[PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Masahiro Yamada]

This is used only for initializing other variables.

Use the empty string "".

Please note newval.tri is unused for S_INT/HEX/STRING.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/kconfig/symbol.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index a76925b46ce6..f7075d148ac7 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -29,12 +29,6 @@ struct symbol symbol_no = {
 	.flags = SYMBOL_CONST|SYMBOL_VALID,
 };
 
-static struct symbol symbol_empty = {
-	.name = "",
-	.curr = { "", no },
-	.flags = SYMBOL_VALID,
-};
-
 struct symbol *modules_sym;
 static tristate modules_val;
 
@@ -346,7 +340,7 @@ void sym_calc_value(struct symbol *sym)
 	case S_INT:
 	case S_HEX:
 	case S_STRING:
-		newval = symbol_empty.curr;
+		newval.val = "";
 		break;
 	case S_BOOLEAN:
 	case S_TRISTATE:
@@ -697,13 +691,12 @@ const char *sym_get_string_default(struct symbol *sym)
 {
 	struct property *prop;
 	struct symbol *ds;
-	const char *str;
+	const char *str = "";
 	tristate val;
 
 	sym_calc_visibility(sym);
 	sym_calc_value(modules_sym);
 	val = symbol_no.curr.tri;
-	str = symbol_empty.curr.val;
 
 	/* If symbol has a default value look it up */
 	prop = sym_get_default_prop(sym);
-- 
2.40.1

[PATCH 2/2] kconfig: default to zero if int/hex symbol lacks default property

[Masahiro Yamada]

When a default property is missing in an int or hex symbol, it defaults
to an empty string, which is not a valid symbol value.

It results in a incorrect .config, and can also lead to an infinite
loop in scripting.

Use "0" for int and "0x0" for hex as a default value.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/kconfig/symbol.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index f7075d148ac7..a5a4f9153eb7 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -338,7 +338,11 @@ void sym_calc_value(struct symbol *sym)
 
 	switch (sym->type) {
 	case S_INT:
+		newval.val = "0";
+		break;
 	case S_HEX:
+		newval.val = "0x0";
+		break;
 	case S_STRING:
 		newval.val = "";
 		break;
@@ -746,14 +750,17 @@ const char *sym_get_string_default(struct symbol *sym)
 		case yes: return "y";
 		}
 	case S_INT:
+		if (!str[0])
+			str = "0";
+		break;
 	case S_HEX:
-		return str;
-	case S_STRING:
-		return str;
-	case S_UNKNOWN:
+		if (!str[0])
+			str = "0x0";
+		break;
+	default:
 		break;
 	}
-	return "";
+	return str;
 }
 
 const char *sym_get_string_value(struct symbol *sym)
-- 
2.40.1

Re: [PATCH 2/2] kconfig: default to zero if int/hex symbol lacks default property

[Yoann Congal]

Le 25/11/2023 à 17:35, Masahiro Yamada a écrit :
> When a default property is missing in an int or hex symbol, it defaults
> to an empty string, which is not a valid symbol value.
> 
> It results in a incorrect .config, and can also lead to an infinite
> loop in scripting.
> 
> Use "0" for int and "0x0" for hex as a default value.
> 
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Thanks! It does fix our problem.

Reviewed-by: Yoann Congal <yoann.congal@smile.fr>

> ---
> 
>  scripts/kconfig/symbol.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
> index f7075d148ac7..a5a4f9153eb7 100644
> --- a/scripts/kconfig/symbol.c
> +++ b/scripts/kconfig/symbol.c
> @@ -338,7 +338,11 @@ void sym_calc_value(struct symbol *sym)
>  
>  	switch (sym->type) {
>  	case S_INT:
> +		newval.val = "0";
> +		break;
>  	case S_HEX:
> +		newval.val = "0x0";
> +		break;
>  	case S_STRING:
>  		newval.val = "";
>  		break;
> @@ -746,14 +750,17 @@ const char *sym_get_string_default(struct symbol *sym)
>  		case yes: return "y";
>  		}
>  	case S_INT:
> +		if (!str[0])
> +			str = "0";
> +		break;
>  	case S_HEX:
> -		return str;
> -	case S_STRING:
> -		return str;
> -	case S_UNKNOWN:
> +		if (!str[0])
> +			str = "0x0";
> +		break;
> +	default:
>  		break;
>  	}
> -	return "";
> +	return str;
>  }
>  
>  const char *sym_get_string_value(struct symbol *sym)

-- 
Yoann Congal
Smile ECS - Tech Expert

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Geert Uytterhoeven]

Hi Yamada-san,

On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> This is used only for initializing other variables.
>
> Use the empty string "".
>
> Please note newval.tri is unused for S_INT/HEX/STRING.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Thanks for your patch, which is now commit 4e244c10eab345a7
("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.

