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Diffstat (limited to 'elf/dl-map-segments.h')
| -rw-r--r-- | elf/dl-map-segments.h | 157 |
1 files changed, 0 insertions, 157 deletions
diff --git a/elf/dl-map-segments.h b/elf/dl-map-segments.h deleted file mode 100644 index d36f9bd2f6..0000000000 --- a/elf/dl-map-segments.h +++ /dev/null @@ -1,157 +0,0 @@ -/* Map in a shared object's segments. Generic version. - Copyright (C) 1995-2017 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 - <http://www.gnu.org/licenses/>. */ - -#include <dl-load.h> - -/* This implementation assumes (as does the corresponding implementation - of _dl_unmap_segments, in dl-unmap-segments.h) that shared objects - are always laid out with all segments contiguous (or with gaps - between them small enough that it's preferable to reserve all whole - pages inside the gaps with PROT_NONE mappings rather than permitting - other use of those parts of the address space). */ - -static __always_inline const char * -_dl_map_segments (struct link_map *l, int fd, - const ElfW(Ehdr) *header, int type, - const struct loadcmd loadcmds[], size_t nloadcmds, - const size_t maplength, bool has_holes, - struct link_map *loader) -{ - const struct loadcmd *c = loadcmds; - - if (__glibc_likely (type == ET_DYN)) - { - /* This is a position-independent shared object. We can let the - kernel map it anywhere it likes, but we must have space for all - the segments in their specified positions relative to the first. - So we map the first segment without MAP_FIXED, but with its - extent increased to cover all the segments. Then we remove - access from excess portion, and there is known sufficient space - there to remap from the later segments. - - As a refinement, sometimes we have an address that we would - prefer to map such objects at; but this is only a preference, - the OS can do whatever it likes. */ - ElfW(Addr) mappref - = (ELF_PREFERRED_ADDRESS (loader, maplength, - c->mapstart & GLRO(dl_use_load_bias)) - - MAP_BASE_ADDR (l)); - - /* Remember which part of the address space this object uses. */ - l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength, - c->prot, - MAP_COPY|MAP_FILE, - fd, c->mapoff); - if (__glibc_unlikely ((void *) l->l_map_start == MAP_FAILED)) - return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT; - - l->l_map_end = l->l_map_start + maplength; - l->l_addr = l->l_map_start - c->mapstart; - - if (has_holes) - { - /* Change protection on the excess portion to disallow all access; - the portions we do not remap later will be inaccessible as if - unallocated. Then jump into the normal segment-mapping loop to - handle the portion of the segment past the end of the file - mapping. */ - if (__glibc_unlikely - (__mprotect ((caddr_t) (l->l_addr + c->mapend), - loadcmds[nloadcmds - 1].mapstart - c->mapend, - PROT_NONE) < 0)) - return DL_MAP_SEGMENTS_ERROR_MPROTECT; - } - - l->l_contiguous = 1; - - goto postmap; - } - - /* Remember which part of the address space this object uses. */ - l->l_map_start = c->mapstart + l->l_addr; - l->l_map_end = l->l_map_start + maplength; - l->l_contiguous = !has_holes; - - while (c < &loadcmds[nloadcmds]) - { - if (c->mapend > c->mapstart - /* Map the segment contents from the file. */ - && (__mmap ((void *) (l->l_addr + c->mapstart), - c->mapend - c->mapstart, c->prot, - MAP_FIXED|MAP_COPY|MAP_FILE, - fd, c->mapoff) - == MAP_FAILED)) - return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT; - - postmap: - _dl_postprocess_loadcmd (l, header, c); - - if (c->allocend > c->dataend) - { - /* Extra zero pages should appear at the end of this segment, - after the data mapped from the file. */ - ElfW(Addr) zero, zeroend, zeropage; - - zero = l->l_addr + c->dataend; - zeroend = l->l_addr + c->allocend; - zeropage = ((zero + GLRO(dl_pagesize) - 1) - & ~(GLRO(dl_pagesize) - 1)); - - if (zeroend < zeropage) - /* All the extra data is in the last page of the segment. - We can just zero it. */ - zeropage = zeroend; - - if (zeropage > zero) - { - /* Zero the final part of the last page of the segment. */ - if (__glibc_unlikely ((c->prot & PROT_WRITE) == 0)) - { - /* Dag nab it. */ - if (__mprotect ((caddr_t) (zero - & ~(GLRO(dl_pagesize) - 1)), - GLRO(dl_pagesize), c->prot|PROT_WRITE) < 0) - return DL_MAP_SEGMENTS_ERROR_MPROTECT; - } - memset ((void *) zero, '\0', zeropage - zero); - if (__glibc_unlikely ((c->prot & PROT_WRITE) == 0)) - __mprotect ((caddr_t) (zero & ~(GLRO(dl_pagesize) - 1)), - GLRO(dl_pagesize), c->prot); - } - - if (zeroend > zeropage) - { - /* Map the remaining zero pages in from the zero fill FD. */ - caddr_t mapat; - mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage, - c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED, - -1, 0); - if (__glibc_unlikely (mapat == MAP_FAILED)) - return DL_MAP_SEGMENTS_ERROR_MAP_ZERO_FILL; - } - } - - ++c; - } - - /* Notify ELF_PREFERRED_ADDRESS that we have to load this one - fixed. */ - ELF_FIXED_ADDRESS (loader, c->mapstart); - - return NULL; -} |