* [PATCH 1/4] nptl_db: Install libthread_db under a regular implementation name
2021-06-09 11:15 [PATCH 0/4] Add --disable-major-minor-libraries configure option Florian Weimer
@ 2021-06-09 11:16 ` Florian Weimer
2021-06-09 11:16 ` [PATCH 2/4] Makerules: Remove lib-version, $(subdir-version) Florian Weimer
` (2 subsequent siblings)
3 siblings, 0 replies; 10+ messages in thread
From: Florian Weimer @ 2021-06-09 11:16 UTC (permalink / raw)
To: libc-alpha
Currently, the name is always libthread_db-1.0.so. It does not change
with the glibc version, like the other libraries.
GDB hard-codes libthread_db.so.1 (the soname), so this change does not
affect loading libthread_db.
Tested on x86_64-linux-gnu, in an environment where the nptl GDB tests
actually run.
---
nptl_db/Makefile | 2 --
1 file changed, 2 deletions(-)
diff --git a/nptl_db/Makefile b/nptl_db/Makefile
index ea721c1dcf..1f79c018a1 100644
--- a/nptl_db/Makefile
+++ b/nptl_db/Makefile
@@ -21,8 +21,6 @@ subdir := nptl_db
include ../Makeconfig
-nptl_db-version = 1.0
-
extra-libs = libthread_db
extra-libs-others := $(extra-libs)
--
2.31.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 2/4] Makerules: Remove lib-version, $(subdir-version)
2021-06-09 11:15 [PATCH 0/4] Add --disable-major-minor-libraries configure option Florian Weimer
2021-06-09 11:16 ` [PATCH 1/4] nptl_db: Install libthread_db under a regular implementation name Florian Weimer
@ 2021-06-09 11:16 ` Florian Weimer
2021-06-09 11:16 ` [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig Florian Weimer
2021-06-09 11:16 ` [PATCH 4/4] Add --disable-major-minor-libraries configure option Florian Weimer
3 siblings, 0 replies; 10+ messages in thread
From: Florian Weimer @ 2021-06-09 11:16 UTC (permalink / raw)
To: libc-alpha
Also clarify that the “versioned” term refers to the soname, not the glibc
version (which also ends up in the installed file name).
I verified on x86_64-linux-gnu that “make install” produces the same
files.
---
Makerules | 26 ++++----------------------
1 file changed, 4 insertions(+), 22 deletions(-)
diff --git a/Makerules b/Makerules
index ca9885436e..d3f29d0b89 100644
--- a/Makerules
+++ b/Makerules
@@ -982,22 +982,21 @@ install-lib.so := $(filter %.so,$(install-lib:%_pic.a=%.so))
install-lib := $(filter-out %.so %_pic.a,$(install-lib))
ifeq (yes,$(build-shared))
-# Find which .so's have versions.
+# Find which .so's have a version number in their soname.
versioned := $(strip $(foreach so,$(install-lib.so),\
$(patsubst %,$(so),$($(so)-version))))
install-lib.so-versioned := $(filter $(versioned), $(install-lib.so))
install-lib.so-unversioned := $(filter-out $(versioned), $(install-lib.so))
-# For versioned libraries, we install three files:
+# For libraries whose soname have version numbers, we install three files:
# $(inst_libdir)/libfoo.so -- for linking, symlink or ld script
# $(inst_slibdir)/libfoo.so.NN -- for loading by SONAME, symlink
# $(inst_slibdir)/libfoo-X.Y.Z.so -- the real shared object file
-lib-version := $(firstword $($(subdir)-version) $(version))
install-lib-nosubdir: $(install-lib.so-unversioned:%=$(inst_slibdir)/%) \
$(foreach L,$(install-lib.so-versioned),\
$(inst_libdir)/$L \
- $(inst_slibdir)/$(L:.so=)-$(lib-version).so \
+ $(inst_slibdir)/$(L:.so=)-$(version).so \
$(inst_slibdir)/$L$($L-version))