When running "make <foo>_defconfig" with <foo>_defconfig an SMP
defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
the aforementioned commit causes a change in the generated .config:

-CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
+CONFIG_LOG_CPU_MAX_BUF_SHIFT=0

It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
the integer number zero?

init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
KB, 17 => 128KB)"
init/Kconfig-   depends on SMP
init/Kconfig-   range 0 21
init/Kconfig:   default 12 if !BASE_SMALL
init/Kconfig:   default 0 if BASE_SMALL

Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
int/hex symbol lacks default property") does fix it.

Thanks!

> --- a/scripts/kconfig/symbol.c
> +++ b/scripts/kconfig/symbol.c
> @@ -29,12 +29,6 @@ struct symbol symbol_no = {
>         .flags = SYMBOL_CONST|SYMBOL_VALID,
>  };
>
> -static struct symbol symbol_empty = {
> -       .name = "",
> -       .curr = { "", no },
> -       .flags = SYMBOL_VALID,
> -};
> -
>  struct symbol *modules_sym;
>  static tristate modules_val;
>
> @@ -346,7 +340,7 @@ void sym_calc_value(struct symbol *sym)
>         case S_INT:
>         case S_HEX:
>         case S_STRING:
> -               newval = symbol_empty.curr;
> +               newval.val = "";
>                 break;
>         case S_BOOLEAN:
>         case S_TRISTATE:
> @@ -697,13 +691,12 @@ const char *sym_get_string_default(struct symbol *sym)
>  {
>         struct property *prop;
>         struct symbol *ds;
> -       const char *str;
> +       const char *str = "";
>         tristate val;
>
>         sym_calc_visibility(sym);
>         sym_calc_value(modules_sym);
>         val = symbol_no.curr.tri;
> -       str = symbol_empty.curr.val;
>
>         /* If symbol has a default value look it up */
>         prop = sym_get_default_prop(sym);

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Yoann Congal]

Le 23/01/2024 à 13:54, Geert Uytterhoeven a écrit :
> Hi Yamada-san,

Hello,
 
> On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>> This is used only for initializing other variables.
>>
>> Use the empty string "".
>>
>> Please note newval.tri is unused for S_INT/HEX/STRING.
>>
>> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> 
> Thanks for your patch, which is now commit 4e244c10eab345a7
> ("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.
> 
> When running "make <foo>_defconfig" with <foo>_defconfig an SMP
> defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
> the aforementioned commit causes a change in the generated .config:
> 
> -CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> +CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> 
> It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
> the integer number zero?
> 
> init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
> init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
> KB, 17 => 128KB)"
> init/Kconfig-   depends on SMP
> init/Kconfig-   range 0 21
> init/Kconfig:   default 12 if !BASE_SMALL
> init/Kconfig:   default 0 if BASE_SMALL
> 
> Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
> Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
> int/hex symbol lacks default property") does fix it.

(Since I'd really like 6262afa10ef7cc8f ("kconfig: default to zero if int/hex symbol lacks default property") to stay, allow me to try to help)

The problem is quite easy to reproduce:
  $ make x86_64_defconfig
  $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
  CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
  CONFIG_BASE_FULL=y
  CONFIG_BASE_SMALL=0
Here, CONFIG_LOG_CPU_MAX_BUF_SHIFT should be 12 not 0.

For what it is worth, CONFIG_BASE_SMALL is defined as an int but is only used as a bool :
   $ git grep BASE_SMALL
  arch/x86/include/asm/mpspec.h:#if CONFIG_BASE_SMALL == 0
  drivers/tty/vt/vc_screen.c:#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
  include/linux/threads.h:#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
  include/linux/threads.h:#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
  include/linux/udp.h:#define UDP_HTABLE_SIZE_MIN         (CONFIG_BASE_SMALL ? 128 : 256)
  include/linux/xarray.h:#define XA_CHUNK_SHIFT           (CONFIG_BASE_SMALL ? 4 : 6)
  init/Kconfig:   default 12 if !BASE_SMALL
  init/Kconfig:   default 0 if BASE_SMALL
  init/Kconfig:config BASE_SMALL
  kernel/futex/core.c:#if CONFIG_BASE_SMALL
  kernel/user.c:#define UIDHASH_BITS      (CONFIG_BASE_SMALL ? 3 : 7)

Maybe we should change CONFIG_BASE_SMALL to the bool type?

I'll poke around to see if I can understand why a int="0" is true for kconfig.

Regards,
-- 
Yoann Congal
Smile ECS - Tech Expert

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Masahiro Yamada]

On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
>
> Le 23/01/2024 à 13:54, Geert Uytterhoeven a écrit :
> > Hi Yamada-san,
>
> Hello,
>
> > On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> >> This is used only for initializing other variables.
> >>
> >> Use the empty string "".
> >>
> >> Please note newval.tri is unused for S_INT/HEX/STRING.
> >>
> >> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> >
> > Thanks for your patch, which is now commit 4e244c10eab345a7
> > ("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.
> >
> > When running "make <foo>_defconfig" with <foo>_defconfig an SMP
> > defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
> > the aforementioned commit causes a change in the generated .config:
> >
> > -CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> > +CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> >
> > It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
> > the integer number zero?
> >
> > init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
> > init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
> > KB, 17 => 128KB)"
> > init/Kconfig-   depends on SMP
> > init/Kconfig-   range 0 21
> > init/Kconfig:   default 12 if !BASE_SMALL
> > init/Kconfig:   default 0 if BASE_SMALL
> >
> > Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
> > Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
> > int/hex symbol lacks default property") does fix it.
>
> (Since I'd really like 6262afa10ef7cc8f ("kconfig: default to zero if int/hex symbol lacks default property") to stay, allow me to try to help)
>
> The problem is quite easy to reproduce:
>   $ make x86_64_defconfig
>   $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
>   CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
>   CONFIG_BASE_FULL=y
>   CONFIG_BASE_SMALL=0
> Here, CONFIG_LOG_CPU_MAX_BUF_SHIFT should be 12 not 0.



