diff mbox series

[v2,4/4] btrfs: assert sizes of ioctl structures

Message ID 20200713122901.1773-5-johannes.thumshirn@wdc.com (mailing list archive)
State New, archived
Headers show
Series Two furhter additions for fsinfo ioctl | expand

Commit Message

Johannes Thumshirn July 13, 2020, 12:29 p.m. UTC 
When expanding ioctl interfaces we want to make sure we're not changing
the size of the structures, otherwise it can lead to incorrect transfers
between kernel and user-space.

Build time assert the size of each structure so we're not running into any
incompatibilities.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 include/uapi/linux/btrfs.h | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

Comments

David Sterba July 13, 2020, 2:58 p.m. UTC | #1 
On Mon, Jul 13, 2020 at 09:29:01PM +0900, Johannes Thumshirn wrote:
> When expanding ioctl interfaces we want to make sure we're not changing
> the size of the structures, otherwise it can lead to incorrect transfers
> between kernel and user-space.
> 
> Build time assert the size of each structure so we're not running into any
> incompatibilities.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

The structure size is ABI once it's part of the ioctl defintion, ie. in
any of the _IOWR/_IOR/_IOW macros. I don't see the assert added for
btrfs_ioctl_vol_args_v2 or btrfs_ioctl_quota_rescan_args and I haven't
checked all.

Can you please add the static asserts for all of them? The file ioctl.h
in progs should have that already so you can copy or cross-verify from
there.

I'll merge the patches 1-3 now.
Johannes Thumshirn July 13, 2020, 4:13 p.m. UTC | #2 
On 13/07/2020 16:58, David Sterba wrote:
> On Mon, Jul 13, 2020 at 09:29:01PM +0900, Johannes Thumshirn wrote:
>> When expanding ioctl interfaces we want to make sure we're not changing
>> the size of the structures, otherwise it can lead to incorrect transfers
>> between kernel and user-space.
>>
>> Build time assert the size of each structure so we're not running into any
>> incompatibilities.
>>
>> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> 
> The structure size is ABI once it's part of the ioctl defintion, ie. in
> any of the _IOWR/_IOR/_IOW macros. I don't see the assert added for
> btrfs_ioctl_vol_args_v2 or btrfs_ioctl_quota_rescan_args and I haven't
> checked all.
> 
> Can you please add the static asserts for all of them? The file ioctl.h
> in progs should have that already so you can copy or cross-verify from
> there.

OK will do.

> I'll merge the patches 1-3 now.
>
kernel test robot July 13, 2020, 9:01 p.m. UTC | #3 
Hi Johannes,

I love your patch! Yet something to improve:

