Re: [PATCH] xfs: use struct_size() helper
On Thu, Apr 11, 2019 at 08:57:14PM -0500, Gustavo A. R. Silva wrote:
>
>
> On 4/11/19 7:19 PM, Darrick J. Wong wrote:
> > [fixing linux-xfs cc]
> >
>
> Thanks for this.
>
> > On Thu, Apr 11, 2019 at 06:37:58PM -0500, Gustavo A. R. Silva wrote:
> >> Make use of the struct_size() helper instead of an open-coded version
> >> in order to avoid any potential type mistakes, in particular in the
> >> context in which this code is being used.
> >>
> >> So, replace code of the following form:
> >>
> >> sizeof(*alist) + context->count * sizeof(alist->al_offset[0]
> >>
> >> with:
> >>
> >> struct_size(alist, al_offset, context->count)
> >>
> >> and remove unnecessary variable arraytop.
> >>
> >> This code was detected with the help of Coccinelle.
> >>
> >> Signed-off-by: Gustavo A. R. Silva
> >
> > Has this been run through xfstests?
> >
>
> No. Is this a requirement?
Yes, since this is a change to core functionality (and my eyes aren't so
good at digging through preprocessor macros...)
--D
> Thanks
> --
> Gustavo
>
> > --D
> >
> >> fs/xfs/xfs_attr_list.c | 5 +
> >> 1 file changed, 1 insertion(+), 4 deletions(-)
> >>
> >> diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
> >> index 3d213a7394c5..05e03348553e 100644
> >> --- a/fs/xfs/xfs_attr_list.c
> >> +++ b/fs/xfs/xfs_attr_list.c
> >> @@ -553,7 +553,6 @@ xfs_attr_put_listent(
> >> {
> >>struct attrlist *alist = (struct attrlist *)context->alist;
> >>attrlist_ent_t *aep;
> >> - int arraytop;
> >>
> >>ASSERT(!context->seen_enough);
> >>ASSERT(!(context->flags & ATTR_KERNOVAL));
> >> @@ -572,10 +571,8 @@ xfs_attr_put_listent(
> >>((flags & XFS_ATTR_ROOT) == 0))
> >>return;
> >>
> >> - arraytop = sizeof(*alist) +
> >> - context->count * sizeof(alist->al_offset[0]);
> >>context->firstu -= ATTR_ENTSIZE(namelen);
> >> - if (context->firstu < arraytop) {
> >> + if (context->firstu < struct_size(alist, al_offset, context->count)) {
> >>trace_xfs_attr_list_full(context);
> >>alist->al_more = 1;
> >>context->seen_enough = 1;
> >> --
> >> 2.21.0
> >>
Re: [PATCH] xfs: use struct_size() helper
On 4/11/19 7:19 PM, Darrick J. Wong wrote:
> [fixing linux-xfs cc]
>
Thanks for this.
> On Thu, Apr 11, 2019 at 06:37:58PM -0500, Gustavo A. R. Silva wrote:
>> Make use of the struct_size() helper instead of an open-coded version
>> in order to avoid any potential type mistakes, in particular in the
>> context in which this code is being used.
>>
>> So, replace code of the following form:
>>
>> sizeof(*alist) + context->count * sizeof(alist->al_offset[0]
>>
>> with:
>>
>> struct_size(alist, al_offset, context->count)
>>
>> and remove unnecessary variable arraytop.
>>
>> This code was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva
>
> Has this been run through xfstests?
>
No. Is this a requirement?
Thanks
--
Gustavo
> --D
>
>> fs/xfs/xfs_attr_list.c | 5 +
>> 1 file changed, 1 insertion(+), 4 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
>> index 3d213a7394c5..05e03348553e 100644
>> --- a/fs/xfs/xfs_attr_list.c
>> +++ b/fs/xfs/xfs_attr_list.c
>> @@ -553,7 +553,6 @@ xfs_attr_put_listent(
>> {
>> struct attrlist *alist = (struct attrlist *)context->alist;
>> attrlist_ent_t *aep;
>> -int arraytop;
>>
>> ASSERT(!context->seen_enough);
>> ASSERT(!(context->flags & ATTR_KERNOVAL));
>> @@ -572,10 +571,8 @@ xfs_attr_put_listent(
>> ((flags & XFS_ATTR_ROOT) == 0))
>> return;
>>
>> -arraytop = sizeof(*alist) +
>> -context->count * sizeof(alist->al_offset[0]);
>> context->firstu -= ATTR_ENTSIZE(namelen);
>> -if (context->firstu < arraytop) {
>> +if (context->firstu < struct_size(alist, al_offset, context->count)) {
>> trace_xfs_attr_list_full(context);
>> alist->al_more = 1;
>> context->seen_enough = 1;
>> --
>> 2.21.0
>>
Re: [PATCH] xfs: use struct_size() helper
[fixing linux-xfs cc]
On Thu, Apr 11, 2019 at 06:37:58PM -0500, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes, in particular in the
> context in which this code is being used.
>
> So, replace code of the following form:
>
> sizeof(*alist) + context->count * sizeof(alist->al_offset[0]
>
> with:
>
> struct_size(alist, al_offset, context->count)
>
> and remove unnecessary variable arraytop.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva
Has this been run through xfstests?
--D
> fs/xfs/xfs_attr_list.c | 5 +
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
> index 3d213a7394c5..05e03348553e 100644
> --- a/fs/xfs/xfs_attr_list.c
> +++ b/fs/xfs/xfs_attr_list.c
> @@ -553,7 +553,6 @@ xfs_attr_put_listent(
> {
> struct attrlist *alist = (struct attrlist *)context->alist;
> attrlist_ent_t *aep;
> - int arraytop;
>
> ASSERT(!context->seen_enough);
> ASSERT(!(context->flags & ATTR_KERNOVAL));
> @@ -572,10 +571,8 @@ xfs_attr_put_listent(
> ((flags & XFS_ATTR_ROOT) == 0))
> return;
>
> - arraytop = sizeof(*alist) +
> - context->count * sizeof(alist->al_offset[0]);
> context->firstu -= ATTR_ENTSIZE(namelen);
> - if (context->firstu < arraytop) {
> + if (context->firstu < struct_size(alist, al_offset, context->count)) {
> trace_xfs_attr_list_full(context);
> alist->al_more = 1;
> context->seen_enough = 1;
> --
> 2.21.0
>
