s390: Improve static-pie configure tests

Instead of tying based on the linker name and version, check for the
required support:

  * whether it does not generate dynamic TLS relocations in PIE
    (binutils PR ld/22263);
  * if it accepts --no-dynamic-linker (by using -static-pie);
  * and if it adds a DT_JMPREL pointing to .rela.iplt with static pie.

The patch also trims the comments, for binutils one of the tests should
already cover it.  The kernel ones are not clear which version should
have the backport, nor it is something that glibc can do much about
it.  Finally, the glibc is somewhat confusing, since it refers
to commits not related to s390x.

Checked with a build for s390x-linux-gnu.

Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
This commit is contained in:
Adhemerval Zanella 2024-02-27 14:06:06 -03:00
parent 24c8db87c9
commit b53e73ea80
2 changed files with 40 additions and 231 deletions

View File

@ -1,100 +1,6 @@
# This file is generated from configure.ac by Autoconf. DO NOT EDIT!
# Local configure fragment for sysdeps/s390/s390-64.
# Bypass result of runtime configure check for known linker versions as
# e.g. crt-files or libc.so might not be available in bootstrapping
# environments.
case $($LD --version) in
"GNU gold"*)
# As of 2023-08-07, gold does not support static PIE due to
# Bug 22221 - add --no-dynamic-linker option
# https://sourceware.org/bugzilla/show_bug.cgi?id=22221
libc_cv_s390x_staticpie_req_version=no
;;
"LLD"*)
# As of 2023-08-07, there is no lld which supports s390x.
libc_cv_s390x_staticpie_req_version=no
;;
*)
# The required binutils patches are available with bintuils 2.39
libc_cv_s390x_staticpie_req_version=yes
# Skip AC_CHECK_PROGS and just use the result from main configure.ac.
libc_cv_s390x_staticpie_req_LD=$LD
for ac_prog in $LD
do
# Extract the first word of "$ac_prog", so it can be a program name with args.
set dummy $ac_prog; ac_word=$2
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
printf %s "checking for $ac_word... " >&6; }
if test ${ac_cv_prog_libc_cv_s390x_staticpie_req_LD+y}
then :
printf %s "(cached) " >&6
else $as_nop
if test -n "$libc_cv_s390x_staticpie_req_LD"; then
ac_cv_prog_libc_cv_s390x_staticpie_req_LD="$libc_cv_s390x_staticpie_req_LD" # Let the user override the test.
else
as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
for as_dir in $PATH
do
IFS=$as_save_IFS
case $as_dir in #(((
'') as_dir=./ ;;
*/) ;;
*) as_dir=$as_dir/ ;;
esac
for ac_exec_ext in '' $ac_executable_extensions; do
if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
ac_cv_prog_libc_cv_s390x_staticpie_req_LD="$ac_prog"
printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
break 2
fi
done
done
IFS=$as_save_IFS
fi
fi
libc_cv_s390x_staticpie_req_LD=$ac_cv_prog_libc_cv_s390x_staticpie_req_LD
if test -n "$libc_cv_s390x_staticpie_req_LD"; then
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_s390x_staticpie_req_LD" >&5
printf "%s\n" "$libc_cv_s390x_staticpie_req_LD" >&6; }
else
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
printf "%s\n" "no" >&6; }
fi
test -n "$libc_cv_s390x_staticpie_req_LD" && break
done
if test -z "$libc_cv_s390x_staticpie_req_LD"; then
ac_verc_fail=yes
else
# Found it, now check the version.
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking version of $libc_cv_s390x_staticpie_req_LD" >&5
printf %s "checking version of $libc_cv_s390x_staticpie_req_LD... " >&6; }
ac_prog_version=`$libc_cv_s390x_staticpie_req_LD --version 2>&1 | sed -n 's/^.*GNU ld.* \([0-9][0-9]*\.[0-9.]*\).*$/\1/p'`
case $ac_prog_version in
'') ac_prog_version="v. ?.??, bad"; ac_verc_fail=yes;;
2.1[0-9][0-9]*|2.39*|2.[4-9][0-9]*|[3-9].*|[1-9][0-9]*)
ac_prog_version="$ac_prog_version, ok"; ac_verc_fail=no;;
*) ac_prog_version="$ac_prog_version, bad"; ac_verc_fail=yes;;
esac
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_prog_version" >&5
printf "%s\n" "$ac_prog_version" >&6; }
fi
if test $ac_verc_fail = yes; then
libc_cv_s390x_staticpie_req_version=no
fi
;;
esac
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for s390-specific static PIE requirements (version check)" >&5
printf %s "checking for s390-specific static PIE requirements (version check)... " >&6; }
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_s390x_staticpie_req_version" >&5
printf "%s\n" "$libc_cv_s390x_staticpie_req_version" >&6; }
# Minimal checking for static PIE support in ld.
# Compare to ld testcase/bugzilla:
# <binutils-source>/ld/testsuite/ld-elf/pr22263-1.rd
@ -113,20 +19,31 @@ bar (void)
{
*foo = 1;
}
void bar2 (void);
void* bar2_ifunc (void) __asm__ ("bar2");
__asm__ (".type bar2, %gnu_indirect_function");
void* bar2_ifunc (void) { return 0; }
EOF
cat > conftest2.c <<EOF
extern __thread int *foo;
extern void bar (void);
extern void bar2 (void);
static int x;
int
main ()
{
foo = &x;
bar2 ();
return 0;
}
