[PATCH] x86/vdso: Use proper modifier for len's printf in extract

[PATCH] x86/vdso: Use proper modifier for len's printf in extract

[Jiri Slaby]

Commit 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO
functions") added a printf of len which is size_t. Compilers now
complain on 32b:
In file included from arch/x86/entry/vdso/vdso2c.c:162:
arch/x86/entry/vdso/vdso2c.h: In function 'extract64':
arch/x86/entry/vdso/vdso2c.h:38:52: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'}

So use proper modifier (%zu) for size_t.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Fixes: 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO functions")
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jethro Beekman <jethro@fortanix.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
---
 arch/x86/entry/vdso/vdso2c.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
index 1c7cfac7e64a..5264daa8859f 100644
--- a/arch/x86/entry/vdso/vdso2c.h
+++ b/arch/x86/entry/vdso/vdso2c.h
@@ -35,7 +35,7 @@ static void BITSFUNC(extract)(const unsigned char *data, size_t data_len,
 	if (offset + len > data_len)
 		fail("section to extract overruns input data");
 
-	fprintf(outfile, "static const unsigned char %s[%lu] = {", name, len);
+	fprintf(outfile, "static const unsigned char %s[%zu] = {", name, len);
 	BITSFUNC(copy)(outfile, data + offset, len);
 	fprintf(outfile, "\n};\n\n");
 }
-- 
2.30.1

Re: [PATCH] x86/vdso: Use proper modifier for len's printf in extract

[Jarkko Sakkinen]

On Wed, Mar 03, 2021 at 07:43:57AM +0100, Jiri Slaby wrote:
> Commit 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO
> functions") added a printf of len which is size_t. Compilers now
> complain on 32b:
> In file included from arch/x86/entry/vdso/vdso2c.c:162:
> arch/x86/entry/vdso/vdso2c.h: In function 'extract64':
> arch/x86/entry/vdso/vdso2c.h:38:52: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'}
> 
> So use proper modifier (%zu) for size_t.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Fixes: 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO functions")
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> Cc: Jarkko Sakkinen <jarkko@kernel.org>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Jethro Beekman <jethro@fortanix.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: x86@kernel.org


Acked-by: Jarkko Sakkinen <jarkko@kernel.org>

> ---
>  arch/x86/entry/vdso/vdso2c.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
> index 1c7cfac7e64a..5264daa8859f 100644
> --- a/arch/x86/entry/vdso/vdso2c.h
> +++ b/arch/x86/entry/vdso/vdso2c.h
> @@ -35,7 +35,7 @@ static void BITSFUNC(extract)(const unsigned char *data, size_t data_len,
>  	if (offset + len > data_len)
>  		fail("section to extract overruns input data");
>  
> -	fprintf(outfile, "static const unsigned char %s[%lu] = {", name, len);
> +	fprintf(outfile, "static const unsigned char %s[%zu] = {", name, len);
>  	BITSFUNC(copy)(outfile, data + offset, len);
>  	fprintf(outfile, "\n};\n\n");
>  }
> -- 
> 2.30.1
> 
> 

/Jarkko

Re: [PATCH] x86/vdso: Use proper modifier for len's printf in extract

[Borislav Petkov]

On Wed, Mar 03, 2021 at 07:43:57AM +0100, Jiri Slaby wrote:
> Commit 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO
> functions") added a printf of len which is size_t. Compilers now
> complain on 32b:
> In file included from arch/x86/entry/vdso/vdso2c.c:162:
> arch/x86/entry/vdso/vdso2c.h: In function 'extract64':
> arch/x86/entry/vdso/vdso2c.h:38:52: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'}
> 

I know it is obvious but how do you trigger this?

A 32-bit allmodconfig with both debian's gcc-10 and leap15's gcc-7 don't
trigger that warning. Which might answer your question why I haven't
caught it yet. :-)

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

Re: [PATCH] x86/vdso: Use proper modifier for len's printf in extract

[Jiri Slaby]