I could not produce it in this way.
I ran the same commands as yours.

CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 for me.



masahiro@zoe:~/ref/linux(master)$ git describe
v6.8-rc1-29-g615d30064886
masahiro@zoe:~/ref/linux(master)$ git diff
masahiro@zoe:~/ref/linux(master)$ make  x86_64_defconfig
#
# No change to .config
#
masahiro@zoe:~/ref/linux(master)$ grep
'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
CONFIG_BASE_FULL=y
CONFIG_BASE_SMALL=0
















>
> For what it is worth, CONFIG_BASE_SMALL is defined as an int but is only used as a bool :
>    $ git grep BASE_SMALL
>   arch/x86/include/asm/mpspec.h:#if CONFIG_BASE_SMALL == 0
>   drivers/tty/vt/vc_screen.c:#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
>   include/linux/threads.h:#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
>   include/linux/threads.h:#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
>   include/linux/udp.h:#define UDP_HTABLE_SIZE_MIN         (CONFIG_BASE_SMALL ? 128 : 256)
>   include/linux/xarray.h:#define XA_CHUNK_SHIFT           (CONFIG_BASE_SMALL ? 4 : 6)
>   init/Kconfig:   default 12 if !BASE_SMALL
>   init/Kconfig:   default 0 if BASE_SMALL
>   init/Kconfig:config BASE_SMALL
>   kernel/futex/core.c:#if CONFIG_BASE_SMALL
>   kernel/user.c:#define UIDHASH_BITS      (CONFIG_BASE_SMALL ? 3 : 7)
>
> Maybe we should change CONFIG_BASE_SMALL to the bool type?
>
> I'll poke around to see if I can understand why a int="0" is true for kconfig.
>
> Regards,
> --
> Yoann Congal
> Smile ECS - Tech Expert
>


-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Yoann Congal]

Le 24/01/2024 à 09:09, Masahiro Yamada a écrit :
> On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
>>
>> Le 23/01/2024 à 13:54, Geert Uytterhoeven a écrit :
>>> Hi Yamada-san,
>>
>> Hello,
>>
>>> On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>>>> This is used only for initializing other variables.
>>>>
>>>> Use the empty string "".
>>>>
>>>> Please note newval.tri is unused for S_INT/HEX/STRING.
>>>>
>>>> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
>>>
>>> Thanks for your patch, which is now commit 4e244c10eab345a7
>>> ("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.
>>>
>>> When running "make <foo>_defconfig" with <foo>_defconfig an SMP
>>> defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
>>> the aforementioned commit causes a change in the generated .config:
>>>
>>> -CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
>>> +CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
>>>
>>> It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
>>> the integer number zero?
>>>
>>> init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
>>> init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
>>> KB, 17 => 128KB)"
>>> init/Kconfig-   depends on SMP
>>> init/Kconfig-   range 0 21
>>> init/Kconfig:   default 12 if !BASE_SMALL
>>> init/Kconfig:   default 0 if BASE_SMALL
>>>
>>> Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
>>> Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
>>> int/hex symbol lacks default property") does fix it.
>>
>> (Since I'd really like 6262afa10ef7cc8f ("kconfig: default to zero if int/hex symbol lacks default property") to stay, allow me to try to help)
>>
>> The problem is quite easy to reproduce:
>>   $ make x86_64_defconfig
>>   $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
>>   CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
>>   CONFIG_BASE_FULL=y
>>   CONFIG_BASE_SMALL=0
>> Here, CONFIG_LOG_CPU_MAX_BUF_SHIFT should be 12 not 0.
> 
> 
> 
> I could not produce it in this way.
> I ran the same commands as yours.
> 
> CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 for me.
> 
> 
> 
> masahiro@zoe:~/ref/linux(master)$ git describe
> v6.8-rc1-29-g615d30064886
> masahiro@zoe:~/ref/linux(master)$ git diff
> masahiro@zoe:~/ref/linux(master)$ make  x86_64_defconfig
> #
> # No change to .config
> #

You already had a .config with the correct value of LOG_CPU_MAX_BUF_SHIFT (Maybe?)

