OpenVMS System Services Reference Manual

Document revision date: 19 July 1999

OpenVMS System Services Reference Manual

Contents

Index

On VAX systems, this argument is not used for page file sections or physical page frame sections.

Description

The Create and Map Section service allows a process to associate (map) a section of its address space with (1) a specified section of a file (a disk file section) or (2) specified physical addresses represented by page frame numbers (a page frame section). This service also allows the process to create either type of section and to specify that the section be available only to the creating process (private section) or to all processes that map to it (global section).
Creating a disk file section involves defining all or part of a disk file as a section. Mapping a disk file section involves making a correspondence between virtual blocks in the file and pages (on VAX systems) or pagelets (on Alpha systems) in the caller's virtual address space. If the $CRMPSC service specifies a global section that already exists, the service maps it.
Any section created is created as entire pages. See the memory management section in the OpenVMS Programming Concepts Manual.
Depending on the actual operation requested, certain arguments are required or optional. Table SYS-6 summarizes how the $CRMPSC service interprets the arguments passed to it and under what circumstances it requires or ignores arguments.
The $CRMPSC service returns the virtual addresses of the virtual address space created in the retadr argument, if specified. The section is mapped from a low address to a high address, whether the section is mapped in the program or control region.
If an error occurs during the mapping of a global section, the retadr argument, if specified, indicates the pages that were successfully mapped when the error occurred. If no pages were mapped, the value of the longwords is indeterminate. In this case, either both longwords of the retadr argument will contain the value --1, or the value of the longwords will be unaltered.
The SEC$M_PFNMAP flag setting identifies the memory for the section as starting at the page frame number specified in the vbn argument and extending for the number of CPU-specific pages specified in the pagcnt argument. Setting the SEC$M_PFNMAP flag places restrictions on the following arguments.

Argument Restriction

chan Must be 0

pagcnt Must be specified; cannot be 0

vbn Specifies first page frame to be mapped

pfc Does not apply

SEC$M_CRF Must be 0

SEC$M_DZRO Must be 0

SEC$M_PERM Must be 1 if the flags SEC$M_GBL or SEC$M_SYSGBL are set

Setting the SEC$M_PAGFIL flag places the following restrictions on the following flags.

Flag Restriction

SEC$M_CRF Must be 0

SEC$M_DZRO Assumed to be 0

SEC$M_GBL Must be 1

SEC$M_PFNMAP Must be 0

SEC$M_WRT Assumed to be 0

The flags argument bits 4 through 13 and 18 through 31 must be 0.
If the global section is mapped to a file (neither SEC$M_PAGFIL nor SEC$M_PFNMAP is set), the security profile of the file is used to determine access to the global section.
On VAX systems, by default, the initial security profile created for a page file or PFN global section is taken from the group global section template. If the SEC$M_SYSGBL flag is set, the profile is taken from the system global section template. The owner is then set to the process UIC. If the prot argument is nonzero, it replaces the protection mask from the template.
On Alpha and VAX systems, the flag bit SEC$M_WRT applies only to the way in which the newly created section is mapped. For a file to be made writable, the channel used to open the file must allow write access to the file.
If the flag bit SEC$M_SYSGBL is set, the flag bit SEC$M_GBL must be set also.
Required Access or Privileges

If $CRMPSC specifies a global section and the SS$_NOPRIV condition value is returned, the process does not have the required privilege to create that section. In order to create global sections, the process must have the following privileges:

SYSGBL privilege to create a system global section
PRMGBL privilege to create a permanent global section
PFNMAP privilege to create a page frame section
SHMEM privilege to create a global section in memory shared by multiple processors (VAX only)

Note that you do not need PFNMAP privilege to map an existing page frame section.
Required Quota

If the section pages are copy-on-reference, the process must have sufficient paging file quota (PGFLQUOTA). The systemwide number of global page file pages is limited by the SYSGEN parameter GBLPAGFIL.
Related Services

$ADJSTK, $ADJWSL, $CRETVA, $DELTVA, $DGBLSC, $EXPREG, $LCKPAG, $LKWSET, $MGBLSC, $PURGWS, $SETPRT, $SETSTK, $SETSWM, $ULKPAG, $ULWSET, $UPDSEC, $UPDSECW

