diff mbox series

[v2] Check global symbols in static library against shared library

Message ID 20240522175307.604741-1-hjl.tools@gmail.com
State New
Headers show
Series [v2] Check global symbols in static library against shared library | expand

Commit Message

H.J. Lu May 22, 2024, 5:53 p.m. UTC
Here is the v2 patch to check global symbols in static library against
shared library.  The test results may not be clean due to:

https://sourceware.org/bugzilla/show_bug.cgi?id=31781
https://sourceware.org/bugzilla/show_bug.cgi?id=31779
https://sourceware.org/bugzilla/show_bug.cgi?id=31778
https://sourceware.org/bugzilla/show_bug.cgi?id=31777

H.J.
--
Changes in v2:

1. Add export LC_ALL for nm.
2. Pass $* to check-static-abi.sh.
3. Don't pass $(static-only-symbols) to check-static-abi.sh.
4. Get installed static libraries from $(extra-libs).
5. Add shared-only-symbols for powerpc and sparc32.

---
The shared library ABIs are checked against the abilist files.  Extract
global symbol definitions from static libraries and check them against
exported global symbol definitions in shared libraries.  Special cases
are handled:

1. Some global symbols are available only in libc.so.
2. Some math functions are in libc.a, but not in libc.so.
3. The libgcc symbols are in libc.so only on some targets.
4. Internal symbols have global visibility only in the static library.

This check is enabled only if nm displays symbol versions for dynamic
symbols.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
 Makerules                      |  68 ++++++++++++++++++++++
 configure                      |  42 ++++++++++++++
 configure.ac                   |  31 ++++++++++
 elf/Makefile                   |  15 +++++
 math/Makefile                  |   4 ++
 scripts/check-static-abi.sh    | 103 +++++++++++++++++++++++++++++++++
 sysdeps/alpha/Makefile         |   5 ++
 sysdeps/generic/Makefile       |  11 ++++
 sysdeps/powerpc/Makefile       |   5 ++
 sysdeps/s390/Makefile          |   5 ++
 sysdeps/sparc/sparc32/Makefile |  13 +++++
 11 files changed, 302 insertions(+)
 create mode 100644 scripts/check-static-abi.sh
diff mbox series

Patch

diff --git a/Makerules b/Makerules
index 275110dda8..fd38d650c9 100644
--- a/Makerules
+++ b/Makerules
@@ -1238,6 +1238,21 @@  ifeq ($(build-shared),yes)
 	LC_ALL=C $(OBJDUMP) --dynamic-syms $< > $@T
 	mv -f $@T $@
 
+# Extract global symbol definitions from shared and static libraries.
+NM-FLAGS=--extern-only --defined-only --just-symbols
+
+%.dynamicsymlist: %.so
+	LC_ALL=C; export LC_ALL; $(NM) --dynamic $(NM-FLAGS) $< \
+	  | grep -v "^_.*GLIBC_PRIVATE" | grep @@ | sed -e "s/@@.*//" \
+	  | sort > $@T
+	mv -f $@T $@
+
+%.staticsymlist: %.a
+	LC_ALL=C; export LC_ALL; $(NM) $(NM-FLAGS) $< \
+	  | grep -v DW.ref.__gcc_personality_v0 \
+	  | sort > $@T
+	mv -f $@T $@
+
 vpath %.abilist $(+sysdep_dirs)
 
 # The .PRECIOUS rule prevents the files built by an implicit rule whose
@@ -1246,6 +1261,16 @@  vpath %.abilist $(+sysdep_dirs)
 # 'make clean', which is handled by the 'generated' variable.
 .PRECIOUS: %.symlist
 generated += $(extra-libs:=.symlist)
+ifeq (yes,$(nm-has-symbol-version))
+.PRECIOUS: %.dynamicsymlist %.staticsymlist
+# Only check global symbols in static libraries in $(extra-libs).
+static-libs := $(foreach lib, $(extra-libs), \
+		 $(if $($(lib)-inhibit-o),,$(lib)))
+generated += \
+  $(static-libs:=.dynamicsymlist) \
+  $(static-libs:=.staticsymlist) \
+# generated
+endif
 
 $(objpfx)check-abi-%.out: $(common-objpfx)config.make %.abilist \
 			  $(objpfx)%.symlist
@@ -1259,6 +1284,23 @@  define check-abi
 	diff -p -U 0 $(filter %.abilist,$^) $(filter %.symlist,$^) > $@
 endef
 