# Install all the unversioned shared libraries.
@@ -1125,7 +1124,6 @@ include $(o-iterator)
generated += $(foreach o,$(versioned),$o$($o-version))
-ifeq (,$($(subdir)-version))
define o-iterator-doit
$(inst_slibdir)/$o$($o-version): $(inst_slibdir)/$(o:.so=)-$(version).so \
$(+force);
@@ -1140,23 +1138,7 @@ $(inst_slibdir)/$(o:.so=)-$(version).so: $(objpfx)$o $(+force);
endef
object-suffixes-left := $(versioned)
include $(o-iterator)
-else
-define o-iterator-doit
-$(inst_slibdir)/$o$($o-version): \
- $(inst_slibdir)/$(o:.so=)-$($(subdir)-version).so $(+force);
- $$(make-shlib-link)
-endef
-object-suffixes-left := $(versioned)
-include $(o-iterator)
-
-define o-iterator-doit
-$(inst_slibdir)/$(o:.so=)-$($(subdir)-version).so: $(objpfx)$o $(+force);
- $$(do-install-program)
-endef
-object-suffixes-left := $(versioned)
-include $(o-iterator)
-endif
-endif
+endif # ifneq (,$(versioned))
define do-install-so
$(do-install-program)
--
2.31.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig
2021-06-09 11:15 [PATCH 0/4] Add --disable-major-minor-libraries configure option Florian Weimer
2021-06-09 11:16 ` [PATCH 1/4] nptl_db: Install libthread_db under a regular implementation name Florian Weimer
2021-06-09 11:16 ` [PATCH 2/4] Makerules: Remove lib-version, $(subdir-version) Florian Weimer
@ 2021-06-09 11:16 ` Florian Weimer
2021-06-09 11:16 ` [PATCH 4/4] Add --disable-major-minor-libraries configure option Florian Weimer
3 siblings, 0 replies; 10+ messages in thread
From: Florian Weimer @ 2021-06-09 11:16 UTC (permalink / raw)
To: libc-alpha
This introduces <dl-is_dso.h> and the _dl_is_dso function. A
test ensures that the official names of libc.so, ld.so, and their
versioned names are recognized.
---
elf/Makefile | 2 +-
elf/dl-is_dso.h | 33 +++++++++++++++++++++++++++++++++
elf/ldconfig.c | 5 ++---
elf/tst-dl-is_dso.c | 35 +++++++++++++++++++++++++++++++++++
4 files changed, 71 insertions(+), 4 deletions(-)
create mode 100644 elf/dl-is_dso.h
create mode 100644 elf/tst-dl-is_dso.c
diff --git a/elf/Makefile b/elf/Makefile
index e9788d3d4f..5389c35536 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -223,7 +223,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
tst-single_threaded tst-single_threaded-pthread \
tst-tls-ie tst-tls-ie-dlmopen argv0test \
tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
- tst-tls20 tst-tls21 tst-dlmopen-dlerror
+ tst-tls20 tst-tls21 tst-dlmopen-dlerror tst-dl-is_dso
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
diff --git a/elf/dl-is_dso.h b/elf/dl-is_dso.h
new file mode 100644
index 0000000000..94e00966a1
--- /dev/null
+++ b/elf/dl-is_dso.h
@@ -0,0 +1,33 @@
+/* Heuristic for recognizing DSO file names.
+ Copyright (C) 2021 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/>. */
+
+#include <stdbool.h>
+#include <string.h>
+
+/* Returns true if the file name looks like a DSO name. */
+static bool
+_dl_is_dso (const char *name)
+{
+ /* Recognize lib*.so*, ld-*.so*, ld.so.*, ld64.so.*. ld-*.so*
+ matches both platform dynamic linker names like ld-linux.so.2,
+ and versioned dynamic loader names like ld-2.12.so. */
+ return (((strncmp (name, "lib", 3) == 0 || strncmp (name, "ld-", 3) == 0)
+ && strstr (name, ".so") != NULL)
+ || strncmp (name, "ld.so.", 6) == 0
+ || strncmp (name, "ld64.so.", 8) == 0);
+}
diff --git a/elf/ldconfig.c b/elf/ldconfig.c
index 96bf7700b2..1037e8d0cf 100644
--- a/elf/ldconfig.c
+++ b/elf/ldconfig.c
@@ -43,6 +43,7 @@
#include <ldconfig.h>
#include <dl-cache.h>
#include <dl-hwcaps.h>
+#include <dl-is_dso.h>
#include <dl-procinfo.h>
@@ -842,9 +843,7 @@ search_dir (const struct dir_entry *entry)
subdirectory (if not already processing a glibc-hwcaps
subdirectory)? The dynamic linker is also considered as
shared library. */
- if (((strncmp (direntry->d_name, "lib", 3) != 0
- && strncmp (direntry->d_name, "ld-", 3) != 0)
- || strstr (direntry->d_name, ".so") == NULL)
+ if (!_dl_is_dso (direntry->d_name)
&& (direntry->d_type == DT_REG
|| (entry->hwcaps == NULL
&& !is_hwcap_platform (direntry->d_name))))
diff --git a/elf/tst-dl-is_dso.c b/elf/tst-dl-is_dso.c
new file mode 100644
index 0000000000..48d2cc9fbe
--- /dev/null
+++ b/elf/tst-dl-is_dso.c
@@ -0,0 +1,35 @@
+/* Test heuristic for recognizing DSO file names.
