From b3736d1a3c60a3ec9959bf3b38794958546bf6a2 Mon Sep 17 00:00:00 2001
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Tue, 30 Aug 2022 13:35:52 -0300
Subject: [PATCH 118/118] elf: Restore how vDSO dependency is printed with
LD_TRACE_LOADED_OBJECTS (BZ #29539)
The d7703d3176d225d5743b21811d888619eba39e82 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>
(cherry picked from commit 1e903124cec4492463d075c6c061a2a772db77bf)
---
NEWS | 2 +-
elf/rtld.c | 6 ++++++
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/NEWS b/NEWS
index 6d31e5abba13..757ded85e0f7 100644
--- a/NEWS
+++ b/NEWS
@@ -14,7 +14,7 @@ The following bugs are resolved with this release:
[29485] Linux: Terminate subprocess on late failure in tst-pidfd
[29490] alpha: New __brk_call implementation is broken
[29528] elf: Call __libc_early_init for reused namespaces
-
+ [29539] libc: LD_TRACE_LOADED_OBJECTS changed how vDSO library are
Version 2.36
diff --git a/elf/rtld.c b/elf/rtld.c
index cbbaf4a33196..3e771a93d834 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -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),
--
2.37.3
