diff options
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/dl-error.c | 9 | ||||
| -rw-r--r-- | elf/dl-load.c | 7 | ||||
| -rw-r--r-- | elf/dlerror.c | 2 | ||||
| -rw-r--r-- | elf/link.h | 5 | ||||
| -rw-r--r-- | elf/rtld.c | 115 |
5 files changed, 110 insertions, 28 deletions
diff --git a/elf/dl-error.c b/elf/dl-error.c index 2eaa7e03d1..40ded4f1d2 100644 --- a/elf/dl-error.c +++ b/elf/dl-error.c @@ -20,13 +20,15 @@ Cambridge, MA 02139, USA. */ #include <stddef.h> #include <link.h> #include <setjmp.h> +#include <stdlib.h> #include <string.h> /* This structure communicates state between _dl_catch_error and _dl_signal_error. */ struct catch { - const char *errstring, *objname; /* Error detail filled in here. */ + char *errstring; /* Error detail filled in here. */ + const char *objname; jmp_buf env; /* longjmp here on error. */ }; @@ -69,7 +71,7 @@ _dl_signal_error (int errcode, } int -_dl_catch_error (const char **errstring, +_dl_catch_error (char **errstring, const char **objname, void (*operate) (void)) { @@ -82,7 +84,8 @@ _dl_catch_error (const char **errstring, catch = &c; (*operate) (); catch = NULL; - *errstring = *objname = NULL; + *errstring = NULL; + *objname = NULL; return 0; } diff --git a/elf/dl-load.c b/elf/dl-load.c index 6fd6a6cbe0..b56303fa4a 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -481,6 +481,7 @@ _dl_map_object (struct link_map *loader, const char *name, int type) { int fd; char *realname; + char *name_copy; struct link_map *l; /* Look for this name among those already loaded. */ @@ -572,8 +573,8 @@ _dl_map_object (struct link_map *loader, const char *name, int type) if (fd != -1) { - name = local_strdup (name); - if (name == NULL) + name_copy = local_strdup (name); + if (name_copy == NULL) { __close (fd); fd = -1; @@ -583,5 +584,5 @@ _dl_map_object (struct link_map *loader, const char *name, int type) if (fd == -1) _dl_signal_error (errno, name, "cannot open shared object file"); - return _dl_map_object_from_fd (name, fd, realname, loader, type); + return _dl_map_object_from_fd (name_copy, fd, realname, loader, type); } diff --git a/elf/dlerror.c b/elf/dlerror.c index 663207d708..9b78e47a57 100644 --- a/elf/dlerror.c +++ b/elf/dlerror.c @@ -24,7 +24,7 @@ Cambridge, MA 02139, USA. */ #include <stdlib.h> static int last_errcode; -static const char *last_errstring; +static char *last_errstring; static const char *last_object_name; char * diff --git a/elf/link.h b/elf/link.h index a9637000e5..a6281726c3 100644 --- a/elf/link.h +++ b/elf/link.h @@ -178,8 +178,9 @@ extern void _dl_signal_error (int errcode, /* Call OPERATE, catching errors from `dl_signal_error'. If there is no error, *ERRSTRING is set to null. If there is an error, *ERRSTRING and *OBJECT are set to the strings passed to _dl_signal_error, and the error - code passed is the return value. */ -extern int _dl_catch_error (const char **errstring, + code passed is the return value. ERRSTRING if nonzero points to a + malloc'ed string which the caller has to free after use. */ +extern int _dl_catch_error (char **errstring, const char **object, void (*operate) (void)); diff --git a/elf/rtld.c b/elf/rtld.c index 8b754920f8..0736218536 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -38,6 +38,12 @@ extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, ElfW(Addr) *user_entry)); extern void _dl_sysdep_start_cleanup (void); +/* System-dependent function to read a file's whole contents + in the most convenient manner available. */ +extern void *_dl_sysdep_read_whole_file (const char *filename, + size_t *filesize_ptr, + int mmap_prot); + int _dl_argc; char **_dl_argv; const char *_dl_rpath; @@ -138,6 +144,8 @@ dl_main (const ElfW(Phdr) *phdr, enum { normal, list, verify, trace } mode; struct link_map **preloads; unsigned int npreloads; + size_t file_size; + char *file; mode = getenv ("LD_TRACE_LOADED_OBJECTS") != NULL ? trace : normal; @@ -296,8 +304,77 @@ of this helper program; chances are you did not intend to run this program.