[PATCH 4/4] Add --disable-major-minor-libraries configure option
Florian Weimer
fweimer@redhat.com
Wed Jun 9 11:16:26 GMT 2021
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
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