EOF
libc_cv_s390x_staticpie_req_runtime=no
# Check if the static linker does not generate dynamic TLS relocs in PIE
# (binutils PR ld/22263), if it accepts --no-dynamic-linker
# (by using -static-pie), and if it adds a DT_JMPREL pointing to .rela.iplt
# with static pie.
if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest1.c -o conftest1.o'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
@ -139,7 +56,7 @@ EOF
ac_status=$?
printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; } \
&& { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -pie -o conftest conftest1.o conftest2.o'
&& { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -static-pie -nostartfiles -nostdlib -fPIE -o conftest conftest1.o conftest2.o'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
@ -150,6 +67,12 @@ EOF
(eval $ac_try) 2>&5
ac_status=$?
printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; } \
&& { ac_try='LC_ACLL=C $READELF -d conftest | grep JMPREL'
{ { eval echo "\"\$as_me\":${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 $ac_status = 0; }; }
then
libc_cv_s390x_staticpie_req_runtime=yes
@ -161,59 +84,10 @@ libc_cv_s390x_staticpie_req_runtime
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
printf "%s\n" "$ac_res" >&6; }
if test $libc_cv_s390x_staticpie_req_runtime = yes \
|| test $libc_cv_s390x_staticpie_req_version = yes; then
# Static PIE is supported only on 64bit.
# Ensure you also have those patches for:
# - binutils (ld)
# - "[PR ld/22263] s390: Avoid dynamic TLS relocs in PIE"
# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=26b1426577b5dcb32d149c64cca3e603b81948a9
# (Tested by configure check above)
# Otherwise there will be a R_390_TLS_TPOFF relocation, which fails to
# be processed in _dl_relocate_static_pie() as static TLS map is not setup.
# - "s390: Add DT_JMPREL pointing to .rela.[i]plt with static-pie"
# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d942d8db12adf4c9e5c7d9ed6496a779ece7149e
# (We can't test it in configure as we are not able to link a static PIE
# executable if the system glibc lacks static PIE support)
# Otherwise there won't be DT_JMPREL, DT_PLTRELA, DT_PLTRELASZ entries
# and the IFUNC symbols are not processed, which leads to crashes.
#
# - kernel (the mentioned links to the commits belong to 5.19 merge window):
# - "s390/mmap: increase stack/mmap gap to 128MB"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=f2f47d0ef72c30622e62471903ea19446ea79ee2
# - "s390/vdso: move vdso mapping to its own function"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=57761da4dc5cd60bed2c81ba0edb7495c3c740b8
# - "s390/vdso: map vdso above stack"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=9e37a2e8546f9e48ea76c839116fa5174d14e033
# - "s390/vdso: add vdso randomization"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=41cd81abafdc4e58a93fcb677712a76885e3ca25
# (We can't test the kernel of the target system)
# Otherwise if /proc/sys/kernel/randomize_va_space is turned off (0),
# static PIE executables like ldconfig will crash. While startup sbrk is
# used to enlarge the HEAP. Unfortunately the underlying brk syscall fails
# as there is not enough space after the HEAP. Then the address of the TLS
# image is invalid and the following memcpy in __libc_setup_tls() leads
# to a segfault.
# If /proc/sys/kernel/randomize_va_space is activated (default: 2), there
# is enough space after HEAP.
#
# - glibc
# - "Linux: Define MMAP_CALL_INTERNAL"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=c1b68685d438373efe64e5f076f4215723004dfb
# - "i386: Remove OPTIMIZE_FOR_GCC_5 from Linux libc-do-syscall.S"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=6e5c7a1e262961adb52443ab91bd2c9b72316402
# - "i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=60f0f2130d30cfd008ca39743027f1e200592dff
# - "ia64: Always define IA64_USE_NEW_STUB as a flag macro"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=18bd9c3d3b1b6a9182698c85354578d1d58e9d64
# - "Linux: Implement a useful version of _startup_fatal"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=a2a6bce7d7e52c1c34369a7da62c501cc350bc31
# - "Linux: Introduce __brk_call for invoking the brk system call"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=b57ab258c1140bc45464b4b9908713e3e0ee35aa
# - "csu: Implement and use _dl_early_allocate during static startup"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=f787e138aa0bf677bf74fa2a08595c446292f3d7
# The mentioned patch series by Florian Weimer avoids the mentioned failing
# sbrk syscall by falling back to mmap.
if test $libc_cv_s390x_staticpie_req_runtime = yes; then
# Some kernels might fail with /proc/sys/kernel/randomize_va_space set to 0
# due not enough space for a brk call. However, there is no reliable way to
# test it.
printf "%s\n" "#define SUPPORT_STATIC_PIE 1" >>confdefs.h
fi

