diff mbox

[v3,1/2] tty: add compat_ioctl callbacks

Message ID 20170603135111.5444-2-asarai@suse.de (mailing list archive)
State New, archived
Headers show

Commit Message

Aleksa Sarai June 3, 2017, 1:51 p.m. UTC
In order to avoid future diversions between fs/compat_ioctl.c and
drivers/tty/pty.c, define .compat_ioctl callbacks for the relevant
tty_operations structs. Since both pty_unix98_ioctl() and
pty_bsd_ioctl() are compatible between 32-bit and 64-bit userspace no
special translation is required.

Signed-off-by: Aleksa Sarai <asarai@suse.de>
---
 Makefile          |  1 +
 drivers/tty/pty.c | 22 ++++++++++++++++++++++
 fs/compat_ioctl.c |  6 ------
 3 files changed, 23 insertions(+), 6 deletions(-)

Comments

Aleksa Sarai June 3, 2017, 2:13 p.m. UTC | #1
> diff --git a/Makefile b/Makefile
> index 470bd4d9513a..fb689286d83a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -401,6 +401,7 @@ KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
>   		   -fno-strict-aliasing -fno-common \
>   		   -Werror-implicit-function-declaration \
>   		   -Wno-format-security \
> +		   -Wno-error=int-in-bool-context \
>   		   -std=gnu89 $(call cc-option,-fno-PIE)


Ah sorry, I committed that by accident. I'll send a fixed version.
kernel test robot June 3, 2017, 2:16 p.m. UTC | #2
Hi Aleksa,

[auto build test WARNING on linus/master]
[also build test WARNING on v4.12-rc3 next-20170602]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Aleksa-Sarai/tty-add-TIOCGPTPEER-ioctl/20170603-220322
config: i386-randconfig-x018-201722 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All warnings (new ones prefixed by >>):

>> cc1: warning: -malign-functions is obsolete, use -falign-functions
>> cc1: warning: -malign-jumps is obsolete, use -falign-jumps
>> cc1: warning: -malign-loops is obsolete, use -falign-loops
   cc1: error: -Werror=int-in-bool-context: no option -Wint-in-bool-context
   kernel/bounds.c:1:0: error: CPU you selected does not support x86-64 instruction set
    /*
    
   kernel/bounds.c:1:0: error: CPU you selected does not support x86-64 instruction set
   kernel/bounds.c:1:0: warning: -mregparm is ignored in 64-bit mode
   make[2]: *** [kernel/bounds.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [sub-make] Error 2

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kernel test robot June 3, 2017, 2:31 p.m. UTC | #3
Hi Aleksa,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.12-rc3 next-20170602]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Aleksa-Sarai/tty-add-TIOCGPTPEER-ioctl/20170603-220322
config: x86_64-randconfig-x010-201722 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

>> cc1: error: -Werror=int-in-bool-context: no option -Wint-in-bool-context
   make[2]: *** [kernel/bounds.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [sub-make] Error 2

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Arnd Bergmann June 6, 2017, 11:01 a.m. UTC | #4
On Sat, Jun 3, 2017 at 3:51 PM, Aleksa Sarai <asarai@suse.de> wrote:
> In order to avoid future diversions between fs/compat_ioctl.c and
> drivers/tty/pty.c, define .compat_ioctl callbacks for the relevant
> tty_operations structs. Since both pty_unix98_ioctl() and
> pty_bsd_ioctl() are compatible between 32-bit and 64-bit userspace no
> special translation is required.
>
> Signed-off-by: Aleksa Sarai <asarai@suse.de>
> ---
>  Makefile          |  1 +
>  drivers/tty/pty.c | 22 ++++++++++++++++++++++
>  fs/compat_ioctl.c |  6 ------
>  3 files changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 470bd4d9513a..fb689286d83a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -401,6 +401,7 @@ KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
>                    -fno-strict-aliasing -fno-common \
>                    -Werror-implicit-function-declaration \
>                    -Wno-format-security \
> +                  -Wno-error=int-in-bool-context \
>                    -std=gnu89 $(call cc-option,-fno-PIE)

This  slipped in by accident I assume? It seems completely unrelated.

> diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
> index 65799575c666..2a6bd9ae3f8b 100644
> --- a/drivers/tty/pty.c
> +++ b/drivers/tty/pty.c
> @@ -481,6 +481,16 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
>         return -ENOIOCTLCMD;
>  }
>
> +static long pty_bsd_compat_ioctl(struct tty_struct *tty,
> +                                unsigned int cmd, unsigned long arg)
> +{
> +       /*
> +        * PTY ioctls don't require any special translation between 32-bit and
> +        * 64-bit userspace, they are already compatible.
> +        */
> +       return pty_bsd_ioctl(tty, cmd, arg);
> +}
> +

This looks correct but unnecessary, you can simply point both
function pointers to the same function:

>   * not really modular, but the easiest way to keep compat with existing
> @@ -502,6 +512,7 @@ static const struct tty_operations master_pty_ops_bsd = {
>         .chars_in_buffer = pty_chars_in_buffer,
>         .unthrottle = pty_unthrottle,
>         .ioctl = pty_bsd_ioctl,
> +       .compat_ioctl = pty_bsd_compat_ioctl,

           .compat_ioctl = pty_bsd_ioctl,

The separate handler would only be required when you need any kind
of special handling depending on the command.

> diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
> index 6116d5275a3e..112b3e1e20e3 100644
> --- a/fs/compat_ioctl.c
> +++ b/fs/compat_ioctl.c
> @@ -866,8 +866,6 @@ COMPATIBLE_IOCTL(TIOCGDEV)
>  COMPATIBLE_IOCTL(TIOCCBRK)
>  COMPATIBLE_IOCTL(TIOCGSID)
>  COMPATIBLE_IOCTL(TIOCGICOUNT)
> -COMPATIBLE_IOCTL(TIOCGPKT)
> -COMPATIBLE_IOCTL(TIOCGPTLCK)
>  COMPATIBLE_IOCTL(TIOCGEXCL)
>  /* Little t */
>  COMPATIBLE_IOCTL(TIOCGETD)
> @@ -883,16 +881,12 @@ COMPATIBLE_IOCTL(TIOCMGET)
>  COMPATIBLE_IOCTL(TIOCMBIC)
>  COMPATIBLE_IOCTL(TIOCMBIS)
>  COMPATIBLE_IOCTL(TIOCMSET)
> -COMPATIBLE_IOCTL(TIOCPKT)
>  COMPATIBLE_IOCTL(TIOCNOTTY)
>  COMPATIBLE_IOCTL(TIOCSTI)
>  COMPATIBLE_IOCTL(TIOCOUTQ)
>  COMPATIBLE_IOCTL(TIOCSPGRP)
>  COMPATIBLE_IOCTL(TIOCGPGRP)
> -COMPATIBLE_IOCTL(TIOCGPTN)
> -COMPATIBLE_IOCTL(TIOCSPTLCK)
>  COMPATIBLE_IOCTL(TIOCSERGETLSR)
> -COMPATIBLE_IOCTL(TIOCSIG)

Looks good.

       Arnd
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Aleksa Sarai June 6, 2017, 11:05 a.m. UTC | #5
>> diff --git a/Makefile b/Makefile
>> index 470bd4d9513a..fb689286d83a 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -401,6 +401,7 @@ KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
>>                     -fno-strict-aliasing -fno-common \
>>                     -Werror-implicit-function-declaration \
>>                     -Wno-format-security \
>> +                  -Wno-error=int-in-bool-context \
>>                     -std=gnu89 $(call cc-option,-fno-PIE)
> 
> This  slipped in by accident I assume? It seems completely unrelated.

Yeah, I re-sent v4 with this removed immediately afterwards.

> 
>> diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
>> index 65799575c666..2a6bd9ae3f8b 100644
>> --- a/drivers/tty/pty.c
>> +++ b/drivers/tty/pty.c
>> @@ -481,6 +481,16 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
>>          return -ENOIOCTLCMD;
>>   }
>>
>> +static long pty_bsd_compat_ioctl(struct tty_struct *tty,
>> +                                unsigned int cmd, unsigned long arg)
>> +{
>> +       /*
>> +        * PTY ioctls don't require any special translation between 32-bit and
>> +        * 64-bit userspace, they are already compatible.
>> +        */
>> +       return pty_bsd_ioctl(tty, cmd, arg);
>> +}
>> +
> 
> This looks correct but unnecessary, you can simply point both
> function pointers to the same function:

They have different types, since they have different return types:

int  (*ioctl)(struct tty_struct *tty,
	    unsigned int cmd, unsigned long arg);
long (*compat_ioctl)(struct tty_struct *tty,
		     unsigned int cmd, unsigned long arg);

If you like, I can change (*ioctl) to return longs as well, and then 
change all of the call-sites (since unlocked_ioctl also returns long).
Arnd Bergmann June 6, 2017, 12:46 p.m. UTC | #6
On Tue, Jun 6, 2017 at 1:05 PM, Aleksa Sarai <asarai@suse.de> wrote:
>>> diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
>>> index 65799575c666..2a6bd9ae3f8b 100644
>>> --- a/drivers/tty/pty.c
>>> +++ b/drivers/tty/pty.c
>>> @@ -481,6 +481,16 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
>>>          return -ENOIOCTLCMD;
>>>   }
>>>
>>> +static long pty_bsd_compat_ioctl(struct tty_struct *tty,
>>> +                                unsigned int cmd, unsigned long arg)
>>> +{
>>> +       /*
>>> +        * PTY ioctls don't require any special translation between
>>> 32-bit and
>>> +        * 64-bit userspace, they are already compatible.
>>> +        */
>>> +       return pty_bsd_ioctl(tty, cmd, arg);
>>> +}
>>> +
>>
>>
>> This looks correct but unnecessary, you can simply point both
>> function pointers to the same function:
>
>
> They have different types, since they have different return types:
>
> int  (*ioctl)(struct tty_struct *tty,
>             unsigned int cmd, unsigned long arg);
> long (*compat_ioctl)(struct tty_struct *tty,
>                      unsigned int cmd, unsigned long arg);
>
> If you like, I can change (*ioctl) to return longs as well, and then change
> all of the call-sites (since unlocked_ioctl also returns long).

