This is a note to let you know that I've just added the patch titled
libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
libnvdimm-dax-fix-1gb-aligned-namespaces-vs-physical-misalignment.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Feb 26 20:55:53 CET 2018
From: Dan Williams <dan.j.williams@xxxxxxxxx>
Date: Fri, 23 Feb 2018 14:06:05 -0800
Subject: libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment
To: gregkh@xxxxxxxxxxxxxxxxxxx
Cc: Jane Chu <jane.chu@xxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx
Message-ID: <151942356576.21775.15139045279160411096.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
From: Dan Williams <dan.j.williams@xxxxxxxxx>
commit 41fce90f26333c4fa82e8e43b9ace86c4e8a0120 upstream.
The following namespace configuration attempt:
# ndctl create-namespace -e namespace0.0 -m devdax -a 1G -f
libndctl: ndctl_dax_enable: dax0.1: failed to enable
Error: namespace0.0: failed to enable
failed to reconfigure namespace: No such device or address
...fails when the backing memory range is not physically aligned to 1G:
# cat /proc/iomem | grep Persistent
210000000-30fffffff : Persistent Memory (legacy)
In the above example the 4G persistent memory range starts and ends on a
256MB boundary.
We handle this case correctly when needing to handle cases that violate
section alignment (128MB) collisions against "System RAM", and we simply
need to extend that padding/truncation for the 1GB alignment use case.
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 315c562536c4 ("libnvdimm, pfn: add 'align' attribute...")
Reported-and-tested-by: Jane Chu <jane.chu@xxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/nvdimm/pfn_devs.c | 15 ++++++++++++---
include/linux/kernel.h | 1 +
2 files changed, 13 insertions(+), 3 deletions(-)
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -563,6 +563,12 @@ static struct vmem_altmap *__nvdimm_setu
return altmap;
}
+static u64 phys_pmem_align_down(struct nd_pfn *nd_pfn, u64 phys)
+{
+ return min_t(u64, PHYS_SECTION_ALIGN_DOWN(phys),
+ ALIGN_DOWN(phys, nd_pfn->align));
+}
+
static int nd_pfn_init(struct nd_pfn *nd_pfn)
{
u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0;
@@ -618,13 +624,16 @@ static int nd_pfn_init(struct nd_pfn *nd
start = nsio->res.start;
size = PHYS_SECTION_ALIGN_UP(start + size) - start;
if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
- IORES_DESC_NONE) == REGION_MIXED) {
+ IORES_DESC_NONE) == REGION_MIXED
+ || !IS_ALIGNED(start + resource_size(&nsio->res),
+ nd_pfn->align)) {
size = resource_size(&nsio->res);
- end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
+ end_trunc = start + size - phys_pmem_align_down(nd_pfn,
+ start + size);
}
if (start_pad + end_trunc)
- dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
+ dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n",
dev_name(&ndns->dev), start_pad + end_trunc);
/*
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -46,6 +46,7 @@
#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
+#define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a))
#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
Patches currently in stable-queue which might be from dan.j.williams@xxxxxxxxx are
queue-4.9/mm-fix-devm_memremap_pages-collision-handling.patch
queue-4.9/ib-core-disable-memory-registration-of-filesystem-dax-vmas.patch
queue-4.9/mm-avoid-spurious-bad-pmd-warning-messages.patch
queue-4.9/mm-introduce-get_user_pages_longterm.patch
queue-4.9/mm-fail-get_vaddr_frames-for-filesystem-dax-mappings.patch
queue-4.9/fs-dax.c-fix-inefficiency-in-dax_writeback_mapping_range.patch
queue-4.9/device-dax-implement-split-to-catch-invalid-munmap-attempts.patch
queue-4.9/v4l2-disable-filesystem-dax-mapping-support.patch
queue-4.9/libnvdimm-dax-fix-1gb-aligned-namespaces-vs-physical-misalignment.patch
queue-4.9/x86-entry-64-clear-extra-registers-beyond-syscall-arguments-to-reduce-speculation-attack-surface.patch
queue-4.9/libnvdimm-fix-integer-overflow-static-analysis-warning.patch