+ Copyright (C) 2021 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/>. */
+
+#include <dl-is_dso.h>
+#include <gnu/lib-names.h>
+#include <support/check.h>
+
+static int
+do_test (void)
+{
+ /* Official ABI names. */
+ TEST_VERIFY (_dl_is_dso (LIBC_SO));
+ TEST_VERIFY (_dl_is_dso (LD_SO));
+ /* Version-based names. The version number does not matter. */
+ TEST_VERIFY (_dl_is_dso ("libc-2.12.so"));
+ TEST_VERIFY (_dl_is_dso ("ld-2.12.so"));
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.31.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 4/4] Add --disable-major-minor-libraries configure option
2021-06-09 11:15 [PATCH 0/4] Add --disable-major-minor-libraries configure option Florian Weimer
` (2 preceding siblings ...)
2021-06-09 11:16 ` [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig Florian Weimer
@ 2021-06-09 11:16 ` Florian Weimer
2021-06-09 16:03 ` Joseph Myers
3 siblings, 1 reply; 10+ messages in thread
From: Florian Weimer @ 2021-06-09 11:16 UTC (permalink / raw)
To: libc-alpha
This option can be used to increase compatibility with package managers.
The name was choosen to avoid confusion with all the different versions
(glibc release, soname versions, symbol versions).
This patch makes all uses of -$(version).so conditional on the new
$(major-minor-libraries) flag. The alternative install targets write
the implementation DSOs directly to the locations determined by their
sonames, skipping the creation of an intermediate symbolic link.
install-symbolic-link in Makerules is updated not to require the
$(symbolic-link-list) file because it may not exist in
--disable-major-minor-libraries mode.
---
INSTALL | 10 ++++++++++
Makefile | 4 +++-
Makerules | 26 +++++++++++++++++++++++++-
config.make.in | 1 +
configure | 15 +++++++++++++++
configure.ac | 7 +++++++
elf/Makefile | 8 +++++++-
manual/install.texi | 9 +++++++++
8 files changed, 77 insertions(+), 3 deletions(-)
diff --git a/INSTALL b/INSTALL
index bc761ab98b..ed5f66489b 100644
--- a/INSTALL
+++ b/INSTALL
@@ -199,6 +199,16 @@ if 'CFLAGS' is specified it must enable optimization. For example:
RELRO and a read-only global offset table (GOT), at the cost of
slightly increased program load times.
+'--disable-major-minor-libraries'
+ Do not install shared objects under file names that contain the
+ major and minor version of the GNU C Library. By default, such
+ names are used, and the names defined by the ABI are provided as
+ symbolic links only. This causes problems with certain package
+ managers during library upgrades and (in particular) downgrades, so
+ this option can be used to install these shared objects directly
+ under their ABI-defined names, without an additional indirection
+ via symbolic links.
