Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'libnvdimm-fixes-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
"A fix for an issue that could causes users to inadvertantly reserve
too much capacity when debugging the KMSAN and persistent memory
namespace, a lockdep fix, and a kernel-doc build warning:
- Resolve the conflict between KMSAN and NVDIMM with respect to
reserving pmem namespace / volume capacity for larger sizeof(struct
page)
- Fix a lockdep warning in the the NFIT code
- Fix a kernel-doc build warning"
* tag 'libnvdimm-fixes-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
nvdimm: Support sizeof(struct page) > MAX_STRUCT_PAGE_SIZE
ACPI: NFIT: fix a potential deadlock during NFIT teardown
dax: super.c: fix kernel-doc bad line warning
+49
-18
+1
-1
drivers/acpi/nfit/core.c
+1
-1
drivers/acpi/nfit/core.c
···
3297
3297
3298
3298
mutex_lock(&acpi_desc->init_mutex);
3299
3299
set_bit(ARS_CANCEL, &acpi_desc->scrub_flags);
3300
-
cancel_delayed_work_sync(&acpi_desc->dwork);
3301
3300
mutex_unlock(&acpi_desc->init_mutex);
3301
+
cancel_delayed_work_sync(&acpi_desc->dwork);
3302
3302
3303
3303
/*
3304
3304
* Bounce the nvdimm bus lock to make sure any in-flight
+1
-1
drivers/dax/super.c
+1
-1
drivers/dax/super.c
+19
drivers/nvdimm/Kconfig
+19
drivers/nvdimm/Kconfig
···
102
102
depends on ENCRYPTED_KEYS
103
103
depends on (LIBNVDIMM=ENCRYPTED_KEYS) || LIBNVDIMM=m
104
104
105
+
config NVDIMM_KMSAN
106
+
bool
107
+
depends on KMSAN
108
+
help
109
+
KMSAN, and other memory debug facilities, increase the size of
110
+
'struct page' to contain extra metadata. This collides with
111
+
the NVDIMM capability to store a potentially
112
+
larger-than-"System RAM" size 'struct page' array in a
113
+
reservation of persistent memory rather than limited /
114
+
precious DRAM. However, that reservation needs to persist for
115
+
the life of the given NVDIMM namespace. If you are using KMSAN
116
+
to debug an issue unrelated to NVDIMMs or DAX then say N to this
117
+
option. Otherwise, say Y but understand that any namespaces
118
+
(with the page array stored pmem) created with this build of
119
+
the kernel will permanently reserve and strand excess
120
+
capacity compared to the CONFIG_KMSAN=n case.
121
+
122
+
Select N if unsure.
123
+
105
124
config NVDIMM_TEST_BUILD
106
125
tristate "Build the unit test core"
107
126
depends on m
+1
-1
drivers/nvdimm/nd.h
+1
-1
drivers/nvdimm/nd.h
···
652
652
struct nd_namespace_common *ndns);
653
653
#if IS_ENABLED(CONFIG_ND_CLAIM)
654
654
/* max struct page size independent of kernel config */
655
-
#define MAX_STRUCT_PAGE_SIZE 128
655
+
#define MAX_STRUCT_PAGE_SIZE 64
656
656
int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap);
657
657
#else
658
658
static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
+27
-15
drivers/nvdimm/pfn_devs.c
+27
-15
drivers/nvdimm/pfn_devs.c
···
13
13
#include "pfn.h"
14
14
#include "nd.h"
15
15
16
+
static const bool page_struct_override = IS_ENABLED(CONFIG_NVDIMM_KMSAN);
17
+
16
18
static void nd_pfn_release(struct device *dev)
17
19
{
18
20
struct nd_region *nd_region = to_nd_region(dev->parent);
···
760
758
return -ENXIO;
761
759
}
762
760
763
-
/*
764
-
* Note, we use 64 here for the standard size of struct page,
765
-
* debugging options may cause it to be larger in which case the
766
-
* implementation will limit the pfns advertised through
767
-
* ->direct_access() to those that are included in the memmap.
768
-
*/
769
761
start = nsio->res.start;
770
762
size = resource_size(&nsio->res);
771
763
npfns = PHYS_PFN(size - SZ_8K);
···
778
782
}
779
783
end_trunc = start + size - ALIGN_DOWN(start + size, align);
780
784
if (nd_pfn->mode == PFN_MODE_PMEM) {
785
+
unsigned long page_map_size = MAX_STRUCT_PAGE_SIZE * npfns;
786
+
781
787
/*
782
788
* The altmap should be padded out to the block size used
783
789
* when populating the vmemmap. This *should* be equal to
784
790
* PMD_SIZE for most architectures.
785
791
*
786
-
* Also make sure size of struct page is less than 128. We
787
-
* want to make sure we use large enough size here so that
788
-
* we don't have a dynamic reserve space depending on
789
-
* struct page size. But we also want to make sure we notice
790
-
* when we end up adding new elements to struct page.
792
+
* Also make sure size of struct page is less than
793
+
* MAX_STRUCT_PAGE_SIZE. The goal here is compatibility in the
794
+
* face of production kernel configurations that reduce the
795
+
* 'struct page' size below MAX_STRUCT_PAGE_SIZE. For debug
796
+
* kernel configurations that increase the 'struct page' size
797
+
* above MAX_STRUCT_PAGE_SIZE, the page_struct_override allows
798
+
* for continuing with the capacity that will be wasted when
799
+
* reverting to a production kernel configuration. Otherwise,
800
+
* those configurations are blocked by default.
791
801
*/
792
-
BUILD_BUG_ON(sizeof(struct page) > MAX_STRUCT_PAGE_SIZE);
793
-
offset = ALIGN(start + SZ_8K + MAX_STRUCT_PAGE_SIZE * npfns, align)
794
-
- start;
802
+
if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE) {
803
+
if (page_struct_override)
804
+
page_map_size = sizeof(struct page) * npfns;
805
+
else {
806
+
dev_err(&nd_pfn->dev,
807
+
"Memory debug options prevent using pmem for the page map\n");
808
+
return -EINVAL;
809
+
}
810
+
}
811
+
offset = ALIGN(start + SZ_8K + page_map_size, align) - start;
795
812
} else if (nd_pfn->mode == PFN_MODE_RAM)
796
813
offset = ALIGN(start + SZ_8K, align) - start;
797
814
else
···
827
818
pfn_sb->version_minor = cpu_to_le16(4);
828
819
pfn_sb->end_trunc = cpu_to_le32(end_trunc);
829
820
pfn_sb->align = cpu_to_le32(nd_pfn->align);
830
-
pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
821
+
if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE && page_struct_override)
822
+
pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
823
+
else
824
+
pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
831
825
pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
832
826
checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
833
827
pfn_sb->checksum = cpu_to_le64(checksum);