[auto build test ERROR on v5.8-rc5]
[cannot apply to kdave/for-next btrfs/next next-20200713]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Johannes-Thumshirn/Two-furhter-additions-for-fsinfo-ioctl/20200713-203321
base:    11ba468877bb23f28956a35e896356252d63c983
config: x86_64-randconfig-a016-20200713 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 02946de3802d3bc65bc9f2eb9b8d4969b5a7add8)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   In file included from <built-in>:1:
   In file included from ./usr/include/linux/btrfs_tree.h:5:
>> ./usr/include/linux/btrfs.h:35:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_vol_args) == 4096);
                 ^
>> ./usr/include/linux/btrfs.h:35:15: error: expected ')'
   ./usr/include/linux/btrfs.h:35:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_vol_args) == 4096);
                ^
>> ./usr/include/linux/btrfs.h:35:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_vol_args) == 4096);
   ^
   int
   ./usr/include/linux/btrfs.h:192:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_scrub_args) == 1024);
                 ^
   ./usr/include/linux/btrfs.h:192:15: error: expected ')'
   ./usr/include/linux/btrfs.h:192:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_scrub_args) == 1024);
                ^
   ./usr/include/linux/btrfs.h:192:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_scrub_args) == 1024);
   ^
   int
   ./usr/include/linux/btrfs.h:245:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_dev_info_args) == 4096);
                 ^
   ./usr/include/linux/btrfs.h:245:15: error: expected ')'
   ./usr/include/linux/btrfs.h:245:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_dev_info_args) == 4096);
                ^
   ./usr/include/linux/btrfs.h:245:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_dev_info_args) == 4096);
   ^
   int
   ./usr/include/linux/btrfs.h:274:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_fs_info_args) == 1024);
                 ^
   ./usr/include/linux/btrfs.h:274:15: error: expected ')'
   ./usr/include/linux/btrfs.h:274:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_fs_info_args) == 1024);
                ^
   ./usr/include/linux/btrfs.h:274:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_fs_info_args) == 1024);
   ^
   int
   ./usr/include/linux/btrfs.h:457:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_balance_args) == 1024);
                 ^
   ./usr/include/linux/btrfs.h:457:15: error: expected ')'
   ./usr/include/linux/btrfs.h:457:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_balance_args) == 1024);
                ^
   ./usr/include/linux/btrfs.h:457:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_balance_args) == 1024);
   ^
   int
   ./usr/include/linux/btrfs.h:465:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_ino_lookup_args) == 4096);
                 ^
   ./usr/include/linux/btrfs.h:465:15: error: expected ')'
   ./usr/include/linux/btrfs.h:465:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_ino_lookup_args) == 4096);
                ^
   ./usr/include/linux/btrfs.h:465:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_ino_lookup_args) == 4096);
   ^
   int
   ./usr/include/linux/btrfs.h:481:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_ino_lookup_user_args) == 4096);
                 ^
   ./usr/include/linux/btrfs.h:481:15: error: expected ')'
   ./usr/include/linux/btrfs.h:481:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_ino_lookup_user_args) == 4096);
                ^
   ./usr/include/linux/btrfs.h:481:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_ino_lookup_user_args) == 4096);
   ^
   int
   ./usr/include/linux/btrfs.h:560:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_search_args) == 4096);
                 ^
   ./usr/include/linux/btrfs.h:560:15: error: expected ')'
   ./usr/include/linux/btrfs.h:560:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_search_args) == 4096);
                ^
   ./usr/include/linux/btrfs.h:560:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_search_args) == 4096);
   ^
   int
   ./usr/include/linux/btrfs.h:718:15: error: expected parameter declarator
   static_assert(sizeof(struct btrfs_ioctl_get_dev_stats) == 1032);
                 ^
   ./usr/include/linux/btrfs.h:718:15: error: expected ')'
   ./usr/include/linux/btrfs.h:718:14: note: to match this '('
   static_assert(sizeof(struct btrfs_ioctl_get_dev_stats) == 1032);
                ^
   ./usr/include/linux/btrfs.h:718:1: warning: declaration specifier missing, defaulting to 'int'
   static_assert(sizeof(struct btrfs_ioctl_get_dev_stats) == 1032);
   ^
   int
   9 warnings and 18 errors generated.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
David Sterba July 14, 2020, 11:20 a.m. UTC | #4 
On Tue, Jul 14, 2020 at 05:01:21AM +0800, kernel test robot wrote:
> Hi Johannes,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on v5.8-rc5]
> [cannot apply to kdave/for-next btrfs/next next-20200713]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use  as documented in
> https://git-scm.com/docs/git-format-patch]
> 
> url:    https://github.com/0day-ci/linux/commits/Johannes-Thumshirn/Two-furhter-additions-for-fsinfo-ioctl/20200713-203321
> base:    11ba468877bb23f28956a35e896356252d63c983
> config: x86_64-randconfig-a016-20200713 (attached as .config)
> compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 02946de3802d3bc65bc9f2eb9b8d4969b5a7add8)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install x86_64 cross compiling tool for clang build
>         # apt-get install binutils-x86-64-linux-gnu
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All error/warnings (new ones prefixed by >>):
> 
>    In file included from <built-in>:1:
>    In file included from ./usr/include/linux/btrfs_tree.h:5:
> >> ./usr/include/linux/btrfs.h:35:15: error: expected parameter declarator
>    static_assert(sizeof(struct btrfs_ioctl_vol_args) == 4096);
>                  ^

Does that mean that clang (11.0) does not support static_assert? We
aren't doing anything special here, include only the standard kernel
headers and use macros as intended.
David Sterba July 14, 2020, 11:23 a.m. UTC | #5 
On Tue, Jul 14, 2020 at 01:20:53PM +0200, David Sterba wrote:
> On Tue, Jul 14, 2020 at 05:01:21AM +0800, kernel test robot wrote:
> > Hi Johannes,
> > 
> > I love your patch! Yet something to improve:
> > 
> > [auto build test ERROR on v5.8-rc5]
> > [cannot apply to kdave/for-next btrfs/next next-20200713]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use  as documented in
> > https://git-scm.com/docs/git-format-patch]
> > 
> > url:    https://github.com/0day-ci/linux/commits/Johannes-Thumshirn/Two-furhter-additions-for-fsinfo-ioctl/20200713-203321
> > base:    11ba468877bb23f28956a35e896356252d63c983
> > config: x86_64-randconfig-a016-20200713 (attached as .config)
> > compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 02946de3802d3bc65bc9f2eb9b8d4969b5a7add8)
> > reproduce (this is a W=1 build):
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # install x86_64 cross compiling tool for clang build
> >         # apt-get install binutils-x86-64-linux-gnu
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 
> > 
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> > 
> > All error/warnings (new ones prefixed by >>):
> > 
> >    In file included from <built-in>:1:
> >    In file included from ./usr/include/linux/btrfs_tree.h:5:
> > >> ./usr/include/linux/btrfs.h:35:15: error: expected parameter declarator
> >    static_assert(sizeof(struct btrfs_ioctl_vol_args) == 4096);
> >                  ^
> 
> Does that mean that clang (11.0) does not support static_assert? We
> aren't doing anything special here, include only the standard kernel
> headers and use macros as intended.

