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* [PATCH AUTOSEL 4.14 112/170] percpu: convert spin_lock_irq to spin_lock_irqsave.
       [not found] <20190128161200.55107-1-sashal@kernel.org>
@ 2019-01-28 16:11 ` Sasha Levin
  2019-01-28 16:11   ` Sasha Levin
  2019-01-28 16:11 ` [PATCH AUTOSEL 4.14 153/170] mm/page_owner: clamp read count to PAGE_SIZE Sasha Levin
  1 sibling, 1 reply; 4+ messages in thread
From: Sasha Levin @ 2019-01-28 16:11 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: Dennis Zhou, Sasha Levin, linux-mm

From: Dennis Zhou <dennis@kernel.org>

[ Upstream commit 6ab7d47bcbf0144a8cb81536c2cead4cde18acfe ]

>From Michael Cree:
  "Bisection lead to commit b38d08f3181c ("percpu: restructure
   locking") as being the cause of lockups at initial boot on
   the kernel built for generic Alpha.

   On a suggestion by Tejun Heo that:

   So, the only thing I can think of is that it's calling
   spin_unlock_irq() while irq handling isn't set up yet.
   Can you please try the followings?

   1. Convert all spin_[un]lock_irq() to
      spin_lock_irqsave/unlock_irqrestore()."

Fixes: b38d08f3181c ("percpu: restructure locking")
Reported-and-tested-by: Michael Cree <mcree@orcon.net.nz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/percpu-km.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/percpu-km.c b/mm/percpu-km.c
index 0d88d7bd5706..c22d959105b6 100644
--- a/mm/percpu-km.c
+++ b/mm/percpu-km.c
@@ -50,6 +50,7 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp)
 	const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;
 	struct pcpu_chunk *chunk;
 	struct page *pages;
+	unsigned long flags;
 	int i;
 
 	chunk = pcpu_alloc_chunk(gfp);
@@ -68,9 +69,9 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp)
 	chunk->data = pages;
 	chunk->base_addr = page_address(pages) - pcpu_group_offsets[0];
 
-	spin_lock_irq(&pcpu_lock);
+	spin_lock_irqsave(&pcpu_lock, flags);
 	pcpu_chunk_populated(chunk, 0, nr_pages, false);
-	spin_unlock_irq(&pcpu_lock);
+	spin_unlock_irqrestore(&pcpu_lock, flags);
 
 	pcpu_stats_chunk_alloc();
 	trace_percpu_create_chunk(chunk->base_addr);
-- 
2.19.1

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH AUTOSEL 4.14 112/170] percpu: convert spin_lock_irq to spin_lock_irqsave.
  2019-01-28 16:11 ` [PATCH AUTOSEL 4.14 112/170] percpu: convert spin_lock_irq to spin_lock_irqsave Sasha Levin
@ 2019-01-28 16:11   ` Sasha Levin
  0 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2019-01-28 16:11 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: Dennis Zhou, Sasha Levin, linux-mm

From: Dennis Zhou <dennis@kernel.org>

[ Upstream commit 6ab7d47bcbf0144a8cb81536c2cead4cde18acfe ]

From Michael Cree:
  "Bisection lead to commit b38d08f3181c ("percpu: restructure
   locking") as being the cause of lockups at initial boot on
   the kernel built for generic Alpha.

   On a suggestion by Tejun Heo that:

   So, the only thing I can think of is that it's calling
   spin_unlock_irq() while irq handling isn't set up yet.
   Can you please try the followings?

   1. Convert all spin_[un]lock_irq() to
      spin_lock_irqsave/unlock_irqrestore()."

Fixes: b38d08f3181c ("percpu: restructure locking")
Reported-and-tested-by: Michael Cree <mcree@orcon.net.nz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/percpu-km.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/percpu-km.c b/mm/percpu-km.c
index 0d88d7bd5706..c22d959105b6 100644
--- a/mm/percpu-km.c
+++ b/mm/percpu-km.c
@@ -50,6 +50,7 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp)
 	const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;
 	struct pcpu_chunk *chunk;
 	struct page *pages;
+	unsigned long flags;
 	int i;
 
 	chunk = pcpu_alloc_chunk(gfp);
@@ -68,9 +69,9 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp)
 	chunk->data = pages;
 	chunk->base_addr = page_address(pages) - pcpu_group_offsets[0];
 
