diff options
| author |   Dan Williams <dan.j.williams@intel.com> | 2022-09-24 18:14:12 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2022-09-24 18:14:12 -0700 |
| commit | b3bbcc5d1da1b654091dad15980b3d58fdae0fc6 (patch) | |
| tree | 77795fbece4fc61a659ed97c70d798ca81f35bb8 /include/linux/pgtable.h | |
| parent | fsdax: Fix infinite loop in dax_iomap_rw() (diff) | |
| parent | devdax: Fix soft-reservation memory description (diff) | |
Merge branch 'for-6.0/dax' into libnvdimm-fixes
Pick up another "Soft Reservation" fix for v6.0-final on top of some
straggling nvdimm fixes that missed v5.19.
Diffstat (limited to 'include/linux/pgtable.h')
| -rw-r--r-- | include/linux/pgtable.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 3cdc16cfd867..014ee8f0fbaa 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1689,4 +1689,32 @@ typedef unsigned int pgtbl_mod_mask; #define MAX_PTRS_PER_P4D PTRS_PER_P4D #endif +/* description of effects of mapping type and prot in current implementation. + * this is due to the limited x86 page protection hardware. The expected + * behavior is in parens: + * + * map_type prot + * PROT_NONE PROT_READ PROT_WRITE PROT_EXEC + * MAP_SHARED r: (no) no r: (yes) yes r: (no) yes r: (no) yes + * w: (no) no w: (no) no w: (yes) yes w: (no) no + * x: (no) no x: (no) yes x: (no) yes x: (yes) yes + * + * MAP_PRIVATE r: (no) no r: (yes) yes r: (no) yes r: (no) yes + * w: (no) no w: (no) no w: (copy) copy w: (no) no + * x: (no) no x: (no) yes x: (no) yes x: (yes) yes + * + * On arm64, PROT_EXEC has the following behaviour for both MAP_SHARED and + * MAP_PRIVATE (with Enhanced PAN supported): + * r: (no) no + * w: (no) no + * x: (yes) yes + */ +#define DECLARE_VM_GET_PAGE_PROT \ +pgprot_t vm_get_page_prot(unsigned long vm_flags) \ +{ \ + return protection_map[vm_flags & \ + (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)]; \ +} \ +EXPORT_SYMBOL(vm_get_page_prot); + #endif /* _LINUX_PGTABLE_H */ |