* [PATCH for-5.15.x 0/2] DAMON fixes
@ 2021-11-21 11:02 SeongJae Park
2021-11-21 11:02 ` [PATCH for-5.15.x 1/2] mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation SeongJae Park
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: SeongJae Park @ 2021-11-21 11:02 UTC (permalink / raw)
To: stable, gregkh; +Cc: akpm, linux-mm, linux-kernel, SeongJae Park
This patchset is a backport of DAMON fixes that merged in the mainline,
for v5.15.x stable series.
SeongJae Park (2):
mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer
allocation
mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
mm/damon/dbgfs.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
--
2.17.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH for-5.15.x 1/2] mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
2021-11-21 11:02 [PATCH for-5.15.x 0/2] DAMON fixes SeongJae Park
@ 2021-11-21 11:02 ` SeongJae Park
2021-11-21 11:02 ` [PATCH for-5.15.x 2/2] mm/damon/dbgfs: fix missed use of damon_dbgfs_lock SeongJae Park
2021-11-22 12:28 ` [PATCH for-5.15.x 0/2] DAMON fixes Greg KH
2 siblings, 0 replies; 4+ messages in thread
From: SeongJae Park @ 2021-11-21 11:02 UTC (permalink / raw)
To: stable, gregkh
Cc: akpm, linux-mm, linux-kernel, SeongJae Park, Linus Torvalds
commit db7a347b26fe05d2e8c115bb24dfd908d0252bc3 upstream.
Patch series "DAMON fixes".
This patch (of 2):
DAMON users can trigger below warning in '__alloc_pages()' by invoking
write() to some DAMON debugfs files with arbitrarily high count
argument, because DAMON debugfs interface allocates some buffers based
on the user-specified 'count'.
if (unlikely(order >= MAX_ORDER)) {
WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
return NULL;
}
Because the DAMON debugfs interface code checks failure of the
'kmalloc()', this commit simply suppresses the warnings by adding
'__GFP_NOWARN' flag.
Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org
Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/damon/dbgfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index faee070977d8..2741ff79e8e8 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -32,7 +32,7 @@ static char *user_input_str(const char __user *buf, size_t count, loff_t *ppos)
if (*ppos)
return ERR_PTR(-EINVAL);
- kbuf = kmalloc(count + 1, GFP_KERNEL);
+ kbuf = kmalloc(count + 1, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return ERR_PTR(-ENOMEM);
@@ -247,7 +247,7 @@ static ssize_t dbgfs_kdamond_pid_read(struct file *file,
char *kbuf;
ssize_t len;
- kbuf = kmalloc(count, GFP_KERNEL);
+ kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return -ENOMEM;
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH for-5.15.x 2/2] mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
2021-11-21 11:02 [PATCH for-5.15.x 0/2] DAMON fixes SeongJae Park
2021-11-21 11:02 ` [PATCH for-5.15.x 1/2] mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation SeongJae Park
@ 2021-11-21 11:02 ` SeongJae Park
2021-11-22 12:28 ` [PATCH for-5.15.x 0/2] DAMON fixes Greg KH
2 siblings, 0 replies; 4+ messages in thread
From: SeongJae Park @ 2021-11-21 11:02 UTC (permalink / raw)
To: stable, gregkh
Cc: akpm, linux-mm, linux-kernel, SeongJae Park, Linus Torvalds
commit d78f3853f831eee46c6dbe726debf3be9e9c0d05 upstream.
DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and
dbgfs_dirs using damon_dbgfs_lock. However, some of the code is
accessing the variables without the protection. This fixes it by
protecting all such accesses.
Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org
Fixes: 75c1c2b53c78 ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/damon/dbgfs.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index 2741ff79e8e8..f94d19a690df 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -538,12 +538,14 @@ static ssize_t dbgfs_monitor_on_write(struct file *file,
return -EINVAL;
}
+ mutex_lock(&damon_dbgfs_lock);
if (!strncmp(kbuf, "on", count))
err = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs);
else if (!strncmp(kbuf, "off", count))
err = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs);
else
err = -EINVAL;
+ mutex_unlock(&damon_dbgfs_lock);
if (err)
ret = err;
@@ -596,15 +598,16 @@ static int __init __damon_dbgfs_init(void)
static int __init damon_dbgfs_init(void)
{
- int rc;
+ int rc = -ENOMEM;
+ mutex_lock(&damon_dbgfs_lock);
dbgfs_ctxs = kmalloc(sizeof(*dbgfs_ctxs), GFP_KERNEL);
if (!dbgfs_ctxs)
- return -ENOMEM;
+ goto out;
dbgfs_ctxs[0] = dbgfs_new_ctx();
if (!dbgfs_ctxs[0]) {
kfree(dbgfs_ctxs);
- return -ENOMEM;
+ goto out;
}
dbgfs_nr_ctxs = 1;
@@ -615,6 +618,8 @@ static int __init damon_dbgfs_init(void)
pr_err("%s: dbgfs init failed\n", __func__);
}
+out:
+ mutex_unlock(&damon_dbgfs_lock);
return rc;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH for-5.15.x 0/2] DAMON fixes
2021-11-21 11:02 [PATCH for-5.15.x 0/2] DAMON fixes SeongJae Park
2021-11-21 11:02 ` [PATCH for-5.15.x 1/2] mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation SeongJae Park
2021-11-21 11:02 ` [PATCH for-5.15.x 2/2] mm/damon/dbgfs: fix missed use of damon_dbgfs_lock SeongJae Park
@ 2021-11-22 12:28 ` Greg KH
2 siblings, 0 replies; 4+ messages in thread
From: Greg KH @ 2021-11-22 12:28 UTC (permalink / raw)
To: SeongJae Park; +Cc: stable, akpm, linux-mm, linux-kernel
On Sun, Nov 21, 2021 at 11:02:09AM +0000, SeongJae Park wrote:
> This patchset is a backport of DAMON fixes that merged in the mainline,
> for v5.15.x stable series.
>
> SeongJae Park (2):
> mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer
> allocation
> mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
>
> mm/damon/dbgfs.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> --
> 2.17.1
>
Now queued up, thanks for the backports.
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-11-21 11:02 [PATCH for-5.15.x 0/2] DAMON fixes SeongJae Park
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2021-11-21 11:02 ` [PATCH for-5.15.x 2/2] mm/damon/dbgfs: fix missed use of damon_dbgfs_lock SeongJae Park
2021-11-22 12:28 ` [PATCH for-5.15.x 0/2] DAMON fixes Greg KH
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