> masahiro@zoe:~/ref/linux(master)$ grep
> 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> CONFIG_BASE_FULL=y
> CONFIG_BASE_SMALL=0

Try to remove the existing .config:

   $ git describe 
  v6.8-rc1
   $ git diff
   $ rm .config -f
   $ make  x86_64_defconfig
  #
  # configuration written to .config
  #
   $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
  CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
  CONFIG_BASE_FULL=y
  CONFIG_BASE_SMALL=0

>>
>> For what it is worth, CONFIG_BASE_SMALL is defined as an int but is only used as a bool :
>>    $ git grep BASE_SMALL
>>   arch/x86/include/asm/mpspec.h:#if CONFIG_BASE_SMALL == 0
>>   drivers/tty/vt/vc_screen.c:#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
>>   include/linux/threads.h:#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
>>   include/linux/threads.h:#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
>>   include/linux/udp.h:#define UDP_HTABLE_SIZE_MIN         (CONFIG_BASE_SMALL ? 128 : 256)
>>   include/linux/xarray.h:#define XA_CHUNK_SHIFT           (CONFIG_BASE_SMALL ? 4 : 6)
>>   init/Kconfig:   default 12 if !BASE_SMALL
>>   init/Kconfig:   default 0 if BASE_SMALL
>>   init/Kconfig:config BASE_SMALL
>>   kernel/futex/core.c:#if CONFIG_BASE_SMALL
>>   kernel/user.c:#define UIDHASH_BITS      (CONFIG_BASE_SMALL ? 3 : 7)
>>
>> Maybe we should change CONFIG_BASE_SMALL to the bool type?

My first test shows that switching CONFIG_BASE_SMALL to bool type does fix the LOG_CPU_MAX_BUF_SHIFT default value.

>> I'll poke around to see if I can understand why a int="0" is true for kconfig.

Here's what I understood:
To get the default value of LOG_CPU_MAX_BUF_SHIFT, kconfig calls sym_get_default_prop(LOG_CPU_MAX_BUF_SHIFT)
-> expr_calc_value("BASE_SMALL" as an expr)
-> sym_calc_value(BASE_SMALL as a symbol) and returns sym->curr.tri

But, if I understood correctly, sym_calc_value() does not set sym->curr.tri in case of a int type config.

Regards,
-- 
Yoann Congal
Smile ECS - Tech Expert

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Masahiro Yamada]

On Wed, Jan 24, 2024 at 5:56 PM Yoann Congal <yoann.congal@smile.fr> wrote:
>
>
>
> Le 24/01/2024 à 09:09, Masahiro Yamada a écrit :
> > On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
> >>
> >> Le 23/01/2024 à 13:54, Geert Uytterhoeven a écrit :
> >>> Hi Yamada-san,
> >>
> >> Hello,
> >>
> >>> On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> >>>> This is used only for initializing other variables.
> >>>>
> >>>> Use the empty string "".
> >>>>
> >>>> Please note newval.tri is unused for S_INT/HEX/STRING.
> >>>>
> >>>> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> >>>
> >>> Thanks for your patch, which is now commit 4e244c10eab345a7
> >>> ("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.
> >>>
> >>> When running "make <foo>_defconfig" with <foo>_defconfig an SMP
> >>> defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
> >>> the aforementioned commit causes a change in the generated .config:
> >>>
> >>> -CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> >>> +CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> >>>
> >>> It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
> >>> the integer number zero?
> >>>
> >>> init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
> >>> init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
> >>> KB, 17 => 128KB)"
> >>> init/Kconfig-   depends on SMP
> >>> init/Kconfig-   range 0 21
> >>> init/Kconfig:   default 12 if !BASE_SMALL
> >>> init/Kconfig:   default 0 if BASE_SMALL
> >>>
> >>> Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
> >>> Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
> >>> int/hex symbol lacks default property") does fix it.
> >>
> >> (Since I'd really like 6262afa10ef7cc8f ("kconfig: default to zero if int/hex symbol lacks default property") to stay, allow me to try to help)
> >>
> >> The problem is quite easy to reproduce:
> >>   $ make x86_64_defconfig
> >>   $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> >>   CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> >>   CONFIG_BASE_FULL=y
> >>   CONFIG_BASE_SMALL=0
> >> Here, CONFIG_LOG_CPU_MAX_BUF_SHIFT should be 12 not 0.
> >
> >
> >
> > I could not produce it in this way.
> > I ran the same commands as yours.
> >
> > CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 for me.
> >
> >
> >
> > masahiro@zoe:~/ref/linux(master)$ git describe
> > v6.8-rc1-29-g615d30064886
> > masahiro@zoe:~/ref/linux(master)$ git diff
> > masahiro@zoe:~/ref/linux(master)$ make  x86_64_defconfig
> > #
> > # No change to .config
> > #
>
> You already had a .config with the correct value of LOG_CPU_MAX_BUF_SHIFT (Maybe?)
>
> > masahiro@zoe:~/ref/linux(master)$ grep
> > 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> > CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> > CONFIG_BASE_FULL=y
> > CONFIG_BASE_SMALL=0
>
> Try to remove the existing .config:
>
>    $ git describe
>   v6.8-rc1
>    $ git diff
>    $ rm .config -f
>    $ make  x86_64_defconfig
>   #
>   # configuration written to .config
>   #
>    $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
>   CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
>   CONFIG_BASE_FULL=y
>   CONFIG_BASE_SMALL=0
>
> >>
> >> For what it is worth, CONFIG_BASE_SMALL is defined as an int but is only used as a bool :
> >>    $ git grep BASE_SMALL
> >>   arch/x86/include/asm/mpspec.h:#if CONFIG_BASE_SMALL == 0
> >>   drivers/tty/vt/vc_screen.c:#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
> >>   include/linux/threads.h:#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
> >>   include/linux/threads.h:#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
> >>   include/linux/udp.h:#define UDP_HTABLE_SIZE_MIN         (CONFIG_BASE_SMALL ? 128 : 256)
> >>   include/linux/xarray.h:#define XA_CHUNK_SHIFT           (CONFIG_BASE_SMALL ? 4 : 6)
> >>   init/Kconfig:   default 12 if !BASE_SMALL
> >>   init/Kconfig:   default 0 if BASE_SMALL
> >>   init/Kconfig:config BASE_SMALL
> >>   kernel/futex/core.c:#if CONFIG_BASE_SMALL
> >>   kernel/user.c:#define UIDHASH_BITS      (CONFIG_BASE_SMALL ? 3 : 7)
> >>
> >> Maybe we should change CONFIG_BASE_SMALL to the bool type?
>
> My first test shows that switching CONFIG_BASE_SMALL to bool type does fix the LOG_CPU_MAX_BUF_SHIFT default value.
>
> >> I'll poke around to see if I can understand why a int="0" is true for kconfig.
>
> Here's what I understood:
> To get the default value of LOG_CPU_MAX_BUF_SHIFT, kconfig calls sym_get_default_prop(LOG_CPU_MAX_BUF_SHIFT)
> -> expr_calc_value("BASE_SMALL" as an expr)
> -> sym_calc_value(BASE_SMALL as a symbol) and returns sym->curr.tri
>
> But, if I understood correctly, sym_calc_value() does not set sym->curr.tri in case of a int type config.