View File

@ -1,34 +1,6 @@
GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
# Local configure fragment for sysdeps/s390/s390-64.
# Bypass result of runtime configure check for known linker versions as
# e.g. crt-files or libc.so might not be available in bootstrapping
# environments.
case $($LD --version) in
"GNU gold"*)
# As of 2023-08-07, gold does not support static PIE due to
# Bug 22221 - add --no-dynamic-linker option
# https://sourceware.org/bugzilla/show_bug.cgi?id=22221
libc_cv_s390x_staticpie_req_version=no
;;
"LLD"*)
# As of 2023-08-07, there is no lld which supports s390x.
libc_cv_s390x_staticpie_req_version=no
;;
*)
# The required binutils patches are available with bintuils 2.39
libc_cv_s390x_staticpie_req_version=yes
# Skip AC_CHECK_PROGS and just use the result from main configure.ac.
libc_cv_s390x_staticpie_req_LD=$LD
AC_CHECK_PROG_VER(libc_cv_s390x_staticpie_req_LD, $LD, --version,
[GNU ld.* \([0-9][0-9]*\.[0-9.]*\)],
[2.1[0-9][0-9]*|2.39*|2.[4-9][0-9]*|[3-9].*|[1-9][0-9]*],
libc_cv_s390x_staticpie_req_version=no)
;;
esac
AC_MSG_CHECKING([for s390-specific static PIE requirements (version check)])
AC_MSG_RESULT($libc_cv_s390x_staticpie_req_version)
# Minimal checking for static PIE support in ld.
# Compare to ld testcase/bugzilla:
# <binutils-source>/ld/testsuite/ld-elf/pr22263-1.rd
@ -42,81 +14,44 @@ bar (void)
{
*foo = 1;
}
void bar2 (void);
void* bar2_ifunc (void) __asm__ ("bar2");
__asm__ (".type bar2, %gnu_indirect_function");
void* bar2_ifunc (void) { return 0; }
EOF
cat > conftest2.c <<EOF
extern __thread int *foo;
extern void bar (void);
extern void bar2 (void);
static int x;
int
main ()
{
foo = &x;
bar2 ();
return 0;
}
EOF
libc_cv_s390x_staticpie_req_runtime=no
# Check if the static linker does not generate dynamic TLS relocs in PIE
# (binutils PR ld/22263), if it accepts --no-dynamic-linker
# (by using -static-pie), and if it adds a DT_JMPREL pointing to .rela.iplt
# with static pie.
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest1.c -o conftest1.o]) \
&& AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest2.c -o conftest2.o]) \
&& AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -pie -o conftest conftest1.o conftest2.o]) \
&& AC_TRY_COMMAND([! LC_ALL=C $READELF -Wr conftest | grep R_390_TLS_TPOFF])
&& AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -static-pie -nostartfiles -nostdlib -fPIE -o conftest conftest1.o conftest2.o]) \
&& AC_TRY_COMMAND([! LC_ALL=C $READELF -Wr conftest | grep R_390_TLS_TPOFF]) \
&& AC_TRY_COMMAND([LC_ACLL=C $READELF -d conftest | grep JMPREL])
then
libc_cv_s390x_staticpie_req_runtime=yes
fi
rm -rf conftest.*])
if test $libc_cv_s390x_staticpie_req_runtime = yes \
|| test $libc_cv_s390x_staticpie_req_version = yes; then
# Static PIE is supported only on 64bit.
# Ensure you also have those patches for:
# - binutils (ld)
# - "[PR ld/22263] s390: Avoid dynamic TLS relocs in PIE"
# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=26b1426577b5dcb32d149c64cca3e603b81948a9
