[PATCH v2] elf: Restore ldconfig libc6 implicit soname logic [BZ #30125]
Joan Bruguera
joanbrugueram@gmail.com
Thu Feb 16 01:24:42 GMT 2023
While cleaning up old libc version support, the deprecated libc4 code was
accidentally kept in `implicit_soname`, instead of the libc6 code.
This causes additional symlinks to be created by `ldconfig` for libraries
without a soname, e.g. a library `libsomething.123.456.789` without a soname
will create a `libsomething.123` -> `libsomething.123.456.789` symlink.
As the libc6 version of the `implicit_soname` code is a trivial `xstrdup`,
just inline it and remove `implicit_soname` altogether.
Some further simplification looks possible (e.g. the call to `create_links`
looks like a no-op if `soname == NULL`, other than the verbose printfs), but
logic is kept as-is for now.
Fixes: BZ #30125
Fixes: 8ee878592c4a ("Assume only FLAG_ELF_LIBC6 suport")
---
elf/Makefile | 7 ++++++
elf/ldconfig.c | 4 +--
elf/readlib.c | 19 --------------
elf/tst-ldconfig-no-soname.sh | 47 +++++++++++++++++++++++++++++++++++
sysdeps/generic/ldconfig.h | 2 --
5 files changed, 56 insertions(+), 23 deletions(-)
create mode 100644 elf/tst-ldconfig-no-soname.sh
diff --git a/elf/Makefile b/elf/Makefile
index 2fc6391183..476f062dae 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -627,6 +627,7 @@ tests-special += \
$(objpfx)noload-mem.out \
$(objpfx)tst-ldconfig-X.out \
$(objpfx)tst-ldconfig-p.out \
+ $(objpfx)tst-ldconfig-no-soname.out \
$(objpfx)tst-leaks1-mem.out \
$(objpfx)tst-rtld-help.out \
# tests-special
@@ -2402,6 +2403,12 @@ $(objpfx)tst-ldconfig-p.out : tst-ldconfig-p.sh $(objpfx)ldconfig
'$(run-program-env)' > $@; \
$(evaluate-test)
+$(objpfx)tst-ldconfig-no-soname.out : tst-ldconfig-no-soname.sh \
+ $(objpfx)ldconfig
+ $(SHELL) $< '$(CC)' '$(common-objpfx)' '$(test-wrapper-env)' \
+ '$(run-program-env)' > $@; \
+ $(evaluate-test)
+
# Test static linking of all the libraries we can possibly link
# together. Note that in some configurations this may be less than the
# complete list of libraries we build but we try to maxmimize this list.
diff --git a/elf/ldconfig.c b/elf/ldconfig.c
index 3f1b30c570..2fc45ad825 100644
--- a/elf/ldconfig.c
+++ b/elf/ldconfig.c
@@ -616,7 +616,7 @@ manual_link (char *library)
goto out;
}
if (soname == NULL)
- soname = implicit_soname (libname, flag);
+ soname = xstrdup (libname);
create_links (real_path, path, libname, soname);
free (soname);
out:
@@ -849,7 +849,7 @@ search_dir (const struct dir_entry *entry)
}
if (soname == NULL)
- soname = implicit_soname (direntry->d_name, flag);
+ soname = xstrdup (direntry->d_name);
/* A link may just point to itself. */
if (is_link)
diff --git a/elf/readlib.c b/elf/readlib.c
index c5c3591eef..bc13d9acc6 100644
--- a/elf/readlib.c
+++ b/elf/readlib.c
@@ -166,24 +166,5 @@ process_file (const char *real_file_name, const char *file_name,
return ret;
}
-/* Returns made up soname if lib doesn't have explicit DT_SONAME. */
-
-char *
-implicit_soname (const char *lib, int flag)
-{
- char *soname = xstrdup (lib);
-
- /* Aout files don't have a soname, just return the name
- including the major number. */
- char *major = strstr (soname, ".so.");
- if (major)
- {
- char *dot = strstr (major + 4, ".");
- if (dot)
- *dot = '\0';
- }
- return soname;
-}
-
/* Get architecture specific version of process_elf_file. */
#include <readelflib.c>
diff --git a/elf/tst-ldconfig-no-soname.sh b/elf/tst-ldconfig-no-soname.sh
new file mode 100644
index 0000000000..9f0f0cda50
--- /dev/null
+++ b/elf/tst-ldconfig-no-soname.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+# Test that ldconfig does not create symlinks for libraries without a soname.
+# Copyright (C) 2023 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+
+set -ex
+
+CC=$1
+common_objpfx=$2
+test_wrapper_env=$3
+run_program_env=$4
+
+testroot="${common_objpfx}elf/bug30125-test-directory"
+cleanup () {
+ rm -rf "$testroot"
+}
+trap cleanup 0
+
+rm -rf "$testroot"
+mkdir -p $testroot/lib $testroot/etc
+
+$CC /dev/null -o $testroot/lib/libsomething.so.1.2.3 -shared
+
+${test_wrapper_env} \
+${run_program_env} \
+${common_objpfx}elf/ldconfig -f /dev/null \
+ -C $testroot/etc/ld.so.cache \
+ $testroot/lib
+
+if [ -n "$(find $testroot/lib -type l)" ]; then
+ echo "error: $0 - symlink found"
+ exit 1
+fi
diff --git a/sysdeps/generic/ldconfig.h b/sysdeps/generic/ldconfig.h
index 0e1a9a9515..e9e9e19d0f 100644
--- a/sysdeps/generic/ldconfig.h
+++ b/sysdeps/generic/ldconfig.h
@@ -90,8 +90,6 @@ extern int process_file (const char *real_file_name, const char *file_name,
const char *lib, int *flag, unsigned int *isa_level,
char **soname, int is_link, struct stat *stat_buf);
-extern char *implicit_soname (const char *lib, int flag);
-
/* Declared in readelflib.c. */
extern int process_elf_file (const char *file_name, const char *lib,
int *flag, unsigned int *isa_level, char **soname,
--
2.39.2
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