Argument	Restriction
chan	Must be 0
pagcnt	Must be specified; cannot be 0
vbn	Specifies first page frame to be mapped
pfc	Does not apply
SEC$M_CRF	Must be 0
SEC$M_DZRO	Must be 0
SEC$M_PERM	Must be 1 if the flags SEC$M_GBL or SEC$M_SYSGBL are set

Flag	Restriction
SEC$M_CRF	Must be 0
SEC$M_DZRO	Assumed to be 0
SEC$M_GBL	Must be 1
SEC$M_PFNMAP	Must be 0
SEC$M_WRT	Assumed to be 0

Condition Values Returned

SS$_NORMAL The service completed successfully. The specified global section already exists and has been mapped.

SS$_CREATED The service completed successfully. The specified global section did not previously exist and has been created.

SS$_ACCVIO The inadr argument, gsdnam argument, or name descriptor cannot be read by the caller; the inadr argument was omitted; or the retadr argument cannot be written by the caller.

SS$_ENDOFFILE The starting virtual block number specified is beyond the logical end-of-file, or the value in the relpag argument is greater than or equal to the actual size of the global section.

SS$_EXBYTLM The process has exceeded the byte count quota; the system was unable to map the requested file.

SS$_EXGBLPAGFIL The process has exceeded the systemwide limit on global page file pages; no part of the section was mapped.

SS$_EXQUOTA The process exceeded its paging file quota while creating copy-on-reference or page file backing store pages.

SS$_GPTFULL There is no more room in the system global page table to set up page table entries for the section.

SS$_GSDFULL There is no more room in the system space allocated to maintain control information for global sections.

SS$_ILLPAGCNT The page count value is negative or is 0 for a physical page frame section.

SS$_INSFMEM Not enough pages are available in the specified shared memory to create the section.

SS$_INSFWSL The process's working set limit is not large enough to accommodate the increased size of the address space.

SS$_IVCHAN An invalid channel number was specified, that is, a channel number of 0 or a number larger than the number of channels available.

SS$_IVCHNLSEC The channel number specified is currently active.

SS$_IVLOGNAM The specified global section name has a length of 0 or has more than 43 characters.

SS$_IVLVEC The specified section was not installed using the /PROTECT qualifier.

SS$_IVSECFLG An invalid flag, a reserved flag, a flag requiring a privilege you lack, or an invalid combination of flags was specified.

SS$_IVSECIDCTL The match control field of the global section identification is invalid.

SS$_NOPRIV The process does not have the privileges to create a system global section (SYSGBL) or a permanent group global section (PRMGBL).
The process does not have the privilege to create a section starting at a specific physical page frame number (PFNMAP).
The process does not have the privilege to create a global section in memory shared by multiple processors (SHMEM).
A page in the input address range is in the system address space.
The specified channel is not assigned or was assigned from a more privileged access mode.

SS$_NOSHPTS A virtual address within a shared page table region was specified.

SS$_NOTFILEDEV The device is not a file-oriented, random-access, or directory device.

SS$_NOWRT The section cannot be written to because the flag bit SEC$M_WRT is set, the file is read only, and the flag bit SEC$M_CRF is not set.

SS$_PAGOWNVIO A page in the specified input address range is owned by a more privileged access mode.

SS$_SECREFOVF The maximum number of references for a global section has been reached (2,147,483,647).

SS$_SECTBLFUL There are no entries available in the system global section table or in the process section table.

SS$_TOOMANYLNAM The logical name translation of the gsdnam argument exceeded the allowed depth.

SS$_VA_IN_USE A page in the specified input address range is already mapped, and the flag SEC$M_NO_OVERMAP is set, or the existing underlying page cannot be deleted because it is associated with a buffer object.

SS$_VASFULL The process's virtual address space is full; no space is available in the page tables for the pages created to contain the mapped global section.

$CRMPSC_FILE_64 (Alpha Only)

On Alpha systems, allows a process to map a section of its address space to a specified portion of a file. This service creates and maps a private disk file section.
This service accepts 64-bit addresses.

