From: "Christian König" <ckoenig.leichtzumerken@gmail.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org,
linux-media@vger.kernel.org, chris@chris-wilson.co.uk,
airlied@redhat.com, akpm@linux-foundation.org, daniel@ffwll.ch,
sumit.semwal@linaro.org, willy@infradead.org,
jhubbard@nvidia.com
Subject: Re: [PATCH 2/6] mm: introduce vma_set_file function v3
Date: Mon, 12 Oct 2020 10:11:29 +0200 [thread overview]
Message-ID: <9592e3da-a105-b0ec-3fb2-be349c464c2c@gmail.com> (raw)
In-Reply-To: <20201009151418.GW5177@ziepe.ca>
Am 09.10.20 um 17:14 schrieb Jason Gunthorpe:
> On Fri, Oct 09, 2020 at 05:03:38PM +0200, Christian König wrote:
>> +/*
>> + * Change backing file, only valid to use during initial VMA setup.
>> + */
>> +void vma_set_file(struct vm_area_struct *vma, struct file *file)
>> +{
>> + if (file)
>> + get_file(file);
>> +
>> + swap(vma->vm_file, file);
>> +
>> + if (file)
>> + fput(file);
>> +}
> fput crashes when file is NULL so the error handling after
> unmap_and_free_vma: can't handle this case, similarly vm_file can't be
> NULL either.
>
> So just simply:
>
> swap(vma->vm_file, file);
> get_file(vma->vm_file);
> fput(file);
>
> Will do?
I was considering this as well, yes.
> Just let it crash if any of them are wrongly NULL.
Mhm, changing from anonymous to file backed or reverse is probably not
such a good idea.
So yes catching those problems early is probably the best approach we
could do.
Going to do this in v4 if nobody objects.
Regards,
Christian.
>
> Jason
next prev parent reply other threads:[~2020-10-12 8:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 15:03 [PATCH 1/6] mm: mmap: fix fput in error path Christian König
2020-10-09 15:03 ` [PATCH 2/6] mm: introduce vma_set_file function v3 Christian König
2020-10-09 15:14 ` Jason Gunthorpe
2020-10-12 8:11 ` Christian König [this message]
2020-10-09 15:03 ` [PATCH 3/6] drm/radeon: stop using pages with drm_prime_sg_to_page_addr_arrays Christian König
2020-10-09 15:03 ` [PATCH 4/6] drm/amdgpu: " Christian König
2020-10-09 15:03 ` [PATCH 5/6] drm/nouveau: " Christian König
2020-10-09 15:03 ` [PATCH 6/6] drm/prime: document that use the page array is deprecated v2 Christian König
2020-10-09 16:24 ` Daniel Vetter
2020-10-09 16:27 ` Daniel Vetter
2020-10-09 15:15 ` [PATCH 1/6] mm: mmap: fix fput in error path Jason Gunthorpe
2020-10-09 22:04 ` Andrew Morton
2020-10-09 22:25 ` Jason Gunthorpe
2020-10-12 8:13 ` Christian König
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