The patch titled
Subject: mm: validate device_hotplug is held for memory hotplug
has been removed from the -mm tree. Its filename was
mm-validate-device_hotplug-is-held-for-memory-hotplug.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Dan Williams <dan.j.williams@xxxxxxxxx>
Subject: mm: validate device_hotplug is held for memory hotplug
mem_hotplug_begin() assumes that it can set mem_hotplug.active_writer and
run the hotplug process without racing another thread. Validate this
assumption with a lockdep assertion.
Link: http://lkml.kernel.org/r/148693886229.16345.1770484669403334689.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Reported-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/core.c | 5 +++++
include/linux/device.h | 1 +
mm/memory_hotplug.c | 2 ++
3 files changed, 8 insertions(+)
diff -puN drivers/base/core.c~mm-validate-device_hotplug-is-held-for-memory-hotplug drivers/base/core.c
--- a/drivers/base/core.c~mm-validate-device_hotplug-is-held-for-memory-hotplug
+++ a/drivers/base/core.c
@@ -638,6 +638,11 @@ int lock_device_hotplug_sysfs(void)
return restart_syscall();
}
+void assert_held_device_hotplug(void)
+{
+ lockdep_assert_held(&device_hotplug_lock);
+}
+
#ifdef CONFIG_BLOCK
static inline int device_is_not_partition(struct device *dev)
{
diff -puN include/linux/device.h~mm-validate-device_hotplug-is-held-for-memory-hotplug include/linux/device.h
--- a/include/linux/device.h~mm-validate-device_hotplug-is-held-for-memory-hotplug
+++ a/include/linux/device.h
@@ -1139,6 +1139,7 @@ static inline bool device_supports_offli
extern void lock_device_hotplug(void);
extern void unlock_device_hotplug(void);
extern int lock_device_hotplug_sysfs(void);
+void assert_held_device_hotplug(void);
extern int device_offline(struct device *dev);
extern int device_online(struct device *dev);
extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
diff -puN mm/memory_hotplug.c~mm-validate-device_hotplug-is-held-for-memory-hotplug mm/memory_hotplug.c
--- a/mm/memory_hotplug.c~mm-validate-device_hotplug-is-held-for-memory-hotplug
+++ a/mm/memory_hotplug.c
@@ -126,6 +126,8 @@ void put_online_mems(void)
void mem_hotplug_begin(void)
{
+ assert_held_device_hotplug();
+
mem_hotplug.active_writer = current;
memhp_lock_acquire();
_
Patches currently in -mm which might be from dan.j.williams@xxxxxxxxx are
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