+
'--enable-pt_chown'
The file 'pt_chown' is a helper binary for 'grantpt' (*note
Pseudo-Terminals: Allocation.) that is installed setuid root to fix
diff --git a/Makefile b/Makefile
index 242d36de91..4cf422adce 100644
--- a/Makefile
+++ b/Makefile
@@ -112,7 +112,9 @@ ifeq (yes,$(build-shared))
install: install-symbolic-link
.PHONY: install-symbolic-link
install-symbolic-link: subdir_install
- $(symbolic-link-prog) $(symbolic-link-list)
+ if test -e $(symbolic-link-list) ; then \
+ $(symbolic-link-prog) $(symbolic-link-list); \
+ fi
rm -f $(symbolic-link-list)
install:
diff --git a/Makerules b/Makerules
index d3f29d0b89..162b92a4c2 100644
--- a/Makerules
+++ b/Makerules
@@ -989,6 +989,14 @@ versioned := $(strip $(foreach so,$(install-lib.so),\
install-lib.so-versioned := $(filter $(versioned), $(install-lib.so))
install-lib.so-unversioned := $(filter-out $(versioned), $(install-lib.so))
+# $(install-major-minor-libraries) is used within install-lib-nosubdir
+# to trigger installation of the actual implementation file.
+ifeq (yes,$(major-minor-libraries))
+install-major-minor-libraries = $(inst_slibdir)/$(L:.so=)-$(version).so
+else
+install-major-minor-libraries =
+endif
+
# For libraries whose soname have version numbers, we install three files:
# $(inst_libdir)/libfoo.so -- for linking, symlink or ld script
# $(inst_slibdir)/libfoo.so.NN -- for loading by SONAME, symlink
@@ -996,7 +1004,7 @@ install-lib.so-unversioned := $(filter-out $(versioned), $(install-lib.so))
install-lib-nosubdir: $(install-lib.so-unversioned:%=$(inst_slibdir)/%) \
$(foreach L,$(install-lib.so-versioned),\
$(inst_libdir)/$L \
- $(inst_slibdir)/$(L:.so=)-$(version).so \
+ $(install-major-minor-libraries) \
$(inst_slibdir)/$L$($L-version))
# Install all the unversioned shared libraries.
@@ -1049,6 +1057,7 @@ endef
endif
ifdef libc.so-version
+ifeq (yes,$(major-minor-libraries))
# For a library specified to be version N, install three files:
# libc.so -> libc.so.N (e.g. libc.so.6)
# libc.so.6 -> libc-VERSION.so (e.g. libc-1.10.so)
@@ -1058,6 +1067,11 @@ $(inst_slibdir)/libc.so$(libc.so-version): $(inst_slibdir)/libc-$(version).so \
$(make-shlib-link)
$(inst_slibdir)/libc-$(version).so: $(common-objpfx)libc.so $(+force)
$(do-install-program)
+else # !$(major-minor-libraries)
+$(inst_slibdir)/libc.so$(libc.so-version): $(common-objpfx)libc.so $(+force)
+ $(do-install-program)
+endif # !$(major-minor-libraries)
+
install: $(inst_slibdir)/libc.so$(libc.so-version)
# This fragment of linker script gives the OUTPUT_FORMAT statement
@@ -1124,6 +1138,7 @@ include $(o-iterator)
generated += $(foreach o,$(versioned),$o$($o-version))
+ifeq (yes,$(major-minor-libraries))
define o-iterator-doit
$(inst_slibdir)/$o$($o-version): $(inst_slibdir)/$(o:.so=)-$(version).so \
$(+force);
@@ -1138,6 +1153,15 @@ $(inst_slibdir)/$(o:.so=)-$(version).so: $(objpfx)$o $(+force);
endef
object-suffixes-left := $(versioned)
include $(o-iterator)
+
+else # !$(major-minor-libraries)
+define o-iterator-doit
+$(inst_slibdir)/$o$($o-version): $(objpfx)$o $(+force);
+ $$(do-install-program)
+endef
+object-suffixes-left := $(versioned)
+include $(o-iterator)
+endif # !$(major-minor-libraries)
endif # ifneq (,$(versioned))
define do-install-so
diff --git a/config.make.in b/config.make.in
index cbf59114b0..55a8351dd2 100644
--- a/config.make.in
+++ b/config.make.in
@@ -71,6 +71,7 @@ have-libcap = @have_libcap@
have-cc-with-libunwind = @libc_cv_cc_with_libunwind@
fno-unit-at-a-time = @fno_unit_at_a_time@
bind-now = @bindnow@
+major-minor-libraries = @major_minor_libraries@
have-hash-style = @libc_cv_hashstyle@
use-default-link = @use_default_link@
have-cxx-thread_local = @libc_cv_cxx_thread_local@
diff --git a/configure b/configure
index a86bcf7671..cb98b4c047 100755
--- a/configure
+++ b/configure
@@ -681,6 +681,7 @@ experimental_malloc
enable_werror
all_warnings
force_install
+major_minor_libraries
bindnow
hardcoded_path_in_tests
enable_timezone_tools
@@ -774,6 +775,7 @@ enable_hidden_plt
enable_bind_now
enable_stack_protector
enable_static_nss
+enable_major_minor_libraries
enable_force_install
enable_maintainer_mode
enable_kernel
@@ -1435,6 +1437,10 @@ Optional Features:
Use -fstack-protector[-all|-strong] to detect glibc
buffer overflows
--enable-static-nss build static NSS modules [default=no]
+ --enable-major-minor-libraries
+ install most shared objects under names based on the
+ glibc version, with symbolic links to them
+ [default=yes]
--disable-force-install don't force installation of files from this package,
even if they are older than the installed files
--enable-maintainer-mode
@@ -3480,6 +3486,15 @@ if test x"$static_nss" = xyes || test x"$shared" = xno; then
fi
+# Check whether --enable-major-minor-libraries was given.