Right.

The following will restore the original behavior.


--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -349,12 +349,15 @@ void sym_calc_value(struct symbol *sym)
        switch (sym->type) {
        case S_INT:
                newval.val = "0";
+               newval.tri = no;
                break;
        case S_HEX:
                newval.val = "0x0";
+               newval.tri = no;
                break;
        case S_STRING:
                newval.val = "";
+               newval.tri = no;
                break;
        case S_BOOLEAN:
        case S_TRISTATE:





But, I do not think that is the right thing to do.


Presumably, turning CONFIG_BASE_SMALL is correct.





>
> Regards,
> --
> Yoann Congal
> Smile ECS - Tech Expert



-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Yoann Congal]

Hi,

Le 24/01/2024 à 21:12, Masahiro Yamada a écrit :
> On Wed, Jan 24, 2024 at 5:56 PM Yoann Congal <yoann.congal@smile.fr> wrote:
>> Le 24/01/2024 à 09:09, Masahiro Yamada a écrit :
>>> On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
>>>> For what it is worth, CONFIG_BASE_SMALL is defined as an int but is only used as a bool :
>>>>    $ git grep BASE_SMALL
>>>>   arch/x86/include/asm/mpspec.h:#if CONFIG_BASE_SMALL == 0
>>>>   drivers/tty/vt/vc_screen.c:#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
>>>>   include/linux/threads.h:#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
>>>>   include/linux/threads.h:#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
>>>>   include/linux/udp.h:#define UDP_HTABLE_SIZE_MIN         (CONFIG_BASE_SMALL ? 128 : 256)
>>>>   include/linux/xarray.h:#define XA_CHUNK_SHIFT           (CONFIG_BASE_SMALL ? 4 : 6)
>>>>   init/Kconfig:   default 12 if !BASE_SMALL
>>>>   init/Kconfig:   default 0 if BASE_SMALL
>>>>   init/Kconfig:config BASE_SMALL
>>>>   kernel/futex/core.c:#if CONFIG_BASE_SMALL
>>>>   kernel/user.c:#define UIDHASH_BITS      (CONFIG_BASE_SMALL ? 3 : 7)
>>>>
>>>> Maybe we should change CONFIG_BASE_SMALL to the bool type?
>>
>> My first test shows that switching CONFIG_BASE_SMALL to bool type does fix the LOG_CPU_MAX_BUF_SHIFT default value.
>>
>>>> I'll poke around to see if I can understand why a int="0" is true for kconfig.
>>
>> Here's what I understood:
>> To get the default value of LOG_CPU_MAX_BUF_SHIFT, kconfig calls sym_get_default_prop(LOG_CPU_MAX_BUF_SHIFT)
>> -> expr_calc_value("BASE_SMALL" as an expr)
>> -> sym_calc_value(BASE_SMALL as a symbol) and returns sym->curr.tri
>>
>> But, if I understood correctly, sym_calc_value() does not set sym->curr.tri in case of a int type config.
> 
> Right.