Format

SYS$CRMPSC_FILE_64 region_id_64 ,file_offset_64 ,length_64 ,chan ,acmode ,flags ,return_va_64 ,return_length_64 [,fault_cluster [,start_va_64]]

C Prototype

int sys$crmpsc_file_64 (struct _generic_64 *region_id_64, unsigned __int64 file_offset_64, unsigned __int64 length_64, unsigned short int chan, unsigned int acmode, unsigned int flags, void *(*(return_va_64)), unsigned __int64 *return_length_64,...);

Arguments

region_id_64

OpenVMS usage: region identifier

type: quadword (unsigned)

access: read only

mechanism: by 32- or 64-bit reference

The region ID associated with the region to map the private disk file section. The file VADEF.H in SYS$STARLET_C.TLB and the $VADEF macro in STARLET.MLB define a symbolic name for each of the three default regions in P0, P1, and P2 space. The following region IDs are defined:

Symbol Region

VA$C_P0 Program region

VA$C_P1 Control region

VA$C_P2 64-bit program region

Other region IDs, as returned by the $CREATE_REGION_64 service, can be specified.
file_offset_64

OpenVMS usage: byte offset

type: quadword (unsigned)

access: read only

mechanism: by value

Byte offset into the file that marks the beginning of the section. The file_offset_64 argument is a quadword containing this number. If you specify the file_offset_64 argument as 0, the section is created beginning with the first byte in the file.
The file_offset_64 argument must be a multiple of virtual disk blocks.
length_64

OpenVMS usage: byte count

type: quadword (unsigned)

access: read only

mechanism: value

Length, in bytes, of the private disk file section to be created and mapped to. The length specified must be 0 or a multiple of virtual disk blocks. If the length specified is 0 or extends beyond end-of-file (EOF), the disk file is mapped up to and including the virtual block number that contains EOF.
chan

OpenVMS usage: longword

type: longword (unsigned)

access: read only

mechanism: by value

Number of the channel on which the file has been accessed. The chan argument is a longword containing this number. The access mode at which the channel was opened must be equal to or less privileged than the access mode of the caller.
Use the OpenVMS Record Management Services (RMS) macro $OPEN to access a file; the file options parameter in the file access block must indicate a user file open (UFO) keyword.
acmode

OpenVMS usage: access_mode

type: longword (unsigned)

access: read only

mechanism: by value

Access mode that is to be the owner of the pages created during the mapping. The acmode argument is a longword containing the access mode.
The $PSLDEF macro in STARLET.MLB and the file PSLDEF.H in SYS$STARLET_C.TLB define the following symbols and their values for the four access modes:

Value Symbolic Name Access Mode

0 PSL$C_KERNEL Kernel

1 PSL$C_EXEC Executive

2 PSL$C_SUPER Supervisor

3 PSL$C_USER User

The most privileged access mode used is the access mode of the caller. The calling process can delete pages only if those pages are owned by an access mode equal to or less privileged than the access mode of the calling process.
flags

OpenVMS usage: mask_longword

type: longword (unsigned)

access: read only

mechanism: by value

Flag mask specifying the characteristics of the private section to be created. The flags argument is a longword bit vector in which each bit corresponds to a flag. The $SECDEF macro and the SECDEF.H file define a symbolic name for each flag. You construct the flags argument by performing a logical OR operation on the symbol names for all desired flags.
The following table describes each flag that is valid for the $CRMPSC_FILE_64 service:

Flag Description

SEC$M_CRF Pages are copy-on-reference.

SEC$M_DZRO Pages are demand-zero pages. By default, they are not zeroed when copied.
Note that SEC$M_DZRO and SEC$M_CRF cannot both be set and that SEC$M_DZRO set and SEC$M_WRT clear is an invalid combination.

SEC$M_EXPREG Pages are mapped into the first available space at the current end of the specified region.

SEC$M_NO_OVERMAP Pages cannot overmap existing address space. By default, pages can overmap existing address space.

SEC$M_WRT Pages form a read/write section. By default, pages form a read-only section.

