[PATCH] staging: android: ashmem: Declared file operation with const keyword

[PATCH] staging: android: ashmem: Declared file operation with const keyword

[SandeshKenjanaAshok]

Warning found by checkpatch.pl script.

Signed-off-by: SandeshKenjanaAshok <sandeshkenjanaashok@gmail.com>
---
 drivers/staging/android/ashmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 8044510d8ec6..fbb6ac9ba1ab 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -367,7 +367,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
 
 static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	static struct file_operations vmfile_fops;
+	static const struct file_operations vmfile_fops;
 	struct ashmem_area *asma = file->private_data;
 	int ret = 0;
 
-- 
2.17.1

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[Greg Kroah-Hartman]

On Sat, Mar 28, 2020 at 04:15:23PM +0100, SandeshKenjanaAshok wrote:
> Warning found by checkpatch.pl script.
> 
> Signed-off-by: SandeshKenjanaAshok <sandeshkenjanaashok@gmail.com>
> ---
>  drivers/staging/android/ashmem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
> index 8044510d8ec6..fbb6ac9ba1ab 100644
> --- a/drivers/staging/android/ashmem.c
> +++ b/drivers/staging/android/ashmem.c
> @@ -367,7 +367,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
>  
>  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	static struct file_operations vmfile_fops;
> +	static const struct file_operations vmfile_fops;
>  	struct ashmem_area *asma = file->private_data;
>  	int ret = 0;
>  
> -- 
> 2.17.1
> 

Did you try to build this change?  Please do so.

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 8351 bytes --]

Hi SandeshKenjanaAshok,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on staging/staging-testing]
[also build test ERROR on v5.6-rc7 next-20200327]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/SandeshKenjanaAshok/staging-android-ashmem-Declared-file-operation-with-const-keyword/20200329-014353
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git e681bb287f40e7a9dbcb04cef80fd87a2511ab86
config: um-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.5.0-5) 7.5.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=um 

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

All errors (new ones prefixed by >>):

   drivers/staging/android/ashmem.c: In function 'ashmem_mmap':
>> drivers/staging/android/ashmem.c:418:16: error: assignment of read-only variable 'vmfile_fops'
       vmfile_fops = *vmfile->f_op;
                   ^
>> drivers/staging/android/ashmem.c:419:21: error: assignment of member 'mmap' in read-only object
       vmfile_fops.mmap = ashmem_vmfile_mmap;
                        ^
>> drivers/staging/android/ashmem.c:420:34: error: assignment of member 'get_unmapped_area' in read-only object
       vmfile_fops.get_unmapped_area =
                                     ^

vim +/vmfile_fops +418 drivers/staging/android/ashmem.c

6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  367  
11980c2ac4ccfa Robert Love         2011-12-20  368  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
11980c2ac4ccfa Robert Love         2011-12-20  369  {
3e4e9953cadce9 SandeshKenjanaAshok 2020-03-28  370  	static const struct file_operations vmfile_fops;
11980c2ac4ccfa Robert Love         2011-12-20  371  	struct ashmem_area *asma = file->private_data;
11980c2ac4ccfa Robert Love         2011-12-20  372  	int ret = 0;
11980c2ac4ccfa Robert Love         2011-12-20  373  
11980c2ac4ccfa Robert Love         2011-12-20  374  	mutex_lock(&ashmem_mutex);
11980c2ac4ccfa Robert Love         2011-12-20  375  
11980c2ac4ccfa Robert Love         2011-12-20  376  	/* user needs to SET_SIZE before mapping */
59848d6aded59a Alistair Strachan   2018-06-19  377  	if (!asma->size) {
11980c2ac4ccfa Robert Love         2011-12-20  378  		ret = -EINVAL;
11980c2ac4ccfa Robert Love         2011-12-20  379  		goto out;
11980c2ac4ccfa Robert Love         2011-12-20  380  	}
11980c2ac4ccfa Robert Love         2011-12-20  381  
8632c614565d0c Alistair Strachan   2018-06-19  382  	/* requested mapping size larger than object size */
8632c614565d0c Alistair Strachan   2018-06-19  383  	if (vma->vm_end - vma->vm_start > PAGE_ALIGN(asma->size)) {
11980c2ac4ccfa Robert Love         2011-12-20  384  		ret = -EINVAL;
11980c2ac4ccfa Robert Love         2011-12-20  385  		goto out;
11980c2ac4ccfa Robert Love         2011-12-20  386  	}
11980c2ac4ccfa Robert Love         2011-12-20  387  
11980c2ac4ccfa Robert Love         2011-12-20  388  	/* requested protection bits must match our allowed protection mask */
59848d6aded59a Alistair Strachan   2018-06-19  389  	if ((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) &
59848d6aded59a Alistair Strachan   2018-06-19  390  	    calc_vm_prot_bits(PROT_MASK, 0)) {
11980c2ac4ccfa Robert Love         2011-12-20  391  		ret = -EPERM;
11980c2ac4ccfa Robert Love         2011-12-20  392  		goto out;
11980c2ac4ccfa Robert Love         2011-12-20  393  	}
56f76fc68492af Arve Hjønnevåg      2011-12-20  394  	vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask);
11980c2ac4ccfa Robert Love         2011-12-20  395  
11980c2ac4ccfa Robert Love         2011-12-20  396  	if (!asma->file) {
11980c2ac4ccfa Robert Love         2011-12-20  397  		char *name = ASHMEM_NAME_DEF;
11980c2ac4ccfa Robert Love         2011-12-20  398  		struct file *vmfile;
11980c2ac4ccfa Robert Love         2011-12-20  399  
11980c2ac4ccfa Robert Love         2011-12-20  400  		if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0')
11980c2ac4ccfa Robert Love         2011-12-20  401  			name = asma->name;
11980c2ac4ccfa Robert Love         2011-12-20  402  
11980c2ac4ccfa Robert Love         2011-12-20  403  		/* ... and allocate the backing shmem file */
11980c2ac4ccfa Robert Love         2011-12-20  404  		vmfile = shmem_file_setup(name, asma->size, vma->vm_flags);
7f44cb0ba88b40 Viresh Kumar        2015-07-31  405  		if (IS_ERR(vmfile)) {
11980c2ac4ccfa Robert Love         2011-12-20  406  			ret = PTR_ERR(vmfile);
11980c2ac4ccfa Robert Love         2011-12-20  407  			goto out;
11980c2ac4ccfa Robert Love         2011-12-20  408  		}
97fbfef6bd5978 Shuxiao Zhang       2017-04-06  409  		vmfile->f_mode |= FMODE_LSEEK;
11980c2ac4ccfa Robert Love         2011-12-20  410  		asma->file = vmfile;
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  411  		/*
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  412  		 * override mmap operation of the vmfile so that it can't be
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  413  		 * remapped which would lead to creation of a new vma with no
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  414  		 * asma permission checks. Have to override get_unmapped_area
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  415  		 * as well to prevent VM_BUG_ON check for f_ops modification.
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  416  		 */
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  417  		if (!vmfile_fops.mmap) {
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27 @418  			vmfile_fops = *vmfile->f_op;
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27 @419  			vmfile_fops.mmap = ashmem_vmfile_mmap;
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27 @420  			vmfile_fops.get_unmapped_area =
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  421  					ashmem_vmfile_get_unmapped_area;
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  422  		}
6d67b0290b4b84 Suren Baghdasaryan  2020-01-27  423  		vmfile->f_op = &vmfile_fops;
11980c2ac4ccfa Robert Love         2011-12-20  424  	}
11980c2ac4ccfa Robert Love         2011-12-20  425  	get_file(asma->file);
11980c2ac4ccfa Robert Love         2011-12-20  426  
11980c2ac4ccfa Robert Love         2011-12-20  427  	/*
11980c2ac4ccfa Robert Love         2011-12-20  428  	 * XXX - Reworked to use shmem_zero_setup() instead of
11980c2ac4ccfa Robert Love         2011-12-20  429  	 * shmem_set_file while we're in staging. -jstultz
11980c2ac4ccfa Robert Love         2011-12-20  430  	 */
11980c2ac4ccfa Robert Love         2011-12-20  431  	if (vma->vm_flags & VM_SHARED) {
11980c2ac4ccfa Robert Love         2011-12-20  432  		ret = shmem_zero_setup(vma);
11980c2ac4ccfa Robert Love         2011-12-20  433  		if (ret) {
11980c2ac4ccfa Robert Love         2011-12-20  434  			fput(asma->file);
11980c2ac4ccfa Robert Love         2011-12-20  435  			goto out;
11980c2ac4ccfa Robert Love         2011-12-20  436  		}
44960f2a7b63e2 John Stultz         2018-07-31  437  	} else {
44960f2a7b63e2 John Stultz         2018-07-31  438  		vma_set_anonymous(vma);
11980c2ac4ccfa Robert Love         2011-12-20  439  	}
11980c2ac4ccfa Robert Love         2011-12-20  440  
11980c2ac4ccfa Robert Love         2011-12-20  441  	if (vma->vm_file)
11980c2ac4ccfa Robert Love         2011-12-20  442  		fput(vma->vm_file);
11980c2ac4ccfa Robert Love         2011-12-20  443  	vma->vm_file = asma->file;
11980c2ac4ccfa Robert Love         2011-12-20  444  
11980c2ac4ccfa Robert Love         2011-12-20  445  out:
11980c2ac4ccfa Robert Love         2011-12-20  446  	mutex_unlock(&ashmem_mutex);
11980c2ac4ccfa Robert Love         2011-12-20  447  	return ret;
11980c2ac4ccfa Robert Love         2011-12-20  448  }
11980c2ac4ccfa Robert Love         2011-12-20  449  

