Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Masahiro Yamada <> | Subject | [PATCH 1/2] kconfig: fix reverse dependency with tristate if-conditional | Date | Mon, 26 Nov 2018 16:22:48 +0900 |
| |
A Kconfig property can have an optional if-expression, which describes its visibility. The property is visible when the if-expression part is evaluated to 'y' or 'm'.
The 'select' and 'imply' properties are internally converted to reverse dependencies, but they are wrongly converted if they have a tristate if-expression.
Example:
config A tristate "a"
config B tristate "b" select A if C
config C tristate "c"
Currently, the reverse dependency of 'A' results in 'B && C'. It is incorrect because the combination of B=y and C=m allows 'A' to become 'm', while its lower limit must be 'y'.
The reverse dependency should be 'B && C != n'.
Randy Dunlap reported that people are trying to fix an individual Kconfig file [1], and I also found another example in the past, commit 9d9c98e89ee2 ("pcmcia: fix yenta dependency on PCCARD_NONSTATIC") but I suspect this is a bug of Kconfig itself.
[1] https://www.spinics.net/lists/netfilter-devel/msg56985.html
Reported-by: Taehee Yoo <ap420073@gmail.com> Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> ---
scripts/kconfig/menu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c index 4cf15d4..2b18833 100644 --- a/scripts/kconfig/menu.c +++ b/scripts/kconfig/menu.c @@ -401,11 +401,13 @@ void menu_finalize(struct menu *parent) if (prop->type == P_SELECT) { struct symbol *es = prop_get_symbol(prop); es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr, - expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep))); + expr_alloc_and(expr_alloc_symbol(menu->sym), + expr_trans_compare(dep, E_UNEQUAL, &symbol_no))); } else if (prop->type == P_IMPLY) { struct symbol *es = prop_get_symbol(prop); es->implied.expr = expr_alloc_or(es->implied.expr, - expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep))); + expr_alloc_and(expr_alloc_symbol(menu->sym), + expr_trans_compare(dep, E_UNEQUAL, &symbol_no))); } } } -- 2.7.4
| ![\](/images/icornerr.gif) |