[v2,2/3] kconfig: Ask user if string needs to be changed when dependency changed
diff mbox series

Message ID 20210215181511.2840674-3-mic@digikod.net
State New, archived
Headers show
Series
  • Kconfig oldconfig string update
Related show

Commit Message

Mickaël Salaün Feb. 15, 2021, 6:15 p.m. UTC
From: Mickaël Salaün <mic@linux.microsoft.com>

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.

Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210215181511.2840674-3-mic@digikod.net
---
 scripts/kconfig/conf.c | 37 ++++++++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

Comments

Masahiro Yamada Feb. 21, 2021, 8:47 a.m. UTC | #1
On Tue, Feb 16, 2021 at 3:14 AM Mickaël Salaün <mic@digikod.net> wrote:
>
> From: Mickaël Salaün <mic@linux.microsoft.com>
>
> 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.

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



>
> Cc: Casey Schaufler <casey@schaufler-ca.com>
> Cc: James Morris <jmorris@namei.org>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: Serge E. Hallyn <serge@hallyn.com>
> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
> Link: https://lore.kernel.org/r/20210215181511.2840674-3-mic@digikod.net
> ---
>  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
>
Mickaël Salaün Feb. 21, 2021, 11:10 a.m. UTC | #2
On 21/02/2021 09:47, Masahiro Yamada wrote:
> On Tue, Feb 16, 2021 at 3:14 AM Mickaël Salaün <mic@digikod.net> wrote:
>>
>> From: Mickaël Salaün <mic@linux.microsoft.com>
>>
>> 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@schaufler-ca.com>
>> Cc: James Morris <jmorris@namei.org>
>> Cc: Masahiro Yamada <masahiroy@kernel.org>
>> Cc: Serge E. Hallyn <serge@hallyn.com>
>> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
>> Link: https://lore.kernel.org/r/20210215181511.2840674-3-mic@digikod.net
>> ---
>>  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
>>
> 
>
Masahiro Yamada Feb. 21, 2021, 2:45 p.m. UTC | #3
On Sun, Feb 21, 2021 at 8:09 PM Mickaël Salaün <mic@digikod.net> wrote:
>
>
> On 21/02/2021 09:47, Masahiro Yamada wrote:
> > On Tue, Feb 16, 2021 at 3:14 AM Mickaël Salaün <mic@digikod.net> wrote:
> >>
> >> From: Mickaël Salaün <mic@linux.microsoft.com>
> >>
> >> 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.

Because LSM is doing wrong.


> >
> > 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?


Fix it in the security subsystem.


Hint:
See 050e9baa9dc9fbd9ce2b27f0056990fc9e0a08a0

Patch
diff mbox series

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]) {