+if test "${enable_major_minor_libraries+set}" = set; then :
+ enableval=$enable_major_minor_libraries; major_minor_libraries=$enableval
+else
+ major_minor_libraries=yes
+fi
+
+
+
# Check whether --enable-force-install was given.
if test "${enable_force_install+set}" = set; then :
enableval=$enable_force_install; force_install=$enableval
diff --git a/configure.ac b/configure.ac
index f2588f394f..91d54e6926 100644
--- a/configure.ac
+++ b/configure.ac
@@ -242,6 +242,13 @@ if test x"$static_nss" = xyes || test x"$shared" = xno; then
AC_DEFINE(DO_STATIC_NSS)
fi
+AC_ARG_ENABLE([major-minor-libraries],
+ AC_HELP_STRING([--enable-major-minor-libraries],
+ [install most shared objects under names based on the glibc version, with symbolic links to them @<:@default=yes@:>@]),
+ [major_minor_libraries=$enableval],
+ [major_minor_libraries=yes])
+AC_SUBST(major_minor_libraries)
+
AC_ARG_ENABLE([force-install],
AS_HELP_STRING([--disable-force-install],
[don't force installation of files from this package, even if they are older than the installed files]),
diff --git a/elf/Makefile b/elf/Makefile
index 5389c35536..3211dbfd64 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -628,6 +628,7 @@ $(objpfx)trusted-dirs.st: Makefile $(..)Makeconfig
CPPFLAGS-dl-load.c += -I$(objpfx). -I$(csu-objpfx).
ifeq (yes,$(build-shared))
+ifeq (yes,$(major-minor-libraries))
$(inst_slibdir)/$(rtld-version-installed-name): $(objpfx)ld.so $(+force)
$(make-target-directory)
$(do-install-program)
@@ -637,11 +638,16 @@ $(inst_rtlddir)/$(rtld-installed-name): \
$(inst_slibdir)/libc-$(version).so
$(make-target-directory)
$(make-shlib-link)
+else # !$(major-minor-libraries)
+$(inst_rtlddir)/$(rtld-installed-name): $(objpfx)ld.so $(+force)
+ $(make-target-directory)
+ $(do-install-program)
+endif # !$(major-minor-libraries)
# Special target called by parent to install just the dynamic linker.
.PHONY: ldso_install
ldso_install: $(inst_rtlddir)/$(rtld-installed-name)
-endif
+endif # $(build-shared)
# Workarounds for ${exec_prefix} expansion in configure variables.
diff --git a/manual/install.texi b/manual/install.texi
index f1d858fb78..3e0ae46285 100644
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -226,6 +226,15 @@ provides additional security hardening because it enables full RELRO
and a read-only global offset table (GOT), at the cost of slightly
increased program load times.
+@item --disable-major-minor-libraries
+Do not install shared objects under file names that contain the major
+and minor version of @theglibc. By default, such names are used, and
+the names defined by the ABI are provided as symbolic links only. This
+causes problems with certain package managers during library upgrades
+and (in particular) downgrades, so this option can be used to install
+these shared objects directly under their ABI-defined names, without an
+additional indirection via symbolic links.