All other bits in the flags argument are reserved for future use by Compaq and should be specified as 0. The condition value SS$_IVSECFLG is returned if any undefined bits are set or if an illegal combination of flags is set.
return_va_64

OpenVMS usage: address

type: quadword address

access: write only

mechanism: by 32- or 64-bit reference

The lowest process virtual address into which the private disk file section was mapped. The return_va_64 argument is the 32- or 64-bit virtual address of a naturally aligned quadword into which the service returns the virtual address.
return_length_64

OpenVMS usage: byte count

type: quadword (unsigned)

access: write only

mechanism: by 32- or 64-bit reference

The 32- or 64-bit virtual address of a naturally aligned quadword into which the service returns the length of the usable virtual address range mapped in bytes. This length might differ from the total amount mapped. If the section being mapped does not completely fill the last page used to map the section, the return_va_64 and return_length_64 arguments indicate the highest address that actually maps the section.
fault_cluster

OpenVMS usage: byte count

type: longword (unsigned)

access: read only

mechanism: by value

Page fault cluster in byte units indicating how many pages are to be brought into memory when a page fault occurs for a single page. The fault cluster specified will be rounded up to a multiple of CPU-specific pages.
If this argument is specified as 0, the process default page fault cluster will be used. If this argument is specified as more than the maximum allowed for the system, no condition value will be returned. The systemwide maximum will be used.
start_va_64

OpenVMS usage: address

type: quadword address

access: read only

mechanism: by value

The starting virtual address to map the private disk file section. The specified virtual address must be a CPU-specific page aligned address. If the flag SEC$M_EXPREG is specified, the start_va_64 argument must not be specified or must be specified as 0. If SEC$M_EXPREG is set and the start_va_64 argument is nonzero, the condition value SS$_IVSECFLG is returned.

Symbol	Region
VA$C_P0	Program region
VA$C_P1	Control region
VA$C_P2	64-bit program region

Value	Symbolic Name	Access Mode
0	PSL$C_KERNEL	Kernel
1	PSL$C_EXEC	Executive
2	PSL$C_SUPER	Supervisor
3	PSL$C_USER	User

Flag	Description
SEC$M_CRF	Pages are copy-on-reference.
SEC$M_DZRO	Pages are demand-zero pages. By default, they are not zeroed when copied. Note that SEC$M_DZRO and SEC$M_CRF cannot both be set and that SEC$M_DZRO set and SEC$M_WRT clear is an invalid combination.
SEC$M_EXPREG	Pages are mapped into the first available space at the current end of the specified region.
SEC$M_NO_OVERMAP	Pages cannot overmap existing address space. By default, pages can overmap existing address space.
SEC$M_WRT	Pages form a read/write section. By default, pages form a read-only section.

Description

The Create and Map Private Disk File Section service allows a process to create a map to a private disk file section. Creating a private disk file section involves mapping all or part of a disk file as a section. The section is mapped from a low address to a high address whether the section is mapped in a region that grows from low to high addresses or from high to low addresses.
The flag SEC$M_WRT applies only to the way in which the newly created section is mapped. For a file to be made writable, the channel used to open the file must allow write access to the file.
If the condition value SS$_ACCVIO is returned by this service, a value cannot be returned in the memory locations pointed to by the return_va_64 and return_length_64 arguments.
If a condition value other than SS$_ACCVIO is returned, the returned address and returned length indicate the pages that were successfully mapped before the error occurred. If no pages were mapped, the return_va_64 argument will contain the value --1, and a value cannot be returned in the memory location pointed to by the return_length_64 argument.
Required Privileges

None
Required Quota

The working set quota (WSQUOTA) of the process must be sufficient to accommodate the increased length of the process page table required by the increase in virtual address space.
The process must have sufficient byte count quota to satisfy the request.
If the section pages are copy-on-reference, the process must have sufficient paging file quota (PGFLQUOTA).
Related Services

$CREATE_REGION_64, $CRMPSC, $CRMPSC_GFILE_64, $CRMPSC_GPFILE_64, $CRMPSC_GPFN_64, $CRMPSC_PFN_64, $DELETE_REGION_64, $DELTVA_64, $LCKPAG_64, $LKWSET_64, $PURGE_WS, $SETPRT_64, $ULKPAG_64, $ULWSET_64, $UPDSEC_64, $UPDSEC_64W

Condition Values Returned

SS$_NORMAL The service completed successfully.

SS$_ACCVIO The return_va_64 argument or the return_length_64 argument cannot be written by the caller.

SS$_CHANVIO The specified channel was assigned from a more privileged access mode.

