From: Peter Xu <peterx@redhat.com>
To: Suren Baghdasaryan <surenb@google.com>
Cc: akpm@linux-foundation.org, willy@infradead.org,
hannes@cmpxchg.org, mhocko@suse.com, josef@toxicpanda.com,
jack@suse.cz, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com,
michel@lespinasse.org, liam.howlett@oracle.com,
jglisse@google.com, vbabka@suse.cz, minchan@google.com,
dave@stgolabs.net, punit.agrawal@bytedance.com,
lstoakes@gmail.com, hdanton@sina.com, apopple@nvidia.com,
ying.huang@intel.com, david@redhat.com, yuzhao@google.com,
dhowells@redhat.com, hughd@google.com, viro@zeniv.linux.org.uk,
brauner@kernel.org, pasha.tatashin@soleen.com,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v4 6/6] mm: handle userfaults under VMA lock
Date: Wed, 28 Jun 2023 12:47:13 -0400 [thread overview]
Message-ID: <ZJxkEVWMAXnz8Y9D@x1n> (raw)
In-Reply-To: <CAJuCfpGRresZRacCSDU=E+CNDkGfMwO2u-oTB_H30cASzFgNtA@mail.gmail.com>
On Wed, Jun 28, 2023 at 09:22:24AM -0700, Suren Baghdasaryan wrote:
> Ack. I was not sure if the ctx->mm would always be the same as vmf->mm.
Feel free to look at the entrance of handle_userfault(), where there's:
struct vm_area_struct *vma = vmf->vma;
struct mm_struct *mm = vma->vm_mm;
struct userfaultfd_ctx *ctx;
...
ctx = vma->vm_userfaultfd_ctx.ctx;
...
BUG_ON(ctx->mm != mm);
...
So I think we should be safe. Thanks,
--
Peter Xu
prev parent reply other threads:[~2023-06-28 16:47 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-28 7:17 [PATCH v4 0/6] Per-VMA lock support for swap and userfaults Suren Baghdasaryan
2023-06-28 7:17 ` [PATCH v4 1/6] swap: remove remnants of polling from read_swap_cache_async Suren Baghdasaryan
2023-06-28 7:17 ` [PATCH v4 2/6] mm: add missing VM_FAULT_RESULT_TRACE name for VM_FAULT_COMPLETED Suren Baghdasaryan
2023-06-28 7:17 ` [PATCH v4 3/6] mm: drop per-VMA lock when returning VM_FAULT_RETRY or VM_FAULT_COMPLETED Suren Baghdasaryan
2023-06-28 13:41 ` Peter Xu
2023-06-28 7:17 ` [PATCH v4 4/6] mm: change folio_lock_or_retry to use vm_fault directly Suren Baghdasaryan
2023-06-28 13:42 ` Peter Xu
2023-06-28 7:17 ` [PATCH v4 5/6] mm: handle swap page faults under per-VMA lock Suren Baghdasaryan
2023-06-28 13:43 ` Peter Xu
2023-06-28 16:01 ` Suren Baghdasaryan
2023-06-28 7:18 ` [PATCH v4 6/6] mm: handle userfaults under VMA lock Suren Baghdasaryan
2023-06-28 7:24 ` Suren Baghdasaryan
2023-06-28 13:57 ` Peter Xu
2023-06-28 16:22 ` Suren Baghdasaryan
2023-06-28 16:47 ` Peter Xu [this message]
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