Ah, my mistake. In most other data structures that have a compat_ioctl
callback pointer, the prototypes are the same, and I had not realized
that tty_operations is an exception.

        Arnd
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diff mbox

Patch

diff --git a/Makefile b/Makefile
index 470bd4d9513a..fb689286d83a 100644
--- a/Makefile
+++ b/Makefile
@@ -401,6 +401,7 @@  KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 		   -fno-strict-aliasing -fno-common \
 		   -Werror-implicit-function-declaration \
 		   -Wno-format-security \
+		   -Wno-error=int-in-bool-context \
 		   -std=gnu89 $(call cc-option,-fno-PIE)
 
 
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 65799575c666..2a6bd9ae3f8b 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -481,6 +481,16 @@  static int pty_bsd_ioctl(struct tty_struct *tty,
 	return -ENOIOCTLCMD;
 }
 
+static long pty_bsd_compat_ioctl(struct tty_struct *tty,
+				 unsigned int cmd, unsigned long arg)
+{
+	/*
+	 * PTY ioctls don't require any special translation between 32-bit and
+	 * 64-bit userspace, they are already compatible.
+	 */
+	return pty_bsd_ioctl(tty, cmd, arg);
+}
+
 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
 /*
  * not really modular, but the easiest way to keep compat with existing
@@ -502,6 +512,7 @@  static const struct tty_operations master_pty_ops_bsd = {
 	.chars_in_buffer = pty_chars_in_buffer,
 	.unthrottle = pty_unthrottle,
 	.ioctl = pty_bsd_ioctl,
+	.compat_ioctl = pty_bsd_compat_ioctl,
 	.cleanup = pty_cleanup,
 	.resize = pty_resize,
 	.remove = pty_remove
@@ -609,6 +620,16 @@  static int pty_unix98_ioctl(struct tty_struct *tty,
 	return -ENOIOCTLCMD;
 }
 
+static long pty_unix98_compat_ioctl(struct tty_struct *tty,
+				 unsigned int cmd, unsigned long arg)
+{
+	/*
+	 * PTY ioctls don't require any special translation between 32-bit and
+	 * 64-bit userspace, they are already compatible.
+	 */
+	return pty_unix98_ioctl(tty, cmd, arg);
+}
+
 /**
  *	ptm_unix98_lookup	-	find a pty master
  *	@driver: ptm driver
@@ -681,6 +702,7 @@  static const struct tty_operations ptm_unix98_ops = {
 	.chars_in_buffer = pty_chars_in_buffer,
 	.unthrottle = pty_unthrottle,
 	.ioctl = pty_unix98_ioctl,
+	.compat_ioctl = pty_unix98_compat_ioctl,
 	.resize = pty_resize,
 	.cleanup = pty_cleanup
 };
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 6116d5275a3e..112b3e1e20e3 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -866,8 +866,6 @@  COMPATIBLE_IOCTL(TIOCGDEV)
 COMPATIBLE_IOCTL(TIOCCBRK)
 COMPATIBLE_IOCTL(TIOCGSID)
 COMPATIBLE_IOCTL(TIOCGICOUNT)
-COMPATIBLE_IOCTL(TIOCGPKT)
-COMPATIBLE_IOCTL(TIOCGPTLCK)
 COMPATIBLE_IOCTL(TIOCGEXCL)
 /* Little t */
 COMPATIBLE_IOCTL(TIOCGETD)
@@ -883,16 +881,12 @@  COMPATIBLE_IOCTL(TIOCMGET)
 COMPATIBLE_IOCTL(TIOCMBIC)
 COMPATIBLE_IOCTL(TIOCMBIS)
 COMPATIBLE_IOCTL(TIOCMSET)
-COMPATIBLE_IOCTL(TIOCPKT)
 COMPATIBLE_IOCTL(TIOCNOTTY)
 COMPATIBLE_IOCTL(TIOCSTI)
 COMPATIBLE_IOCTL(TIOCOUTQ)
 COMPATIBLE_IOCTL(TIOCSPGRP)
 COMPATIBLE_IOCTL(TIOCGPGRP)
-COMPATIBLE_IOCTL(TIOCGPTN)
-COMPATIBLE_IOCTL(TIOCSPTLCK)
 COMPATIBLE_IOCTL(TIOCSERGETLSR)
-COMPATIBLE_IOCTL(TIOCSIG)
 #ifdef TIOCSRS485
 COMPATIBLE_IOCTL(TIOCSRS485)
 #endif