linux-3.18.y: Add "kconfig: Fix warning "‘jump’ may be used uninitialized""

linux-3.18.y: Add "kconfig: Fix warning "‘jump’ may be used uninitialized""

[Sedat Dilek]

Hi,

I see the following...

$ yes "" | make oldconfig && make silentoldconfig </dev/null
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  SHIPPED scripts/kconfig/zconf.tab.c
  SHIPPED scripts/kconfig/zconf.lex.c
  SHIPPED scripts/kconfig/zconf.hash.c
  HOSTCC  scripts/kconfig/zconf.tab.o
In file included from scripts/kconfig/zconf.tab.c:2537:0:
scripts/kconfig/menu.c: In function ‘get_symbol_str’:
scripts/kconfig/menu.c:590:18: warning: ‘jump’ may be used
uninitialized in this function [-Wmaybe-uninitialized]
     jump->offset = strlen(r->s);
                  ^
scripts/kconfig/menu.c:551:19: note: ‘jump’ was declared here
  struct jump_key *jump;
                   ^
  HOSTLD  scripts/kconfig/conf
scripts/kconfig/conf --oldconfig Kconfig
#
# configuration written to .config
#
scripts/kconfig/conf --silentoldconfig Kconfig

The fix is "kconfig: Fix warning "‘jump’ may be used uninitialized"" upstream.

Greg can you take it for next -stable cycle?

Thanks.

Regards,
- Sedat -

[1] http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2d560306096739e2251329ab5c16059311a151b0

Re: linux-3.18.y: Add "kconfig: Fix warning "‘jump’ may be used uninitialized""

[Greg Kroah-Hartman]

On Fri, Feb 06, 2015 at 04:40:28PM +0100, Sedat Dilek wrote:
> Hi,
> 
> I see the following...
> 
> $ yes "" | make oldconfig && make silentoldconfig </dev/null
>   HOSTCC  scripts/basic/fixdep
>   HOSTCC  scripts/kconfig/conf.o
>   SHIPPED scripts/kconfig/zconf.tab.c
>   SHIPPED scripts/kconfig/zconf.lex.c
>   SHIPPED scripts/kconfig/zconf.hash.c
>   HOSTCC  scripts/kconfig/zconf.tab.o
> In file included from scripts/kconfig/zconf.tab.c:2537:0:
> scripts/kconfig/menu.c: In function ‘get_symbol_str’:
> scripts/kconfig/menu.c:590:18: warning: ‘jump’ may be used
> uninitialized in this function [-Wmaybe-uninitialized]
>      jump->offset = strlen(r->s);
>                   ^
> scripts/kconfig/menu.c:551:19: note: ‘jump’ was declared here
>   struct jump_key *jump;
>                    ^
>   HOSTLD  scripts/kconfig/conf
> scripts/kconfig/conf --oldconfig Kconfig
> #
> # configuration written to .config
> #
> scripts/kconfig/conf --silentoldconfig Kconfig
> 
> The fix is "kconfig: Fix warning "‘jump’ may be used uninitialized"" upstream.


Sure, what's the git commit id of the patch in Linus's tree?  That's
annoying to me as well, thanks for reminding me about it.

greg k-h

Re: linux-3.18.y: Add "kconfig: Fix warning "‘jump’ may be used uninitialized""

[Sedat Dilek]

On Fri, Feb 6, 2015 at 4:50 PM, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> On Fri, Feb 06, 2015 at 04:40:28PM +0100, Sedat Dilek wrote:
>> Hi,
>>
>> I see the following...
>>
>> $ yes "" | make oldconfig && make silentoldconfig </dev/null
>>   HOSTCC  scripts/basic/fixdep
>>   HOSTCC  scripts/kconfig/conf.o
>>   SHIPPED scripts/kconfig/zconf.tab.c
>>   SHIPPED scripts/kconfig/zconf.lex.c
>>   SHIPPED scripts/kconfig/zconf.hash.c
>>   HOSTCC  scripts/kconfig/zconf.tab.o
>> In file included from scripts/kconfig/zconf.tab.c:2537:0:
>> scripts/kconfig/menu.c: In function ‘get_symbol_str’:
>> scripts/kconfig/menu.c:590:18: warning: ‘jump’ may be used
>> uninitialized in this function [-Wmaybe-uninitialized]
>>      jump->offset = strlen(r->s);
>>                   ^
>> scripts/kconfig/menu.c:551:19: note: ‘jump’ was declared here
>>   struct jump_key *jump;
>>                    ^
>>   HOSTLD  scripts/kconfig/conf
>> scripts/kconfig/conf --oldconfig Kconfig
>> #
>> # configuration written to .config
>> #
>> scripts/kconfig/conf --silentoldconfig Kconfig
>>
>> The fix is "kconfig: Fix warning "‘jump’ may be used uninitialized"" upstream.
>
>
> Sure, what's the git commit id of the patch in Linus's tree?  That's
> annoying to me as well, thanks for reminding me about it.
>

commit 2d560306096739e2251329ab5c16059311a151b0
kconfig: Fix warning "‘jump’ may be used uninitialized"