:::::: The code at line 418 was first introduced by commit
:::::: 6d67b0290b4b84c477e6a2fc6e005e174d3c7786 staging: android: ashmem: Disallow ashmem memory from being remapped

:::::: TO: Suren Baghdasaryan <surenb@google.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 22352 bytes --]

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[kernel test robot]

Hi ratnesh-r1,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on staging/staging-testing]

url:    https://github.com/0day-ci/linux/commits/ratnesh-r1/staging-android-ashmem-Declared-file-operation-with-const-keyword/20220124-151116
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git fa783154524a71ab74e293cd8251155e5971952b
config: riscv-randconfig-c006-20220124 (https://download.01.org/0day-ci/archive/20220124/202201242027.9RTdyW5P-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 2e58a18910867ba6795066e044293e6daf89edf5)
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/c24fe2afe4abdf6436628abd13a0109ec420f373
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review ratnesh-r1/staging-android-ashmem-Declared-file-operation-with-const-keyword/20220124-151116
        git checkout c24fe2afe4abdf6436628abd13a0109ec420f373
        # 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/staging/android/

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 >>):

>> drivers/staging/android/ashmem.c:431:16: error: cannot assign to variable 'vmfile_fops' with const-qualified type 'const struct file_operations'
                           vmfile_fops = *vmfile->f_op;
                           ~~~~~~~~~~~ ^
   drivers/staging/android/ashmem.c:380:38: note: variable 'vmfile_fops' declared const here
           static const struct file_operations vmfile_fops;
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
   drivers/staging/android/ashmem.c:432:21: error: cannot assign to variable 'vmfile_fops' with const-qualified type 'const struct file_operations'
                           vmfile_fops.mmap = ashmem_vmfile_mmap;
                           ~~~~~~~~~~~~~~~~ ^
   drivers/staging/android/ashmem.c:380:38: note: variable 'vmfile_fops' declared const here
           static const struct file_operations vmfile_fops;
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
   drivers/staging/android/ashmem.c:433:34: error: cannot assign to variable 'vmfile_fops' with const-qualified type 'const struct file_operations'
                           vmfile_fops.get_unmapped_area =
                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
   drivers/staging/android/ashmem.c:380:38: note: variable 'vmfile_fops' declared const here
           static const struct file_operations vmfile_fops;
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
   3 errors generated.


