elf: ld.so --help calls _dl_init_paths without a main map [BZ #27577]

In this case, use the link map of the dynamic loader itself as
a replacement.  This is more than just a hack: if we ever support
DT_RUNPATH/DT_RPATH for the dynamic loader, reporting it for
ld.so --help (without further command line arguments) would be the
right thing to do.

Fixes commit 3324213125 ("elf: Always
set l in _dl_init_paths (bug 23462)").
This commit is contained in:
Florian Weimer 2021-03-15 10:33:43 +01:00
parent f53ffc9b90
commit 4e6db99c66
2 changed files with 23 additions and 3 deletions

View File

@ -245,7 +245,7 @@ tests += $(tests-execstack-$(have-z-execstack))
ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)tst-leaks1-mem.out \
$(objpfx)tst-leaks1-static-mem.out $(objpfx)noload-mem.out \
$(objpfx)tst-ldconfig-X.out
$(objpfx)tst-ldconfig-X.out $(objpfx)tst-rtld-help.out
endif
tlsmod17a-suffixes = 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
tlsmod18a-suffixes = 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
@ -433,7 +433,8 @@ endif
ifeq (yes,$(build-shared))
ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)tst-pathopt.out $(objpfx)tst-rtld-load-self.out \
$(objpfx)tst-rtld-preload.out $(objpfx)argv0test.out
$(objpfx)tst-rtld-preload.out $(objpfx)argv0test.out \
$(objpfx)tst-rtld-help.out
endif
tests-special += $(objpfx)check-textrel.out $(objpfx)check-execstack.out \
$(objpfx)check-wx-segment.out \
@ -1907,3 +1908,16 @@ $(objpfx)list-tunables.out: tst-rtld-list-tunables.sh $(objpfx)ld.so
$(evaluate-test)
tst-dst-static-ENV = LD_LIBRARY_PATH='$$ORIGIN'
$(objpfx)tst-rtld-help.out: $(objpfx)ld.so
$(test-wrapper) $(rtld-prefix) --help > $@; \
status=$$?; \
echo "info: ld.so exit status: $$status" >> $@; \
if ! grep -q 'Legacy HWCAP subdirectories under library search path directories' $@; then \
echo "error: missing subdirectory pattern" >> $@; \
if test $$status -eq 0; then \
status=1; \
fi; \
fi; \
(exit $$status); \
$(evaluate-test)

View File

@ -758,8 +758,14 @@ _dl_init_paths (const char *llp, const char *source,
max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
*aelem = NULL;
/* This points to the map of the main object. */
/* This points to the map of the main object. If there is no main
object (e.g., under --help, use the dynamic loader itself as a
stand-in. */
l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
#ifdef SHARED
if (l == NULL)
l = &GL (dl_rtld_map);
#endif
assert (l->l_type != lt_loaded);
if (l->l_info[DT_RUNPATH])