+
@pindex pt_chown
@findex grantpt
@item --enable-pt_chown
--
2.31.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 4/4] Add --disable-major-minor-libraries configure option
2021-06-09 11:16 ` [PATCH 4/4] Add --disable-major-minor-libraries configure option Florian Weimer
@ 2021-06-09 16:03 ` Joseph Myers
2021-06-09 17:09 ` Florian Weimer
0 siblings, 1 reply; 10+ messages in thread
From: Joseph Myers @ 2021-06-09 16:03 UTC (permalink / raw)
To: Florian Weimer; +Cc: libc-alpha
This needs a NEWS entry.
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 4/4] Add --disable-major-minor-libraries configure option
2021-06-09 16:03 ` Joseph Myers
@ 2021-06-09 17:09 ` Florian Weimer
2021-06-09 17:28 ` Joseph Myers
0 siblings, 1 reply; 10+ messages in thread
From: Florian Weimer @ 2021-06-09 17:09 UTC (permalink / raw)
To: Joseph Myers; +Cc: libc-alpha
* Joseph Myers:
> This needs a NEWS entry.
What about this?
* glibc can now be configured with the --disable-major-minor-libraries
option. In this case, the various shared objects that are part of
glibc will be installed under their ABI sonames (such as libc.so.6)
rather than version-specific file names (such as libc-2.34.so). As
before, by default, glibc installs them as version-specific file
names, with the ABI sonames added as symbolic links. The
--disable-major-minor-libraries option enables safer downgrades with
package managers which delete removed files very late, after invoking
ldconfig.
Indepdently of the implementation of the patch, do you think this is
something that needs to be configurable, or can we remove versioned file
names altogether?
Thanks,
Florian
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 4/4] Add --disable-major-minor-libraries configure option
2021-06-09 17:09 ` Florian Weimer
@ 2021-06-09 17:28 ` Joseph Myers
0 siblings, 0 replies; 10+ messages in thread
From: Joseph Myers @ 2021-06-09 17:28 UTC (permalink / raw)
To: Florian Weimer; +Cc: libc-alpha
On Wed, 9 Jun 2021, Florian Weimer via Libc-alpha wrote:
> * Joseph Myers:
>
> > This needs a NEWS entry.
>
> What about this?
>
> * glibc can now be configured with the --disable-major-minor-libraries
> option. In this case, the various shared objects that are part of
> glibc will be installed under their ABI sonames (such as libc.so.6)
> rather than version-specific file names (such as libc-2.34.so). As
> before, by default, glibc installs them as version-specific file
> names, with the ABI sonames added as symbolic links. The
> --disable-major-minor-libraries option enables safer downgrades with
> package managers which delete removed files very late, after invoking
> ldconfig.
That seems reasonable (if we have this option at all).
> Indepdently of the implementation of the patch, do you think this is
> something that needs to be configurable, or can we remove versioned file
> names altogether?
I don't know why we have the versioned file names, but my guess would be
it was intended to help with downgrades after a non-package-manager
installation directly into the root filesystem went wrong (someone could
try to use sln to recover by linking back to the older-version files).
I don't think we should expect installation directly into the root
filesystem by "make install" to work reliably anyway, let alone provide a
downgrade mechanism, so I don't see the need to support versioned file
names any more.
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig
2021-06-10 8:22 [PATCH 0/4] Do not install shared objects under versioned names Florian Weimer
@ 2021-06-10 8:23 ` Florian Weimer
2021-06-27 21:32 ` Carlos O'Donell
0 siblings, 1 reply; 10+ messages in thread
From: Florian Weimer @ 2021-06-10 8:23 UTC (permalink / raw)
To: libc-alpha
This introduces <dl-is_dso.h> and the _dl_is_dso function. A
test ensures that the official names of libc.so, ld.so, and their
versioned names are recognized.
