diff options
| -rw-r--r-- | Makerules | 9 | ||||
| -rw-r--r-- | extra/Configs/Config.in | 11 | ||||
| -rw-r--r-- | ldso/include/dl-elf.h | 43 | ||||
| -rw-r--r-- | ldso/ldso/Makefile.in | 8 | ||||
| -rw-r--r-- | ldso/ldso/dl-elf.c | 9 | ||||
| -rw-r--r-- | ldso/ldso/dl-hash.c | 4 | ||||
| -rw-r--r-- | ldso/ldso/dl-startup.c | 33 | ||||
| -rw-r--r-- | ldso/ldso/ldso.c | 69 |
8 files changed, 177 insertions, 9 deletions
@@ -294,6 +294,15 @@ endef cmd_hcompile.u = $(HOSTCC) $(filter-out $(PHONY),$^) $(DEPS-$(notdir $@)) -o $@ $(BUILD_LDFLAGS) $(BUILD_LDFLAGS-$(notdir $(^D))) $(BUILD_LDFLAGS-$(notdir $@)) $(BUILD_CFLAGS) $(BUILD_CFLAGS-$(notdir $(^D))) $(BUILD_CFLAGS-$(notdir $@)) cmd_hcompile.o = $(HOSTCC) $(filter-out $(PHONY),$<) $(DEPS-$(notdir $@)) -c -o $@ $(BUILD_CFLAGS) $(BUILD_CFLAGS-$(notdir $(^D))) $(BUILD_CFLAGS-$(notdir $@)) +define create-lds + $(Q)$(RM) $@.lds + $(Q)$(CC) -nostdlib -nostartfiles -shared -Wl,-z,combreloc \ + -Wl,-z,relro -Wl,--hash-style=gnu -Wl,-z,defs \ + -Wl,--verbose 2>&1 | LC_ALL=C \ + sed -e '/^=========/,/^=========/!d;/^=========/d' \ + -e 's/\. = .* + SIZEOF_HEADERS;/& _begin = . - SIZEOF_HEADERS;/' > $@.lds +endef + define link.so $(Q)$(RM) $@ $@.$(2) $(dir $@)$(1) @$(disp_ld) diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index 97211864b..801669a17 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -359,6 +359,17 @@ config LDSO_STANDALONE_SUPPORT capabilities to uClibc dynamic linker, as well useful for testing an updated version of the dynamic linker without breaking the system. +config LDSO_PRELINK_SUPPORT + bool "Dynamic linker prelink support" + depends on HAVE_SHARED + default n + select LDSO_STANDALONE_SUPPORT + help + The dynamic linker can be used in stand-alone mode by the prelink tool + for prelinking ELF shared libraries and binaries to speed up startup + time. It also is able to load and handle prelinked libraries and + binaries at runtime. + config UCLIBC_STATIC_LDCONFIG bool "Link ldconfig statically" depends on HAVE_SHARED diff --git a/ldso/include/dl-elf.h b/ldso/include/dl-elf.h index 3e8586444..40c88b9da 100644 --- a/ldso/include/dl-elf.h +++ b/ldso/include/dl-elf.h @@ -85,24 +85,47 @@ extern void _dl_protect_relro (struct elf_resolve *l); #endif /* OS and/or GNU dynamic extensions */ + +#define OS_NUM_BASE 1 /* for DT_RELOCCOUNT */ + #ifdef __LDSO_GNU_HASH_SUPPORT__ -# define OS_NUM 2 /* for DT_RELOCCOUNT and DT_GNU_HASH entries */ +# define OS_NUM_GNU_HASH 1 /* for DT_GNU_HASH entry */ +#else +# define OS_NUM_GNU_HASH 0 +#endif + +#ifdef __LDSO_PRELINK_SUPPORT__ +# define OS_NUM_PRELINK 6 /* for DT_GNU_PRELINKED entry */ #else -# define OS_NUM 1 /* for DT_RELOCCOUNT entry */ +# define OS_NUM_PRELINK 0 #endif +#define OS_NUM (OS_NUM_BASE + OS_NUM_GNU_HASH + OS_NUM_PRELINK) + #ifndef ARCH_DYNAMIC_INFO /* define in arch specific code, if needed */ # define ARCH_NUM 0 #endif -#define DYNAMIC_SIZE (DT_NUM+OS_NUM+ARCH_NUM) +#define DYNAMIC_SIZE (DT_NUM + OS_NUM + ARCH_NUM) /* Keep ARCH specific entries into dynamic section at the end