vim +431 drivers/staging/android/ashmem.c

6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  377  
11980c2ac4ccfa Robert Love        2011-12-20  378  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
11980c2ac4ccfa Robert Love        2011-12-20  379  {
c24fe2afe4abdf ratnesh-r1         2022-01-23  380  	static const struct file_operations vmfile_fops;
11980c2ac4ccfa Robert Love        2011-12-20  381  	struct ashmem_area *asma = file->private_data;
11980c2ac4ccfa Robert Love        2011-12-20  382  	int ret = 0;
11980c2ac4ccfa Robert Love        2011-12-20  383  
11980c2ac4ccfa Robert Love        2011-12-20  384  	mutex_lock(&ashmem_mutex);
11980c2ac4ccfa Robert Love        2011-12-20  385  
11980c2ac4ccfa Robert Love        2011-12-20  386  	/* user needs to SET_SIZE before mapping */
59848d6aded59a Alistair Strachan  2018-06-19  387  	if (!asma->size) {
11980c2ac4ccfa Robert Love        2011-12-20  388  		ret = -EINVAL;
11980c2ac4ccfa Robert Love        2011-12-20  389  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  390  	}
11980c2ac4ccfa Robert Love        2011-12-20  391  
8632c614565d0c Alistair Strachan  2018-06-19  392  	/* requested mapping size larger than object size */
8632c614565d0c Alistair Strachan  2018-06-19  393  	if (vma->vm_end - vma->vm_start > PAGE_ALIGN(asma->size)) {
11980c2ac4ccfa Robert Love        2011-12-20  394  		ret = -EINVAL;
11980c2ac4ccfa Robert Love        2011-12-20  395  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  396  	}
11980c2ac4ccfa Robert Love        2011-12-20  397  
11980c2ac4ccfa Robert Love        2011-12-20  398  	/* requested protection bits must match our allowed protection mask */
59848d6aded59a Alistair Strachan  2018-06-19  399  	if ((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) &
59848d6aded59a Alistair Strachan  2018-06-19  400  	    calc_vm_prot_bits(PROT_MASK, 0)) {
11980c2ac4ccfa Robert Love        2011-12-20  401  		ret = -EPERM;
11980c2ac4ccfa Robert Love        2011-12-20  402  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  403  	}
56f76fc68492af Arve Hjønnevåg     2011-12-20  404  	vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask);
11980c2ac4ccfa Robert Love        2011-12-20  405  
11980c2ac4ccfa Robert Love        2011-12-20  406  	if (!asma->file) {
11980c2ac4ccfa Robert Love        2011-12-20  407  		char *name = ASHMEM_NAME_DEF;
11980c2ac4ccfa Robert Love        2011-12-20  408  		struct file *vmfile;
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  409  		struct inode *inode;
11980c2ac4ccfa Robert Love        2011-12-20  410  
11980c2ac4ccfa Robert Love        2011-12-20  411  		if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0')
11980c2ac4ccfa Robert Love        2011-12-20  412  			name = asma->name;
11980c2ac4ccfa Robert Love        2011-12-20  413  
11980c2ac4ccfa Robert Love        2011-12-20  414  		/* ... and allocate the backing shmem file */
11980c2ac4ccfa Robert Love        2011-12-20  415  		vmfile = shmem_file_setup(name, asma->size, vma->vm_flags);
7f44cb0ba88b40 Viresh Kumar       2015-07-31  416  		if (IS_ERR(vmfile)) {
11980c2ac4ccfa Robert Love        2011-12-20  417  			ret = PTR_ERR(vmfile);
11980c2ac4ccfa Robert Love        2011-12-20  418  			goto out;
11980c2ac4ccfa Robert Love        2011-12-20  419  		}
97fbfef6bd5978 Shuxiao Zhang      2017-04-06  420  		vmfile->f_mode |= FMODE_LSEEK;
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  421  		inode = file_inode(vmfile);
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  422  		lockdep_set_class(&inode->i_rwsem, &backing_shmem_inode_class);
11980c2ac4ccfa Robert Love        2011-12-20  423  		asma->file = vmfile;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  424  		/*
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  425  		 * override mmap operation of the vmfile so that it can't be
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  426  		 * remapped which would lead to creation of a new vma with no
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  427  		 * asma permission checks. Have to override get_unmapped_area
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  428  		 * as well to prevent VM_BUG_ON check for f_ops modification.
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  429  		 */
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  430  		if (!vmfile_fops.mmap) {
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27 @431  			vmfile_fops = *vmfile->f_op;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  432  			vmfile_fops.mmap = ashmem_vmfile_mmap;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  433  			vmfile_fops.get_unmapped_area =
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  434  					ashmem_vmfile_get_unmapped_area;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  435  		}
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  436  		vmfile->f_op = &vmfile_fops;
11980c2ac4ccfa Robert Love        2011-12-20  437  	}
11980c2ac4ccfa Robert Love        2011-12-20  438  	get_file(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  439  
11980c2ac4ccfa Robert Love        2011-12-20  440  	/*
11980c2ac4ccfa Robert Love        2011-12-20  441  	 * XXX - Reworked to use shmem_zero_setup() instead of
11980c2ac4ccfa Robert Love        2011-12-20  442  	 * shmem_set_file while we're in staging. -jstultz
11980c2ac4ccfa Robert Love        2011-12-20  443  	 */
11980c2ac4ccfa Robert Love        2011-12-20  444  	if (vma->vm_flags & VM_SHARED) {
11980c2ac4ccfa Robert Love        2011-12-20  445  		ret = shmem_zero_setup(vma);
11980c2ac4ccfa Robert Love        2011-12-20  446  		if (ret) {
11980c2ac4ccfa Robert Love        2011-12-20  447  			fput(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  448  			goto out;
11980c2ac4ccfa Robert Love        2011-12-20  449  		}
44960f2a7b63e2 John Stultz        2018-07-31  450  	} else {
44960f2a7b63e2 John Stultz        2018-07-31  451  		vma_set_anonymous(vma);
11980c2ac4ccfa Robert Love        2011-12-20  452  	}
11980c2ac4ccfa Robert Love        2011-12-20  453  
295992fb815e79 Christian König    2020-09-14  454  	vma_set_file(vma, asma->file);
295992fb815e79 Christian König    2020-09-14  455  	/* XXX: merge this with the get_file() above if possible */
295992fb815e79 Christian König    2020-09-14  456  	fput(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  457  
11980c2ac4ccfa Robert Love        2011-12-20  458  out:
11980c2ac4ccfa Robert Love        2011-12-20  459  	mutex_unlock(&ashmem_mutex);
11980c2ac4ccfa Robert Love        2011-12-20  460  	return ret;
11980c2ac4ccfa Robert Love        2011-12-20  461  }
11980c2ac4ccfa Robert Love        2011-12-20  462  

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

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[kernel test robot]

