From e0b6c9706c91a642c781918eea52588ee8dc9f09 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 18 Oct 2023 14:22:59 +0200 Subject: Revert "elf: Remove unused l_text_end field from struct link_map" This reverts commit 750f19526ae71aac801c77a3f7ef5374890c09b7. Reason for revert: Restore ABI after revert of commit a3189f66a5f. --- elf/dl-load.c | 2 +- elf/dl-load.h | 7 +++++-- elf/rtld.c | 6 ++++++ elf/setup-vdso.h | 4 ++++ include/link.h | 2 ++ 5 files changed, 18 insertions(+), 3 deletions(-) diff --git a/elf/dl-load.c b/elf/dl-load.c index 2923b1141d..9a87fda9c9 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1253,7 +1253,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, /* Now process the load commands and map segments into memory. This is responsible for filling in: - l_map_start, l_map_end, l_addr, l_contiguous, l_phdr + l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr */ errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds, maplength, has_holes, loader); diff --git a/elf/dl-load.h b/elf/dl-load.h index 1d5207694b..ecf6910c68 100644 --- a/elf/dl-load.h +++ b/elf/dl-load.h @@ -83,11 +83,14 @@ struct loadcmd /* This is a subroutine of _dl_map_segments. It should be called for each load command, some time after L->l_addr has been set correctly. It is - responsible for setting the l_phdr fields */ + responsible for setting up the l_text_end and l_phdr fields. */ static __always_inline void _dl_postprocess_loadcmd (struct link_map *l, const ElfW(Ehdr) *header, const struct loadcmd *c) { + if (c->prot & PROT_EXEC) + l->l_text_end = l->l_addr + c->mapend; + if (l->l_phdr == 0 && c->mapoff <= header->e_phoff && ((size_t) (c->mapend - c->mapstart + c->mapoff) @@ -100,7 +103,7 @@ _dl_postprocess_loadcmd (struct link_map *l, const ElfW(Ehdr) *header, /* This is a subroutine of _dl_map_object_from_fd. It is responsible for filling in several fields in *L: l_map_start, l_map_end, l_addr, - l_contiguous, l_phdr. On successful return, all the + l_contiguous, l_text_end, l_phdr. On successful return, all the segments are mapped (or copied, or whatever) from the file into their final places in the address space, with the correct page permissions, and any bss-like regions already zeroed. It returns a null pointer diff --git a/elf/rtld.c b/elf/rtld.c index 5107d16fe3..a91e2a4471 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -477,6 +477,7 @@ _dl_start_final (void *arg, struct dl_start_final_info *info) GL(dl_rtld_map).l_real = &GL(dl_rtld_map); GL(dl_rtld_map).l_map_start = (ElfW(Addr)) &__ehdr_start; GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end; + GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext; /* Copy the TLS related data if necessary. */ #ifndef DONT_USE_BOOTSTRAP_MAP # if NO_TLS_OFFSET != 0 @@ -1118,6 +1119,7 @@ rtld_setup_main_map (struct link_map *main_map) bool has_interp = false; main_map->l_map_end = 0; + main_map->l_text_end = 0; /* Perhaps the executable has no PT_LOAD header entries at all. */ main_map->l_map_start = ~0; /* And it was opened directly. */ @@ -1209,6 +1211,8 @@ rtld_setup_main_map (struct link_map *main_map) allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz; if (main_map->l_map_end < allocend) main_map->l_map_end = allocend; + if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end) + main_map->l_text_end = allocend; /* The next expected address is the page following this load segment. */ @@ -1268,6 +1272,8 @@ rtld_setup_main_map (struct link_map *main_map) = (char *) main_map->l_tls_initimage + main_map->l_addr; if (! main_map->l_map_end) main_map->l_map_end = ~0; + if (! main_map->l_text_end) + main_map->l_text_end = ~0; if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name) { /* We were invoked directly, so the program might not have a diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h index d92b12a7aa..0079842d1f 100644 --- a/elf/setup-vdso.h +++ b/elf/setup-vdso.h @@ -51,6 +51,9 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), l->l_addr = ph->p_vaddr; if (ph->p_vaddr + ph->p_memsz >= l->l_map_end) l->l_map_end = ph->p_vaddr + ph->p_memsz; + if ((ph->p_flags & PF_X) + && ph->p_vaddr + ph->p_memsz >= l->l_text_end) + l->l_text_end = ph->p_vaddr + ph->p_memsz; } else /* There must be no TLS segment. */ @@ -59,6 +62,7 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso); l->l_addr = l->l_map_start - l->l_addr; l->l_map_end += l->l_addr; + l->l_text_end += l->l_addr; l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr); elf_get_dynamic_info (l, false, false); _dl_setup_hash (l); diff --git a/include/link.h b/include/link.h index 686813f281..a02d5f2eba 100644 --- a/include/link.h +++ b/include/link.h @@ -253,6 +253,8 @@ struct link_map /* Start and finish of memory map for this object. l_map_start need not be the same as l_addr. */ ElfW(Addr) l_map_start, l_map_end; + /* End of the executable part of the mapping. */ + ElfW(Addr) l_text_end; /* Linked list of objects in reverse ELF constructor execution order. Head of list is stored in _dl_init_called_list. */ -- cgit 1.4.1