---
elf/Makefile | 2 +-
elf/dl-is_dso.h | 33 +++++++++++++++++++++++++++++++++
elf/ldconfig.c | 5 ++---
elf/tst-dl-is_dso.c | 35 +++++++++++++++++++++++++++++++++++
4 files changed, 71 insertions(+), 4 deletions(-)
create mode 100644 elf/dl-is_dso.h
create mode 100644 elf/tst-dl-is_dso.c
diff --git a/elf/Makefile b/elf/Makefile
index 5c47daee12..1751f5ec67 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -223,7 +223,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
tst-single_threaded tst-single_threaded-pthread \
tst-tls-ie tst-tls-ie-dlmopen argv0test \
tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
- tst-tls20 tst-tls21 tst-dlmopen-dlerror
+ tst-tls20 tst-tls21 tst-dlmopen-dlerror tst-dl-is_dso
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
diff --git a/elf/dl-is_dso.h b/elf/dl-is_dso.h
new file mode 100644
index 0000000000..94e00966a1
--- /dev/null
+++ b/elf/dl-is_dso.h
@@ -0,0 +1,33 @@
+/* Heuristic for recognizing DSO file names.
+ Copyright (C) 2021 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/>. */
+
+#include <stdbool.h>
+#include <string.h>
+
+/* Returns true if the file name looks like a DSO name. */
+static bool
+_dl_is_dso (const char *name)
+{
+ /* Recognize lib*.so*, ld-*.so*, ld.so.*, ld64.so.*. ld-*.so*
+ matches both platform dynamic linker names like ld-linux.so.2,
+ and versioned dynamic loader names like ld-2.12.so. */
+ return (((strncmp (name, "lib", 3) == 0 || strncmp (name, "ld-", 3) == 0)
+ && strstr (name, ".so") != NULL)
+ || strncmp (name, "ld.so.", 6) == 0
+ || strncmp (name, "ld64.so.", 8) == 0);
+}
diff --git a/elf/ldconfig.c b/elf/ldconfig.c
index 96bf7700b2..1037e8d0cf 100644
--- a/elf/ldconfig.c
+++ b/elf/ldconfig.c
@@ -43,6 +43,7 @@
#include <ldconfig.h>
#include <dl-cache.h>
#include <dl-hwcaps.h>
+#include <dl-is_dso.h>
#include <dl-procinfo.h>
@@ -842,9 +843,7 @@ search_dir (const struct dir_entry *entry)
subdirectory (if not already processing a glibc-hwcaps
subdirectory)? The dynamic linker is also considered as
shared library. */
- if (((strncmp (direntry->d_name, "lib", 3) != 0
- && strncmp (direntry->d_name, "ld-", 3) != 0)
- || strstr (direntry->d_name, ".so") == NULL)
+ if (!_dl_is_dso (direntry->d_name)
&& (direntry->d_type == DT_REG
|| (entry->hwcaps == NULL
&& !is_hwcap_platform (direntry->d_name))))
diff --git a/elf/tst-dl-is_dso.c b/elf/tst-dl-is_dso.c
new file mode 100644
index 0000000000..48d2cc9fbe
--- /dev/null
+++ b/elf/tst-dl-is_dso.c
@@ -0,0 +1,35 @@
+/* Test heuristic for recognizing DSO file names.
+ Copyright (C) 2021 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/>. */
+
+#include <dl-is_dso.h>
+#include <gnu/lib-names.h>
+#include <support/check.h>
+
+static int
+do_test (void)
+{
+ /* Official ABI names. */
+ TEST_VERIFY (_dl_is_dso (LIBC_SO));
+ TEST_VERIFY (_dl_is_dso (LD_SO));
+ /* Version-based names. The version number does not matter. */
+ TEST_VERIFY (_dl_is_dso ("libc-2.12.so"));
+ TEST_VERIFY (_dl_is_dso ("ld-2.12.so"));
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.31.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig
2021-06-10 8:23 ` [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig Florian Weimer
@ 2021-06-27 21:32 ` Carlos O'Donell
0 siblings, 0 replies; 10+ messages in thread
From: Carlos O'Donell @ 2021-06-27 21:32 UTC (permalink / raw)
To: Florian Weimer, libc-alpha
On 6/10/21 4:23 AM, Florian Weimer via Libc-alpha wrote:
> This introduces <dl-is_dso.h> and the _dl_is_dso function. A
> test ensures that the official names of libc.so, ld.so, and their
> versioned names are recognized.