Hi ratnesh-r1,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on staging/staging-testing]

url:    https://github.com/0day-ci/linux/commits/ratnesh-r1/staging-android-ashmem-Declared-file-operation-with-const-keyword/20220124-151116
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git fa783154524a71ab74e293cd8251155e5971952b
config: x86_64-randconfig-a002-20220124 (https://download.01.org/0day-ci/archive/20220124/202201241907.69JG769L-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/c24fe2afe4abdf6436628abd13a0109ec420f373
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review ratnesh-r1/staging-android-ashmem-Declared-file-operation-with-const-keyword/20220124-151116
        git checkout c24fe2afe4abdf6436628abd13a0109ec420f373
        # 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 >>):

   drivers/staging/android/ashmem.c: In function 'ashmem_mmap':
>> drivers/staging/android/ashmem.c:431:16: error: assignment of read-only variable 'vmfile_fops'
     431 |    vmfile_fops = *vmfile->f_op;
         |                ^
>> drivers/staging/android/ashmem.c:432:21: error: assignment of member 'mmap' in read-only object
     432 |    vmfile_fops.mmap = ashmem_vmfile_mmap;
         |                     ^
>> drivers/staging/android/ashmem.c:433:34: error: assignment of member 'get_unmapped_area' in read-only object
     433 |    vmfile_fops.get_unmapped_area =
         |                                  ^


vim +/vmfile_fops +431 drivers/staging/android/ashmem.c

6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  377  
11980c2ac4ccfa Robert Love        2011-12-20  378  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
11980c2ac4ccfa Robert Love        2011-12-20  379  {
c24fe2afe4abdf ratnesh-r1         2022-01-23  380  	static const struct file_operations vmfile_fops;
11980c2ac4ccfa Robert Love        2011-12-20  381  	struct ashmem_area *asma = file->private_data;
11980c2ac4ccfa Robert Love        2011-12-20  382  	int ret = 0;
11980c2ac4ccfa Robert Love        2011-12-20  383  
11980c2ac4ccfa Robert Love        2011-12-20  384  	mutex_lock(&ashmem_mutex);
11980c2ac4ccfa Robert Love        2011-12-20  385  
11980c2ac4ccfa Robert Love        2011-12-20  386  	/* user needs to SET_SIZE before mapping */
59848d6aded59a Alistair Strachan  2018-06-19  387  	if (!asma->size) {
11980c2ac4ccfa Robert Love        2011-12-20  388  		ret = -EINVAL;
11980c2ac4ccfa Robert Love        2011-12-20  389  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  390  	}
11980c2ac4ccfa Robert Love        2011-12-20  391  
8632c614565d0c Alistair Strachan  2018-06-19  392  	/* requested mapping size larger than object size */
8632c614565d0c Alistair Strachan  2018-06-19  393  	if (vma->vm_end - vma->vm_start > PAGE_ALIGN(asma->size)) {
11980c2ac4ccfa Robert Love        2011-12-20  394  		ret = -EINVAL;
11980c2ac4ccfa Robert Love        2011-12-20  395  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  396  	}
11980c2ac4ccfa Robert Love        2011-12-20  397  
11980c2ac4ccfa Robert Love        2011-12-20  398  	/* requested protection bits must match our allowed protection mask */
59848d6aded59a Alistair Strachan  2018-06-19  399  	if ((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) &
59848d6aded59a Alistair Strachan  2018-06-19  400  	    calc_vm_prot_bits(PROT_MASK, 0)) {
11980c2ac4ccfa Robert Love        2011-12-20  401  		ret = -EPERM;
11980c2ac4ccfa Robert Love        2011-12-20  402  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  403  	}
56f76fc68492af Arve Hjønnevåg     2011-12-20  404  	vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask);
11980c2ac4ccfa Robert Love        2011-12-20  405  
11980c2ac4ccfa Robert Love        2011-12-20  406  	if (!asma->file) {
11980c2ac4ccfa Robert Love        2011-12-20  407  		char *name = ASHMEM_NAME_DEF;
11980c2ac4ccfa Robert Love        2011-12-20  408  		struct file *vmfile;
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  409  		struct inode *inode;
11980c2ac4ccfa Robert Love        2011-12-20  410  
11980c2ac4ccfa Robert Love        2011-12-20  411  		if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0')
11980c2ac4ccfa Robert Love        2011-12-20  412  			name = asma->name;
11980c2ac4ccfa Robert Love        2011-12-20  413  
11980c2ac4ccfa Robert Love        2011-12-20  414  		/* ... and allocate the backing shmem file */
11980c2ac4ccfa Robert Love        2011-12-20  415  		vmfile = shmem_file_setup(name, asma->size, vma->vm_flags);
7f44cb0ba88b40 Viresh Kumar       2015-07-31  416  		if (IS_ERR(vmfile)) {
11980c2ac4ccfa Robert Love        2011-12-20  417  			ret = PTR_ERR(vmfile);
11980c2ac4ccfa Robert Love        2011-12-20  418  			goto out;
11980c2ac4ccfa Robert Love        2011-12-20  419  		}
97fbfef6bd5978 Shuxiao Zhang      2017-04-06  420  		vmfile->f_mode |= FMODE_LSEEK;
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  421  		inode = file_inode(vmfile);
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  422  		lockdep_set_class(&inode->i_rwsem, &backing_shmem_inode_class);
11980c2ac4ccfa Robert Love        2011-12-20  423  		asma->file = vmfile;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  424  		/*
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  425  		 * override mmap operation of the vmfile so that it can't be
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  426  		 * remapped which would lead to creation of a new vma with no
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  427  		 * asma permission checks. Have to override get_unmapped_area
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  428  		 * as well to prevent VM_BUG_ON check for f_ops modification.
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  429  		 */
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  430  		if (!vmfile_fops.mmap) {
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27 @431  			vmfile_fops = *vmfile->f_op;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27 @432  			vmfile_fops.mmap = ashmem_vmfile_mmap;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27 @433  			vmfile_fops.get_unmapped_area =
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  434  					ashmem_vmfile_get_unmapped_area;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  435  		}
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  436  		vmfile->f_op = &vmfile_fops;
11980c2ac4ccfa Robert Love        2011-12-20  437  	}
11980c2ac4ccfa Robert Love        2011-12-20  438  	get_file(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  439  
11980c2ac4ccfa Robert Love        2011-12-20  440  	/*
11980c2ac4ccfa Robert Love        2011-12-20  441  	 * XXX - Reworked to use shmem_zero_setup() instead of
11980c2ac4ccfa Robert Love        2011-12-20  442  	 * shmem_set_file while we're in staging. -jstultz
11980c2ac4ccfa Robert Love        2011-12-20  443  	 */
11980c2ac4ccfa Robert Love        2011-12-20  444  	if (vma->vm_flags & VM_SHARED) {
11980c2ac4ccfa Robert Love        2011-12-20  445  		ret = shmem_zero_setup(vma);
11980c2ac4ccfa Robert Love        2011-12-20  446  		if (ret) {
11980c2ac4ccfa Robert Love        2011-12-20  447  			fput(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  448  			goto out;
11980c2ac4ccfa Robert Love        2011-12-20  449  		}
44960f2a7b63e2 John Stultz        2018-07-31  450  	} else {
44960f2a7b63e2 John Stultz        2018-07-31  451  		vma_set_anonymous(vma);
11980c2ac4ccfa Robert Love        2011-12-20  452  	}
11980c2ac4ccfa Robert Love        2011-12-20  453  
295992fb815e79 Christian König    2020-09-14  454  	vma_set_file(vma, asma->file);
295992fb815e79 Christian König    2020-09-14  455  	/* XXX: merge this with the get_file() above if possible */
295992fb815e79 Christian König    2020-09-14  456  	fput(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  457  
11980c2ac4ccfa Robert Love        2011-12-20  458  out:
11980c2ac4ccfa Robert Love        2011-12-20  459  	mutex_unlock(&ashmem_mutex);
11980c2ac4ccfa Robert Love        2011-12-20  460  	return ret;
11980c2ac4ccfa Robert Love        2011-12-20  461  }
11980c2ac4ccfa Robert Love        2011-12-20  462  

