diff options
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/dl-load.c | 7 | ||||
| -rw-r--r-- | elf/dl-reloc.c | 20 | ||||
| -rw-r--r-- | elf/elf.h | 3 | ||||
| -rw-r--r-- | elf/rtld.c | 84 |
4 files changed, 74 insertions, 40 deletions
diff --git a/elf/dl-load.c b/elf/dl-load.c index c7e3716cb6..dc993a5894 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1,5 +1,5 @@ /* Map in a shared object's segments from the file. - Copyright (C) 1995-2002, 2003 Free Software Foundation, Inc. + Copyright (C) 1995-2002, 2003, 2004 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 @@ -1065,6 +1065,11 @@ cannot allocate TLS data structures for initial thread"); case PT_GNU_STACK: stack_flags = ph->p_flags; break; + + case PT_GNU_RELRO: + l->l_relro_addr = ph->p_vaddr; + l->l_relro_size = ph->p_memsz; + break; } if (__builtin_expect (nloadcmds == 0, 0)) diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c index e5abba41dd..21d1871c6d 100644 --- a/elf/dl-reloc.c +++ b/elf/dl-reloc.c @@ -1,5 +1,5 @@ /* Relocate a shared object and resolve its references to other loaded objects. - Copyright (C) 1995-2002, 2003 Free Software Foundation, Inc. + Copyright (C) 1995-2002, 2003, 2004 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 @@ -307,6 +307,24 @@ _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[], textrels = textrels->next; } + + /* In case we can protect the data now that the relocations are + done, do it. */ + if (l->l_relro_size != 0) + { + ElfW(Addr) start = ((l->l_addr + l->l_relro_addr) + & ~(GL(dl_pagesize) - 1)); + ElfW(Addr) end = ((l->l_addr + l->l_relro_addr + l->l_relro_size) + & ~(GL(dl_pagesize) - 1)); + + if (start != end + && __mprotect ((void *) start, end - start, PROT_READ) < 0) + { + errstring = N_("\ +cannot apply additional memory protection after relocation"); + goto call_error; + } + } } INTDEF (_dl_relocate_object) diff --git a/elf/elf.h b/elf/elf.h index 56b711da36..9a4da6591e 100644 --- a/elf/elf.h +++ b/elf/elf.h @@ -1,5 +1,5 @@ /* This file defines standard ELF types, structures, and macros. - Copyright (C) 1995-1999,2000,2001,2002,2003 Free Software Foundation, Inc. + Copyright (C) 1995-2003, 2004 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 @@ -567,6 +567,7 @@ typedef struct #define PT_LOOS 0x60000000 /* Start of OS-specific */ #define PT_GNU_EH_FRAME 0x6474e550 /* GCC .eh_frame_hdr segment */ #define PT_GNU_STACK 0x6474e551 /* Indicates stack executability */ +#define PT_GNU_RELRO 0x6474e552 /* Read-only after relocation */ #define PT_LOSUNW 0x6ffffffa #define PT_SUNWBSS 0x6ffffffa /* Sun Specific segment */ #define PT_SUNWSTACK 0x6ffffffb /* Stack segment */ diff --git a/elf/rtld.c b/elf/rtld.c index 392ccb6dcb..4273a6fb07 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1,5 +1,5 @@ /* Run time dynamic linker. - Copyright (C) 1995-2002, 2003 Free Software Foundation, Inc. + Copyright (C) 1995-2002, 2003, 2004 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 @@ -332,13 +332,14 @@ _dl_start (void *arg) bootstrap_map.l_tls_offset = NO_TLS_OFFSET; #endif -#if USE___THREAD /* Get the dynamic linker's own program header. First we need the ELF file header. The `_begin' symbol created by the linker script points to it. When we have something like GOTOFF relocs, we can use a plain reference to find the runtime address. Without that, we have to rely on the `l_addr' value, which is not the value we want when prelinked. */ +#if USE___THREAD dtv_t initdtv[3]; +#endif /* USE___THREAD */ ElfW(Ehdr) *ehdr # ifdef DONT_USE_BOOTSTRAP_MAP = (ElfW(Ehdr) *) &_begin; @@ -348,6 +349,7 @@ _dl_start (void *arg) ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff); size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */ while (cnt-- > 0) +#if USE___THREAD if (phdr[cnt].p_type == PT_TLS) { void *tlsblock; @@ -442,11 +444,14 @@ _dl_start (void *arg) /* So far this is module number one. */ bootstrap_map.l_tls_modid = 1; - - /* There can only be one PT_TLS entry. */ - break; } + else #endif /* USE___THREAD */ + if (phdr[cnt].p_type == PT_GNU_RELRO) + { + bootstrap_map.l_relro_addr = phdr[cnt].p_vaddr; + bootstrap_map.l_relro_size = phdr[cnt].p_memsz; + } #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); @@ -777,6 +782,11 @@ of this helper program; chances are you did not intend to run this program.\n\ GL(dl_stack_flags) = ph->p_flags; break; } + else if (ph->p_type == PT_GNU_RELRO) + { + GL(dl_loaded)->l_relro_addr = ph->p_vaddr; + GL(dl_loaded)->l_relro_size = ph->p_memsz; + } if (__builtin_expect (mode, normal) == verify) { @@ -1598,6 +1608,35 @@ cannot allocate TLS data structures for initial thread"); _dl_printf ("\nprelink checking: %s\n", prelinked ? "ok" : "failed"); } + + /* Initialize _r_debug. */ + struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr); + { + struct link_map *l; + + l = GL(dl_loaded); + +#ifdef ELF_MACHINE_DEBUG_SETUP + + /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ + + ELF_MACHINE_DEBUG_SETUP (l, r); + ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r); + +#else + + if (l->l_info[DT_DEBUG] != NULL) + /* There is a DT_DEBUG entry in the dynamic section. Fill it in + with the run-time address of the r_debug structure */ + l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; + + /* Fill in the pointer in the dynamic linker's own dynamic section, in + case you run gdb on the dynamic linker directly. */ + if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL) + GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; +#endif + } + if (prelinked) { struct link_map *l; @@ -1738,38 +1777,9 @@ cannot allocate TLS data structures for initial thread"); #endif NONTLS_INIT_TP; - { - /* Initialize _r_debug. */ - struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr); - struct link_map *l; - - l = GL(dl_loaded); - -#ifdef ELF_MACHINE_DEBUG_SETUP - - /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ - - ELF_MACHINE_DEBUG_SETUP (l, r); - ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r); - -#else - - if (l->l_info[DT_DEBUG] != NULL) - /* There is a DT_DEBUG entry in the dynamic section. Fill it in - with the run-time address of the r_debug structure */ - l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; - - /* Fill in the pointer in the dynamic linker's own dynamic section, in - case you run gdb on the dynamic linker directly. */ - if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL) - GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; - -#endif - - /* Notify the debugger that all objects are now mapped in. */ - r->r_state = RT_ADD; - INTUSE(_dl_debug_state) (); - } + /* Notify the debugger that all objects are now mapped in. */ + r->r_state = RT_ADD; + INTUSE(_dl_debug_state) (); #ifndef MAP_COPY /* We must munmap() the cache file. */ |