LGTM.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
> ---
> elf/Makefile | 2 +-
> elf/dl-is_dso.h | 33 +++++++++++++++++++++++++++++++++
> elf/ldconfig.c | 5 ++---
> elf/tst-dl-is_dso.c | 35 +++++++++++++++++++++++++++++++++++
> 4 files changed, 71 insertions(+), 4 deletions(-)
> create mode 100644 elf/dl-is_dso.h
> create mode 100644 elf/tst-dl-is_dso.c
>
> diff --git a/elf/Makefile b/elf/Makefile
> index 5c47daee12..1751f5ec67 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -223,7 +223,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
> tst-single_threaded tst-single_threaded-pthread \
> tst-tls-ie tst-tls-ie-dlmopen argv0test \
> tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
> - tst-tls20 tst-tls21 tst-dlmopen-dlerror
> + tst-tls20 tst-tls21 tst-dlmopen-dlerror tst-dl-is_dso
OK.
> # reldep9
> tests-internal += loadtest unload unload2 circleload1 \
> neededtest neededtest2 neededtest3 neededtest4 \
> diff --git a/elf/dl-is_dso.h b/elf/dl-is_dso.h
> new file mode 100644
> index 0000000000..94e00966a1
> --- /dev/null
> +++ b/elf/dl-is_dso.h
> @@ -0,0 +1,33 @@
> +/* Heuristic for recognizing DSO file names.
> + Copyright (C) 2021 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/>. */
> +
> +#include <stdbool.h>
> +#include <string.h>
> +
> +/* Returns true if the file name looks like a DSO name. */
> +static bool
> +_dl_is_dso (const char *name)
> +{
> + /* Recognize lib*.so*, ld-*.so*, ld.so.*, ld64.so.*. ld-*.so*
> + matches both platform dynamic linker names like ld-linux.so.2,
> + and versioned dynamic loader names like ld-2.12.so. */
> + return (((strncmp (name, "lib", 3) == 0 || strncmp (name, "ld-", 3) == 0)
> + && strstr (name, ".so") != NULL)
> + || strncmp (name, "ld.so.", 6) == 0
> + || strncmp (name, "ld64.so.", 8) == 0);
OK. Refactor and change. This expands the definition a bit, but it should
still be correct to capture the wider set of names.
> +}
> diff --git a/elf/ldconfig.c b/elf/ldconfig.c
> index 96bf7700b2..1037e8d0cf 100644
> --- a/elf/ldconfig.c
> +++ b/elf/ldconfig.c
> @@ -43,6 +43,7 @@
> #include <ldconfig.h>
> #include <dl-cache.h>
> #include <dl-hwcaps.h>
> +#include <dl-is_dso.h>
OK.
>
> #include <dl-procinfo.h>
>
> @@ -842,9 +843,7 @@ search_dir (const struct dir_entry *entry)
> subdirectory (if not already processing a glibc-hwcaps
> subdirectory)? The dynamic linker is also considered as
> shared library. */
> - if (((strncmp (direntry->d_name, "lib", 3) != 0
> - && strncmp (direntry->d_name, "ld-", 3) != 0)
> - || strstr (direntry->d_name, ".so") == NULL)
> + if (!_dl_is_dso (direntry->d_name)
OK.
> && (direntry->d_type == DT_REG
> || (entry->hwcaps == NULL
> && !is_hwcap_platform (direntry->d_name))))
> diff --git a/elf/tst-dl-is_dso.c b/elf/tst-dl-is_dso.c
> new file mode 100644
> index 0000000000..48d2cc9fbe
> --- /dev/null
> +++ b/elf/tst-dl-is_dso.c
> @@ -0,0 +1,35 @@
> +/* Test heuristic for recognizing DSO file names.
> + Copyright (C) 2021 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/>. */
> +
> +#include <dl-is_dso.h>
> +#include <gnu/lib-names.h>
> +#include <support/check.h>
> +
> +static int
> +do_test (void)
> +{
> + /* Official ABI names. */
> + TEST_VERIFY (_dl_is_dso (LIBC_SO));
> + TEST_VERIFY (_dl_is_dso (LD_SO));
OK.
> + /* Version-based names. The version number does not matter. */
> + TEST_VERIFY (_dl_is_dso ("libc-2.12.so"));
> + TEST_VERIFY (_dl_is_dso ("ld-2.12.so"));
OK.
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
>
--
Cheers,
Carlos.
^ permalink raw reply [flat|nested] 10+ messages in thread