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| author | H.J. Lu <hjl.tools@gmail.com> | 2020-12-28 05:28:49 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2021-01-13 15:17:05 -0800 |
| commit | 44fd8887d0dc705ee5a8e52153282292841e0a01 (patch) | |
| tree | b8bd935001f5a84bd73010b65f0d9d978f1dfed0 /sysdeps/i386 | |
| parent | 4a68828e3781cd6f61f792daa1dd5904a8f45288 (diff) | |
| download | glibc-44fd8887d0dc705ee5a8e52153282292841e0a01.tar.gz glibc-44fd8887d0dc705ee5a8e52153282292841e0a01.tar.xz glibc-44fd8887d0dc705ee5a8e52153282292841e0a01.zip | |
x86: Check IFUNC definition in unrelocated executable [BZ #20019]
Calling an IFUNC function defined in unrelocated executable also leads to segfault. Issue a fatal error message when calling IFUNC function defined in the unrelocated executable from a shared library. On x86, ifuncmain6pie failed with: [hjl@gnu-cfl-2 build-i686-linux]$ ./elf/ifuncmain6pie --direct ./elf/ifuncmain6pie: IFUNC symbol 'foo' referenced in '/export/build/gnu/tools-build/glibc-32bit/build-i686-linux/elf/ifuncmod6.so' is defined in the executable and creates an unsatisfiable circular dependency. [hjl@gnu-cfl-2 build-i686-linux]$ readelf -rW elf/ifuncmod6.so | grep foo 00003ff4 00000706 R_386_GLOB_DAT 0000400c foo_ptr 00003ff8 00000406 R_386_GLOB_DAT 00000000 foo 0000400c 00000401 R_386_32 00000000 foo [hjl@gnu-cfl-2 build-i686-linux]$ Remove non-JUMP_SLOT relocations against foo in ifuncmod6.so, which trigger the circular IFUNC dependency, and build ifuncmain6pie with -Wl,-z,lazy. (cherry picked from commits 6ea5b57afa5cdc9ce367d2b69a2cebfb273e4617 and 7137d682ebfcb6db5dfc5f39724718699922f06c)
Diffstat (limited to 'sysdeps/i386')
| -rw-r--r-- | sysdeps/i386/dl-machine.h | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index f6cfb90e21..1e3ef25498 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -338,16 +338,22 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc, { # ifndef RTLD_BOOTSTRAP if (sym_map != map - && sym_map->l_type != lt_executable && !sym_map->l_relocated) { const char *strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]); - _dl_error_printf ("\ + if (sym_map->l_type == lt_executable) + _dl_fatal_printf ("\ +%s: IFUNC symbol '%s' referenced in '%s' is defined in the executable \ +and creates an unsatisfiable circular dependency.\n", + RTLD_PROGNAME, strtab + refsym->st_name, + map->l_name); + else + _dl_error_printf ("\ %s: Relink `%s' with `%s' for IFUNC symbol `%s'\n", - RTLD_PROGNAME, map->l_name, - sym_map->l_name, - strtab + refsym->st_name); + RTLD_PROGNAME, map->l_name, + sym_map->l_name, + strtab + refsym->st_name); } # endif value = ((Elf32_Addr (*) (void)) value) (); |