[v3,3/5] libnvdimm/namespace: Enforce memremap_compat_align()
diff mbox series

Message ID 158291748226.1609624.8971922874557923784.stgit@dwillia2-desk3.amr.corp.intel.com
State Superseded
Headers show
Series
  • libnvdimm: Cross-arch compatible namespace alignment
Related show

Commit Message

Dan Williams Feb. 28, 2020, 7:18 p.m. UTC
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")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/namespace_devs.c |   12 ++++++++++++
 drivers/nvdimm/pfn_devs.c       |   26 +++++++++++++++++++++++---
 2 files changed, 35 insertions(+), 3 deletions(-)

Comments

Aneesh Kumar K.V March 2, 2020, 12:08 p.m. UTC | #1
Dan Williams <dan.j.williams@intel.com> writes:

> 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.
>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

> 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")
> Signed-off-by: Dan Williams <dan.j.williams@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);
>  	}

May be add a comment here that both dax/fsdax namespace details are
checked in nd_pfn_validate() so that we look at start_pad and end_trunc
while validating the namespace?

>  
> +	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;
> +	}

This validates start in case of a new namespace creation where the user
updated nd_region->align value? A comment there would help when looking
at the code later?

>  	end_trunc = start + size - ALIGN_DOWN(start + size, align);
>  	if (nd_pfn->mode == PFN_MODE_PMEM) {
>  		/*
> _______________________________________________
> Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
> To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
Dan Williams March 2, 2020, 6:45 p.m. UTC | #2
On Mon, Mar 2, 2020 at 4:09 AM Aneesh Kumar K.V
<aneesh.kumar@linux.ibm.com> wrote:
>
> Dan Williams <dan.j.williams@intel.com> writes:
>
> > 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.
> >
>
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>
> > 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")
> > Signed-off-by: Dan Williams <dan.j.williams@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);
> >       }
>
> May be add a comment here that both dax/fsdax namespace details are
> checked in nd_pfn_validate() so that we look at start_pad and end_trunc
> while validating the namespace?
>
> >
> > +     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;
> > +     }
>
> This validates start in case of a new namespace creation where the user
> updated nd_region->align value? A comment there would help when looking
> at the code later?

Yeah, sounds good will respin with those updates.

Patch
diff mbox series

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) {
 		/*