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

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[Greg Kroah-Hartman]

On Sun, Jan 23, 2022 at 11:09:47PM -0800, ratnesh-r1 wrote:
> warning found by checkpatch.pl script.
> 
> Signed-off-by: ratnesh-r1 <me.ratnesh682@gmail.com>
> ---
>  drivers/staging/android/ashmem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
> index c05a214..f9cfa15 100644
> --- a/drivers/staging/android/ashmem.c
> +++ b/drivers/staging/android/ashmem.c
> @@ -367,7 +367,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
>  
>  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	static struct file_operations vmfile_fops;
> +	static const struct file_operations vmfile_fops;
>  	struct ashmem_area *asma = file->private_data;
>  	int ret = 0;
>  
> -- 
> 2.7.4
> 
> _______________________________________________
> devel mailing list
> devel@linuxdriverproject.org
> http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- Your patch breaks the build.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

[PATCH] staging: android: ashmem: Declared file operation with const keyword

[ratnesh-r1]

warning found by checkpatch.pl script.

Signed-off-by: ratnesh-r1 <me.ratnesh682@gmail.com>
---
 drivers/staging/android/ashmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index c05a214..f9cfa15 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -367,7 +367,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
 
 static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	static struct file_operations vmfile_fops;
+	static const struct file_operations vmfile_fops;
 	struct ashmem_area *asma = file->private_data;
 	int ret = 0;
 
-- 
2.7.4

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Hriday Hegde]

On 19-05-2021 20:25, Greg Kroah-Hartman wrote:
> On Wed, May 19, 2021 at 08:06:14PM +0530, Hriday Hegde wrote:
>> On 19-05-2021 15:20, Greg Kroah-Hartman wrote:
>>> A: http://en.wikipedia.org/wiki/Top_post
>>> Q: Were do I find info about this thing called top-posting?
>>> A: Because it messes up the order in which people normally read text.
>>> Q: Why is top-posting such a bad thing?
>>> A: Top-posting.
>>> Q: What is the most annoying thing in e-mail?
>>>
>>> http://daringfireball.net/2007/07/on_top
>>>
>>> On Wed, May 19, 2021 at 03:00:08PM +0530, Hriday Hegde wrote:
>>>> I am not really sure how to do that and how to reflect it in the patch i followed what was taught in the Beginners course and it does not mention building. I know i need to test it out but is running 'patch -p1 < x.patch what i need to do?
>>> That does not build the code you changed, right?
>>>
>>> I'm sure whatever course you took, it did reference the fact that you
>>> need to ensure that your change actually works properly by the very
>>> least being able to be compiled correctly.  Please go over those
>>> instructions again.
>>>
>>> good luck!
>>>
>>> greg k-h
>> I am using the A Beginner's Guide to Linux Kernel Development (LFD103) by the linux foundation for this but i cant find any commands to as to build and test , the only way i tried compiling is with a custom Makefile and it didn't work, i've got a few errors so the const keyword might not work here since the variable is being written to.
>>
>>
> That is correct, when compiling (i.e. building), the compiler shows that
> this is not a correct change.
>
> thanks,
>
> greg k-h
Oh ok will work with something else.

Thanks.

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Hriday Hegde]

On 19-05-2021 20:21, Fabio Aiuto wrote:
> Hi Hriday,
>
> On Wed, May 19, 2021 at 08:06:14PM +0530, Hriday Hegde wrote:
>> On 19-05-2021 15:20, Greg Kroah-Hartman wrote:
>>> A: http://en.wikipedia.org/wiki/Top_post
>>> Q: Were do I find info about this thing called top-posting?
>>> A: Because it messes up the order in which people normally read text.
>>> Q: Why is top-posting such a bad thing?
>>> A: Top-posting.
>>> Q: What is the most annoying thing in e-mail?
>>>
>>> http://daringfireball.net/2007/07/on_top
>>>
>>> On Wed, May 19, 2021 at 03:00:08PM +0530, Hriday Hegde wrote:
>>>> I am not really sure how to do that and how to reflect it in the patch i followed what was taught in the Beginners course and it does not mention building. I know i need to test it out but is running 'patch -p1 < x.patch what i need to do?
>>> That does not build the code you changed, right?
>>>
>>> I'm sure whatever course you took, it did reference the fact that you
>>> need to ensure that your change actually works properly by the very
>>> least being able to be compiled correctly.  Please go over those
>>> instructions again.
>>>
>>> good luck!
>>>
>>> greg k-h
>> I am using the A Beginner's Guide to Linux Kernel Development (LFD103) by the linux foundation for this but i cant find any commands to as to build and test , the only way i tried compiling is with a custom Makefile and it didn't work, i've got a few errors so the const keyword might not work here since the variable is being written to.
>>
>>
> try following this tutorial from scratch:
>
> https://kernelnewbies.org/FirstKernelPatch
>
> it's simply complete and helps a lot, from
> gathering all tools needed to contribute to the
> community to sending whole patchsets.
>
> In your emails don't go over 80-100 character per line,
> when you ask things or your mails will be difficult
> to read.
>
> thank you,
>
> fabio
Thank you for the guidance,  and will keep the char limit in
mind.

