From: David Hildenbrand <david@xxxxxxxxxx> [ Upstream commit 5666848774ef43d3db5151ec518f1deb63515c20 ] Let's perform all checking + offlining + removing under device_hotplug_lock, so nobody can mess with these devices via sysfs concurrently. [david@xxxxxxxxxx: take device_hotplug_lock outside of loop] Link: http://lkml.kernel.org/r/20180927092554.13567-6-david@xxxxxxxxxx Link: http://lkml.kernel.org/r/20180925091457.28651-6-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx> Reviewed-by: Rashmica Gupta <rashmica.g@xxxxxxxxx> Acked-by: Balbir Singh <bsingharora@xxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Rashmica Gupta <rashmica.g@xxxxxxxxx> Cc: Michael Neuling <mikey@xxxxxxxxxxx> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: John Allen <jallen@xxxxxxxxxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: Kate Stewart <kstewart@xxxxxxxxxxxxxxxxxxx> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Mathieu Malaterre <malat@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Nathan Fontenot <nfont@xxxxxxxxxxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Philippe Ombredanne <pombredanne@xxxxxxxx> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: YASUAKI ISHIMATSU <yasu.isimatu@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/powerpc/platforms/powernv/memtrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index c9a6d4f3403ce..cfbd242c3e011 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -99,6 +99,7 @@ static int change_memblock_state(struct memory_block *mem, void *arg) return 0; } +/* called with device_hotplug_lock held */ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) { u64 end_pfn = start_pfn + nr_pages - 1; @@ -139,6 +140,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) /* Trace memory needs to be aligned to the size */ end_pfn = round_down(end_pfn - nr_pages, nr_pages); + lock_device_hotplug(); for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) { if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) { /* @@ -147,7 +149,6 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) * we never try to remove memory that spans two iomem * resources. */ - lock_device_hotplug(); end_pfn = base_pfn + nr_pages; for (pfn = base_pfn; pfn < end_pfn; pfn += bytes>> PAGE_SHIFT) { remove_memory(nid, pfn << PAGE_SHIFT, bytes); @@ -156,6 +157,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) return base_pfn << PAGE_SHIFT; } } + unlock_device_hotplug(); return 0; } -- 2.20.1