\n", l->l_next = &_dl_rtld_map; _dl_rtld_map.l_prev = l; + /* We have two ways to specify objects to preload: via environment + variable and via the file /etc/ld.so.preload. The later can also + be used when security is enabled. */ preloads = NULL; npreloads = 0; + + /* Read the contents of the file. */ + file = _dl_sysdep_read_whole_file ("/etc/ld.so.preload", &file_size, + PROT_READ | PROT_WRITE); + if (file) + { + /* 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; + + 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] != '\t' + && file[file_size] != '\n') + { + problem = &file[file_size]; + while (problem > file && problem[-1] != ' ' && problem[-1] != '\t' + && problem[-1] != '\n') + --problem; + + if (problem > file) + problem[-1] = '\0'; + } + else + problem = NULL; + + if (file != problem) + { + char *p; + runp = file; + while ((p = strsep (&runp, ": \t\n")) != NULL) + { + (void) _dl_map_object (NULL, p, lt_library); + ++npreloads; + } + } + + if (problem != NULL) + { + char *p = strndupa (problem, file_size - (problem - file)); + (void) _dl_map_object (NULL, p, lt_library); + } + + /* We don't need the file anymore. */ + __munmap (file, file_size); + } + if (! __libc_enable_secure) { const char *preloadlist = getenv ("LD_PRELOAD"); @@ -313,25 +390,25 @@ of this helper program; chances are you did not intend to run this program.\n", (void) _dl_map_object (NULL, p, lt_library); ++npreloads; } - - if (npreloads != 0) - { - /* Set up PRELOADS with a vector of the preloaded libraries. */ - struct link_map *l; - unsigned int i; - preloads = __alloca (npreloads * sizeof preloads[0]); - l = _dl_rtld_map.l_next; /* End of the chain before preloads. */ - i = 0; - do - { - preloads[i++] = l; - l = l->l_next; - } while (l); - assert (i == npreloads); - } } } + if (npreloads != 0) + { + /* Set up PRELOADS with a vector of the preloaded libraries. */ + struct link_map *l; + unsigned int i; + preloads = __alloca (npreloads * sizeof preloads[0]); + l = _dl_rtld_map.l_next; /* End of the chain before preloads. */ + i = 0; + do + { + preloads[i++] = l; + l = l->l_next; + } while (l); + assert (i == npreloads); + } + /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD specified some libraries to load, these are inserted before the actual dependencies in the executable's searchlist for symbol resolution. */ @@ -386,7 +463,7 @@ of this helper program; chances are you did not intend to run this program.\n", char buf[20], *bp; buf[sizeof buf - 1] = '\0'; bp = _itoa (l->l_addr, &buf[sizeof buf - 1], 16, 0); - while (&buf[sizeof buf - 1] - bp < sizeof l->l_addr * 2) + while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof l->l_addr * 2) *--bp = '0'; _dl_sysdep_message ("\t", l->l_libname, " => ", l->l_name, " (0x", bp, ")\n", NULL); @@ -403,12 +480,12 @@ of this helper program; chances are you did not intend to run this program.\n", char buf[20], *bp; buf[sizeof buf - 1] = '\0'; bp = _itoa (ref->st_value, &buf[sizeof buf - 1], 16, 0); - while (&buf[sizeof buf - 1] - bp < sizeof loadbase * 2) + while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) *--bp = '0'; _dl_sysdep_message (_dl_argv[i], " found at 0x", bp, NULL); buf[sizeof buf - 1] = '\0'; bp = _itoa (loadbase, &buf[sizeof buf - 1], 16, 0); - while (&buf[sizeof buf - 1] - bp < sizeof loadbase * 2) + while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) *--bp = '0'; _dl_sysdep_message (" in object at 0x", bp, "\n", NULL); } |