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Greg Kroah-Hartman]

On Wed, May 19, 2021 at 08:06:14PM +0530, Hriday Hegde wrote:
> On 19-05-2021 15:20, Greg Kroah-Hartman wrote:
> > A: http://en.wikipedia.org/wiki/Top_post
> > Q: Were do I find info about this thing called top-posting?
> > A: Because it messes up the order in which people normally read text.
> > Q: Why is top-posting such a bad thing?
> > A: Top-posting.
> > Q: What is the most annoying thing in e-mail?
> >
> > http://daringfireball.net/2007/07/on_top
> >
> > On Wed, May 19, 2021 at 03:00:08PM +0530, Hriday Hegde wrote:
> >> I am not really sure how to do that and how to reflect it in the patch i followed what was taught in the Beginners course and it does not mention building. I know i need to test it out but is running 'patch -p1 < x.patch what i need to do?
> > That does not build the code you changed, right?
> >
> > I'm sure whatever course you took, it did reference the fact that you
> > need to ensure that your change actually works properly by the very
> > least being able to be compiled correctly.  Please go over those
> > instructions again.
> >
> > good luck!
> >
> > greg k-h
> 
> I am using the A Beginner's Guide to Linux Kernel Development (LFD103) by the linux foundation for this but i cant find any commands to as to build and test , the only way i tried compiling is with a custom Makefile and it didn't work, i've got a few errors so the const keyword might not work here since the variable is being written to.
> 
> 

That is correct, when compiling (i.e. building), the compiler shows that
this is not a correct change.

thanks,

greg k-h

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Fabio Aiuto]

Hi Hriday,

On Wed, May 19, 2021 at 08:06:14PM +0530, Hriday Hegde wrote:
> On 19-05-2021 15:20, Greg Kroah-Hartman wrote:
> > A: http://en.wikipedia.org/wiki/Top_post
> > Q: Were do I find info about this thing called top-posting?
> > A: Because it messes up the order in which people normally read text.
> > Q: Why is top-posting such a bad thing?
> > A: Top-posting.
> > Q: What is the most annoying thing in e-mail?
> >
> > http://daringfireball.net/2007/07/on_top
> >
> > On Wed, May 19, 2021 at 03:00:08PM +0530, Hriday Hegde wrote:
> >> I am not really sure how to do that and how to reflect it in the patch i followed what was taught in the Beginners course and it does not mention building. I know i need to test it out but is running 'patch -p1 < x.patch what i need to do?
> > That does not build the code you changed, right?
> >
> > I'm sure whatever course you took, it did reference the fact that you
> > need to ensure that your change actually works properly by the very
> > least being able to be compiled correctly.  Please go over those
> > instructions again.
> >
> > good luck!
> >
> > greg k-h
> 
> I am using the A Beginner's Guide to Linux Kernel Development (LFD103) by the linux foundation for this but i cant find any commands to as to build and test , the only way i tried compiling is with a custom Makefile and it didn't work, i've got a few errors so the const keyword might not work here since the variable is being written to.
> 
> 

try following this tutorial from scratch:

https://kernelnewbies.org/FirstKernelPatch

it's simply complete and helps a lot, from
gathering all tools needed to contribute to the
community to sending whole patchsets.

In your emails don't go over 80-100 character per line,
when you ask things or your mails will be difficult
to read.

thank you,

fabio

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Hriday Hegde]

On 19-05-2021 15:20, Greg Kroah-Hartman wrote:
> A: http://en.wikipedia.org/wiki/Top_post
> Q: Were do I find info about this thing called top-posting?
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?
>
> http://daringfireball.net/2007/07/on_top
>
> On Wed, May 19, 2021 at 03:00:08PM +0530, Hriday Hegde wrote:
>> I am not really sure how to do that and how to reflect it in the patch i followed what was taught in the Beginners course and it does not mention building. I know i need to test it out but is running 'patch -p1 < x.patch what i need to do?
> That does not build the code you changed, right?
>
> I'm sure whatever course you took, it did reference the fact that you
> need to ensure that your change actually works properly by the very
> least being able to be compiled correctly.  Please go over those
> instructions again.
>
> good luck!
>
> greg k-h

I am using the A Beginner's Guide to Linux Kernel Development (LFD103) by the linux foundation for this but i cant find any commands to as to build and test , the only way i tried compiling is with a custom Makefile and it didn't work, i've got a few errors so the const keyword might not work here since the variable is being written to.

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Greg Kroah-Hartman]

A: http://en.wikipedia.org/wiki/Top_post
Q: Were do I find info about this thing called top-posting?
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

http://daringfireball.net/2007/07/on_top

On Wed, May 19, 2021 at 03:00:08PM +0530, Hriday Hegde wrote:
> I am not really sure how to do that and how to reflect it in the patch i followed what was taught in the Beginners course and it does not mention building. I know i need to test it out but is running 'patch -p1 < x.patch what i need to do?

That does not build the code you changed, right?

I'm sure whatever course you took, it did reference the fact that you
need to ensure that your change actually works properly by the very
least being able to be compiled correctly.  Please go over those
instructions again.

good luck!

greg k-h

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Hriday Hegde]

I am not really sure how to do that and how to reflect it in the patch i followed what was taught in the Beginners course and it does not mention building. I know i need to test it out but is running 'patch -p1 < x.patch what i need to do?

On 19-05-2021 14:01, Greg Kroah-Hartman wrote:
> On Wed, May 19, 2021 at 01:19:58AM -0700, Hriday Hegde wrote:
>> Fixing following warnings found by checkpatch.pl
>> WARNING: struct file_operations should normally be const
>> 380: FILE: drivers/staging/android/ashmem.c:380:
>> +	static struct file_operations vmfile_fops;
>>
>> Signed-off-by: Hriday Hegde <hridayhegde1999@gmail.com>
>> ---
>>  drivers/staging/android/ashmem.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
>> index 8ee4320a5dc6..8ff2794b08e3 100644
>> --- a/drivers/staging/android/ashmem.c
>> +++ b/drivers/staging/android/ashmem.c
>> @@ -377,7 +377,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
>>  
>>  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
>>  {
>> -	static struct file_operations vmfile_fops;
>> +	static const struct file_operations vmfile_fops;
>>  	struct ashmem_area *asma = file->private_data;
>>  	int ret = 0;
>>  
>> -- 
>> 2.25.1
>>
>>
> Any reason why you didn't build your change before submitting this
> patch?
>
> thanks,
>
> greg k-h

Re: [PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Greg Kroah-Hartman]

On Wed, May 19, 2021 at 01:19:58AM -0700, Hriday Hegde wrote:
> Fixing following warnings found by checkpatch.pl
> WARNING: struct file_operations should normally be const
> 380: FILE: drivers/staging/android/ashmem.c:380:
> +	static struct file_operations vmfile_fops;
> 
> Signed-off-by: Hriday Hegde <hridayhegde1999@gmail.com>
> ---
>  drivers/staging/android/ashmem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
> index 8ee4320a5dc6..8ff2794b08e3 100644
> --- a/drivers/staging/android/ashmem.c
> +++ b/drivers/staging/android/ashmem.c
> @@ -377,7 +377,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
>  
>  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	static struct file_operations vmfile_fops;
> +	static const struct file_operations vmfile_fops;
>  	struct ashmem_area *asma = file->private_data;
>  	int ret = 0;
>  
> -- 
> 2.25.1
> 
> 

