diff mbox series

net/802: use struct_size over open coded arithmetic

Message ID 20220128080541.1211668-1-chi.minghao@zte.com.cn (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net/802: use struct_size over open coded arithmetic | expand

Checks

Context Check Description
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 8 this patch: 15
netdev/cc_maintainers warning 1 maintainers not CCed: yangyingliang@huawei.com
netdev/build_clang fail Errors and warnings before: 0 this patch: 17
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 8 this patch: 15
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

CGEL Jan. 28, 2022, 8:05 a.m. UTC 
From: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>

Replace zero-length array with flexible-array member and make use
of the struct_size() helper in kmalloc(). For example:

struct garp_attr {
	struct rb_node			node;
	enum garp_applicant_state	state;
	u8				type;
	u8				dlen;
	unsigned char			data[];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
---
 net/802/garp.c | 2 +-
 net/802/mrp.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Comments

kernel test robot Jan. 28, 2022, 12:40 p.m. UTC | #1 
Hi,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]
[also build test ERROR on net/master horms-ipvs/master linus/master v5.17-rc1 next-20220128]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/cgel-zte-gmail-com/net-802-use-struct_size-over-open-coded-arithmetic/20220128-160925
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 72d044e4bfa6bd9096536e2e1c62aecfe1a525e4
config: riscv-randconfig-r042-20220124 (https://download.01.org/0day-ci/archive/20220128/202201282017.0TQvVTtf-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 33b45ee44b1f32ffdbc995e6fec806271b4b3ba4)
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 riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/9b64e5078d3d779fc56432d43129479f63996c74
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review cgel-zte-gmail-com/net-802-use-struct_size-over-open-coded-arithmetic/20220128-160925
        git checkout 9b64e5078d3d779fc56432d43129479f63996c74
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/net/wireless/ath/wcn36xx/ net/802/

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

All errors (new ones prefixed by >>):

>> net/802/garp.c:187:17: error: member reference type 'struct garp_attr' is not a pointer; did you mean to use '.'?
           attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:18: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                               ~~~^
>> net/802/garp.c:187:17: error: indirection requires pointer operand ('unsigned char[]' invalid)
           attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:14: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                              ^~~~~~~~~~~~
>> net/802/garp.c:187:17: error: member reference type 'struct garp_attr' is not a pointer; did you mean to use '.'?
           attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:49: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                                              ~~~~~~~~~~~~~~~~~~~^~~~~~~~~
   include/linux/compiler.h:258:59: note: expanded from macro '__must_be_array'
   #define __must_be_array(a)      BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
   include/linux/compiler_types.h:287:63: note: expanded from macro '__same_type'
   #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
                                                                 ^
   include/linux/build_bug.h:16:62: note: expanded from macro 'BUILD_BUG_ON_ZERO'
   #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
                                                                ^
>> net/802/garp.c:187:17: error: member reference type 'struct garp_attr' is not a pointer; did you mean to use '.'?
           attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:49: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                                              ~~~~~~~~~~~~~~~~~~~^~~~~~~~~
   include/linux/compiler.h:258:65: note: expanded from macro '__must_be_array'
   #define __must_be_array(a)      BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
   include/linux/compiler_types.h:287:74: note: expanded from macro '__same_type'
   #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
                                                                            ^
   include/linux/build_bug.h:16:62: note: expanded from macro 'BUILD_BUG_ON_ZERO'
   #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
                                                                ^
>> net/802/garp.c:187:17: error: indirection requires pointer operand ('struct garp_attr' invalid)
           attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:195:14: note: expanded from macro 'struct_size'
                       sizeof(*(p)))
                              ^~~~
   5 errors generated.
--
>> net/802/mrp.c:276:17: error: member reference type 'struct mrp_attr' is not a pointer; did you mean to use '.'?
           attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:18: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                               ~~~^
>> net/802/mrp.c:276:17: error: indirection requires pointer operand ('unsigned char[]' invalid)
           attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:14: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                              ^~~~~~~~~~~~
>> net/802/mrp.c:276:17: error: member reference type 'struct mrp_attr' is not a pointer; did you mean to use '.'?
           attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:49: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                                              ~~~~~~~~~~~~~~~~~~~^~~~~~~~~
   include/linux/compiler.h:258:59: note: expanded from macro '__must_be_array'
   #define __must_be_array(a)      BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
   include/linux/compiler_types.h:287:63: note: expanded from macro '__same_type'
   #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
                                                                 ^
   include/linux/build_bug.h:16:62: note: expanded from macro 'BUILD_BUG_ON_ZERO'
   #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
                                                                ^
>> net/802/mrp.c:276:17: error: member reference type 'struct mrp_attr' is not a pointer; did you mean to use '.'?
           attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:49: note: expanded from macro 'struct_size'
                       sizeof(*(p)->member) + __must_be_array((p)->member),\
                                              ~~~~~~~~~~~~~~~~~~~^~~~~~~~~
   include/linux/compiler.h:258:65: note: expanded from macro '__must_be_array'
   #define __must_be_array(a)      BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
   include/linux/compiler_types.h:287:74: note: expanded from macro '__same_type'
   #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
                                                                            ^
   include/linux/build_bug.h:16:62: note: expanded from macro 'BUILD_BUG_ON_ZERO'
   #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
                                                                ^
>> net/802/mrp.c:276:17: error: indirection requires pointer operand ('struct mrp_attr' invalid)
           attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:195:14: note: expanded from macro 'struct_size'
                       sizeof(*(p)))
                              ^~~~
   5 errors generated.


