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-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/Makefile13
-rw-r--r--arch/s390/include/asm/elf.h2
-rw-r--r--arch/s390/include/asm/vdso.h25
-rw-r--r--arch/s390/include/asm/vdso/gettimeofday.h1
-rw-r--r--arch/s390/kernel/Makefile1
-rw-r--r--arch/s390/kernel/vdso.c48
-rw-r--r--arch/s390/kernel/vdso32/.gitignore2
-rw-r--r--arch/s390/kernel/vdso32/Makefile75
-rwxr-xr-xarch/s390/kernel/vdso32/gen_vdso_offsets.sh15
-rw-r--r--arch/s390/kernel/vdso32/note.S13
-rw-r--r--arch/s390/kernel/vdso32/vdso32.lds.S141
-rw-r--r--arch/s390/kernel/vdso32/vdso32_wrapper.S15
-rw-r--r--arch/s390/kernel/vdso32/vdso_user_wrapper.S21
-rw-r--r--arch/s390/kernel/vdso64/Makefile8
-rwxr-xr-xarch/s390/kernel/vdso64/gen_vdso_offsets.sh15
16 files changed, 371 insertions, 25 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index ceaa50947d64..a0e2130f0100 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -437,6 +437,7 @@ config COMPAT
select COMPAT_OLD_SIGACTION
select HAVE_UID16
depends on MULTIUSER
+ depends on !CC_IS_CLANG
help
Select this option if you want to enable your system kernel to
handle system-calls from ELF binaries for 31 bit ESA. This option
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 098abe3a56f3..95c75e653e43 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -166,6 +166,19 @@ archheaders:
archprepare:
$(Q)$(MAKE) $(build)=$(syscalls) kapi
$(Q)$(MAKE) $(build)=$(tools) kapi
+ifeq ($(KBUILD_EXTMOD),)
+# We need to generate vdso-offsets.h before compiling certain files in kernel/.
+# In order to do that, we should use the archprepare target, but we can't since
+# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
+# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
+# Therefore we need to generate the header after prepare0 has been made, hence
+# this hack.
+prepare: vdso_prepare
+vdso_prepare: prepare0
+ $(Q)$(MAKE) $(build)=arch/s390/kernel/vdso64 include/generated/vdso64-offsets.h
+ $(if $(CONFIG_COMPAT),$(Q)$(MAKE) \
+ $(build)=arch/s390/kernel/vdso32 include/generated/vdso32-offsets.h)
+endif
# Don't use tabs in echo arguments
define archhelp
diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h
index 6476655d7ce9..1376bd2b0392 100644
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h
@@ -144,8 +144,6 @@ typedef s390_compat_regs compat_elf_gregset_t;
#include <linux/sched/mm.h> /* for task_struct */
#include <asm/mmu_context.h>
-#include <asm/vdso.h>
-
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
index 6eaf4a3f2273..53165aa7813a 100644
--- a/arch/s390/include/asm/vdso.h
+++ b/arch/s390/include/asm/vdso.h
@@ -4,18 +4,31 @@
#include <vdso/datapage.h>
-/* Default link address for the vDSO */
-#define VDSO_LBASE 0
-
-#define __VVAR_PAGES 2
+#ifndef __ASSEMBLY__
-#define VDSO_VERSION_STRING LINUX_2.6.29
+#include <generated/vdso64-offsets.h>
+#ifdef CONFIG_COMPAT
+#include <generated/vdso32-offsets.h>
+#endif
-#ifndef __ASSEMBLY__
+#define VDSO64_SYMBOL(tsk, name) ((tsk)->mm->context.vdso_base + (vdso64_offset_##name))
+#ifdef CONFIG_COMPAT
+#define VDSO32_SYMBOL(tsk, name) ((tsk)->mm->context.vdso_base + (vdso32_offset_##name))
+#else
+#define VDSO32_SYMBOL(tsk, name) (-1UL)
+#endif
extern struct vdso_data *vdso_data;
int vdso_getcpu_init(void);
#endif /* __ASSEMBLY__ */
+
+/* Default link address for the vDSO */
+#define VDSO_LBASE 0
+
+#define __VVAR_PAGES 2
+
+#define VDSO_VERSION_STRING LINUX_2.6.29
+
#endif /* __S390_VDSO_H__ */
diff --git a/arch/s390/include/asm/vdso/gettimeofday.h b/arch/s390/include/asm/vdso/gettimeofday.h
index 383c53c3dddd..d6465b22ffe3 100644
--- a/arch/s390/include/asm/vdso/gettimeofday.h
+++ b/arch/s390/include/asm/vdso/gettimeofday.h
@@ -8,7 +8,6 @@
#include <asm/timex.h>
#include <asm/unistd.h>
-#include <asm/vdso.h>
#include <linux/compiler.h>
#define vdso_calc_delta __arch_vdso_calc_delta
