never shows the 'WARNING: unmet direct dependencies detected for ...' for this case. Because 'imply' is considered to be weaker than 'depends on', Kconfig should take the direct dependency into account. For clarification, describe this case in kconfig-language.rst too. Signed-off-by: Masahiro Yamada Acked-by: Nicolas Pitre Tested-by: Geert Uytterhoeven

kconfig: allow symbols implied by y to become m

2020-03-13T01:05:34+00:00

The 'imply' keyword restricts a symbol to y or n, excluding m when it is implied by y. This is the original behavior since commit 237e3ad0f195 ("Kconfig: Introduce the "imply" keyword"). However, the author of this feature, Nicolas Pitre, stated that the 'imply' keyword should not impose any restrictions. (https://lkml.org/lkml/2020/2/19/714) I agree, and want to get rid of this tricky behavior. Suggested-by: Nicolas Pitre Signed-off-by: Masahiro Yamada Acked-by: Nicolas Pitre

kconfig: squash prop_alloc() into menu_add_prop()

2020-01-06T17:18:44+00:00

prop_alloc() is only called from menu_add_prop(). Squash it. Signed-off-by: Masahiro Yamada

kconfig: remove sym from struct property

2020-01-06T17:18:44+00:00

struct property can reference to the symbol that it is associated with by prop->menu->sym. Fix up the one usage of prop->sym, and remove sym from struct property. Signed-off-by: Masahiro Yamada

Merge tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2019-07-12T23:06:27+00:00

Pull Kconfig updates from Masahiro Yamada: - always require argument for --defconfig and remove the hard-coded arch/$(ARCH)/defconfig path - make arch/$(SRCARCH)/configs/defconfig the new default of defconfig - some code cleanups * tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove meaningless if-conditional in conf_read() kconfig: Fix spelling of sym_is_changable unicore32: rename unicore32_defconfig to defconfig kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG kconfig: add static qualifier to expand_string() kconfig: require the argument of --defconfig kconfig: remove always false ifeq ($(KBUILD_DEFCONFIG,) conditional

kconfig: Fix spelling of sym_is_changable

2019-07-06T12:58:23+00:00

There is a spelling mistake in "changable", it is corrected to "changeable" and all call sites are updated accordingly. Signed-off-by: Marco Ammon Signed-off-by: Masahiro Yamada