Never mind, Johanness fixed it in v2, the macro is not defined for
non-kernel build.
diff mbox series

Patch

diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 69b88f6cb57f..d3c363398e10 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -32,6 +32,7 @@  struct btrfs_ioctl_vol_args {
 	__s64 fd;
 	char name[BTRFS_PATH_NAME_MAX + 1];
 };
+static_assert(sizeof(struct btrfs_ioctl_vol_args) == 4096);
 
 #define BTRFS_DEVICE_PATH_NAME_MAX	1024
 #define BTRFS_SUBVOL_NAME_MAX 		4039
@@ -190,6 +191,7 @@  struct btrfs_ioctl_scrub_args {
 	/* pad to 1k */
 	__u64 unused[(1024-32-sizeof(struct btrfs_scrub_progress))/8];
 };
+static_assert(sizeof(struct btrfs_ioctl_scrub_args) == 1024);
 
 #define BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS	0
 #define BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID	1
@@ -242,6 +244,7 @@  struct btrfs_ioctl_dev_info_args {
 	__u64 unused[379];			/* pad to 4k */
 	__u8 path[BTRFS_DEVICE_PATH_NAME_MAX];	/* out */
 };
+static_assert(sizeof(struct btrfs_ioctl_dev_info_args) == 4096);
 
 /*
  * Retrieve information about the filesystem
@@ -270,7 +273,7 @@  struct btrfs_ioctl_fs_info_args {
 	__u8 metadata_uuid[BTRFS_FSID_SIZE];	/* out */
 	__u8 reserved[944];			/* pad to 1k */
 };
-
+static_assert(sizeof(struct btrfs_ioctl_fs_info_args) == 1024);
 
 /*
  * feature flags
@@ -453,6 +456,7 @@  struct btrfs_ioctl_balance_args {
 
 	__u64 unused[72];			/* pad to 1k */
 };
+static_assert(sizeof(struct btrfs_ioctl_balance_args) == 1024);
 
 #define BTRFS_INO_LOOKUP_PATH_MAX 4080
 struct btrfs_ioctl_ino_lookup_args {
@@ -460,6 +464,7 @@  struct btrfs_ioctl_ino_lookup_args {
 	__u64 objectid;
 	char name[BTRFS_INO_LOOKUP_PATH_MAX];
 };
+static_assert(sizeof(struct btrfs_ioctl_ino_lookup_args) == 4096);
 
 #define BTRFS_INO_LOOKUP_USER_PATH_MAX (4080 - BTRFS_VOL_NAME_MAX - 1)
 struct btrfs_ioctl_ino_lookup_user_args {
@@ -475,6 +480,7 @@  struct btrfs_ioctl_ino_lookup_user_args {
 	 */
 	char path[BTRFS_INO_LOOKUP_USER_PATH_MAX];
 };
+static_assert(sizeof(struct btrfs_ioctl_ino_lookup_user_args) == 4096);
 
 /* Search criteria for the btrfs SEARCH ioctl family. */
 struct btrfs_ioctl_search_key {
@@ -553,6 +559,7 @@  struct btrfs_ioctl_search_args {
 	struct btrfs_ioctl_search_key key;
 	char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
 };
+static_assert(sizeof(struct btrfs_ioctl_search_args) == 4096);
 
 struct btrfs_ioctl_search_args_v2 {
 	struct btrfs_ioctl_search_key key; /* in/out - search parameters */
@@ -710,6 +717,7 @@  struct btrfs_ioctl_get_dev_stats {
 	 */
 	__u64 unused[128 - 2 - BTRFS_DEV_STAT_VALUES_MAX];
 };
+static_assert(sizeof(struct btrfs_ioctl_get_dev_stats) == 1032);
 
 #define BTRFS_QUOTA_CTL_ENABLE	1
 #define BTRFS_QUOTA_CTL_DISABLE	2