-	spin_lock_irq(&pcpu_lock);
+	spin_lock_irqsave(&pcpu_lock, flags);
 	pcpu_chunk_populated(chunk, 0, nr_pages, false);
-	spin_unlock_irq(&pcpu_lock);
+	spin_unlock_irqrestore(&pcpu_lock, flags);
 
 	pcpu_stats_chunk_alloc();
 	trace_percpu_create_chunk(chunk->base_addr);
-- 
2.19.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH AUTOSEL 4.14 153/170] mm/page_owner: clamp read count to PAGE_SIZE
       [not found] <20190128161200.55107-1-sashal@kernel.org>
  2019-01-28 16:11 ` [PATCH AUTOSEL 4.14 112/170] percpu: convert spin_lock_irq to spin_lock_irqsave Sasha Levin
@ 2019-01-28 16:11 ` Sasha Levin
  2019-01-28 16:11   ` Sasha Levin
  1 sibling, 1 reply; 4+ messages in thread
From: Sasha Levin @ 2019-01-28 16:11 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Miles Chen, Joe Perches, Matthew Wilcox, Andrew Morton,
	Linus Torvalds, Sasha Levin, linux-mm

From: Miles Chen <miles.chen@mediatek.com>

[ Upstream commit c8f61cfc871fadfb73ad3eacd64fda457279e911 ]

The (root-only) page owner read might allocate a large size of memory with
a large read count.  Allocation fails can easily occur when doing high
order allocations.

Clamp buffer size to PAGE_SIZE to avoid arbitrary size allocation
and avoid allocation fails due to high order allocation.

[akpm@linux-foundation.org: use min_t()]
Link: http://lkml.kernel.org/r/1541091607-27402-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/page_owner.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/page_owner.c b/mm/page_owner.c
index a71fe4c623ef..7232c6e24234 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -351,6 +351,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
 		.skip = 0
 	};
 
+	count = min_t(size_t, count, PAGE_SIZE);
 	kbuf = kmalloc(count, GFP_KERNEL);
 	if (!kbuf)
 		return -ENOMEM;
-- 
2.19.1

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH AUTOSEL 4.14 153/170] mm/page_owner: clamp read count to PAGE_SIZE
  2019-01-28 16:11 ` [PATCH AUTOSEL 4.14 153/170] mm/page_owner: clamp read count to PAGE_SIZE Sasha Levin
@ 2019-01-28 16:11   ` Sasha Levin
  0 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2019-01-28 16:11 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Miles Chen, Joe Perches, Matthew Wilcox, Andrew Morton,
	Linus Torvalds, Sasha Levin, linux-mm

From: Miles Chen <miles.chen@mediatek.com>

[ Upstream commit c8f61cfc871fadfb73ad3eacd64fda457279e911 ]

The (root-only) page owner read might allocate a large size of memory with
a large read count.  Allocation fails can easily occur when doing high
order allocations.

Clamp buffer size to PAGE_SIZE to avoid arbitrary size allocation
and avoid allocation fails due to high order allocation.

[akpm@linux-foundation.org: use min_t()]
Link: http://lkml.kernel.org/r/1541091607-27402-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/page_owner.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/page_owner.c b/mm/page_owner.c
index a71fe4c623ef..7232c6e24234 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -351,6 +351,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
 		.skip = 0
 	};
 
+	count = min_t(size_t, count, PAGE_SIZE);
 	kbuf = kmalloc(count, GFP_KERNEL);
 	if (!kbuf)
 		return -ENOMEM;
-- 
2.19.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2019-01-28 16:18 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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     [not found] <20190128161200.55107-1-sashal@kernel.org>
2019-01-28 16:11 ` [PATCH AUTOSEL 4.14 112/170] percpu: convert spin_lock_irq to spin_lock_irqsave Sasha Levin
2019-01-28 16:11   ` Sasha Levin
2019-01-28 16:11 ` [PATCH AUTOSEL 4.14 153/170] mm/page_owner: clamp read count to PAGE_SIZE Sasha Levin
2019-01-28 16:11   ` Sasha Levin

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