+$(objpfx)check-static-abi-%.out: $(common-objpfx)config.make \
+				 $(objpfx)%.dynamicsymlist \
+				 $(objpfx)%.staticsymlist
+	$(check-static-abi); \
+	$(evaluate-test)
+$(objpfx)check-static-abi-%.out: $(common-objpfx)config.make \
+				 $(common-objpfx)%.dynamicsymlist \
+				 $(common-objpfx)%.staticsymlist
+	$(check-static-abi); \
+	$(evaluate-test)
+define check-static-abi
+	$(SHELL) $(..)scripts/check-static-abi.sh $* \
+	  $(filter %.dynamicsymlist,$^) \
+	  $(filter %.staticsymlist,$^) \
+	  "$(shared-only-symbols)" > $@
+endef
+
 update-abi-%: $(objpfx)%.symlist %.abilist
 	$(update-abi)
 update-abi-%: $(common-objpfx)%.symlist %.abilist
@@ -1290,6 +1332,11 @@  update-all-abi: $(patsubst %.so,update-all-abi-%,$(install-lib.so-versioned))
 check-abi-list = $(patsubst %.so,$(objpfx)check-abi-%.out, \
 				 $(install-lib.so-versioned))
 check-abi: $(check-abi-list)
+ifeq (yes,$(nm-has-symbol-version))
+check-static-abi-list = $(patsubst %.a,$(objpfx)check-static-abi-%.out, \
+				       $(static-libs:=.a))
+check-abi: $(check-static-abi-list)
+endif
 ifdef subdir
 subdir_check-abi: check-abi
 subdir_update-abi: update-abi
@@ -1298,6 +1345,10 @@  else
 check-abi: subdir_check-abi
 	if grep -q '^FAIL:' $(objpfx)*/check-abi*.test-result; then \
 		cat $(objpfx)*/check-abi*.out && exit 1; fi
+ifeq (yes,$(nm-has-symbol-version))
+	if grep -q '^FAIL:' $(objpfx)*/check-static-abi*.test-result; \
+	then cat $(objpfx)*/check-static-abi*.out && exit 1; fi
+endif
 update-abi: subdir_update-abi
 update-all-abi: subdir_update-all-abi
 endif
@@ -1308,11 +1359,28 @@  tests-special += $(objpfx)check-abi-libc.out
 update-abi: update-abi-libc
 update-all-abi: update-all-abi-libc
 common-generated += libc.symlist
+ifeq (yes,$(nm-has-symbol-version))
+check-abi: $(objpfx)check-static-abi-libc.out
+tests-special += $(objpfx)check-static-abi-libc.out
+common-generated += \
+  libc.dynamicsymlist \
+  libc.staticsymlist \
+  libc_nonshared.staticsymlist \
+  # common-generated
+# check-static-abi.sh needs libc_nonshared.staticsymlist and
+# libm.dynamicsymlist to check the global symbol list in libc.a.
+$(objpfx)check-static-abi-libc.out: \
+  $(common-objpfx)libc_nonshared.staticsymlist \
+  $(common-objpfx)math/libm.dynamicsymlist
+endif
 endif
 
 ifeq ($(build-shared),yes)
 ifdef subdir
 tests-special += $(check-abi-list)
+ifeq (yes,$(nm-has-symbol-version))
+tests-special += $(check-static-abi-list)
+endif
 endif
 endif
 
diff --git a/configure b/configure
index 432e40a592..8328bc59e0 100755
--- a/configure
+++ b/configure
@@ -7566,6 +7566,48 @@  if test "$libc_cv_symver_needs_alias" = yes; then
 
 fi
 
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether nm displays symbol versions for dynamic symbols" >&5
+printf %s "checking whether nm displays symbol versions for dynamic symbols... " >&6; }
+if test ${libc_cv_nm_has_symbol_version+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+    cat > conftest.s <<EOF
+	.text
+	.globl	new_foo
+	.type	new_foo, %function
+new_foo:
+	.byte 0
+	.symver new_foo,foo@@VERS_2.0
+EOF
+  cat > conftest.t <<EOF
+VERS_2.0 {
+global:
+  foo;
+local:
+  *;
+};
+EOF
+  libc_cv_nm_has_symbol_version=no
+  if { ac_try='${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.s -Wl,-version-script=conftest.t -o conftest.so'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then
+    if $NM --dynamic --extern-only --defined-only --just-symbols conftest.so 2>&1 \
+       | grep -q foo@@VERS_2.0; then
+      libc_cv_nm_has_symbol_version=yes
+    fi
+  fi
+  rm conftest.*
+
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_nm_has_symbol_version" >&5
+printf "%s\n" "$libc_cv_nm_has_symbol_version" >&6; }
+config_vars="$config_vars
+nm-has-symbol-version = $libc_cv_nm_has_symbol_version"
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for __builtin_trap with no external dependencies" >&5
 printf %s "checking for __builtin_trap with no external dependencies... " >&6; }
 if test ${libc_cv_builtin_trap+y}
diff --git a/configure.ac b/configure.ac
index bdc385d03c..db27a6ce2a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1554,6 +1554,37 @@  if test "$libc_cv_symver_needs_alias" = yes; then
   AC_DEFINE(SYMVER_NEEDS_ALIAS)
 fi
 