Thanks :)

> The following will restore the original behavior.
> 
> 
> --- a/scripts/kconfig/symbol.c
> +++ b/scripts/kconfig/symbol.c
> @@ -349,12 +349,15 @@ void sym_calc_value(struct symbol *sym)
>         switch (sym->type) {
>         case S_INT:
>                 newval.val = "0";
> +               newval.tri = no;
>                 break;
>         case S_HEX:
>                 newval.val = "0x0";
> +               newval.tri = no;
>                 break;
>         case S_STRING:
>                 newval.val = "";
> +               newval.tri = no;
>                 break;
>         case S_BOOLEAN:
>         case S_TRISTATE:
> > 
> But, I do not think that is the right thing to do.
> 
> Presumably, turning CONFIG_BASE_SMALL is correct.

I'm working on a patch to do that.

Regards,
-- 
Yoann Congal
Smile ECS - Tech Expert

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Masahiro Yamada]

On Thu, Jan 25, 2024 at 11:42 PM Yoann Congal <yoann.congal@smile.fr> wrote:
>
> Hi,
>
> Le 24/01/2024 à 21:12, Masahiro Yamada a écrit :
> > On Wed, Jan 24, 2024 at 5:56 PM Yoann Congal <yoann.congal@smile.fr> wrote:
> >> Le 24/01/2024 à 09:09, Masahiro Yamada a écrit :
> >>> On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
> >>>> For what it is worth, CONFIG_BASE_SMALL is defined as an int but is only used as a bool :
> >>>>    $ git grep BASE_SMALL
> >>>>   arch/x86/include/asm/mpspec.h:#if CONFIG_BASE_SMALL == 0
> >>>>   drivers/tty/vt/vc_screen.c:#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
> >>>>   include/linux/threads.h:#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
> >>>>   include/linux/threads.h:#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
> >>>>   include/linux/udp.h:#define UDP_HTABLE_SIZE_MIN         (CONFIG_BASE_SMALL ? 128 : 256)
> >>>>   include/linux/xarray.h:#define XA_CHUNK_SHIFT           (CONFIG_BASE_SMALL ? 4 : 6)
> >>>>   init/Kconfig:   default 12 if !BASE_SMALL
> >>>>   init/Kconfig:   default 0 if BASE_SMALL
> >>>>   init/Kconfig:config BASE_SMALL
> >>>>   kernel/futex/core.c:#if CONFIG_BASE_SMALL
> >>>>   kernel/user.c:#define UIDHASH_BITS      (CONFIG_BASE_SMALL ? 3 : 7)
> >>>>
> >>>> Maybe we should change CONFIG_BASE_SMALL to the bool type?
> >>
> >> My first test shows that switching CONFIG_BASE_SMALL to bool type does fix the LOG_CPU_MAX_BUF_SHIFT default value.
> >>
> >>>> I'll poke around to see if I can understand why a int="0" is true for kconfig.
> >>
> >> Here's what I understood:
> >> To get the default value of LOG_CPU_MAX_BUF_SHIFT, kconfig calls sym_get_default_prop(LOG_CPU_MAX_BUF_SHIFT)
> >> -> expr_calc_value("BASE_SMALL" as an expr)
> >> -> sym_calc_value(BASE_SMALL as a symbol) and returns sym->curr.tri
> >>
> >> But, if I understood correctly, sym_calc_value() does not set sym->curr.tri in case of a int type config.
> >
> > Right.
>
> Thanks :)
>
> > The following will restore the original behavior.
> >
> >
> > --- a/scripts/kconfig/symbol.c
> > +++ b/scripts/kconfig/symbol.c
> > @@ -349,12 +349,15 @@ void sym_calc_value(struct symbol *sym)
> >         switch (sym->type) {
> >         case S_INT:
> >                 newval.val = "0";
> > +               newval.tri = no;
> >                 break;
> >         case S_HEX:
> >                 newval.val = "0x0";
> > +               newval.tri = no;
> >                 break;
> >         case S_STRING:
> >                 newval.val = "";
> > +               newval.tri = no;
> >                 break;
> >         case S_BOOLEAN:
> >         case S_TRISTATE:
> > >
> > But, I do not think that is the right thing to do.
> >
> > Presumably, turning CONFIG_BASE_SMALL is correct.
>
> I'm working on a patch to do that.
>

OK, please go ahead.


I will restore the Kconfig original behavior for now
and send a pull-req.