of the array */ #define DT_RELCONT_IDX (DYNAMIC_SIZE - OS_NUM - ARCH_NUM) #ifdef __LDSO_GNU_HASH_SUPPORT__ /* GNU hash comes just after the relocation count */ # define DT_GNU_HASH_IDX (DT_RELCONT_IDX + 1) +#else +# define DT_GNU_HASH_IDX DT_RELCONT_IDX +#endif + +#ifdef __LDSO_PRELINK_SUPPORT__ +/* GNU prelink comes just after the GNU hash if present */ +#define DT_GNU_PRELINKED_IDX (DT_GNU_HASH_IDX + 1) +#define DT_GNU_CONFLICT_IDX (DT_GNU_HASH_IDX + 2) +#define DT_GNU_CONFLICTSZ_IDX (DT_GNU_HASH_IDX + 3) +#define DT_GNU_LIBLIST_IDX (DT_GNU_HASH_IDX + 4) +#define DT_GNU_LIBLISTSZ_IDX (DT_GNU_HASH_IDX + 5) +#define DT_CHECKSUM_IDX (DT_GNU_HASH_IDX + 6) #endif extern unsigned int _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[], @@ -151,6 +174,20 @@ unsigned int __dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info if (dpnt->d_tag == DT_GNU_HASH) dynamic_info[DT_GNU_HASH_IDX] = dpnt->d_un.d_ptr; #endif +#ifdef __LDSO_PRELINK_SUPPORT__ + if (dpnt->d_tag == DT_GNU_PRELINKED) + dynamic_info[DT_GNU_PRELINKED_IDX] = dpnt->d_un.d_val; + if (dpnt->d_tag == DT_GNU_CONFLICT) + dynamic_info[DT_GNU_CONFLICT_IDX] = dpnt->d_un.d_ptr; + if (dpnt->d_tag == DT_GNU_CONFLICTSZ) + dynamic_info[DT_GNU_CONFLICTSZ_IDX] = dpnt->d_un.d_val; + if (dpnt->d_tag == DT_GNU_LIBLIST) + dynamic_info[DT_GNU_LIBLIST_IDX] = dpnt->d_un.d_ptr; + if (dpnt->d_tag == DT_GNU_LIBLISTSZ) + dynamic_info[DT_GNU_LIBLISTSZ_IDX] = dpnt->d_un.d_val; + if (dpnt->d_tag == DT_CHECKSUM) + dynamic_info[DT_CHECKSUM_IDX] = dpnt->d_un.d_val; +#endif } #ifdef ARCH_DYNAMIC_INFO else { diff --git a/ldso/ldso/Makefile.in b/ldso/ldso/Makefile.in index e71ae1563..c9dcebd60 100644 --- a/ldso/ldso/Makefile.in +++ b/ldso/ldso/Makefile.in @@ -62,8 +62,16 @@ ldso-y := $($(UCLIBC_LDSO_NAME)_OBJS:.o=.oS) lib-so-y += $(ldso) objclean-y += CLEAN_ldso/ldso +ifeq ($(LDSO_PRELINK_SUPPORT),y) +# Use a specific linker script for ld.so +LDFLAGS-$(UCLIBC_LDSO_NAME).so += -T $(ldso:.$(ABI_VERSION)=).lds +endif + $(ldso): $(ldso:.$(ABI_VERSION)=) $(ldso:.$(ABI_VERSION)=): $($(UCLIBC_LDSO_NAME)_OUT)/$(UCLIBC_LDSO_NAME)_so.a +ifeq ($(LDSO_PRELINK_SUPPORT),y) + $(call create-lds) +endif $(call link.so,$(ldso_FULL_NAME),$(ABI_VERSION)) $($(UCLIBC_LDSO_NAME)_OUT)/$(UCLIBC_LDSO_NAME)_so.a: $(ldso-y) diff --git a/ldso/ldso/dl-elf.c b/ldso/ldso/dl-elf.c index a8ccc5e91..9625f5ae5 100644 --- a/ldso/ldso/dl-elf.c +++ b/ldso/ldso/dl-elf.c @@ -343,7 +343,7 @@ struct elf_resolve *_dl_load_elf_shared_library(int secure, size_t relro_size = 0; struct stat st; uint32_t *p32; - DL_LOADADDR_TYPE lib_loadaddr; + DL_LOADADDR_TYPE lib_loadaddr = 0; DL_INIT_LOADADDR_EXTRA_DECLS libaddr = 0; @@ -880,7 +880,12 @@ int _dl_fixup(struct dyn_elf *rpnt, struct r_scope_elem *scope, int now_flag) relative_count = tpnt->dynamic_info[DT_RELCONT_IDX]; if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */ reloc_size -= relative_count * sizeof(ELF_RELOC); - elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count); + if (tpnt->loadaddr +#ifdef __LDSO_PRELINK_SUPPORT__ + || (!tpnt->dynamic_info[DT_GNU_PRELINKED_IDX]) +#endif + ) + elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count); reloc_addr += relative_count * sizeof(ELF_RELOC); } goof += _dl_parse_relocation_information(rpnt, scope, diff --git a/ldso/ldso/dl-hash.c b/ldso/ldso/dl-hash.c index 2e2111fa9..f0683c60f 100644 --- a/ldso/ldso/dl-hash.c +++ b/ldso/ldso/dl-hash.c @@ -145,7 +145,11 @@ struct elf_resolve *_dl_add_elf_hash_table(const char *libname, hash_addr += tpnt->nbucket; tpnt->chains = hash_addr; } +#ifdef __LDSO_PRELINK_SUPPORT__ + tpnt->loadaddr = dynamic_info[DT_GNU_PRELINKED_IDX] ? 0 : loadaddr; +#else tpnt->loadaddr = loadaddr; +#endif tpnt->mapaddr = DL_RELOC_ADDR(loadaddr, 0); for (i = 0; i < DYNAMIC_SIZE; i++) tpnt->dynamic_info[i] = dynamic_info[i]; diff --git a/ldso/ldso/dl-startup.c b/ldso/ldso/dl-startup.c index feffa787b..4799846ee 100644 --- a/ldso/ldso/dl-startup.c +++ b/ldso/ldso/dl-startup.c @@ -94,6 +94,11 @@ /* Pull in all the arch specific stuff */ #include "dl-startup.h" +#ifdef __LDSO_PRELINK_SUPPORT__ +/* These defined magically in the linker script. */ +extern char _begin[] attribute_hidden; +#endif + /* Static declarations */ static int (*_dl_elf_main) (int, char **, char **); @@ -164,11 +169,26 @@ DL_START(unsigned long args) aux_dat += 2; } - /* locate the ELF header. We need this done as soon as possible - * (esp since SEND_STDERR() needs this on some platforms... */ + /* + * Locate the dynamic linker ELF header. We need this done as soon as + * possible (esp since SEND_STDERR() needs this on some platforms... + */ + +#ifdef __LDSO_PRELINK_SUPPORT__ + /* + * The `_begin' symbol created by the linker script points to ld.so ELF + * We use it if the kernel is not passing a valid address through the auxvt. + */ + + if (!auxvt[AT_BASE].a_un.a_val) + auxvt[AT_BASE].a_un.a_val = (Elf32_Addr) &_begin; + /* Note: if the dynamic linker itself is prelinked, the load_addr is 0 */ + DL_INIT_LOADADDR_BOOT(load_addr, elf_machine_load_address()); +#else if (!auxvt[AT_BASE].a_un.a_val) auxvt[AT_BASE].a_un.a_val = elf_machine_load_address(); DL_INIT_LOADADDR_BOOT(load_addr, auxvt[AT_BASE].a_un.a_val); +#endif header = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val; /* Check the ELF header to make sure everything looks ok. */ @@ -183,7 +203,7 @@ DL_START(unsigned long args) _dl_exit(0); } SEND_EARLY_STDERR_DEBUG("ELF header="); - SEND_ADDRESS_STDERR_DEBUG(DL_LOADADDR_BASE(load_addr), 1); + SEND_ADDRESS_STDERR_DEBUG(DL_LOADADDR_BASE(header), 1); /* Locate the global offset table. Since this code must be PIC * we can take advantage of the magic offset register, if we @@ -258,7 +278,12 @@ DL_START(unsigned long args) if (!indx && relative_count) { rel_size -= relative_count * sizeof(ELF_RELOC); - elf_machine_relative(load_addr, rel_addr, relative_count); + if (load_addr +#ifdef __LDSO_PRELINK_SUPPORT__ + || !tpnt->dynamic_info[DT_GNU_PRELINKED_IDX] +#endif + ) + elf_machine_relative(load_addr, rel_addr, relative_count); rel_addr += relative_count * sizeof(ELF_RELOC); } diff --git