+dnl Starting with binutils 2.35, NM displays symbol versions for dynamic
+dnl symbols (PR 25708).
+AC_CACHE_CHECK(whether nm displays symbol versions for dynamic symbols,
+               libc_cv_nm_has_symbol_version, [dnl
+  cat > conftest.s <<EOF
+	.text
+	.globl	new_foo
+	.type	new_foo, %function
+new_foo:
+	.byte 0
+	.symver new_foo,foo@@VERS_2.0
+EOF
+  cat > conftest.t <<EOF
+VERS_2.0 {
+global:
+  foo;
+local:
+  *;
+};
+EOF
+  libc_cv_nm_has_symbol_version=no
+  if AC_TRY_COMMAND([${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.s -Wl,-version-script=conftest.t -o conftest.so]); then
+    if $NM --dynamic --extern-only --defined-only --just-symbols conftest.so 2>&1 \
+       | grep -q foo@@VERS_2.0; then
+      libc_cv_nm_has_symbol_version=yes
+    fi
+  fi
+  rm conftest.*
+])
+LIBC_CONFIG_VAR([nm-has-symbol-version], [$libc_cv_nm_has_symbol_version])
+
 AC_CACHE_CHECK(for __builtin_trap with no external dependencies,
 	       libc_cv_builtin_trap, [dnl
 libc_cv_builtin_trap=no
diff --git a/elf/Makefile b/elf/Makefile
index 280e777c19..8acfa46c62 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -182,6 +182,21 @@  CFLAGS-rtld.os += $(rtld-early-cflags)
 ifeq ($(unwind-find-fde),yes)
 routines += unwind-dw2-fde-glibc
 shared-only-routines += unwind-dw2-fde-glibc
+
+# These global symbols are only in libc.so.
+shared-only-symbols += \
+  _Unwind_Find_FDE \
+  __deregister_frame \
+  __deregister_frame_info \
+  __deregister_frame_info_bases \
+  __register_frame \
+  __register_frame_info \
+  __register_frame_info_bases \
+  __register_frame_info_bases \
+  __register_frame_info_table \
+  __register_frame_info_table_bases \
+  __register_frame_table \
+# shared-only-symbols
 endif
 
 before-compile  += $(objpfx)trusted-dirs.h
diff --git a/math/Makefile b/math/Makefile
index 58e5c070cf..ae268e0088 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -1674,3 +1674,7 @@  object-suffixes-left := $(libmvec-tests)
 include $(o-iterator)
 
 $(objpfx)test-fenv-tls: $(shared-thread-library)
+
+# check-static-abi.sh needs libc.staticsymlist to check the global symbol
+# list in libm.a.
+$(objpfx)check-static-abi-libm.out: $(common-objpfx)libc.staticsymlist
diff --git a/scripts/check-static-abi.sh b/scripts/check-static-abi.sh
new file mode 100644
index 0000000000..70dfb63ff1
--- /dev/null
+++ b/scripts/check-static-abi.sh
@@ -0,0 +1,103 @@ 
+#!/bin/sh
+# Check global symbols in static library against global symbols in shared
+# library.
+# Copyright (C) 2024 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/>.
+
+export LC_ALL=C
+
+lib="$1"
+shift
+dynamicsymlist="$1"
+shift
+if test $lib = libc; then
+  libm_dynamicsymlist="$1"
+  shift
+fi
+staticsymlist="$1"
+shift
+if test $lib = libc; then
+  libc_nonshared_staticsymlist="$1"
+  shift
+elif test $lib = libm; then
+  libc_staticsymlist="$1"
+  shift
+fi
+shared_only_functions="$1"
+
+staticdiff="$(mktemp)"
+
+cleanup () {
+  rm -f -- "$staticdiff"
+}
+
+trap cleanup 0
+
+status=0
+
+diff -up $dynamicsymlist $staticsymlist > $staticdiff
+
+# Check missing global symbols, including symbols with a leading
+# underscore, in static library.
+shared_only="$(grep '^-[^-]' $staticdiff | sed -e 's/^-//')"
+if test -n "$shared_only"; then
+  # Exclude shared only functions.
+  for f in $shared_only; do
+    case " $shared_only_functions " in
+    *" $f "*)
+      ;;
+    *)
+      # Skip the missing function, $f, in libm.a if $f is in libc.a.
+      if test $lib = libm \
+	 && grep -q "^$f$" $libc_staticsymlist; then
+	continue
+      fi
+      missing="$missing $f"
+      ;;
+    esac
+  done
+  if test -n "$missing"; then
+    status=1
+    echo Missing functions in ${lib}.a:
+    echo "$missing"
+  fi
+fi
+
+# Check extra global symbols, excluding symbols with a leading underscore
+# which can be internal symbols, in static library.
+static_only="$(grep '^+[^_^\+]' $staticdiff | sed -e 's/^+//')"
+if test -n "$static_only"; then
+  # Exclude static only functions.
+  for f in $static_only; do
+    # Skip the extra function, $f, in libc.a if $f is in libc_nonshared.a
+    # or libm.so.
+    if test $lib = libc; then
+      if grep -q "^$f$" $libc_nonshared_staticsymlist \
+	 || grep -q "^$f$" $libm_dynamicsymlist; then
+	continue
+      fi
+    fi
+    extra="$extra $f"
+  done
+  if test -n "$extra"; then
+    status=1
+    echo Extra functions in ${lib}.a:
+    echo "$extra"
+  fi
+fi
+
+exit $status
diff --git a/sysdeps/alpha/Makefile b/sysdeps/alpha/Makefile
index 11d5e65503..9e3486bd23 100644
--- a/sysdeps/alpha/Makefile
+++ b/sysdeps/alpha/Makefile
@@ -33,6 +33,11 @@  sysdep_routines += stxcpy stxncpy
 endif
 
