elf: Restore how vDSO dependency is printed with LD_TRACE_LOADED_OBJECTS (BZ #29539)

The d7703d3176 changed how vDSO like
dependencies are printed, instead of just the name and address it
follows other libraries mode and prints 'name => path'.

Unfortunately, this broke some ldd consumer that uses the output to
filter out the program's dependencies.  For instance CMake
bundleutilities module [1], where GetPrequirite uses the regex to filter
out 'name => path' [2].

This patch restore the previous way to print just the name and the
mapping address.

Checked on x86_64-linux-gnu.

[1] https://github.com/Kitware/CMake/tree/master/Tests/BundleUtilities
[2] https://github.com/Kitware/CMake/blob/master/Modules/GetPrerequisites.cmake#L733

Reviewed-by: Florian Weimer <fweimer@redhat.com>
This commit is contained in:
Adhemerval Zanella 2022-08-30 13:35:52 -03:00
parent 8cd559cf5a
commit 1e903124ce

View File

@ -2122,6 +2122,12 @@ dl_main (const ElfW(Phdr) *phdr,
if (l->l_faked)
/* The library was not found. */
_dl_printf ("\t%s => not found\n", l->l_libname->name);
else if (strcmp (l->l_libname->name, l->l_name) == 0)
/* Print vDSO like libraries without duplicate name. Some
consumers depend of this format. */
_dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
(int) sizeof l->l_map_start * 2,
(size_t) l->l_map_start);
else
_dl_printf ("\t%s => %s (0x%0*Zx)\n",
DSO_FILENAME (l->l_libname->name),