a/ldso/ldso/ldso.c b/ldso/ldso/ldso.c index 4a7b6398f..b056f8af2 100644 --- a/ldso/ldso/ldso.c +++ b/ldso/ldso/ldso.c @@ -61,6 +61,7 @@ void (*_dl_free_function) (void *p) = NULL; char *_dl_trace_prelink = NULL; /* Library for prelinking trace */ struct elf_resolve *_dl_trace_prelink_map = NULL; /* Library module for prelinking trace */ bool _dl_verbose = true; /* On by default */ +bool prelinked = false; #endif static int _dl_secure = 1; /* Are we dealing with setuid stuff? */ @@ -1189,8 +1190,75 @@ of this helper program; chances are you did not intend to run this program.\n\ _dl_exit(-1); _dl_exit(0); } + + if (_dl_loaded_modules->dynamic_info[DT_GNU_LIBLIST_IDX]) { + ElfW(Lib) *liblist, *liblistend; + struct elf_resolve **r_list, **r_listend, *l; + const char *strtab = (const char *)_dl_loaded_modules->dynamic_info[DT_STRTAB]; + + _dl_assert (_dl_loaded_modules->dynamic_info[DT_GNU_LIBLISTSZ_IDX] != 0); + liblist = (ElfW(Lib) *) _dl_loaded_modules->dynamic_info[DT_GNU_LIBLIST_IDX]; + liblistend = (ElfW(Lib) *) + ((char *) liblist + _dl_loaded_modules->dynamic_info[DT_GNU_LIBLISTSZ_IDX]); + r_list = _dl_loaded_modules->symbol_scope.r_list; + r_listend = r_list + nscope_elem; + + for (; r_list < r_listend && liblist < liblistend; r_list++) { + l = *r_list; + + if (l == _dl_loaded_modules) + continue; + + /* If the library is not mapped where it should, fail. */ + if (l->loadaddr) + break; + + /* Next, check if checksum matches. */ + if (l->dynamic_info[DT_CHECKSUM_IDX] == 0 || + l->dynamic_info[DT_CHECKSUM_IDX] != liblist->l_checksum) + break; + + if (l->dynamic_info[DT_GNU_PRELINKED_IDX] == 0 || + (l->dynamic_info[DT_GNU_PRELINKED_IDX] != liblist->l_time_stamp)) + break; + + if (_dl_strcmp(strtab + liblist->l_name, _dl_get_last_path_component(l->libname)) != 0) + break; + + ++liblist; + } + + + if (r_list == r_listend && liblist == liblistend) + prelinked = true; + + } + + _dl_debug_early ("\nprelink checking: %s\n", prelinked ? "ok" : "failed"); + + if (prelinked) { + if (_dl_loaded_modules->dynamic_info[DT_GNU_CONFLICT_IDX]) { + ELF_RELOC *conflict; + unsigned long conflict_size; + + _dl_assert (_dl_loaded_modules->dynamic_info[DT_GNU_CONFLICTSZ_IDX] != 0); + conflict = (ELF_RELOC *) _dl_loaded_modules->dynamic_info[DT_GNU_CONFLICT_IDX]; + conflict_size = _dl_loaded_modules->dynamic_info[DT_GNU_CONFLICTSZ_IDX]; + _dl_parse_relocation_information(_dl_symbol_tables, global_scope, + (unsigned long) conflict, conflict_size); + } + + /* Mark all the objects so we know they have been already relocated. */ + for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) { + tpnt->init_flag |= RELOCS_DONE; + if (tpnt->relro_size) + _dl_protect_relro (tpnt); + } + } else #endif + { + _dl_debug_early("Beginning relocation fixups\n"); #ifdef __mips__ @@ -1215,6 +1283,7 @@ of this helper program; chances are you did not intend to run this program.\n\ if (tpnt->relro_size) _dl_protect_relro (tpnt); } + } /* not prelinked */ #if defined(USE_TLS) && USE_TLS if (!was_tls_init_tp_called && _dl_tls_max_dtv_idx > 0) |