* + mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch added to -mm tree
@ 2018-03-16 21:17 akpm
0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2018-03-16 21:17 UTC (permalink / raw)
To: ebaskakov, jglisse, jhubbard, mhairgrove, mm-commits, rcampbell,
stable
The patch titled
Subject: mm/hmm: HMM should have a callback before MM is destroyed
has been added to the -mm tree. Its filename is
mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
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
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Ralph Campbell <rcampbell@nvidia.com>
Subject: mm/hmm: HMM should have a callback before MM is destroyed
hmm_mirror_register() registers a callback for when the CPU pagetable is
modified. Normally, the device driver will call hmm_mirror_unregister()
when the process using the device is finished. However, if the process
exits uncleanly, the struct_mm can be destroyed with no warning to the
device driver.
Link: http://lkml.kernel.org/r/20180316191414.3223-4-jglisse@redhat.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Evgeny Baskakov <ebaskakov@nvidia.com>
Cc: Mark Hairgrove <mhairgrove@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/hmm.h | 10 ++++++++++
mm/hmm.c | 18 +++++++++++++++++-
2 files changed, 27 insertions(+), 1 deletion(-)
diff -puN include/linux/hmm.h~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2 include/linux/hmm.h
--- a/include/linux/hmm.h~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2
+++ a/include/linux/hmm.h
@@ -218,6 +218,16 @@ enum hmm_update_type {
* @update: callback to update range on a device
*/
struct hmm_mirror_ops {
+ /* release() - release hmm_mirror
+ *
+ * @mirror: pointer to struct hmm_mirror
+ *
+ * This is called when the mm_struct is being released.
+ * The callback should make sure no references to the mirror occur
+ * after the callback returns.
+ */
+ void (*release)(struct hmm_mirror *mirror);
+
/* sync_cpu_device_pagetables() - synchronize page tables
*
* @mirror: pointer to struct hmm_mirror
diff -puN mm/hmm.c~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2 mm/hmm.c
--- a/mm/hmm.c~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2
+++ a/mm/hmm.c
@@ -160,6 +160,21 @@ static void hmm_invalidate_range(struct
up_read(&hmm->mirrors_sem);
}
+static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+ struct hmm *hmm = mm->hmm;
+ struct hmm_mirror *mirror;
+ struct hmm_mirror *mirror_next;
+
+ down_write(&hmm->mirrors_sem);
+ list_for_each_entry_safe(mirror, mirror_next, &hmm->mirrors, list) {
+ list_del_init(&mirror->list);
+ if (mirror->ops->release)
+ mirror->ops->release(mirror);
+ }
+ up_write(&hmm->mirrors_sem);
+}
+
static void hmm_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
@@ -185,6 +200,7 @@ static void hmm_invalidate_range_end(str
}
static const struct mmu_notifier_ops hmm_mmu_notifier_ops = {
+ .release = hmm_release,
.invalidate_range_start = hmm_invalidate_range_start,
.invalidate_range_end = hmm_invalidate_range_end,
};
@@ -230,7 +246,7 @@ void hmm_mirror_unregister(struct hmm_mi
struct hmm *hmm = mirror->hmm;
down_write(&hmm->mirrors_sem);
- list_del(&mirror->list);
+ list_del_init(&mirror->list);
up_write(&hmm->mirrors_sem);
}
EXPORT_SYMBOL(hmm_mirror_unregister);
_
Patches currently in -mm which might be from rcampbell@nvidia.com are
mm-hmm-documentation-editorial-update-to-hmm-documentation.patch
mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
^ permalink raw reply [flat|nested] 2+ messages in thread* + mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch added to -mm tree
@ 2018-03-20 20:59 akpm
0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2018-03-20 20:59 UTC (permalink / raw)
To: bsingharora, ebaskakov, jgg, jglisse, jhubbard, logang,
mhairgrove, mm-commits, rcampbell, sbates, stable
The patch titled
Subject: mm/hmm: HMM should have a callback before MM is destroyed v2
has been added to the -mm tree. Its filename is
mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
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
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Ralph Campbell <rcampbell@nvidia.com>
Subject: mm/hmm: HMM should have a callback before MM is destroyed v2
The hmm_mirror_register() function registers a callback for when the CPU
pagetable is modified. Normally, the device driver will call
hmm_mirror_unregister() when the process using the device is finished.
However, if the process exits uncleanly, the struct_mm can be destroyed
with no warning to the device driver.
Link: http://lkml.kernel.org/r/20180320020038.3360-4-jglisse@redhat.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Evgeny Baskakov <ebaskakov@nvidia.com>
Cc: Mark Hairgrove <mhairgrove@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Stephen Bates <sbates@raithlin.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
diff -puN include/linux/hmm.h~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2 include/linux/hmm.h
--- a/include/linux/hmm.h~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2
+++ a/include/linux/hmm.h
@@ -218,6 +218,16 @@ enum hmm_update_type {
* @update: callback to update range on a device
*/
struct hmm_mirror_ops {
+ /* release() - release hmm_mirror
+ *
+ * @mirror: pointer to struct hmm_mirror
+ *
+ * This is called when the mm_struct is being released.
+ * The callback should make sure no references to the mirror occur
+ * after the callback returns.
+ */
+ void (*release)(struct hmm_mirror *mirror);
+
/* sync_cpu_device_pagetables() - synchronize page tables
*
* @mirror: pointer to struct hmm_mirror
diff -puN mm/hmm.c~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2 mm/hmm.c
--- a/mm/hmm.c~mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2
+++ a/mm/hmm.c
@@ -160,6 +160,21 @@ static void hmm_invalidate_range(struct
up_read(&hmm->mirrors_sem);
}
+static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+ struct hmm *hmm = mm->hmm;
+ struct hmm_mirror *mirror;
+ struct hmm_mirror *mirror_next;
+
+ down_write(&hmm->mirrors_sem);
+ list_for_each_entry_safe(mirror, mirror_next, &hmm->mirrors, list) {
+ list_del_init(&mirror->list);
+ if (mirror->ops->release)
+ mirror->ops->release(mirror);
+ }
+ up_write(&hmm->mirrors_sem);
+}
+
static void hmm_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
@@ -185,6 +200,7 @@ static void hmm_invalidate_range_end(str
}
static const struct mmu_notifier_ops hmm_mmu_notifier_ops = {
+ .release = hmm_release,
.invalidate_range_start = hmm_invalidate_range_start,
.invalidate_range_end = hmm_invalidate_range_end,
};
@@ -230,7 +246,7 @@ void hmm_mirror_unregister(struct hmm_mi
struct hmm *hmm = mirror->hmm;
down_write(&hmm->mirrors_sem);
- list_del(&mirror->list);
+ list_del_init(&mirror->list);
up_write(&hmm->mirrors_sem);
}
EXPORT_SYMBOL(hmm_mirror_unregister);
_
Patches currently in -mm which might be from rcampbell@nvidia.com are
mm-hmm-documentation-editorial-update-to-hmm-documentation.patch
mm-hmm-hmm-should-have-a-callback-before-mm-is-destroyed-v2.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
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