On 03. 03. 21, 19:36, Borislav Petkov wrote:
> On Wed, Mar 03, 2021 at 07:43:57AM +0100, Jiri Slaby wrote:
>> Commit 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO
>> functions") added a printf of len which is size_t. Compilers now
>> complain on 32b:
>> In file included from arch/x86/entry/vdso/vdso2c.c:162:
>> arch/x86/entry/vdso/vdso2c.h: In function 'extract64':
>> arch/x86/entry/vdso/vdso2c.h:38:52: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'}
>>
> 
> I know it is obvious but how do you trigger this?
> 
> A 32-bit allmodconfig with both debian's gcc-10 and leap15's gcc-7 don't
> trigger that warning. Which might answer your question why I haven't
> caught it yet. :-)

It was caught by suse's build bot while merging the stable branch. But 
it can be also seen in OBS in Kernel:stable:

https://build.opensuse.org/public/build/Kernel:stable/standard/i586/kernel-pae/_log
https://build.opensuse.org/public/build/Kernel:stable/standard/i586/kernel-vanilla/_log

It's built with gcc 10 from tumbleweed and it's a standard config from 
kerncvs:
https://github.com/openSUSE/kernel-source/blob/stable/config/i386/pae

thanks,
-- 
js
suse labs

Re: [PATCH] x86/vdso: Use proper modifier for len's printf in extract

[Borislav Petkov]

On Thu, Mar 04, 2021 at 06:18:25AM +0100, Jiri Slaby wrote:
> It's built with gcc 10 from tumbleweed and it's a standard config from
> kerncvs:
> https://github.com/openSUSE/kernel-source/blob/stable/config/i386/pae

Nope, can't trigger with that one either. :-\

Anyway, it is obvious enough so applied.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

[tip: x86/vdso] x86/vdso: Use proper modifier for len's format specifier in extract()

[tip-bot2 for Jiri Slaby]

The following commit has been merged into the x86/vdso branch of tip:

Commit-ID:     6bdbe1760651484b0fe6f6d0cc3a2fe8741e6f87
Gitweb:        https://git.kernel.org/tip/6bdbe1760651484b0fe6f6d0cc3a2fe8741e6f87
Author:        Jiri Slaby <jslaby@suse.cz>
AuthorDate:    Wed, 03 Mar 2021 07:43:57 +01:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 04 Mar 2021 11:47:01 +01:00

x86/vdso: Use proper modifier for len's format specifier in extract()

Commit

  8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO functions")

prints length "len" which is size_t. Compilers now complain on 32-bit:

  In file included from arch/x86/entry/vdso/vdso2c.c:162:
  arch/x86/entry/vdso/vdso2c.h: In function 'extract64':
  arch/x86/entry/vdso/vdso2c.h:38:52: warning: format '%lu' expects argument of \
	type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'}

So use proper modifier (%zu) for size_t.

 [ bp: Massage commit message. ]

Fixes: 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO functions")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20210303064357.17056-1-jslaby@suse.cz
---
 arch/x86/entry/vdso/vdso2c.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
index 1c7cfac..5264daa 100644
--- a/arch/x86/entry/vdso/vdso2c.h
+++ b/arch/x86/entry/vdso/vdso2c.h
@@ -35,7 +35,7 @@ static void BITSFUNC(extract)(const unsigned char *data, size_t data_len,
 	if (offset + len > data_len)
 		fail("section to extract overruns input data");
 
-	fprintf(outfile, "static const unsigned char %s[%lu] = {", name, len);
+	fprintf(outfile, "static const unsigned char %s[%zu] = {", name, len);
 	BITSFUNC(copy)(outfile, data + offset, len);
 	fprintf(outfile, "\n};\n\n");
 }

Re: [PATCH] x86/vdso: Use proper modifier for len's printf in extract

[Jiri Slaby]

On 04. 03. 21, 11:48, Borislav Petkov wrote:
> On Thu, Mar 04, 2021 at 06:18:25AM +0100, Jiri Slaby wrote:
>> It's built with gcc 10 from tumbleweed and it's a standard config from
>> kerncvs:
>> https://github.com/openSUSE/kernel-source/blob/stable/config/i386/pae
> 
> Nope, can't trigger with that one either. :-\

Beware:
HOSTCC  arch/x86/entry/vdso/vdso2c
^^^^^^
You would need to _be_ on i586. Or try with -m32:

> gcc -m32 -Wp,-MMD,arch/x86/entry/vdso/.vdso2c.d -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89     -I/dev/shm/jslaby/linux/tools/include -I/dev/shm/jslaby/linux/include/uapi -I/dev/shm/jslaby/linux/arch/i386/include/uapi  -I ./arch/x86/entry/vdso   -o /dev/null /dev/shm/jslaby/linux/arch/x86/entry/vdso/vdso2c.c
> In file included from /dev/shm/jslaby/linux/arch/x86/entry/vdso/vdso2c.c:162:0:
> /dev/shm/jslaby/linux/arch/x86/entry/vdso/vdso2c.h: In function ‘extract64’:
> /dev/shm/jslaby/linux/arch/x86/entry/vdso/vdso2c.h:38:52: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘size_t {aka unsigned int}’ [-Wformat=]
>   fprintf(outfile, "static const unsigned char %s[%lu] = {", name, len);
>                                                   ~~^
>                                                   %u
> In file included from /dev/shm/jslaby/linux/arch/x86/entry/vdso/vdso2c.c:166:0:
> /dev/shm/jslaby/linux/arch/x86/entry/vdso/vdso2c.h: In function ‘extract32’:
> /dev/shm/jslaby/linux/arch/x86/entry/vdso/vdso2c.h:38:52: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘size_t {aka unsigned int}’ [-Wformat=]
>   fprintf(outfile, "static const unsigned char %s[%lu] = {", name, len);
>                                                   ~~^
>                                                   %u

regards,
-- 
js
suse labs

Re: [PATCH] x86/vdso: Use proper modifier for len's printf in extract

[Borislav Petkov]

On Thu, Mar 04, 2021 at 11:55:18AM +0100, Jiri Slaby wrote:
> On 04. 03. 21, 11:48, Borislav Petkov wrote:
> > On Thu, Mar 04, 2021 at 06:18:25AM +0100, Jiri Slaby wrote:
> > > It's built with gcc 10 from tumbleweed and it's a standard config from
> > > kerncvs:
> > > https://github.com/openSUSE/kernel-source/blob/stable/config/i386/pae
> > 
> > Nope, can't trigger with that one either. :-\
> 
> Beware:
> HOSTCC  arch/x86/entry/vdso/vdso2c
> ^^^^^^
> You would need to _be_ on i586. Or try with -m32:

Yah, that is the explanation. I would've never seen because - although I
do the regular 32-bit builds - I don't do them on a 32-bit platform. But
hey, OBS does. :)

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

[tip: x86/vdso] x86/vdso: Use proper modifier for len's format specifier in extract()

[tip-bot2 for Jiri Slaby]

The following commit has been merged into the x86/vdso branch of tip:

Commit-ID:     70c9d959226b7c5c48c119e2c1cfc1424f87b023
Gitweb:        https://git.kernel.org/tip/70c9d959226b7c5c48c119e2c1cfc1424f87b023
Author:        Jiri Slaby <jslaby@suse.cz>
AuthorDate:    Wed, 03 Mar 2021 07:43:57 +01:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Sat, 06 Mar 2021 11:34:07 +01:00

x86/vdso: Use proper modifier for len's format specifier in extract()

Commit

  8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO functions")

prints length "len" which is size_t.

Compilers now complain when building on a 32-bit host:

  HOSTCC  arch/x86/entry/vdso/vdso2c
  ...
  In file included from arch/x86/entry/vdso/vdso2c.c:162:
  arch/x86/entry/vdso/vdso2c.h: In function 'extract64':
  arch/x86/entry/vdso/vdso2c.h:38:52: warning: format '%lu' expects argument of \
	type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'}

So use proper modifier (%zu) for size_t.

 [ bp: Massage commit message. ]

Fixes: 8382c668ce4f ("x86/vdso: Add support for exception fixup in vDSO functions")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20210303064357.17056-1-jslaby@suse.cz
---
 arch/x86/entry/vdso/vdso2c.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
index 1c7cfac..5264daa 100644
--- a/arch/x86/entry/vdso/vdso2c.h
+++ b/arch/x86/entry/vdso/vdso2c.h
@@ -35,7 +35,7 @@ static void BITSFUNC(extract)(const unsigned char *data, size_t data_len,
 	if (offset + len > data_len)
 		fail("section to extract overruns input data");
 
-	fprintf(outfile, "static const unsigned char %s[%lu] = {", name, len);
+	fprintf(outfile, "static const unsigned char %s[%zu] = {", name, len);
 	BITSFUNC(copy)(outfile, data + offset, len);
 	fprintf(outfile, "\n};\n\n");
 }