Any reason why you didn't build your change before submitting this
patch?

thanks,

greg k-h

[PATCH] staging: android: ashmem: Declared file operation with 'const' keyword

[Hriday Hegde]

Fixing following warnings found by checkpatch.pl
WARNING: struct file_operations should normally be const
380: FILE: drivers/staging/android/ashmem.c:380:
+	static struct file_operations vmfile_fops;

Signed-off-by: Hriday Hegde <hridayhegde1999@gmail.com>
---
 drivers/staging/android/ashmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 8ee4320a5dc6..8ff2794b08e3 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -377,7 +377,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
 
 static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	static struct file_operations vmfile_fops;
+	static const struct file_operations vmfile_fops;
 	struct ashmem_area *asma = file->private_data;
 	int ret = 0;
 
-- 
2.25.1

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[Greg Kroah-Hartman]

On Sat, Feb 13, 2021 at 11:31:36PM -0300, Thais Camacho wrote:
> Warning found by checkpatch.pl script
> 
> Signed-off-by: Thais Camacho <thaiscamachoo@gmail.com>
> ---
>  drivers/staging/android/ashmem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
> index 4789d36ddfd3..2cb665e0228c 100644
> --- a/drivers/staging/android/ashmem.c
> +++ b/drivers/staging/android/ashmem.c
> @@ -376,7 +376,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
>  
>  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	static struct file_operations vmfile_fops;
> +	static const struct file_operations vmfile_fops;
>  	struct ashmem_area *asma = file->private_data;
>  	int ret = 0;
>  
> -- 
> 2.20.1

Any specific reason why you did not test-build your change before
sending it to us?  Please always do so, otherwise it causes lots of
problems, and makes maintainers grumpy :)

thanks,

greg k-h

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 9621 bytes --]

Hi Thais,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on staging/staging-testing]

url:    https://github.com/0day-ci/linux/commits/Thais-Camacho/staging-android-ashmem-Declared-file-operation-with-const-keyword/20210214-103440
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git 4eb839aef182fccf8995ee439fc2b48d43e45918
config: x86_64-randconfig-a014-20210214 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476)
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
        # https://github.com/0day-ci/linux/commit/32b5e3c9154f059b60686c16a3c3a316f85b6976
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Thais-Camacho/staging-android-ashmem-Declared-file-operation-with-const-keyword/20210214-103440
        git checkout 32b5e3c9154f059b60686c16a3c3a316f85b6976
        # 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 errors (new ones prefixed by >>):

>> drivers/staging/android/ashmem.c:430:16: error: cannot assign to variable 'vmfile_fops' with const-qualified type 'const struct file_operations'
                           vmfile_fops = *vmfile->f_op;
                           ~~~~~~~~~~~ ^
   drivers/staging/android/ashmem.c:379:38: note: variable 'vmfile_fops' declared const here
           static const struct file_operations vmfile_fops;
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
   drivers/staging/android/ashmem.c:431:21: error: cannot assign to variable 'vmfile_fops' with const-qualified type 'const struct file_operations'
                           vmfile_fops.mmap = ashmem_vmfile_mmap;
                           ~~~~~~~~~~~~~~~~ ^
   drivers/staging/android/ashmem.c:379:38: note: variable 'vmfile_fops' declared const here
           static const struct file_operations vmfile_fops;
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
   drivers/staging/android/ashmem.c:432:34: error: cannot assign to variable 'vmfile_fops' with const-qualified type 'const struct file_operations'
                           vmfile_fops.get_unmapped_area =
                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
   drivers/staging/android/ashmem.c:379:38: note: variable 'vmfile_fops' declared const here
           static const struct file_operations vmfile_fops;
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
   3 errors generated.


