From 4af6982e4c9fc465ffb7a54b794aaaa134241f05 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 11 Oct 2021 16:01:49 -0300 Subject: [PATCH] elf: Fix elf_get_dynamic_info definition Before to 490e6c62aa31a8a ('elf: Avoid nested functions in the loader [BZ #27220]'), elf_get_dynamic_info() was defined twice on rtld.c: on the first dynamic-link.h include and later within _dl_start(). The former definition did not define DONT_USE_BOOTSTRAP_MAP and it is used on setup_vdso() (since it is a global definition), while the former does define DONT_USE_BOOTSTRAP_MAP and it is used on loader self-relocation. With the commit change, the function is now included and defined once instead of defined as a nested function. So rtld.c defines without defining RTLD_BOOTSTRAP and it brokes at least powerpc32. This patch fixes by moving the get-dynamic-info.h include out of dynamic-link.h, which then the caller can corirectly set the expected semantic by defining STATIC_PIE_BOOTSTRAP, RTLD_BOOTSTRAP, and/or RESOLVE_MAP. It also required to enable some asserts only for the loader bootstrap to avoid issues when called from setup_vdso(). As a side note, this is another issues with nested functions: it is not clear from pre-processed output (-E -dD) how the function will be build and its semantic (since nested function will be local and extra C defines may change it). I checked on x86_64-linux-gnu (w/o --enable-static-pie), i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4, aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and s390x-linux-gnu. Reviewed-by: Fangrui Song --- elf/dl-conflict.c | 1 + elf/dl-load.c | 3 ++- elf/dl-reloc-static-pie.c | 3 ++- elf/dl-runtime.c | 1 + elf/dynamic-link.h | 1 - elf/get-dynamic-info.h | 25 ++++++++++++++----------- elf/rtld.c | 5 +++-- elf/setup-vdso.h | 2 +- sysdeps/arm/dl-machine.h | 1 + sysdeps/i386/dl-machine.h | 1 + sysdeps/x86_64/dl-machine.h | 1 + 11 files changed, 27 insertions(+), 17 deletions(-) diff --git a/elf/dl-conflict.c b/elf/dl-conflict.c index b58929cc5d..fb501e0373 100644 --- a/elf/dl-conflict.c +++ b/elf/dl-conflict.c @@ -16,6 +16,7 @@ License along with the GNU C Library; see the file COPYING.LIB. If not, see . */ +#include #include #include #include diff --git a/elf/dl-load.c b/elf/dl-load.c index 99c5ab83b3..335c79fad5 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -58,6 +58,7 @@ struct filebuf }; #include "dynamic-link.h" +#include "get-dynamic-info.h" #include #include #include @@ -1297,7 +1298,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, else l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr); - elf_get_dynamic_info (l); + elf_get_dynamic_info (l, false); /* Make sure we are not dlopen'ing an object that has the DF_1_NOOPEN flag set, or a PIE object. */ diff --git a/elf/dl-reloc-static-pie.c b/elf/dl-reloc-static-pie.c index 4007580453..8a99c4995b 100644 --- a/elf/dl-reloc-static-pie.c +++ b/elf/dl-reloc-static-pie.c @@ -28,6 +28,7 @@ #define STATIC_PIE_BOOTSTRAP #define RESOLVE_MAP(map, scope, sym, version, flags) map #include "dynamic-link.h" +#include "get-dynamic-info.h" /* Relocate static executable with PIE. */ @@ -51,7 +52,7 @@ _dl_relocate_static_pie (void) break; } - elf_get_dynamic_info (main_map); + elf_get_dynamic_info (main_map, false); # ifdef ELF_MACHINE_BEFORE_RTLD_RELOC ELF_MACHINE_BEFORE_RTLD_RELOC (main_map, main_map->l_info); diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c index 9d0d941000..61c260ddb8 100644 --- a/elf/dl-runtime.c +++ b/elf/dl-runtime.c @@ -19,6 +19,7 @@ #define IN_DL_RUNTIME 1 /* This can be tested in dl-machine.h. */ #include +#include #include #include #include diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h index 7cc3021164..21cdfc88bb 100644 --- a/elf/dynamic-link.h +++ b/elf/dynamic-link.h @@ -93,7 +93,6 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[], #include -#include "get-dynamic-info.h" #ifdef RESOLVE_MAP diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h index 15c316b38c..d169099fbc 100644 --- a/elf/get-dynamic-info.h +++ b/elf/get-dynamic-info.h @@ -25,7 +25,7 @@ #include static inline void __attribute__ ((unused, always_inline)) -elf_get_dynamic_info (struct link_map *l) +elf_get_dynamic_info (struct link_map *l, bool check) { #if __ELF_NATIVE_CLASS == 32 typedef Elf32_Word d_tag_utype; @@ -112,16 +112,19 @@ elf_get_dynamic_info (struct link_map *l) assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel))); #endif #ifdef RTLD_BOOTSTRAP - /* Only the bind now flags are allowed. */ - assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL - || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0); - /* Flags must not be set for ld.so. */ - assert (info[DT_FLAGS] == NULL - || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0); -#endif -#if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP - assert (info[DT_RUNPATH] == NULL); - assert (info[DT_RPATH] == NULL); + if (check) + { + /* Only the bind now flags are allowed. */ + assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL + || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0); + /* Flags must not be set for ld.so. */ + assert (info[DT_FLAGS] == NULL + || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0); +# ifdef STATIC_PIE_BOOTSTRAP + assert (info[DT_RUNPATH] == NULL); + assert (info[DT_RPATH] == NULL); +# endif + } #else if (info[DT_FLAGS] != NULL) { diff --git a/elf/rtld.c b/elf/rtld.c index 5eee9e1091..fe5ee9ec4d 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -513,6 +513,7 @@ _dl_start_final (void *arg, struct dl_start_final_info *info) is trivial: always the map of ld.so itself. */ #define RTLD_BOOTSTRAP #define RESOLVE_MAP(map, scope, sym, version, flags) map +#include "get-dynamic-info.h" #include "dynamic-link.h" static ElfW(Addr) __attribute_used__ @@ -547,7 +548,7 @@ _dl_start (void *arg) /* Read our own dynamic section and fill in the info array. */ bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); - elf_get_dynamic_info (&bootstrap_map); + elf_get_dynamic_info (&bootstrap_map, true); #if NO_TLS_OFFSET != 0 bootstrap_map.l_tls_offset = NO_TLS_OFFSET; @@ -1615,7 +1616,7 @@ dl_main (const ElfW(Phdr) *phdr, if (! rtld_is_main) { /* Extract the contents of the dynamic section for easy access. */ - elf_get_dynamic_info (main_map); + elf_get_dynamic_info (main_map, false); /* If the main map is libc.so, update the base namespace to refer to this map. If libc.so is loaded later, this happens diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h index f44748bc98..6fdffafcca 100644 --- a/elf/setup-vdso.h +++ b/elf/setup-vdso.h @@ -64,7 +64,7 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), 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); + elf_get_dynamic_info (l, false); _dl_setup_hash (l); l->l_relocated = 1; diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h index 68a0b4b476..dfa05eee44 100644 --- a/sysdeps/arm/dl-machine.h +++ b/sysdeps/arm/dl-machine.h @@ -21,6 +21,7 @@ #define ELF_MACHINE_NAME "ARM" +#include #include #include #include diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 9f578e536a..78bed03eee 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -21,6 +21,7 @@ #define ELF_MACHINE_NAME "i386" +#include #include #include #include diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h index 9c0182d597..20afb0b4bc 100644 --- a/sysdeps/x86_64/dl-machine.h +++ b/sysdeps/x86_64/dl-machine.h @@ -21,6 +21,7 @@ #define ELF_MACHINE_NAME "x86_64" +#include #include #include #include