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Subject: [RFC] vsprintf: compile error on %09pK
Reply-To: jaewon31.kim@samsung.com
Sender: Jaewon Kim <jaewon31.kim@samsung.com>
From:   Jaewon Kim <jaewon31.kim@samsung.com>
To:     "pmladek@suse.com" <pmladek@suse.com>,
        "senozhatsky@chromium.org" <senozhatsky@chromium.org>
CC:     "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "jaewon31.kim@gmail.com" <jaewon31.kim@gmail.com>,
        GyeongHwan Hong <gh21.hong@samsung.com>
Message-ID: <20230403104617epcms1p383bacbca705c0d7e4fffca6833050e42@epcms1p3>
Date:   Mon, 03 Apr 2023 19:46:17 +0900
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Hello

I've just changed %09lx to %09pK on my driver code to hide the address, but=
 I
faced compiler error. The %9pK without 0 worked.

Is there restriction on %pK which does now allow %0 ? I've wondered whether=
 I
did wrong or it is a printk problem.

To show easily I tried to add pr_info(=22%09pK=5Cn=22, nodemask); in page_a=
lloc.c
Then here's what I did.

=24 ARCH=3Dx86 make x86_64_defconfig ; make mm/page_alloc.o
=23
=23 No change to .config
=23
  CALL    scripts/checksyscalls.sh
  DESCEND objtool
  INSTALL libsubcmd_headers
  CC      mm/page_alloc.o
In file included from ./include/asm-generic/bug.h:22:0,
                 from ./arch/x86/include/asm/bug.h:87,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/mmdebug.h:5,
                 from ./include/linux/mm.h:6,
                 from mm/page_alloc.c:19:
mm/page_alloc.c: In function =E2=80=98__alloc_pages=E2=80=99:=0D=0A./includ=
e/linux/kern_levels.h:5:18:=20error:=20'0'=20flag=20used=20with=20=E2=80=98=
%p=E2=80=99=20gnu_printf=20format=20=5B-Werror=3Dformat=3D=5D=0D=0A=20=23de=
fine=20KERN_SOH=20=22=5C001=22=20=20/*=20ASCII=20Start=20Of=20Header=20*/=
=0D=0A=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=5E=0D=0A./incl=
ude/linux/printk.h:427:11:=20note:=20in=20definition=20of=20macro=20=E2=80=
=98printk_index_wrap=E2=80=99=0D=0A=20=20=20_p_func(_fmt,=20=23=23__VA_ARGS=
__);=20=20=20=20=5C=0D=0A=20=20=20=20=20=20=20=20=20=20=20=5E=0D=0A./includ=
e/linux/printk.h:528:2:=20note:=20in=20expansion=20of=20macro=20=E2=80=98pr=
intk=E2=80=99=0D=0A=20=20printk(KERN_INFO=20pr_fmt(fmt),=20=23=23__VA_ARGS_=
_)=0D=0A=20=20=5E=0D=0A./include/linux/kern_levels.h:14:19:=20note:=20in=20=
expansion=20of=20macro=20=E2=80=98KERN_SOH=E2=80=99=0D=0A=20=23define=20KER=
N_INFO=20KERN_SOH=20=226=22=20/*=20informational=20*/=0D=0A=20=20=20=20=20=
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=5E=0D=0A./include/linux/printk.h=
:528:9:=20note:=20in=20expansion=20of=20macro=20=E2=80=98KERN_INFO=E2=80=99=
=0D=0A=20=20printk(KERN_INFO=20pr_fmt(fmt),=20=23=23__VA_ARGS__)=0D=0A=20=
=20=20=20=20=20=20=20=20=5E=0D=0Amm/page_alloc.c:5564:2:=20note:=20in=20exp=
ansion=20of=20macro=20=E2=80=98pr_info=E2=80=99=0D=0A=20=20pr_info(=22%09pK=
=5Cn=22,=20nodemask);=0D=0A=20=20=5E=0D=0A=0D=0AJaewon=20Kim