vim +430 drivers/staging/android/ashmem.c

6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  376  
11980c2ac4ccfa Robert Love        2011-12-20  377  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
11980c2ac4ccfa Robert Love        2011-12-20  378  {
32b5e3c9154f05 Thais Camacho      2021-02-13  379  	static const struct file_operations vmfile_fops;
11980c2ac4ccfa Robert Love        2011-12-20  380  	struct ashmem_area *asma = file->private_data;
11980c2ac4ccfa Robert Love        2011-12-20  381  	int ret = 0;
11980c2ac4ccfa Robert Love        2011-12-20  382  
11980c2ac4ccfa Robert Love        2011-12-20  383  	mutex_lock(&ashmem_mutex);
11980c2ac4ccfa Robert Love        2011-12-20  384  
11980c2ac4ccfa Robert Love        2011-12-20  385  	/* user needs to SET_SIZE before mapping */
59848d6aded59a Alistair Strachan  2018-06-19  386  	if (!asma->size) {
11980c2ac4ccfa Robert Love        2011-12-20  387  		ret = -EINVAL;
11980c2ac4ccfa Robert Love        2011-12-20  388  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  389  	}
11980c2ac4ccfa Robert Love        2011-12-20  390  
8632c614565d0c Alistair Strachan  2018-06-19  391  	/* requested mapping size larger than object size */
8632c614565d0c Alistair Strachan  2018-06-19  392  	if (vma->vm_end - vma->vm_start > PAGE_ALIGN(asma->size)) {
11980c2ac4ccfa Robert Love        2011-12-20  393  		ret = -EINVAL;
11980c2ac4ccfa Robert Love        2011-12-20  394  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  395  	}
11980c2ac4ccfa Robert Love        2011-12-20  396  
11980c2ac4ccfa Robert Love        2011-12-20  397  	/* requested protection bits must match our allowed protection mask */
59848d6aded59a Alistair Strachan  2018-06-19  398  	if ((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) &
59848d6aded59a Alistair Strachan  2018-06-19  399  	    calc_vm_prot_bits(PROT_MASK, 0)) {
11980c2ac4ccfa Robert Love        2011-12-20  400  		ret = -EPERM;
11980c2ac4ccfa Robert Love        2011-12-20  401  		goto out;
11980c2ac4ccfa Robert Love        2011-12-20  402  	}
56f76fc68492af Arve Hjønnevåg     2011-12-20  403  	vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask);
11980c2ac4ccfa Robert Love        2011-12-20  404  
11980c2ac4ccfa Robert Love        2011-12-20  405  	if (!asma->file) {
11980c2ac4ccfa Robert Love        2011-12-20  406  		char *name = ASHMEM_NAME_DEF;
11980c2ac4ccfa Robert Love        2011-12-20  407  		struct file *vmfile;
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  408  		struct inode *inode;
11980c2ac4ccfa Robert Love        2011-12-20  409  
11980c2ac4ccfa Robert Love        2011-12-20  410  		if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0')
11980c2ac4ccfa Robert Love        2011-12-20  411  			name = asma->name;
11980c2ac4ccfa Robert Love        2011-12-20  412  
11980c2ac4ccfa Robert Love        2011-12-20  413  		/* ... and allocate the backing shmem file */
11980c2ac4ccfa Robert Love        2011-12-20  414  		vmfile = shmem_file_setup(name, asma->size, vma->vm_flags);
7f44cb0ba88b40 Viresh Kumar       2015-07-31  415  		if (IS_ERR(vmfile)) {
11980c2ac4ccfa Robert Love        2011-12-20  416  			ret = PTR_ERR(vmfile);
11980c2ac4ccfa Robert Love        2011-12-20  417  			goto out;
11980c2ac4ccfa Robert Love        2011-12-20  418  		}
97fbfef6bd5978 Shuxiao Zhang      2017-04-06  419  		vmfile->f_mode |= FMODE_LSEEK;
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  420  		inode = file_inode(vmfile);
3e338d3c95c735 Suren Baghdasaryan 2020-07-30  421  		lockdep_set_class(&inode->i_rwsem, &backing_shmem_inode_class);
11980c2ac4ccfa Robert Love        2011-12-20  422  		asma->file = vmfile;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  423  		/*
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  424  		 * override mmap operation of the vmfile so that it can't be
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  425  		 * remapped which would lead to creation of a new vma with no
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  426  		 * asma permission checks. Have to override get_unmapped_area
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  427  		 * as well to prevent VM_BUG_ON check for f_ops modification.
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  428  		 */
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  429  		if (!vmfile_fops.mmap) {
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27 @430  			vmfile_fops = *vmfile->f_op;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  431  			vmfile_fops.mmap = ashmem_vmfile_mmap;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  432  			vmfile_fops.get_unmapped_area =
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  433  					ashmem_vmfile_get_unmapped_area;
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  434  		}
6d67b0290b4b84 Suren Baghdasaryan 2020-01-27  435  		vmfile->f_op = &vmfile_fops;
11980c2ac4ccfa Robert Love        2011-12-20  436  	}
11980c2ac4ccfa Robert Love        2011-12-20  437  	get_file(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  438  
11980c2ac4ccfa Robert Love        2011-12-20  439  	/*
11980c2ac4ccfa Robert Love        2011-12-20  440  	 * XXX - Reworked to use shmem_zero_setup() instead of
11980c2ac4ccfa Robert Love        2011-12-20  441  	 * shmem_set_file while we're in staging. -jstultz
11980c2ac4ccfa Robert Love        2011-12-20  442  	 */
11980c2ac4ccfa Robert Love        2011-12-20  443  	if (vma->vm_flags & VM_SHARED) {
11980c2ac4ccfa Robert Love        2011-12-20  444  		ret = shmem_zero_setup(vma);
11980c2ac4ccfa Robert Love        2011-12-20  445  		if (ret) {
11980c2ac4ccfa Robert Love        2011-12-20  446  			fput(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  447  			goto out;
11980c2ac4ccfa Robert Love        2011-12-20  448  		}
44960f2a7b63e2 John Stultz        2018-07-31  449  	} else {
44960f2a7b63e2 John Stultz        2018-07-31  450  		vma_set_anonymous(vma);
11980c2ac4ccfa Robert Love        2011-12-20  451  	}
11980c2ac4ccfa Robert Love        2011-12-20  452  
295992fb815e79 Christian König    2020-09-14  453  	vma_set_file(vma, asma->file);
295992fb815e79 Christian König    2020-09-14  454  	/* XXX: merge this with the get_file() above if possible */
295992fb815e79 Christian König    2020-09-14  455  	fput(asma->file);
11980c2ac4ccfa Robert Love        2011-12-20  456  
11980c2ac4ccfa Robert Love        2011-12-20  457  out:
11980c2ac4ccfa Robert Love        2011-12-20  458  	mutex_unlock(&ashmem_mutex);
11980c2ac4ccfa Robert Love        2011-12-20  459  	return ret;
11980c2ac4ccfa Robert Love        2011-12-20  460  }
11980c2ac4ccfa Robert Love        2011-12-20  461  

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

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 29152 bytes --]

[PATCH] staging: android: ashmem: Declared file operation with const keyword

[Thais Camacho]

Warning found by checkpatch.pl script

Signed-off-by: Thais Camacho <thaiscamachoo@gmail.com>
---
 drivers/staging/android/ashmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 4789d36ddfd3..2cb665e0228c 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -376,7 +376,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
 
 static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	static struct file_operations vmfile_fops;
+	static const struct file_operations vmfile_fops;
 	struct ashmem_area *asma = file->private_data;
 	int ret = 0;
 
-- 
2.20.1

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[Dan Carpenter]

On Mon, Dec 28, 2020 at 12:13:00AM -0500, jovin555 wrote:
> Warning found by checkpatch.pl script.
> 
> Signed-off-by: jovin555 <jovin555@gmail.com>

Your Mama didn't name you "jovin555".  You need to use your real name
like signing a legal document.  Same for the "From:" header.

regards,
dan carpenter

Re: [PATCH] staging: android: ashmem: Declared file operation with const keyword

[Greg Kroah-Hartman]

On Mon, Dec 28, 2020 at 12:13:00AM -0500, jovin555 wrote:
> Warning found by checkpatch.pl script.
> 
> Signed-off-by: jovin555 <jovin555@gmail.com>
> ---
>  drivers/staging/android/ashmem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
> index c05a214191da..f9cfa15b785f 100644
> --- a/drivers/staging/android/ashmem.c
> +++ b/drivers/staging/android/ashmem.c
> @@ -367,7 +367,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
>  
>  static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	static struct file_operations vmfile_fops;
> +	static const struct file_operations vmfile_fops;
>  	struct ashmem_area *asma = file->private_data;
>  	int ret = 0;
>  

Did you build your modified kernel with this change in it?

Always do so...

greg k-h

[PATCH] staging: android: ashmem: Declared file operation with const keyword

[jovin555]

Warning found by checkpatch.pl script.

Signed-off-by: jovin555 <jovin555@gmail.com>
---
 drivers/staging/android/ashmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index c05a214191da..f9cfa15b785f 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -367,7 +367,7 @@ ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr,
 
 static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	static struct file_operations vmfile_fops;
+	static const struct file_operations vmfile_fops;
 	struct ashmem_area *asma = file->private_data;
 	int ret = 0;
 
-- 
2.20.1