# (Tested by configure check above)
# Otherwise there will be a R_390_TLS_TPOFF relocation, which fails to
# be processed in _dl_relocate_static_pie() as static TLS map is not setup.
# - "s390: Add DT_JMPREL pointing to .rela.[i]plt with static-pie"
# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d942d8db12adf4c9e5c7d9ed6496a779ece7149e
# (We can't test it in configure as we are not able to link a static PIE
# executable if the system glibc lacks static PIE support)
# Otherwise there won't be DT_JMPREL, DT_PLTRELA, DT_PLTRELASZ entries
# and the IFUNC symbols are not processed, which leads to crashes.
#
# - kernel (the mentioned links to the commits belong to 5.19 merge window):
# - "s390/mmap: increase stack/mmap gap to 128MB"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=f2f47d0ef72c30622e62471903ea19446ea79ee2
# - "s390/vdso: move vdso mapping to its own function"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=57761da4dc5cd60bed2c81ba0edb7495c3c740b8
# - "s390/vdso: map vdso above stack"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=9e37a2e8546f9e48ea76c839116fa5174d14e033
# - "s390/vdso: add vdso randomization"
# https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=41cd81abafdc4e58a93fcb677712a76885e3ca25
# (We can't test the kernel of the target system)
# Otherwise if /proc/sys/kernel/randomize_va_space is turned off (0),
# static PIE executables like ldconfig will crash. While startup sbrk is
# used to enlarge the HEAP. Unfortunately the underlying brk syscall fails
# as there is not enough space after the HEAP. Then the address of the TLS
# image is invalid and the following memcpy in __libc_setup_tls() leads
# to a segfault.
# If /proc/sys/kernel/randomize_va_space is activated (default: 2), there
# is enough space after HEAP.
#
# - glibc
# - "Linux: Define MMAP_CALL_INTERNAL"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=c1b68685d438373efe64e5f076f4215723004dfb
# - "i386: Remove OPTIMIZE_FOR_GCC_5 from Linux libc-do-syscall.S"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=6e5c7a1e262961adb52443ab91bd2c9b72316402
# - "i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=60f0f2130d30cfd008ca39743027f1e200592dff
# - "ia64: Always define IA64_USE_NEW_STUB as a flag macro"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=18bd9c3d3b1b6a9182698c85354578d1d58e9d64
# - "Linux: Implement a useful version of _startup_fatal"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=a2a6bce7d7e52c1c34369a7da62c501cc350bc31
# - "Linux: Introduce __brk_call for invoking the brk system call"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=b57ab258c1140bc45464b4b9908713e3e0ee35aa
# - "csu: Implement and use _dl_early_allocate during static startup"
# https://sourceware.org/git/?p=glibc.git;a=commit;h=f787e138aa0bf677bf74fa2a08595c446292f3d7
# The mentioned patch series by Florian Weimer avoids the mentioned failing
# sbrk syscall by falling back to mmap.
if test $libc_cv_s390x_staticpie_req_runtime = yes; then
# Some kernels might fail with /proc/sys/kernel/randomize_va_space set to 0
# due not enough space for a brk call. However, there is no reliable way to
# test it.
AC_DEFINE(SUPPORT_STATIC_PIE)
fi