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-rw-r--r--sysdeps/s390/s390-64/configure122
-rw-r--r--sysdeps/s390/s390-64/configure.ac92
-rw-r--r--sysdeps/s390/s390-64/start.S28
3 files changed, 242 insertions, 0 deletions
diff --git a/sysdeps/s390/s390-64/configure b/sysdeps/s390/s390-64/configure
new file mode 100644
index 0000000000..101c570d2e
--- /dev/null
+++ b/sysdeps/s390/s390-64/configure
@@ -0,0 +1,122 @@
+# This file is generated from configure.ac by Autoconf.  DO NOT EDIT!
+ # Local configure fragment for sysdeps/s390/s390-64.
+
+# Minimal checking for static PIE support in ld.
+# Compare to ld testcase/bugzilla:
+# <binutils-source>/ld/testsuite/ld-elf/pr22263-1.rd
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for s390-specific static PIE requirements" >&5
+$as_echo_n "checking for s390-specific static PIE requirements... " >&6; }
+if { as_var=\
+libc_cv_s390x_staticpie_req; eval \${$as_var+:} false; }; then :
+  $as_echo_n "(cached) " >&6
+else
+    cat > conftest1.c <<EOF
+__thread int * foo;
+
+void
+bar (void)
+{
+  *foo = 1;
+}
+EOF
+  cat > conftest2.c <<EOF
+extern __thread int *foo;
+extern void bar (void);
+static int x;
+
+int
+main ()
+{
+  foo = &x;
+  return 0;
+}
+EOF
+  libc_cv_s390x_staticpie_req=no
+  if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest1.c -o conftest1.o'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; } \
+     && { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest2.c -o conftest2.o'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; } \
+     && { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -pie -o conftest conftest1.o conftest2.o'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; } \
+     && { ac_try='! readelf -Wr conftest | grep R_390_TLS_TPOFF'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+  then
+    libc_cv_s390x_staticpie_req=yes
+  fi
+  rm -rf conftest.*
+fi
+eval ac_res=\$\
+libc_cv_s390x_staticpie_req
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if test $libc_cv_s390x_staticpie_req = 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.
+   $as_echo "#define SUPPORT_STATIC_PIE 1" >>confdefs.h
+
+fi
diff --git a/sysdeps/s390/s390-64/configure.ac b/sysdeps/s390/s390-64/configure.ac
new file mode 100644
index 0000000000..2583a4a335
--- /dev/null
+++ b/sysdeps/s390/s390-64/configure.ac
@@ -0,0 +1,92 @@
+GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
+# Local configure fragment for sysdeps/s390/s390-64.
+
+# Minimal checking for static PIE support in ld.
+# Compare to ld testcase/bugzilla:
+# <binutils-source>/ld/testsuite/ld-elf/pr22263-1.rd
+AC_CACHE_CHECK([for s390-specific static PIE requirements], \
+[libc_cv_s390x_staticpie_req], [dnl
+  cat > conftest1.c <<EOF
+__thread int * foo;
+
+void
+bar (void)
+{
+  *foo = 1;
+}
+EOF
+  cat > conftest2.c <<EOF
+extern __thread int *foo;
+extern void bar (void);
+static int x;
+
+int
+main ()
+{
+  foo = &x;
+  return 0;
+}
+EOF
+  libc_cv_s390x_staticpie_req=no
+  if AC_TRY_COMMAND([${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([! readelf -Wr conftest | grep R_390_TLS_TPOFF])
+  then
+    libc_cv_s390x_staticpie_req=yes
+  fi
+  rm -rf conftest.*])
+if test $libc_cv_s390x_staticpie_req = 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.
+   AC_DEFINE(SUPPORT_STATIC_PIE)
+fi
diff --git a/sysdeps/s390/s390-64/start.S b/sysdeps/s390/s390-64/start.S
index 4e6526308a..b4a66e4a97 100644
--- a/sysdeps/s390/s390-64/start.S
+++ b/sysdeps/s390/s390-64/start.S
@@ -85,10 +85,25 @@ _start:
 
 	/* Ok, now branch to the libc main routine.  */
 #ifdef PIC
+# ifdef SHARED
+	/* Used for dynamic linked position independent executable.
+	   => Scrt1.o  */
 	larl	%r2,main@GOTENT		# load pointer to main
 	lg	%r2,0(%r2)
+# else
+	/* Used for dynamic linked position dependent executable.
+	   => crt1.o (glibc configured without --disable-default-pie:
+	   PIC is defined)
+	   Or for static linked position independent executable.
+	   => rcrt1.o (only available if glibc configured without
+	   --disable-default-pie: PIC is defined) */
+	larl	%r2,__wrap_main
+# endif
 	brasl	%r14,__libc_start_main@plt
 #else
+	/* Used for dynamic/static linked position dependent executable.
+	   => crt1.o (glibc configured with --disable-default-pie:
+	   PIC and SHARED are not defined)  */
 	larl	%r2,main		# load pointer to main
 	brasl	%r14,__libc_start_main
 #endif
@@ -98,6 +113,19 @@ _start:
 
 	cfi_endproc
 
+#if defined PIC && !defined SHARED
+	/* When main is not defined in the executable but in a shared library
+	   then a wrapper is needed in crt1.o of the static-pie enabled libc,
+	   because crt1.o and rcrt1.o share code and the later must avoid the
+	   use of GOT relocations before __libc_start_main is called.  */
+__wrap_main:
+	cfi_startproc
+	larl	%r1,main@GOTENT		# load pointer to main
+	lg	%r1,0(%r1)
+	br	%r1
+	cfi_endproc
+#endif
+
 	/* Define a symbol for the first piece of initialized data.  */
 	.data
 	.globl __data_start