SS$_ENDOFFILE The file_offset_64 argument specified is beyond the logical end-of-file.

SS$_EXBYTLM The process has exceeded the byte count quota; the system was unable to map the requested file.

SS$_EXPGFLQUOTA The process exceeded its paging file quota.

SS$_INSFWSL The process's working set limit is not large enough to accommodate the increased virtual address space.

SS$_IVCHAN An invalid channel number was specified; the channel number specified was 0 or a channel that is unassigned.

SS$_IVCHNLSEC The channel number specified is currently active, or there are no files opened on the specified channel.

SS$_IVIDENT An invalid channel number was specified; the channel number specified is larger than the number of channels available.

SS$_IVLOGNAM The specified global section name has a length of 0 or has more than 43 characters.

SS$_IVREGID Invalid region ID specified.

SS$_IVSECFLG An invalid flag, a reserved flag, or an invalid combination of flags and arguments was specified.

SS$_LEN_NOTBLKMULT The length_64 argument is not a multiple of virtual disk blocks.

SS$_NOSHPTS A virtual address within a shared page table region was specified.

SS$_NOTFILEDEV The device is not a file-oriented, random-access, or directory device.

SS$_OFF_NOTBLKALGN The file_offset_64 argument is not a multiple of virtual disk blocks.

SS$_NOWRT The file is read-only, the flag bit SEC$M_WRT was set, and the flag bit SEC$M_CRF is not set.

SS$_PAGNOTINREG A page in the specified range is not within the specified region.

SS$_PAGOWNVIO A page in the specified range already exists and cannot be deleted because it is owned by a more privileged access mode than that of the caller.

SS$_REGISFULL The specified virtual region is full; no space is available in the region for the pages created to contain the mapped section.

SS$_VA_IN_USE A page in the specified input address range is already mapped and the flag SEC$M_NO_OVERMAP is set, or the existing underlying page cannot be deleted because it is associated with a buffer object.

SS$_VA_NOTPAGALGN The start_va_64 argument is not CPU-specific page aligned.

Contents

Index

privacy and legal statement

4527PRO_020.HTML

SS$_NORMAL	The service completed successfully. The specified global section already exists and has been mapped.
SS$_CREATED	The service completed successfully. The specified global section did not previously exist and has been created.
SS$_ACCVIO	The inadr argument, gsdnam argument, or name descriptor cannot be read by the caller; the inadr argument was omitted; or the retadr argument cannot be written by the caller.
SS$_ENDOFFILE	The starting virtual block number specified is beyond the logical end-of-file, or the value in the relpag argument is greater than or equal to the actual size of the global section.
SS$_EXBYTLM	The process has exceeded the byte count quota; the system was unable to map the requested file.
SS$_EXGBLPAGFIL	The process has exceeded the systemwide limit on global page file pages; no part of the section was mapped.
SS$_EXQUOTA	The process exceeded its paging file quota while creating copy-on-reference or page file backing store pages.
SS$_GPTFULL	There is no more room in the system global page table to set up page table entries for the section.
SS$_GSDFULL	There is no more room in the system space allocated to maintain control information for global sections.
SS$_ILLPAGCNT	The page count value is negative or is 0 for a physical page frame section.
SS$_INSFMEM	Not enough pages are available in the specified shared memory to create the section.
SS$_INSFWSL	The process's working set limit is not large enough to accommodate the increased size of the address space.
SS$_IVCHAN	An invalid channel number was specified, that is, a channel number of 0 or a number larger than the number of channels available.
SS$_IVCHNLSEC	The channel number specified is currently active.
SS$_IVLOGNAM	The specified global section name has a length of 0 or has more than 43 characters.
SS$_IVLVEC	The specified section was not installed using the /PROTECT qualifier.
SS$_IVSECFLG	An invalid flag, a reserved flag, a flag requiring a privilege you lack, or an invalid combination of flags was specified.
SS$_IVSECIDCTL	The match control field of the global section identification is invalid.
SS$_NOPRIV	The process does not have the privileges to create a system global section (SYSGBL) or a permanent group global section (PRMGBL). The process does not have the privilege to create a section starting at a specific physical page frame number (PFNMAP). The process does not have the privilege to create a global section in memory shared by multiple processors (SHMEM). A page in the input address range is in the system address space. The specified channel is not assigned or was assigned from a more privileged access mode.
SS$_NOSHPTS	A virtual address within a shared page table region was specified.
SS$_NOTFILEDEV	The device is not a file-oriented, random-access, or directory device.
SS$_NOWRT	The section cannot be written to because the flag bit SEC$M_WRT is set, the file is read only, and the flag bit SEC$M_CRF is not set.
SS$_PAGOWNVIO	A page in the specified input address range is owned by a more privileged access mode.
SS$_SECREFOVF	The maximum number of references for a global section has been reached (2,147,483,647).
SS$_SECTBLFUL	There are no entries available in the system global section table or in the process section table.
SS$_TOOMANYLNAM	The logical name translation of the gsdnam argument exceeded the allowed depth.
SS$_VA_IN_USE	A page in the specified input address range is already mapped, and the flag SEC$M_NO_OVERMAP is set, or the existing underlying page cannot be deleted because it is associated with a buffer object.
SS$_VASFULL	The process's virtual address space is full; no space is available in the page tables for the pages created to contain the mapped global section.