vim +187 net/802/garp.c

   166	
   167	static struct garp_attr *garp_attr_create(struct garp_applicant *app,
   168						  const void *data, u8 len, u8 type)
   169	{
   170		struct rb_node *parent = NULL, **p = &app->gid.rb_node;
   171		struct garp_attr *attr;
   172		int d;
   173	
   174		while (*p) {
   175			parent = *p;
   176			attr = rb_entry(parent, struct garp_attr, node);
   177			d = garp_attr_cmp(attr, data, len, type);
   178			if (d > 0)
   179				p = &parent->rb_left;
   180			else if (d < 0)
   181				p = &parent->rb_right;
   182			else {
   183				/* The attribute already exists; re-use it. */
   184				return attr;
   185			}
   186		}
 > 187		attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
   188		if (!attr)
   189			return attr;
   190		attr->state = GARP_APPLICANT_VO;
   191		attr->type  = type;
   192		attr->dlen  = len;
   193		memcpy(attr->data, data, len);
   194	
   195		rb_link_node(&attr->node, parent, p);
   196		rb_insert_color(&attr->node, &app->gid);
   197		return attr;
   198	}
   199	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
kernel test robot Jan. 28, 2022, 12:51 p.m. UTC | #2 
Hi,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]
[also build test ERROR on net/master horms-ipvs/master linus/master v5.17-rc1 next-20220128]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/cgel-zte-gmail-com/net-802-use-struct_size-over-open-coded-arithmetic/20220128-160925
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 72d044e4bfa6bd9096536e2e1c62aecfe1a525e4
config: x86_64-randconfig-a015 (https://download.01.org/0day-ci/archive/20220128/202201282010.gkSF8kZF-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/9b64e5078d3d779fc56432d43129479f63996c74
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review cgel-zte-gmail-com/net-802-use-struct_size-over-open-coded-arithmetic/20220128-160925
        git checkout 9b64e5078d3d779fc56432d43129479f63996c74
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

