HP-UX Reference (11i v2 04/09) - 2 System Calls (vol 5)
m
mmap(2) mmap(2)
ERRORS
The mmap() function will fail if:
[EBADF] The fildes argument is not a valid open file descriptor.
[EACCES] The fildes argument is not open for read, regardless of the protection specified, or
fildes is not open for write and
PROT_WRITE was specified for a MAP_SHARED type
mapping, or
PROT_EXECUTE was set for a
MAP_SHARED mapping operation and
the underlying file does not have execute permission.
[ENXIO] Addresses in the range [off, off+len ] are invalid for fildes .
[EINVAL] The addr argument (if
MAP_FIXED was specified) or off is not a multiple of the
page size as returned by
sysconf(), or are considered invalid by the implementa-
tion.
[EINVAL] The value of flags is invalid (neither
MAP_PRIVATE nor MAP_SHARED is set).
[EINVAL] The mapping already exists in 64-bit address space, but the application performing
the current
mmap() request has been compiled as a 32-bit executable.
[EINVAL] The mapping already exists in 32-bit address space, but the application performing
the current
mmap() request has been compiled as a 64-bit executable and did not
specify MAP_ADDR32 in the flags argument.
[EINVAL] The value of off+len exceeds the maximum supported offset for mapped files.
[EINVAL] The mapping request used the
MAP_IO flag and the requested range is not a valid
range of I/O memory, the requested range is already mapped as restricted to kernel
usage, or the mapping is for an address range which overlaps but is not equal to an
existing mapping.
[EMFILE] The number of mapped regions would exceed an implementation-dependent limit
(per process or per system).
[ENODEV] The fildes argument refers to a file whose type is not supported by
mmap().
[ENOMEM]
MAP_FIXED was specified, and the range [addr, addr +len ] exceeds that allowed
for the address space of a process. Or, MAP_FIXED was not specified and there is
insufficient room in the address space to effect the mapping.
[EOVERFLOW]
The file is a regular file and the value of off+len exceeds the offset maximum esta-
blished in the open file description associated with fildes.
[EPERM] The mapping request used the
MAP_IO flag and the calling process does not have
superuser privilege and is not a Real Time process.
[ETXTBSY]
MAP_SHARED and MAP_FILE are set, and PROT_EXECUTE is set and
PROT_WRITE is not set, and the file being mapped is currently open for writing.
DEPENDENCIES
PA-RISC Architecture
Because the PA-RISC memory architecture utilizes a globally shared virtual address space between
processes and discourages multiple virtual address translations to the same physical address, all con-
currently existing
MAP_SHARED mappings of a file range must share the same virtual address offsets
and hardware translations. PA-RISC-based HP-UX systems allocate virtual address ranges for shared
memory and shared mapped files in the range 0x80000000 through 0xefffffff for those applications com-
piled as 32-bit executables or for those 64-bit applications which specify MAP_SHARED and
MAP_ADDR32 in the flags argument of the mmap() function. For applications compiled as 64-bit execut-
ables which specify MAP_SHARED and do not specify MAP_ADDR32, the shared mapped files are in the
range 0x00000011 00000000 through 0x000003ff ffffffff and 0xc0000000 00000000 through 0xc00003ff
ffffffff. These address ranges are used globally for all memory objects shared between processes.
This implies the following:
• Any single range of a file cannot be mapped multiple times into different virtual address ranges.
• After the initial
MAP_SHARED mmap() of a file range, all subsequent MAP_SHARED calls to
mmap() to map the same range of a file must either specify MAP_VARIABLE in flags and
inherit the virtual address range the system has chosen for this range, or specify MAP_FIXED
with an addr that corresponds exactly to the address chosen by the system for the initial
Section 2−−158 Hewlett-Packard Company − 5 − HP-UX 11i Version 2: September 2004