#include <paging_types.h>

Data Fields
union {

uint64_t raw

struct {

uint64_t present: 1
	If set the page is present in memory and readable. More...

uint64_t write: 1
	If set the page is writable. More...

uint64_t user: 1
	If set the page is accessible from user mode. More...

uint64_t writeThrough: 1
	If set write-through caching is enabled for the page. More...

uint64_t cacheDisabled: 1
	If set caching is disabled for the page. More...

uint64_t accessed: 1
	If set the page has been accessed (read or written to). More...

uint64_t dirty: 1
	If set the page has been written to. More...

uint64_t size: 1

uint64_t global: 1
	If set the page is not flushed from the TLB on a context switch. More...

uint64_t owned: 1

uint64_t pinned: 1

uint64_t lowCallbackId: 1

uint64_t addr: 40
	The address contained in the entry, note that this is shifted right by 12 bits. More...

uint64_t highCallbackId: 7

uint64_t protection: 4

uint64_t noExecute: 1

}

};

Detailed Description

Definition at line 37 of file paging_types.h.

Field Documentation

◆ [union]

union { ... } pml_entry_t

◆ accessed

uint64_t pml_entry_t::accessed

If set the page has been accessed (read or written to).

Definition at line 48 of file paging_types.h.

◆ addr

uint64_t pml_entry_t::addr

The address contained in the entry, note that this is shifted right by 12 bits.

Definition at line 79 of file paging_types.h.

Referenced by page_table_get_phys_addr(), page_table_map(), page_table_map_pages(), and pml_accessible_addr().

◆ cacheDisabled

uint64_t pml_entry_t::cacheDisabled

If set caching is disabled for the page.

Definition at line 47 of file paging_types.h.

◆ dirty

uint64_t pml_entry_t::dirty

If set the page has been written to.

Definition at line 49 of file paging_types.h.

◆ global

uint64_t pml_entry_t::global

If set the page is not flushed from the TLB on a context switch.

Definition at line 51 of file paging_types.h.

◆ highCallbackId

uint64_t pml_entry_t::highCallbackId

The high bits of the callback ID associated with this page.

Check the virtual memory manager for more information. (Defined by PatchworkOS)

Definition at line 85 of file paging_types.h.

Referenced by page_table_collect_callbacks(), page_table_map(), and page_table_map_pages().

◆ lowCallbackId

uint64_t pml_entry_t::lowCallbackId

The low bit of the callback ID associated with this page.

Check the virtual memory manager for more information. (Defined by PatchworkOS)

Definition at line 78 of file paging_types.h.

Referenced by page_table_collect_callbacks(), page_table_map(), and page_table_map_pages().

◆ noExecute

uint64_t pml_entry_t::noExecute

Definition at line 87 of file paging_types.h.

◆ owned

uint64_t pml_entry_t::owned

If set, then when the entry is unmapped or the page table is freed, the physical page will be freed. (Defined by PatchworkOS)

Definition at line 56 of file paging_types.h.

Referenced by page_table_clear(), page_table_set_flags(), pml_free(), and space_map_kernel_space_region().

◆ pinned

uint64_t pml_entry_t::pinned

If set, the page is pinned and cannot be unmapped or have its mappings modified.

Used to prevent TOCTOU vulnerabilities by preventing a page from being unmapped or its mappings modified while its being used, in for example a system call.

For performance the paging code will never check this flag instead its the responsibility of the virtual memory manager to check this flag.

Note that recursive pinning is implemented in the virtual memory manager, not here, meaning that this flag only indicates if the page is pinned or not, for faster access, while the pin depth is tracked elsewhere.

(Defined by PatchworkOS)

Definition at line 72 of file paging_types.h.

Referenced by page_table_is_pinned(), space_pin_depth_dec(), and space_pin_depth_inc().

◆ present

uint64_t pml_entry_t::present

If set the page is present in memory and readable.

Definition at line 43 of file paging_types.h.

Referenced by page_table_clear(), page_table_collect_callbacks(), page_table_find_unmapped_region(), page_table_get_phys_addr(), page_table_get_pml(), page_table_is_mapped(), page_table_is_pinned(), page_table_is_unmapped(), page_table_map(), page_table_map_pages(), page_table_set_flags(), page_table_unmap(), pml_free(), space_pin_depth_dec(), and space_pin_depth_inc().

◆ protection

uint64_t pml_entry_t::protection

Definition at line 86 of file paging_types.h.

◆ raw

uint64_t pml_entry_t::raw

Definition at line 40 of file paging_types.h.

Referenced by page_table_clear(), page_table_clear_pml1_pml2_pml3(), page_table_get_pml(), page_table_map(), page_table_map_pages(), page_table_set_flags(), pml_is_empty(), space_unmap_kernel_space_region(), and vmm_unmap_bootloader_lower_half().

◆ size

uint64_t pml_entry_t::size

Definition at line 50 of file paging_types.h.

◆ user

uint64_t pml_entry_t::user

If set the page is accessible from user mode.

Definition at line 45 of file paging_types.h.

◆ write

uint64_t pml_entry_t::write

If set the page is writable.

Definition at line 44 of file paging_types.h.

◆ writeThrough

uint64_t pml_entry_t::writeThrough

If set write-through caching is enabled for the page.

Definition at line 46 of file paging_types.h.

The documentation for this struct was generated from the following file:

include/kernel/mem/paging_types.h

Data Fields