   In file included from include/linux/mm.h:30,
                    from arch/x86/include/asm/cacheflush.h:5,
                    from include/linux/cacheflush.h:5,
                    from include/linux/highmem.h:8,
                    from include/linux/bvec.h:10,
                    from include/linux/skbuff.h:17,
                    from net/802/mrp.c:12:
   net/802/mrp.c: In function 'mrp_attr_create':
>> include/linux/overflow.h:194:18: error: invalid type argument of '->' (have 'struct mrp_attr')
     194 |       sizeof(*(p)->member) + __must_be_array((p)->member),\
         |                  ^~
   net/802/mrp.c:276:17: note: in expansion of macro 'struct_size'
     276 |  attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
         |                 ^~~~~~~~~~~
   In file included from include/linux/container_of.h:5,
                    from include/linux/kernel.h:21,
                    from net/802/mrp.c:10:
   include/linux/overflow.h:194:49: error: invalid type argument of '->' (have 'struct mrp_attr')
     194 |       sizeof(*(p)->member) + __must_be_array((p)->member),\
         |                                                 ^~
   include/linux/build_bug.h:16:62: note: in definition of macro 'BUILD_BUG_ON_ZERO'
      16 | #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
         |                                                              ^
   include/linux/compiler.h:258:46: note: in expansion of macro '__same_type'
     258 | #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
         |                                              ^~~~~~~~~~~
   include/linux/overflow.h:194:30: note: in expansion of macro '__must_be_array'
     194 |       sizeof(*(p)->member) + __must_be_array((p)->member),\
         |                              ^~~~~~~~~~~~~~~
   net/802/mrp.c:276:17: note: in expansion of macro 'struct_size'
     276 |  attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
         |                 ^~~~~~~~~~~
   include/linux/overflow.h:194:49: error: invalid type argument of '->' (have 'struct mrp_attr')
     194 |       sizeof(*(p)->member) + __must_be_array((p)->member),\
         |                                                 ^~
   include/linux/build_bug.h:16:62: note: in definition of macro 'BUILD_BUG_ON_ZERO'
      16 | #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
         |                                                              ^
   include/linux/compiler.h:258:46: note: in expansion of macro '__same_type'
     258 | #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
         |                                              ^~~~~~~~~~~
   include/linux/overflow.h:194:30: note: in expansion of macro '__must_be_array'
     194 |       sizeof(*(p)->member) + __must_be_array((p)->member),\
         |                              ^~~~~~~~~~~~~~~
   net/802/mrp.c:276:17: note: in expansion of macro 'struct_size'
     276 |  attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
         |                 ^~~~~~~~~~~
   include/linux/build_bug.h:16:51: error: bit-field '<anonymous>' width not an integer constant
      16 | #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
         |                                                   ^
   include/linux/compiler.h:258:28: note: in expansion of macro 'BUILD_BUG_ON_ZERO'
     258 | #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
         |                            ^~~~~~~~~~~~~~~~~
   include/linux/overflow.h:194:30: note: in expansion of macro '__must_be_array'
     194 |       sizeof(*(p)->member) + __must_be_array((p)->member),\
         |                              ^~~~~~~~~~~~~~~
   net/802/mrp.c:276:17: note: in expansion of macro 'struct_size'
     276 |  attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
         |                 ^~~~~~~~~~~
   In file included from include/linux/mm.h:30,
                    from arch/x86/include/asm/cacheflush.h:5,
                    from include/linux/cacheflush.h:5,
                    from include/linux/highmem.h:8,
                    from include/linux/bvec.h:10,
                    from include/linux/skbuff.h:17,
                    from net/802/mrp.c:12:
>> include/linux/overflow.h:195:14: error: invalid type argument of unary '*' (have 'struct mrp_attr')
     195 |       sizeof(*(p)))
         |              ^~~~
   net/802/mrp.c:276:17: note: in expansion of macro 'struct_size'
     276 |  attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
         |                 ^~~~~~~~~~~


vim +194 include/linux/overflow.h

610b15c50e86eb Kees Cook           2018-05-07  180  
610b15c50e86eb Kees Cook           2018-05-07  181  /**
610b15c50e86eb Kees Cook           2018-05-07  182   * struct_size() - Calculate size of structure with trailing array.
610b15c50e86eb Kees Cook           2018-05-07  183   * @p: Pointer to the structure.
610b15c50e86eb Kees Cook           2018-05-07  184   * @member: Name of the array member.
b19d57d0f3cc6f Gustavo A. R. Silva 2020-06-08  185   * @count: Number of elements in the array.
610b15c50e86eb Kees Cook           2018-05-07  186   *
610b15c50e86eb Kees Cook           2018-05-07  187   * Calculates size of memory needed for structure @p followed by an
b19d57d0f3cc6f Gustavo A. R. Silva 2020-06-08  188   * array of @count number of @member elements.
610b15c50e86eb Kees Cook           2018-05-07  189   *
610b15c50e86eb Kees Cook           2018-05-07  190   * Return: number of bytes needed or SIZE_MAX on overflow.
610b15c50e86eb Kees Cook           2018-05-07  191   */
b19d57d0f3cc6f Gustavo A. R. Silva 2020-06-08  192  #define struct_size(p, member, count)					\
b19d57d0f3cc6f Gustavo A. R. Silva 2020-06-08  193  	__ab_c_size(count,						\
610b15c50e86eb Kees Cook           2018-05-07 @194  		    sizeof(*(p)->member) + __must_be_array((p)->member),\
610b15c50e86eb Kees Cook           2018-05-07 @195  		    sizeof(*(p)))
610b15c50e86eb Kees Cook           2018-05-07  196  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/net/802/garp.c b/net/802/garp.c
index f6012f8e59f0..746763a76f83 100644
--- a/net/802/garp.c
+++ b/net/802/garp.c
@@ -184,7 +184,7 @@  static struct garp_attr *garp_attr_create(struct garp_applicant *app,
 			return attr;
 		}
 	}
-	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+	attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
 	if (!attr)
 		return attr;
 	attr->state = GARP_APPLICANT_VO;
diff --git a/net/802/mrp.c b/net/802/mrp.c
index 35e04cc5390c..ce3f1b610a3f 100644
--- a/net/802/mrp.c
+++ b/net/802/mrp.c
@@ -273,7 +273,7 @@  static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
 			return attr;
 		}
 	}
-	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+	attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
 	if (!attr)
 		return attr;
 	attr->state = MRP_APPLICANT_VO;