- Sedat -

Re: linux-3.18.y: Add "kconfig: Fix warning "‘jump’ may be used uninitialized""

[Sedat Dilek]

[-- Attachment #1: Type: text/plain, Size: 1966 bytes --]

On Fri, Feb 6, 2015 at 4:50 PM, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> On Fri, Feb 06, 2015 at 04:40:28PM +0100, Sedat Dilek wrote:
>> Hi,
>>
>> I see the following...
>>
>> $ yes "" | make oldconfig && make silentoldconfig </dev/null
>>   HOSTCC  scripts/basic/fixdep
>>   HOSTCC  scripts/kconfig/conf.o
>>   SHIPPED scripts/kconfig/zconf.tab.c
>>   SHIPPED scripts/kconfig/zconf.lex.c
>>   SHIPPED scripts/kconfig/zconf.hash.c
>>   HOSTCC  scripts/kconfig/zconf.tab.o
>> In file included from scripts/kconfig/zconf.tab.c:2537:0:
>> scripts/kconfig/menu.c: In function ‘get_symbol_str’:
>> scripts/kconfig/menu.c:590:18: warning: ‘jump’ may be used
>> uninitialized in this function [-Wmaybe-uninitialized]
>>      jump->offset = strlen(r->s);
>>                   ^
>> scripts/kconfig/menu.c:551:19: note: ‘jump’ was declared here
>>   struct jump_key *jump;
>>                    ^
>>   HOSTLD  scripts/kconfig/conf
>> scripts/kconfig/conf --oldconfig Kconfig
>> #
>> # configuration written to .config
>> #
>> scripts/kconfig/conf --silentoldconfig Kconfig
>>
>> The fix is "kconfig: Fix warning "‘jump’ may be used uninitialized"" upstream.
>
>
> Sure, what's the git commit id of the patch in Linus's tree?  That's
> annoying to me as well, thanks for reminding me about it.
>

Yesterday, I played with llvmlinux and this patch is also required for
Linux v3.10.y.

Checking for "Peter Kümmel" shows no hits.

commit 2d560306096739e2251329ab5c16059311a151b0 upstream
"kconfig: Fix warning "‘jump’ may be used uninitialized""

The patch needs some adaptation to fit.

Unfortunately, I cannot add a "3.10" to the subject-line as it is
"UTF-8-truncated" (see attached file).

Shall I resend w/ all CCs and how can I fix the subject-line?

- Sedat -

[1] http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/log/?h=linux-3.10.y&qt=grep&q=Peter+K%C3%BCmmel

[-- Attachment #2: 0001-kconfig-Fix-warning-jump-may-be-used-uninitialized-3.10.patch --]
[-- Type: text/x-diff, Size: 1859 bytes --]

From 683b07dc2061ca8d4086d3480ca86cc9dad892c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Peter=20K=C3=BCmmel?= <syntheticpp@gmx.net>
Date: Tue, 4 Nov 2014 12:01:59 +0100
Subject: [PATCH] =?UTF-8?q?kconfig:=20Fix=20warning=20"=E2=80=98jump?=
 =?UTF-8?q?=E2=80=99=20may=20be=20used=20uninitialized"?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Warning:
In file included from scripts/kconfig/zconf.tab.c:2537:0:
scripts/kconfig/menu.c: In function ‘get_symbol_str’:
scripts/kconfig/menu.c:590:18: warning: ‘jump’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     jump->offset = strlen(r->s);

Simplifies the test logic because (head && local) means (jump != 0)
and makes GCC happy when checking if the jump pointer was initialized.

Signed-off-by: Peter Kümmel <syntheticpp@gmx.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
---
[ dileks: v2: Backported to fit v3.10 ]

 scripts/kconfig/menu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index fd3f0180e08f..6af1c42a9cf3 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -525,7 +525,7 @@ static void get_prompt_str(struct gstr *r, struct property *prop,
 {
 	int i, j;
 	struct menu *submenu[8], *menu, *location = NULL;
-	struct jump_key *jump;
+	struct jump_key *jump = NULL;
 
 	str_printf(r, _("Prompt: %s\n"), _(prop->text));
 	menu = prop->menu->parent;
@@ -563,7 +563,7 @@ static void get_prompt_str(struct gstr *r, struct property *prop,
 		str_printf(r, _("  Location:\n"));
 		for (j = 4; --i >= 0; j += 2) {
 			menu = submenu[i];
-			if (head && location && menu == location)
+			if (jump && menu == location)
 				jump->offset = r->len - 1;
 			str_printf(r, "%*c-> %s", j, ' ',
 				   _(menu_get_prompt(menu)));
-- 
2.3.1