Message ID | 20230713131348.985999-1-stli@linux.ibm.com |
---|---|
State | New |
Headers | show |
Series | Fix getting return address in elf/tst-audit28.c. | expand |
Ping On 13.07.23 15:13, Stefan Liebler wrote: > Starting with commit 1bcfe0f732066ae5336b252295591ebe7e51c301, the > test was enhanced and the object for __builtin_return_address (0) > is searched with _dl_find_object. > > Unfortunately on e.g. s390 (31bit), a postprocessing step is needed > as the highest bit has to be masked out. This can be done with > __builtin_extract_return_addr. > > Without this postprocessing, _dl_find_object returns with -1 and the > content of dlfo is invalid, which may lead to segfaults in basename. > Therefore those checks are now only done on success. > --- > elf/tst-auditmod28.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/elf/tst-auditmod28.c b/elf/tst-auditmod28.c > index f6dfbbe202..35180208ba 100644 > --- a/elf/tst-auditmod28.c > +++ b/elf/tst-auditmod28.c > @@ -73,12 +73,19 @@ la_version (unsigned int current) > > /* Check _dl_find_object. */ > struct dl_find_object dlfo; > - TEST_COMPARE (_dl_find_object (__builtin_return_address (0), &dlfo), 0); > - /* "ld.so" is seen with --enable-hardcoded-path-in-tests. */ > - if (strcmp (basename (dlfo.dlfo_link_map->l_name), "ld.so") != 0) > - TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LD_SO); > - TEST_COMPARE (_dl_find_object (dlsym (handle, "environ"), &dlfo), 0); > - TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LIBC_SO); > + void *ret_addr = __builtin_extract_return_addr (__builtin_return_address (0)); > + int ret_dl_find_object =_dl_find_object (ret_addr, &dlfo); > + TEST_COMPARE (ret_dl_find_object, 0); > + if (ret_dl_find_object == 0) > + { > + /* "ld.so" is seen with --enable-hardcoded-path-in-tests. */ > + if (strcmp (basename (dlfo.dlfo_link_map->l_name), "ld.so") != 0) > + TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LD_SO); > + } > + ret_dl_find_object = _dl_find_object (dlsym (handle, "environ"), &dlfo); > + TEST_COMPARE (ret_dl_find_object, 0); > + if (ret_dl_find_object == 0) > + TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LIBC_SO); > TEST_COMPARE (_dl_find_object ((void *) 1, &dlfo), -1); > TEST_COMPARE (_dl_find_object ((void *) -1, &dlfo), -1); >
* Stefan Liebler: > Starting with commit 1bcfe0f732066ae5336b252295591ebe7e51c301, the > test was enhanced and the object for __builtin_return_address (0) > is searched with _dl_find_object. > > Unfortunately on e.g. s390 (31bit), a postprocessing step is needed > as the highest bit has to be masked out. This can be done with > __builtin_extract_return_addr. > > Without this postprocessing, _dl_find_object returns with -1 and the > content of dlfo is invalid, which may lead to segfaults in basename. > Therefore those checks are now only done on success. > --- > elf/tst-auditmod28.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/elf/tst-auditmod28.c b/elf/tst-auditmod28.c > index f6dfbbe202..35180208ba 100644 > --- a/elf/tst-auditmod28.c > +++ b/elf/tst-auditmod28.c > @@ -73,12 +73,19 @@ la_version (unsigned int current) > > /* Check _dl_find_object. */ > struct dl_find_object dlfo; > - TEST_COMPARE (_dl_find_object (__builtin_return_address (0), &dlfo), 0); > - /* "ld.so" is seen with --enable-hardcoded-path-in-tests. */ > - if (strcmp (basename (dlfo.dlfo_link_map->l_name), "ld.so") != 0) > - TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LD_SO); > - TEST_COMPARE (_dl_find_object (dlsym (handle, "environ"), &dlfo), 0); > - TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LIBC_SO); > + void *ret_addr = __builtin_extract_return_addr (__builtin_return_address (0)); > + int ret_dl_find_object =_dl_find_object (ret_addr, &dlfo); > + TEST_COMPARE (ret_dl_find_object, 0); > + if (ret_dl_find_object == 0) > + { > + /* "ld.so" is seen with --enable-hardcoded-path-in-tests. */ > + if (strcmp (basename (dlfo.dlfo_link_map->l_name), "ld.so") != 0) > + TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LD_SO); > + } > + ret_dl_find_object = _dl_find_object (dlsym (handle, "environ"), &dlfo); > + TEST_COMPARE (ret_dl_find_object, 0); > + if (ret_dl_find_object == 0) > + TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LIBC_SO); > TEST_COMPARE (_dl_find_object ((void *) 1, &dlfo), -1); > TEST_COMPARE (_dl_find_object ((void *) -1, &dlfo), -1); Based on the GCC documentation, this should be reasinable portable. Reviewed-by: Florian Weimer <fweimer@redhat.com> Thanks, Florian
On 19.07.23 11:15, Florian Weimer wrote: > Reviewed-by: Florian Weimer <fweimer@redhat.com> > > Thanks, > Florian > Committed. Thanks for reviewing.
diff --git a/elf/tst-auditmod28.c b/elf/tst-auditmod28.c index f6dfbbe202..35180208ba 100644 --- a/elf/tst-auditmod28.c +++ b/elf/tst-auditmod28.c @@ -73,12 +73,19 @@ la_version (unsigned int current) /* Check _dl_find_object. */ struct dl_find_object dlfo; - TEST_COMPARE (_dl_find_object (__builtin_return_address (0), &dlfo), 0); - /* "ld.so" is seen with --enable-hardcoded-path-in-tests. */ - if (strcmp (basename (dlfo.dlfo_link_map->l_name), "ld.so") != 0) - TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LD_SO); - TEST_COMPARE (_dl_find_object (dlsym (handle, "environ"), &dlfo), 0); - TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LIBC_SO); + void *ret_addr = __builtin_extract_return_addr (__builtin_return_address (0)); + int ret_dl_find_object =_dl_find_object (ret_addr, &dlfo); + TEST_COMPARE (ret_dl_find_object, 0); + if (ret_dl_find_object == 0) + { + /* "ld.so" is seen with --enable-hardcoded-path-in-tests. */ + if (strcmp (basename (dlfo.dlfo_link_map->l_name), "ld.so") != 0) + TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LD_SO); + } + ret_dl_find_object = _dl_find_object (dlsym (handle, "environ"), &dlfo); + TEST_COMPARE (ret_dl_find_object, 0); + if (ret_dl_find_object == 0) + TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LIBC_SO); TEST_COMPARE (_dl_find_object ((void *) 1, &dlfo), -1); TEST_COMPARE (_dl_find_object ((void *) -1, &dlfo), -1);