 ifeq ($(subdir),elf)
+# These global symbols are only in libc.so.
+shared-only-symbols += \
+  __nldbl__IO_vfscanf \
+# shared-only-symbols
+
 # The ld.so startup code cannot use literals until it self-relocates.
 CFLAGS-rtld.c = -mbuild-constants
 endif
diff --git a/sysdeps/generic/Makefile b/sysdeps/generic/Makefile
index 72522d1f0e..fd059582e6 100644
--- a/sysdeps/generic/Makefile
+++ b/sysdeps/generic/Makefile
@@ -25,7 +25,18 @@  ifeq (yes:yes,$(build-shared):$(unwind-find-fde))
 # This is needed to support g++ v2 and v3.
 sysdep_routines += framestate unwind-pe
 shared-only-routines += framestate unwind-pe
+
+# These global symbols are only in libc.so.
+shared-only-symbols += __frame_state_for
 endif
+
+# These global symbols are only in libc.so.
+shared-only-symbols += \
+  __xmknod \
+  __xmknodat \
+  _dl_mcount_wrapper_check \
+  re_max_failures \
+# shared-only-symbols
 endif
 
 ifeq ($(subdir),malloc)
diff --git a/sysdeps/powerpc/Makefile b/sysdeps/powerpc/Makefile
index 5e6cb07ce6..ece1805e62 100644
--- a/sysdeps/powerpc/Makefile
+++ b/sysdeps/powerpc/Makefile
@@ -3,6 +3,11 @@  CFLAGS-memcmp.c += -Wno-uninitialized
 endif
 
 ifeq ($(subdir),elf)
+# These global symbols are only in libc.so.
+shared-only-symbols += \
+  __nldbl__IO_vfscanf \
+  # shared-only-symbols
+
 # extra shared linker files to link into dl-allobjs.so and libc
 sysdep-dl-routines += dl-machine hwcapinfo
 sysdep_routines += dl-machine hwcapinfo
diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
index b793b26112..3d218bfeab 100644
--- a/sysdeps/s390/Makefile
+++ b/sysdeps/s390/Makefile
@@ -43,6 +43,11 @@  $(modpfx)gconv-modules-s390.conf: ../sysdeps/s390/gconv-modules-s390.conf \
 endif
 
 ifeq ($(subdir),elf)
+# These global symbols are only in libc.so.
+shared-only-symbols += \
+  __nldbl__IO_vfscanf \
+# shared-only-symbols
+
 sysdep-dl-routines += dl-procinfo-s390
 
 ifeq ($(build-shared),yes)
diff --git a/sysdeps/sparc/sparc32/Makefile b/sysdeps/sparc/sparc32/Makefile
index 4ba8794aa0..51012604fd 100644
--- a/sysdeps/sparc/sparc32/Makefile
+++ b/sysdeps/sparc/sparc32/Makefile
@@ -15,6 +15,19 @@ 
 # License along with the GNU C Library; if not, see
 # <https://www.gnu.org/licenses/>.
 
+ifeq ($(subdir),elf)
+# These global symbols are only in libc.so.  Filter out the
+# $(shared-only-routines) routines.
+shared-only-symbols += \
+  __nldbl__IO_vfscanf \
+  .div \
+  .rem \
+  .udiv \
+  .umul \
+  .urem \
+  # shared-only-symbols
+endif
+
 ifeq ($(subdir),gnulib)
 sysdep_routines = dotmul umul $(divrem) alloca
 shared-only-routines += umul $(divrem)