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charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Rspamd-Server: rspam01 X-Stat-Signature: i5ei6mr6ius3xx3yn5dd4qdrdtmuw8bw X-Rspam-User: X-Rspamd-Queue-Id: 1365520004 X-HE-Tag: 1743557219-183520 X-HE-Meta: U2FsdGVkX1+dVI+YCjDOu+h1cYtEXTF7v7jCDFwf3Z1Fy8uRLRSpA8ArXyexMwQPtPzljqMLiFrhVnVu2kF974p5UUyH3uh867DhQyJp+EP8KcujKhiMCUWJOrHWyzUCkt7oW1Kfd0Axtvm/E6VLQkI12tH9MGwjBLjtFQpO1w7JIh51CbIzT0KD7TVPBH1g6J2QkyHOH7lMzLpGtqWzHr8acfnbdOK5i7cR2k4W0eRhsRoGkfrWW+Ea7b5zB91C5/eXTRb6IFVEss5VRqxXEDP5VwiAa1vCm5vqES2826di3TC2gJ4Ll07fmg/Al1HqXFeZMbBTHITz92GwMtFB4NBsFqPVDuphfAtG73zZ6pUdRbx/Wab+qZQfhY5mbe3ZtH/EEQszYka+znaB7P3p1a/nb/xfzwxXO7SMuvpNR0hGtn53c4gSDe3ErivSHLu09pl49/ZKVpJ78he9490QW8t86rN5FyttnlnzIbbB51e9M1YQ2D6NrL2Iz44ITt4m5srusRQrB+SLu8ccBrLIKhLdlUygAsVW2y5QzYTuVLbE6wP137I7Pkz32qBjror6oZ0yWhj4gEtcp2LWMtZKvnwqrqV9+06Wltro95uFPpIM4qniaGN/9dhTdago+GzxQW8MA7Gg/dNKqpC+Nbo7d+fuHRsDRGbJKBtqqxJgAVaXAgSQWw5jws1jvcYLmnW+XRuToJCPrQgZIYOfjRJKtK4B7BuP5wD0KUVLAvyCP7tq35Q1p/feU02Jo83RyqF1zagA/5ygXR+3aDhAVkvacQv2xIdCdMtIfgeclaZg/+71cBOGehs77PiMfRTybC4W0xW9fVIBK1QZlrxdRVV2z5OzWRM4v6gQ9QtpZPLCLkH8J0iCpHq5IZCZ+wtacgF+Dy6g/gMKMt1eFcnWKFGqXH+gyRIO2AX8amM8xIawMb7QGqQgItFm8eXaVcd3PMWFu7uMF2U8DH7Vx7hZQxz T92EvRJV s58+GOZnWYYdOZbOVujhLZ8o8gsdF/mIp8XSqTPPvHNfs7h5h8GR9eeGbf5PaXHi1oq+TrLSdl1XxVAbETwVgpxMT88EGESUTWw/SI0CujDlAgeeu7Dr+EGxLWjY9/LhrlMe1qmLWX0+MjteatZliW1CJKgj6EbSpHHI8wuoXaR3k57vhatQN7vc1c4/zD5/d1u66dYtbQq785Lw5B8UzkUqzMW1K9n78QCcCgLMOoYoZYzu84VfwCEvnTkREbliwtZI/C+1JqUWxRcxWS+giR3+bUeHPQMoS256nbA/HQbzWD8L+1S+slXmj56j1xkp/5LMY8soRM2nNJnRvx8I/Qmg0Wgv7yV0SahubMUf9Setuz++8GDchGD8Mnr6YXj9YJD9Ul22Y7zabDZsw2BBWLydVuuZPrI6sYDFZBSgC9dmhDl4700kqXpHijLeh5Mc4x4u/ X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 04/01/25 at 04:37pm, David Hildenbrand wrote: > On 01.04.25 16:34, Baoquan He wrote: > > On 04/01/25 at 10:02am, David Hildenbrand wrote: > > > On 31.03.25 10:13, Baoquan He wrote: ...snip... > > > We already have that check in is_valid_gup_args(), that catches all external > > > users that could possibly mess this up. > > > > Right. > > > > > > > > So we can just convert that into a VM_WARN_ON_ONCE(), and while doing that, > > > we should convert the VM_BUG_ON() above to a VM_WARN_ON_ONCE() as well. > > > > Sounds great to me, will put below change into this patch of v3 as suggested. > > Thanks. > > > > diff --git a/mm/gup.c b/mm/gup.c > > index 9e4ed09c578b..d551da9549b1 100644 > > --- a/mm/gup.c > > +++ b/mm/gup.c > > @@ -1427,10 +1427,10 @@ static long __get_user_pages(struct mm_struct *mm, > > start = untagged_addr_remote(mm, start); > > - VM_BUG_ON(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN))); > > + VM_WARN_ON_ONCE(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN))); > > /* FOLL_GET and FOLL_PIN are mutually exclusive. */ > > - if (WARN_ON_ONCE((gup_flags & (FOLL_PIN | FOLL_GET)) == > > + if (VM_WARN_ON_ONCE((gup_flags & (FOLL_PIN | FOLL_GET)) == > > (FOLL_PIN | FOLL_GET))) > > That won't work (or shouldn't work :) ). Just drop the handling, it's a > sanity check we don't expect to ever trigger, just like the old VM_BUG_ON > above. Ah, I misunderstood it. Will add below change into this patch of v3. diff --git a/mm/gup.c b/mm/gup.c index 9e4ed09c578b..a8a10a8ebf14 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1427,12 +1427,9 @@ static long __get_user_pages(struct mm_struct *mm, start = untagged_addr_remote(mm, start); - VM_BUG_ON(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN))); - - /* FOLL_GET and FOLL_PIN are mutually exclusive. */ - if (WARN_ON_ONCE((gup_flags & (FOLL_PIN | FOLL_GET)) == - (FOLL_PIN | FOLL_GET))) - return -EINVAL; + VM_WARN_ON_ONCE(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN))); + VM_WARN_ON_ONCE((gup_flags & (FOLL_PIN | FOLL_GET)) == + (FOLL_PIN | FOLL_GET)); do { struct page *page;