[PATCH v3 3/5] libnvdimm/namespace: Enforce memremap_compat_align()
From: Dan Williams <hidden>
Date: 2020-02-28 19:34:10
Also in:
lkml, nvdimm
Subsystem:
libnvdimm: non-volatile memory device subsystem, the rest · Maintainers:
Dan Williams, Vishal Verma, Dave Jiang, Ira Weiny, Linus Torvalds
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 <redacted>
Cc: Jeff Moyer <redacted>
Fixes: a3619190d62e ("libnvdimm/pfn: stop padding pmem namespaces to section alignment")
Signed-off-by: Dan Williams <redacted>
---
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) { /*