-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Geert Uytterhoeven]

Hi Yamada-san,

On Wed, Jan 24, 2024 at 9:13 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> On Wed, Jan 24, 2024 at 5:56 PM Yoann Congal <yoann.congal@smile.fr> wrote:
> > Le 24/01/2024 à 09:09, Masahiro Yamada a écrit :
> > > On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
> > >> Le 23/01/2024 à 13:54, Geert Uytterhoeven a écrit :
> > >>> On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > >>>> This is used only for initializing other variables.
> > >>>>
> > >>>> Use the empty string "".
> > >>>>
> > >>>> Please note newval.tri is unused for S_INT/HEX/STRING.
> > >>>>
> > >>>> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> > >>>
> > >>> Thanks for your patch, which is now commit 4e244c10eab345a7
> > >>> ("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.
> > >>>
> > >>> When running "make <foo>_defconfig" with <foo>_defconfig an SMP
> > >>> defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
> > >>> the aforementioned commit causes a change in the generated .config:
> > >>>
> > >>> -CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> > >>> +CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> > >>>
> > >>> It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
> > >>> the integer number zero?
> > >>>
> > >>> init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
> > >>> init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
> > >>> KB, 17 => 128KB)"
> > >>> init/Kconfig-   depends on SMP
> > >>> init/Kconfig-   range 0 21
> > >>> init/Kconfig:   default 12 if !BASE_SMALL
> > >>> init/Kconfig:   default 0 if BASE_SMALL
> > >>>
> > >>> Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
> > >>> Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
> > >>> int/hex symbol lacks default property") does fix it.
> > >>
> > >> (Since I'd really like 6262afa10ef7cc8f ("kconfig: default to zero if int/hex symbol lacks default property") to stay, allow me to try to help)
> > >>
> > >> The problem is quite easy to reproduce:
> > >>   $ make x86_64_defconfig
> > >>   $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> > >>   CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> > >>   CONFIG_BASE_FULL=y
> > >>   CONFIG_BASE_SMALL=0
> > >> Here, CONFIG_LOG_CPU_MAX_BUF_SHIFT should be 12 not 0.

> > >> For what it is worth, CONFIG_BASE_SMALL is defined as an int but is only used as a bool :
> > >>    $ git grep BASE_SMALL
> > >>   arch/x86/include/asm/mpspec.h:#if CONFIG_BASE_SMALL == 0
> > >>   drivers/tty/vt/vc_screen.c:#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
> > >>   include/linux/threads.h:#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000)
> > >>   include/linux/threads.h:#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
> > >>   include/linux/udp.h:#define UDP_HTABLE_SIZE_MIN         (CONFIG_BASE_SMALL ? 128 : 256)
> > >>   include/linux/xarray.h:#define XA_CHUNK_SHIFT           (CONFIG_BASE_SMALL ? 4 : 6)
> > >>   init/Kconfig:   default 12 if !BASE_SMALL
> > >>   init/Kconfig:   default 0 if BASE_SMALL
> > >>   init/Kconfig:config BASE_SMALL
> > >>   kernel/futex/core.c:#if CONFIG_BASE_SMALL
> > >>   kernel/user.c:#define UIDHASH_BITS      (CONFIG_BASE_SMALL ? 3 : 7)
> > >>
> > >> Maybe we should change CONFIG_BASE_SMALL to the bool type?
> >
> > My first test shows that switching CONFIG_BASE_SMALL to bool type does fix the LOG_CPU_MAX_BUF_SHIFT default value.
> >
> > >> I'll poke around to see if I can understand why a int="0" is true for kconfig.
> >
> > Here's what I understood:
> > To get the default value of LOG_CPU_MAX_BUF_SHIFT, kconfig calls sym_get_default_prop(LOG_CPU_MAX_BUF_SHIFT)
> > -> expr_calc_value("BASE_SMALL" as an expr)
> > -> sym_calc_value(BASE_SMALL as a symbol) and returns sym->curr.tri
> >
> > But, if I understood correctly, sym_calc_value() does not set sym->curr.tri in case of a int type config.
>
> Right.
>
> The following will restore the original behavior.
>
> --- a/scripts/kconfig/symbol.c
> +++ b/scripts/kconfig/symbol.c
> @@ -349,12 +349,15 @@ void sym_calc_value(struct symbol *sym)
>         switch (sym->type) {
>         case S_INT:
>                 newval.val = "0";
> +               newval.tri = no;
>                 break;
>         case S_HEX:
>                 newval.val = "0x0";
> +               newval.tri = no;
>                 break;
>         case S_STRING:
>                 newval.val = "";
> +               newval.tri = no;
>                 break;
>         case S_BOOLEAN:
>         case S_TRISTATE:

Thank you, that works for me.
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Geert Uytterhoeven]

