Re: [PATCH v2 2/3] kconfig: Ask user if string needs to be changed when dependency changed

From: Mickaël Salaün
Date: Sun Feb 21 2021 - 06:10:21 EST



On 21/02/2021 09:47, Masahiro Yamada wrote:
> On Tue, Feb 16, 2021 at 3:14 AM Mickaël Salaün <mic@xxxxxxxxxxx> wrote:
>>
>> From: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx>
>>
>> Content of string configuration may depend on related kernel
>> configurations. Modify oldconfig and syncconfig to inform users about
>> possible required configuration update and give them the opportunity to
>> update it:
>> * if dependencies of this string has changed (e.g. enabled or disabled),
>> * and if the current value of this string is different than the (new)
>> default one.
>>
>> This is particularly relevant for CONFIG_LSM which contains a list of
>> LSMs enabled at boot, but users will not have a chance to update this
>> list with a make oldconfig.
>
> If CONFIG_LSM already exists in the .config,
> oldconfig does not show a prompt.
> This is the expected behavior.

It is not the behavior wished for LSM stacking.

>
> You are trying to fix your problem in a wrong way.
> NACK.

What do you suggest to ensure that users will be asked to update the
CONFIG_LSM string if they add or remove an LSM?



>
>
>
>>
>> Cc: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
>> Cc: James Morris <jmorris@xxxxxxxxx>
>> Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
>> Cc: Serge E. Hallyn <serge@xxxxxxxxxx>
>> Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx>
>> Link: https://lore.kernel.org/r/20210215181511.2840674-3-mic@xxxxxxxxxxx
>> ---
>> scripts/kconfig/conf.c | 37 ++++++++++++++++++++++++++++++++++---
>> 1 file changed, 34 insertions(+), 3 deletions(-)
>>
>> diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
>> index 18a233d27a8d..8633dacd39a9 100644
>> --- a/scripts/kconfig/conf.c
>> +++ b/scripts/kconfig/conf.c
>> @@ -82,6 +82,26 @@ static void xfgets(char *str, int size, FILE *in)
>> printf("%s", str);
>> }
>>
>> +static bool may_need_string_update(struct symbol *sym, const char *def)
>> +{
>> + const struct symbol *dep_sym;
>> + const struct expr *e;
>> +
>> + if (sym->type != S_STRING)
>> + return false;
>> + if (strcmp(def, sym_get_string_default(sym)) == 0)
>> + return false;
>> + /*
>> + * The user may want to synchronize the content of a string related to
>> + * changed dependencies (e.g. CONFIG_LSM).
>> + */
>> + expr_list_for_each_sym(sym->dir_dep.expr, e, dep_sym) {
>> + if (dep_sym->flags & SYMBOL_CHANGED)
>> + return true;
>> + }
>> + return false;
>> +}
>> +
>> static int conf_askvalue(struct symbol *sym, const char *def)
>> {
>> enum symbol_type type = sym_get_type(sym);
>> @@ -102,7 +122,7 @@ static int conf_askvalue(struct symbol *sym, const char *def)
>> switch (input_mode) {
>> case oldconfig:
>> case syncconfig:
>> - if (sym_has_value(sym)) {
>> + if (sym_has_value(sym) && !may_need_string_update(sym, def)) {
>> printf("%s\n", def);
>> return 0;
>> }
>> @@ -137,8 +157,19 @@ static int conf_string(struct menu *menu)
>> printf("%*s%s ", indent - 1, "", menu->prompt->text);
>> printf("(%s) ", sym->name);
>> def = sym_get_string_value(sym);
>> - if (def)
>> - printf("[%s] ", def);
>> + if (def) {
>> + if (may_need_string_update(sym, def)) {
>> + indent += 2;
>> + printf("\n%*sDefault value is [%s]\n",
>> + indent - 1, "",
>> + sym_get_string_default(sym));
>> + printf("%*sCurrent value is [%s] ",
>> + indent - 1, "", def);
>> + indent -= 2;
>> + } else {
>> + printf("[%s] ", def);
>> + }
>> + }
>> if (!conf_askvalue(sym, def))
>> return 0;
>> switch (line[0]) {
>> --
>> 2.30.0
>>
>
>