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charset="us-ascii" Content-ID: <836DD39E6FD9E046B74ED0286061B0B3@namprd22.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: mips.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5cd89efc-933c-4cfc-9f59-08d68d8a43bf X-MS-Exchange-CrossTenant-originalarrivaltime: 08 Feb 2019 05:57:10.0137 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-id: 463607d3-1db3-40a0-8a29-970c56230104 X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR2201MB1070 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Hi Andrew, On Thu, Feb 07, 2019 at 09:44:07PM -0800, akpm@linux-foundation.org wrote: >=20 > The patch titled > Subject: arch/mips/mm/c-r4k.c: do not use mmap_sem for gup_fast() > has been added to the -mm tree. Its filename is > mips-c-r4k-do-no-use-mmap_sem-for-gup_fast.patch >=20 > This patch should soon appear at > http://ozlabs.org/~akpm/mmots/broken-out/mips-c-r4k-do-no-use-mmap_se= m-for-gup_fast.patch > and later at > http://ozlabs.org/~akpm/mmotm/broken-out/mips-c-r4k-do-no-use-mmap_se= m-for-gup_fast.patch >=20 > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's >=20 > *** Remember to use Documentation/process/submit-checklist.rst when testi= ng your code *** >=20 > The -mm tree is included into linux-next and is updated > there every 3-4 working days >=20 > ------------------------------------------------------ > From: Davidlohr Bueso > Subject: arch/mips/mm/c-r4k.c: do not use mmap_sem for gup_fast() >=20 > It is well known that because the mm can internally call the regular > gup_unlocked if the lockless approach fails and take the sem there, the > caller must not hold the mmap_sem already. >=20 > Link: http://lkml.kernel.org/r/20190207053740.26915-3-dave@stgolabs.net > Fixes: e523f289fe4d ("MIPS: c-r4k: Fix sigtramp SMP call to use kmap") > Signed-off-by: Davidlohr Bueso > Cc: Ralf Baechle > Cc: Paul Burton > Cc: James Hogan > Signed-off-by: Andrew Morton Whilst I don't object to you merging this too strongly, I thought I'd point out again that as I already replied to Davidlohr [1] the code being changed here is unused in mainline & all affected stable branches. In mips-next it's entirely removed. As such this patch will have no effect on the kernel's behaviour & cause a minor conflict with mips-next. Thanks, Paul [1] https://lore.kernel.org/linux-mips/20190207190007.jz4rz6e6qxwazxm7@pbur= ton-laptop/