Hi Yamada-san,

On Wed, Jan 24, 2024 at 9:10 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
> On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
> > Le 23/01/2024 à 13:54, Geert Uytterhoeven a écrit :
> > > On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > >> This is used only for initializing other variables.
> > >>
> > >> Use the empty string "".
> > >>
> > >> Please note newval.tri is unused for S_INT/HEX/STRING.
> > >>
> > >> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> > >
> > > Thanks for your patch, which is now commit 4e244c10eab345a7
> > > ("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.
> > >
> > > When running "make <foo>_defconfig" with <foo>_defconfig an SMP
> > > defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
> > > the aforementioned commit causes a change in the generated .config:
> > >
> > > -CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> > > +CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> > >
> > > It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
> > > the integer number zero?
> > >
> > > init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
> > > init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
> > > KB, 17 => 128KB)"
> > > init/Kconfig-   depends on SMP
> > > init/Kconfig-   range 0 21
> > > init/Kconfig:   default 12 if !BASE_SMALL
> > > init/Kconfig:   default 0 if BASE_SMALL
> > >
> > > Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
> > > Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
> > > int/hex symbol lacks default property") does fix it.
> >
> > (Since I'd really like 6262afa10ef7cc8f ("kconfig: default to zero if int/hex symbol lacks default property") to stay, allow me to try to help)
> >
> > The problem is quite easy to reproduce:
> >   $ make x86_64_defconfig
> >   $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> >   CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> >   CONFIG_BASE_FULL=y
> >   CONFIG_BASE_SMALL=0
> > Here, CONFIG_LOG_CPU_MAX_BUF_SHIFT should be 12 not 0.
>
>
>
> I could not produce it in this way.
> I ran the same commands as yours.
>
> CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 for me.
>
>
>
> masahiro@zoe:~/ref/linux(master)$ git describe
> v6.8-rc1-29-g615d30064886
> masahiro@zoe:~/ref/linux(master)$ git diff
> masahiro@zoe:~/ref/linux(master)$ make  x86_64_defconfig
> #
> # No change to .config
> #
> masahiro@zoe:~/ref/linux(master)$ grep
> 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> CONFIG_BASE_FULL=y
> CONFIG_BASE_SMALL=0

Interesting...

$ git describe
v6.8-rc1-29-g615d300648869c77
$ make  x86_64_defconfig
[...]
$ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
CONFIG_BASE_FULL=y
CONFIG_BASE_SMALL=0

Does it depend on the flex/bison version?
I have Ubuntu LTS flex 2.6.4-8build2 and bison 2:3.8.2+dfsg-1build1.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

[Masahiro Yamada]

On Wed, Jan 24, 2024 at 6:52 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Yamada-san,
>
> On Wed, Jan 24, 2024 at 9:10 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > On Wed, Jan 24, 2024 at 12:11 AM Yoann Congal <yoann.congal@smile.fr> wrote:
> > > Le 23/01/2024 à 13:54, Geert Uytterhoeven a écrit :
> > > > On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > > >> This is used only for initializing other variables.
> > > >>
> > > >> Use the empty string "".
> > > >>
> > > >> Please note newval.tri is unused for S_INT/HEX/STRING.
> > > >>
> > > >> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> > > >
> > > > Thanks for your patch, which is now commit 4e244c10eab345a7
> > > > ("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.
> > > >
> > > > When running "make <foo>_defconfig" with <foo>_defconfig an SMP
> > > > defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
> > > > the aforementioned commit causes a change in the generated .config:
> > > >
> > > > -CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> > > > +CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> > > >
> > > > It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
> > > > the integer number zero?
> > > >
> > > > init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
> > > > init/Kconfig-   int "CPU kernel log buffer size contribution (13 => 8
> > > > KB, 17 => 128KB)"
> > > > init/Kconfig-   depends on SMP
> > > > init/Kconfig-   range 0 21
> > > > init/Kconfig:   default 12 if !BASE_SMALL
> > > > init/Kconfig:   default 0 if BASE_SMALL
> > > >
> > > > Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
> > > > Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
> > > > int/hex symbol lacks default property") does fix it.
> > >
> > > (Since I'd really like 6262afa10ef7cc8f ("kconfig: default to zero if int/hex symbol lacks default property") to stay, allow me to try to help)
> > >
> > > The problem is quite easy to reproduce:
> > >   $ make x86_64_defconfig
> > >   $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> > >   CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> > >   CONFIG_BASE_FULL=y
> > >   CONFIG_BASE_SMALL=0
> > > Here, CONFIG_LOG_CPU_MAX_BUF_SHIFT should be 12 not 0.
> >
> >
> >
> > I could not produce it in this way.
> > I ran the same commands as yours.
> >
> > CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 for me.
> >
> >
> >
> > masahiro@zoe:~/ref/linux(master)$ git describe
> > v6.8-rc1-29-g615d30064886
> > masahiro@zoe:~/ref/linux(master)$ git diff
> > masahiro@zoe:~/ref/linux(master)$ make  x86_64_defconfig
> > #
> > # No change to .config
> > #
> > masahiro@zoe:~/ref/linux(master)$ grep
> > 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> > CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
> > CONFIG_BASE_FULL=y
> > CONFIG_BASE_SMALL=0
>
> Interesting...
>
> $ git describe
> v6.8-rc1-29-g615d300648869c77
> $ make  x86_64_defconfig
> [...]
> $ grep 'LOG_CPU_MAX_BUF_SHIFT\|BASE_SMALL\|BASE_FULL' .config
> CONFIG_LOG_CPU_MAX_BUF_SHIFT=0
> CONFIG_BASE_FULL=y
> CONFIG_BASE_SMALL=0
>
> Does it depend on the flex/bison version?
> I have Ubuntu LTS flex 2.6.4-8build2 and bison 2:3.8.2+dfsg-1build1.
>


Interesting.

The result depends on the distro.



I got CONFIG_LOG_CPU_MAX_BUF_SHIFT=0 in
the Ubuntu 22.04 docker container, but
CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 in
the Ubuntu 23.10 docker container.






--
Best Regards
Masahiro Yamada