The pmem driver on PowerPC crashes with the following signature when
instantiating misaligned namespaces that map their capacity via
memremap_pages().
BUG: Unable to handle kernel data access at 0xc001000406000000
Faulting instruction address: 0xc000000000090790
NIP [c000000000090790] arch_add_memory+0xc0/0x130
LR [c000000000090744] arch_add_memory+0x74/0x130
Call Trace:
arch_add_memory+0x74/0x130 (unreliable)
memremap_pages+0x74c/0xa30
devm_memremap_pages+0x3c/0xa0
pmem_attach_disk+0x188/0x770
nvdimm_bus_probe+0xd8/0x470
With the assumption that only memremap_pages() has alignment
constraints, enforce memremap_compat_align() for
pmem_should_map_pages(), nd_pfn, and nd_dax cases. This includes
preventing the creation of namespaces where the base address is
misaligned and cases there infoblock padding parameters are invalid.
Reported-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
Cc: Jeff Moyer <jmo...@redhat.com>
Fixes: a3619190d62e ("libnvdimm/pfn: stop padding pmem namespaces to section
alignment")
Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
---
drivers/nvdimm/namespace_devs.c | 12 ++++++++++++
drivers/nvdimm/pfn_devs.c | 26 +++++++++++++++++++++++---
2 files changed, 35 insertions(+), 3 deletions(-)
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 032dc61725ff..68e89855f779 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -10,6 +10,7 @@
#include <linux/nd.h>
#include "nd-core.h"
#include "pmem.h"
+#include "pfn.h"
#include "nd.h"
static void namespace_io_release(struct device *dev)
@@ -1739,6 +1740,17 @@ struct nd_namespace_common
*nvdimm_namespace_common_probe(struct device *dev)
return ERR_PTR(-ENODEV);
}
+ if (pmem_should_map_pages(dev)) {
+ struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+ struct resource *res = &nsio->res;
+
+ if (!IS_ALIGNED(res->start | (res->end + 1),
+ memremap_compat_align())) {
+ dev_err(&ndns->dev, "%pr misaligned, unable to map\n",
res);
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+ }
+
if (is_namespace_pmem(&ndns->dev)) {
struct nd_namespace_pmem *nspm;
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 79fe02d6f657..3bdd4b883d05 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -446,6 +446,7 @@ static bool nd_supported_alignment(unsigned long align)
int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
{
u64 checksum, offset;
+ struct resource *res;
enum nd_pfn_mode mode;
struct nd_namespace_io *nsio;
unsigned long align, start_pad;
@@ -578,13 +579,14 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char
*sig)
* established.
*/
nsio = to_nd_namespace_io(&ndns->dev);
- if (offset >= resource_size(&nsio->res)) {
+ res = &nsio->res;
+ if (offset >= resource_size(res)) {
dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
dev_name(&ndns->dev));
return -EOPNOTSUPP;
}
- if ((align && !IS_ALIGNED(nsio->res.start + offset + start_pad, align))
+ if ((align && !IS_ALIGNED(res->start + offset + start_pad, align))
|| !IS_ALIGNED(offset, PAGE_SIZE)) {
dev_err(&nd_pfn->dev,
"bad offset: %#llx dax disabled align: %#lx\n",
@@ -592,6 +594,18 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
return -EOPNOTSUPP;
}
+ if (!IS_ALIGNED(res->start + le32_to_cpu(pfn_sb->start_pad),
+ memremap_compat_align())) {
+ dev_err(&nd_pfn->dev, "resource start misaligned\n");
+ return -EOPNOTSUPP;
+ }
+
+ if (!IS_ALIGNED(res->end + 1 - le32_to_cpu(pfn_sb->end_trunc),
+ memremap_compat_align())) {
+ dev_err(&nd_pfn->dev, "resource end misaligned\n");
+ return -EOPNOTSUPP;
+ }
+
return 0;
}
EXPORT_SYMBOL(nd_pfn_validate);
@@ -750,7 +764,13 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
start = nsio->res.start;
size = resource_size(&nsio->res);
npfns = PHYS_PFN(size - SZ_8K);
- align = max(nd_pfn->align, SUBSECTION_SIZE);
+ align = max(nd_pfn->align, memremap_compat_align());
+ if (!IS_ALIGNED(start, memremap_compat_align())) {
+ dev_err(&nd_pfn->dev, "%s: start %pa misaligned to %#lx\n",
+ dev_name(&ndns->dev), &start,
+ memremap_compat_align());
+ return -EINVAL;
+ }
end_trunc = start + size - ALIGN_DOWN(start + size, align);
if (nd_pfn->mode == PFN_MODE_PMEM) {
/*
