diff options
Diffstat (limited to 'sysdeps/mach/hurd/mremap.c')
| -rw-r--r-- | sysdeps/mach/hurd/mremap.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/mremap.c b/sysdeps/mach/hurd/mremap.c new file mode 100644 index 0000000..b710019 --- /dev/null +++ b/sysdeps/mach/hurd/mremap.c @@ -0,0 +1,180 @@ +/* Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <sys/types.h> +#include <sys/mman.h> +#include <errno.h> +#include <stdarg.h> +#include <hurd.h> + +#include <stdio.h> + +/* Remap pages mapped by the range [ADDR,ADDR+OLD_LEN) to new length + NEW_LEN. If MREMAP_MAYMOVE is set in FLAGS the returned address + may differ from ADDR. If MREMAP_FIXED is set in FLAGS the function + takes another parameter which is a fixed address at which the block + resides after a successful call. */ + +void * +__mremap (void *addr, size_t old_len, size_t new_len, int flags, ...) +{ + error_t err; + vm_address_t vm_addr = (vm_address_t) addr; + vm_offset_t new_vm_addr = 0; + + vm_address_t begin = vm_addr; + vm_address_t end; + vm_size_t len; + vm_prot_t prot; + vm_prot_t max_prot; + vm_inherit_t inherit; + boolean_t shared; + memory_object_name_t obj; + vm_offset_t offset; + + if ((flags & ~(MREMAP_MAYMOVE | MREMAP_FIXED)) || + ((flags & MREMAP_FIXED) && !(flags & MREMAP_MAYMOVE)) || + (old_len == 0 && !(flags & MREMAP_MAYMOVE))) + return (void *) (long int) __hurd_fail (EINVAL); + + if (flags & MREMAP_FIXED) + { + va_list arg; + va_start (arg, flags); + new_vm_addr = (vm_offset_t) va_arg (arg, void *); + va_end (arg); + } + + err = __vm_region (__mach_task_self (), + &begin, &len, &prot, &max_prot, &inherit, + &shared, &obj, &offset); + if (err) + return (void *) (uintptr_t) __hurd_fail (err); + + if (begin > vm_addr) + { + err = EFAULT; + goto out; + } + + if (begin < vm_addr || (old_len != 0 && old_len != len)) + { + err = EINVAL; + goto out; + } + + end = begin + len; + + if ((flags & MREMAP_FIXED) && + ((new_vm_addr + new_len > vm_addr && new_vm_addr < end))) + { + /* Overlapping is not supported, like in Linux. */ + err = EINVAL; + goto out; + } + + /* FIXME: locked memory. */ + + if (old_len != 0 && !(flags & MREMAP_FIXED)) + { + /* A mere change of the existing map. */ + + if (new_len == len) + { + new_vm_addr = vm_addr; + goto out; + } + + if (new_len < len) + { + /* Shrink. */ + __mach_port_deallocate (__mach_task_self (), obj); + err = __vm_deallocate (__mach_task_self (), + begin + new_len, len - new_len); + new_vm_addr = vm_addr; + goto out; + } + + /* Try to expand. */ + err = __vm_map (__mach_task_self (), + &end, new_len - len, 0, 0, + obj, offset + len, 0, prot, max_prot, inherit); + if (!err) + { + /* Ok, that worked. Now coalesce them. */ + new_vm_addr = vm_addr; + + /* XXX this is not atomic as it is in unix! */ + err = __vm_deallocate (__mach_task_self (), begin, new_len); + if (err) + { + __vm_deallocate (__mach_task_self (), end, new_len - len); + goto out; + } + + err = __vm_map (__mach_task_self (), + &begin, new_len, 0, 0, + obj, offset, 0, prot, max_prot, inherit); + if (err) + { + /* Oops, try to remap before reporting. */ + __vm_map (__mach_task_self (), + &begin, len, 0, 0, + obj, offset, 0, prot, max_prot, inherit); + } + + goto out; + } + } + + if (!(flags & MREMAP_MAYMOVE)) + { + /* Can not map here */ + err = ENOMEM; + goto out; + } + + err = __vm_map (__mach_task_self (), + &new_vm_addr, new_len, 0, + new_vm_addr == 0, obj, offset, + old_len == 0, prot, max_prot, inherit); + + if (err == KERN_NO_SPACE && (flags & MREMAP_FIXED)) + { + /* XXX this is not atomic as it is in unix! */ + /* The region is already allocated; deallocate it first. */ + err = __vm_deallocate (__mach_task_self (), new_vm_addr, new_len); + if (! err) + err = __vm_map (__mach_task_self (), + &new_vm_addr, new_len, 0, + 0, obj, offset, + old_len == 0, prot, max_prot, inherit); + } + + if (!err) + /* Alright, can remove old mapping. */ + __vm_deallocate (__mach_task_self (), begin, len); + +out: + __mach_port_deallocate (__mach_task_self (), obj); + if (err) + return (void *) (uintptr_t) __hurd_fail (err); + return (void *) new_vm_addr; +} + +libc_hidden_def (__mremap) +weak_alias (__mremap, mremap) |