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author | Dan Williams <dan.j.williams@intel.com> | 2020-02-27 21:39:23 -0800 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2020-03-17 12:23:21 -0700 |
commit | 6acd7d5ef264d8e9a8988cebf6eeb3567eaf60c6 (patch) | |
tree | 38b3ebe83d3d4dbd380c7da6e7769f8a17c92463 /drivers/nvdimm | |
parent | b2ba7e91fa81bec9b64c47ab852145559cad2b68 (diff) | |
download | linux-6acd7d5ef264d8e9a8988cebf6eeb3567eaf60c6.tar.gz linux-6acd7d5ef264d8e9a8988cebf6eeb3567eaf60c6.tar.bz2 linux-6acd7d5ef264d8e9a8988cebf6eeb3567eaf60c6.zip |
libnvdimm/namespace: Enforce memremap_compat_align()
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.kumar@linux.ibm.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Fixes: a3619190d62e ("libnvdimm/pfn: stop padding pmem namespaces to section alignment")
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm')
-rw-r--r-- | drivers/nvdimm/namespace_devs.c | 17 | ||||
-rw-r--r-- | drivers/nvdimm/pfn.h | 12 | ||||
-rw-r--r-- | drivers/nvdimm/pfn_devs.c | 32 |
3 files changed, 58 insertions, 3 deletions
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index 032dc61725ff..77e211c7d94d 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 +1740,22 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev) return ERR_PTR(-ENODEV); } + /* + * Note, alignment validation for fsdax and devdax mode + * namespaces happens in nd_pfn_validate() where infoblock + * padding parameters can be applied. + */ + 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.h b/drivers/nvdimm/pfn.h index acb19517f678..37cb1b8a2a39 100644 --- a/drivers/nvdimm/pfn.h +++ b/drivers/nvdimm/pfn.h @@ -24,6 +24,18 @@ struct nd_pfn_sb { __le64 npfns; __le32 mode; /* minor-version-1 additions for section alignment */ + /** + * @start_pad: Deprecated attribute to pad start-misaligned namespaces + * + * start_pad is deprecated because the original definition did + * not comprehend that dataoff is relative to the base address + * of the namespace not the start_pad adjusted base. The result + * is that the dax path is broken, but the block-I/O path is + * not. The kernel will no longer create namespaces using start + * padding, but it still supports block-I/O for legacy + * configurations mainly to allow a backup, reconfigure the + * namespace, and restore flow to repair dax operation. + */ __le32 start_pad; __le32 end_trunc; /* minor-version-2 record the base alignment of the mapping */ diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 79fe02d6f657..34db557dbad1 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 +764,19 @@ 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()); + + /* + * When @start is misaligned fail namespace creation. See + * the 'struct nd_pfn_sb' commentary on why ->start_pad is not + * an option. + */ + 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) { /* |