OpenVMS usage:	region identifier
type:	quadword (unsigned)
access:	read only
mechanism:	by 32- or 64-bit reference

OpenVMS usage:	byte offset
type:	quadword (unsigned)
access:	read only
mechanism:	by value

OpenVMS usage:	byte count
type:	quadword (unsigned)
access:	read only
mechanism:	value

OpenVMS usage:	longword
type:	longword (unsigned)
access:	read only
mechanism:	by value

OpenVMS usage:	access_mode
type:	longword (unsigned)
access:	read only
mechanism:	by value

OpenVMS usage:	mask_longword
type:	longword (unsigned)
access:	read only
mechanism:	by value

OpenVMS usage:	address
type:	quadword address
access:	write only
mechanism:	by 32- or 64-bit reference

SS$_NORMAL	The service completed successfully.
SS$_ACCVIO	The return_va_64 argument or the return_length_64 argument cannot be written by the caller.
SS$_CHANVIO	The specified channel was assigned from a more privileged access mode.
SS$_ENDOFFILE	The file_offset_64 argument specified is beyond the logical end-of-file.
SS$_EXBYTLM	The process has exceeded the byte count quota; the system was unable to map the requested file.
SS$_EXPGFLQUOTA	The process exceeded its paging file quota.
SS$_INSFWSL	The process's working set limit is not large enough to accommodate the increased virtual address space.
SS$_IVCHAN	An invalid channel number was specified; the channel number specified was 0 or a channel that is unassigned.
SS$_IVCHNLSEC	The channel number specified is currently active, or there are no files opened on the specified channel.
SS$_IVIDENT	An invalid channel number was specified; the channel number specified is larger than the number of channels available.
SS$_IVLOGNAM	The specified global section name has a length of 0 or has more than 43 characters.
SS$_IVREGID	Invalid region ID specified.
SS$_IVSECFLG	An invalid flag, a reserved flag, or an invalid combination of flags and arguments was specified.
SS$_LEN_NOTBLKMULT	The length_64 argument is not a multiple of virtual disk blocks.
SS$_NOSHPTS	A virtual address within a shared page table region was specified.
SS$_NOTFILEDEV	The device is not a file-oriented, random-access, or directory device.
SS$_OFF_NOTBLKALGN	The file_offset_64 argument is not a multiple of virtual disk blocks.
SS$_NOWRT	The file is read-only, the flag bit SEC$M_WRT was set, and the flag bit SEC$M_CRF is not set.
SS$_PAGNOTINREG	A page in the specified range is not within the specified region.
SS$_PAGOWNVIO	A page in the specified range already exists and cannot be deleted because it is owned by a more privileged access mode than that of the caller.
SS$_REGISFULL	The specified virtual region is full; no space is available in the region for the pages created to contain the mapped section.
SS$_VA_IN_USE	A page in the specified input address range is already mapped and the flag SEC$M_NO_OVERMAP is set, or the existing underlying page cannot be deleted because it is associated with a buffer object.
SS$_VA_NOTPAGALGN	The start_va_64 argument is not CPU-specific page aligned.