diff options
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/rtld.c | 181 |
1 files changed, 96 insertions, 85 deletions
diff --git a/elf/rtld.c b/elf/rtld.c index a65e9c4c7c..e015477c19 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1138,103 +1138,114 @@ of this helper program; chances are you did not intend to run this program.\n\ HP_TIMING_ACCUM_NT (load_time, diff); } - /* Read the contents of the file. */ - const char preload_file[] = "/etc/ld.so.preload"; - file = _dl_sysdep_read_whole_file (preload_file, &file_size, - PROT_READ | PROT_WRITE); - if (__builtin_expect (file != MAP_FAILED, 0)) + /* There usually is no ld.so.preload file, it should only be used + for emergencies and testing. So the open call etc should usually + fail. Using access() on a non-existing file is faster than using + open(). So we do this first. If it succeeds we do almost twice + the work but this does not matter, since it is not for production + use. */ + static const char preload_file[] = "/etc/ld.so.preload"; + if (__builtin_expect (__access (preload_file, R_OK) == 0, 0)) { - /* Parse the file. It contains names of libraries to be loaded, - separated by white spaces or `:'. It may also contain - comments introduced by `#'. */ - char *problem; - char *runp; - size_t rest; - - /* Eliminate comments. */ - runp = file; - rest = file_size; - while (rest > 0) + /* Read the contents of the file. */ + file = _dl_sysdep_read_whole_file (preload_file, &file_size, + PROT_READ | PROT_WRITE); + if (__builtin_expect (file != MAP_FAILED, 0)) { - char *comment = memchr (runp, '#', rest); - if (comment == NULL) - break; - - rest -= comment - runp; - do - *comment = ' '; - while (--rest > 0 && *++comment != '\n'); - } - - /* We have one problematic case: if we have a name at the end of - the file without a trailing terminating characters, we cannot - place the \0. Handle the case separately. */ - if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' - && file[file_size - 1] != '\n' && file[file_size - 1] != ':') - { - problem = &file[file_size]; - while (problem > file && problem[-1] != ' ' && problem[-1] != '\t' - && problem[-1] != '\n' && problem[-1] != ':') - --problem; - - if (problem > file) - problem[-1] = '\0'; - } - else - { - problem = NULL; - file[file_size - 1] = '\0'; - } + /* Parse the file. It contains names of libraries to be loaded, + separated by white spaces or `:'. It may also contain + comments introduced by `#'. */ + char *problem; + char *runp; + size_t rest; + + /* Eliminate comments. */ + runp = file; + rest = file_size; + while (rest > 0) + { + char *comment = memchr (runp, '#', rest); + if (comment == NULL) + break; - HP_TIMING_NOW (start); + rest -= comment - runp; + do + *comment = ' '; + while (--rest > 0 && *++comment != '\n'); + } - if (file != problem) - { - char *p; - runp = file; - while ((p = strsep (&runp, ": \t\n")) != NULL) - if (p[0] != '\0') - { - const char *objname; - const char *err_str = NULL; - struct map_args args; + /* We have one problematic case: if we have a name at the end of + the file without a trailing terminating characters, we cannot + place the \0. Handle the case separately. */ + if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' + && file[file_size - 1] != '\n' && file[file_size - 1] != ':') + { + problem = &file[file_size]; + while (problem > file && problem[-1] != ' ' + && problem[-1] != '\t' + && problem[-1] != '\n' && problem[-1] != ':') + --problem; + + if (problem > file) + problem[-1] = '\0'; + } + else + { + problem = NULL; + file[file_size - 1] = '\0'; + } - args.str = p; - args.loader = GL(dl_loaded); - args.is_preloaded = 1; - args.mode = 0; + HP_TIMING_NOW (start); - (void) _dl_catch_error (&objname, &err_str, map_doit, &args); - if (__builtin_expect (err_str != NULL, 0)) + if (file != problem) + { + char *p; + runp = file; + while ((p = strsep (&runp, ": \t\n")) != NULL) + if (p[0] != '\0') { - _dl_error_printf ("\ + const char *objname; + const char *err_str = NULL; + struct map_args args; + + args.str = p; + args.loader = GL(dl_loaded); + args.is_preloaded = 1; + args.mode = 0; + + (void) _dl_catch_error (&objname, &err_str, map_doit, + &args); + if (__builtin_expect (err_str != NULL, 0)) + { + _dl_error_printf ("\ ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n", - p, preload_file); - /* No need to call free, this is still before the libc's - malloc is used. */ + p, preload_file); + /* No need to call free, this is still before + the libc's malloc is used. */ + } + else if (++args.map->l_opencount == 1) + /* It is no duplicate. */ + ++npreloads; } - else if (++args.map->l_opencount == 1) - /* It is no duplicate. */ - ++npreloads; - } - } + } - if (problem != NULL) - { - char *p = strndupa (problem, file_size - (problem - file)); - struct link_map *new_map = _dl_map_object (GL(dl_loaded), p, 1, - lt_library, 0, 0); - if (++new_map->l_opencount == 1) - /* It is no duplicate. */ - ++npreloads; - } + if (problem != NULL) + { + char *p = strndupa (problem, file_size - (problem - file)); + struct link_map *new_map = _dl_map_object (GL(dl_loaded), p, 1, + lt_library, 0, 0); + if (++new_map->l_opencount == 1) + /* It is no duplicate. */ + ++npreloads; + } - HP_TIMING_NOW (stop); - HP_TIMING_DIFF (diff, start, stop); - HP_TIMING_ACCUM_NT (load_time, diff); + HP_TIMING_NOW (stop); + HP_TIMING_DIFF (diff, start, stop); + HP_TIMING_ACCUM_NT (load_time, diff); - /* We don't need the file anymore. */ - __munmap (file, file_size); + /* We don't need the file anymore. */ + __munmap (file, file_size); + } } if (__builtin_expect (npreloads, 0) != 0) |