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 7a77f7f6f9d8..4a44ba5a2d73 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -77,3 +77,4 @@ obj-$(findstring y, $(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) $(CONFIG_PGSTE)) +=
# vdso
obj-y += vdso64/
+obj-$(CONFIG_COMPAT) += vdso32/
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index f786246e621a..99694260cac9 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -20,7 +20,7 @@
#include <asm/vdso.h>
extern char vdso64_start[], vdso64_end[];
-static unsigned int vdso_pages;
+extern char vdso32_start[], vdso32_end[];
static struct vm_special_mapping vvar_mapping;
@@ -143,7 +143,12 @@ static struct vm_special_mapping vvar_mapping = {
.fault = vvar_fault,
};
-static struct vm_special_mapping vdso_mapping = {
+static struct vm_special_mapping vdso64_mapping = {
+ .name = "[vdso]",
+ .mremap = vdso_mremap,
+};
+
+static struct vm_special_mapping vdso32_mapping = {
.name = "[vdso]",
.mremap = vdso_mremap,
};
@@ -159,16 +164,22 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
unsigned long vdso_text_len, vdso_mapping_len;
unsigned long vvar_start, vdso_text_start;
+ struct vm_special_mapping *vdso_mapping;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
int rc;
BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
- if (is_compat_task())
- return 0;
if (mmap_write_lock_killable(mm))
return -EINTR;
- vdso_text_len = vdso_pages << PAGE_SHIFT;
+
+ if (is_compat_task()) {
+ vdso_text_len = vdso32_end - vdso32_start;
+ vdso_mapping = &vdso32_mapping;
+ } else {
+ vdso_text_len = vdso64_end - vdso64_start;
+ vdso_mapping = &vdso64_mapping;
+ }
vdso_mapping_len = vdso_text_len + VVAR_NR_PAGES * PAGE_SIZE;
vvar_start = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
rc = vvar_start;
@@ -186,7 +197,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
vma = _install_special_mapping(mm, vdso_text_start, vdso_text_len,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- &vdso_mapping);
+ vdso_mapping);
if (IS_ERR(vma)) {
do_munmap(mm, vvar_start, PAGE_SIZE, NULL);
rc = PTR_ERR(vma);
@@ -199,20 +210,25 @@ out:
return rc;
}
-static int __init vdso_init(void)
+static struct page ** __init vdso_setup_pages(void *start, void *end)
{
- struct page **pages;
+ int pages = (end - start) >> PAGE_SHIFT;
+ struct page **pagelist;
int i;
- vdso_pages = (vdso64_end - vdso64_start) >> PAGE_SHIFT;
- pages = kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
- if (!pages)
- panic("failed to allocate VDSO pages");
+ pagelist = kcalloc(pages + 1, sizeof(struct page *), GFP_KERNEL);
+ if (!pagelist)
+ panic("%s: Cannot allocate page list for VDSO", __func__);
+ for (i = 0; i < pages; i++)
+ pagelist[i] = virt_to_page(start + i * PAGE_SIZE);
+ return pagelist;
+}
- for (i = 0; i < vdso_pages; i++)
- pages[i] = virt_to_page(vdso64_start + i * PAGE_SIZE);
- pages[vdso_pages] = NULL;
- vdso_mapping.pages = pages;
+static int __init vdso_init(void)
+{
+ vdso64_mapping.pages = vdso_setup_pages(vdso64_start, vdso64_end);
+ if (IS_ENABLED(CONFIG_COMPAT))
+ vdso32_mapping.pages = vdso_setup_pages(vdso32_start, vdso32_end);
return 0;
}
arch_initcall(vdso_init);
diff --git a/arch/s390/kernel/vdso32/.gitignore b/arch/s390/kernel/vdso32/.gitignore
new file mode 100644
index 000000000000..5167384843b9
--- /dev/null
+++ b/arch/s390/kernel/vdso32/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+vdso32.lds
diff --git a/arch/s390/kernel/vdso32/Makefile b/arch/s390/kernel/vdso32/Makefile
new file mode 100644
index 000000000000..b2349a3f4fa3
--- /dev/null
+++ b/arch/s390/kernel/vdso32/Makefile
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: GPL-2.0
+# List of files in the vdso
+
+KCOV_INSTRUMENT := n
+ARCH_REL_TYPE_ABS := R_390_COPY|R_390_GLOB_DAT|R_390_JMP_SLOT|R_390_RELATIVE
+ARCH_REL_TYPE_ABS += R_390_GOT|R_390_PLT
+
+include $(srctree)/lib/vdso/Makefile
+obj-vdso32 = vdso_user_wrapper-32.o note-32.o
+
+# Build rules
+
+targets := $(obj-vdso32) vdso32.so vdso32.so.dbg
+obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))
+
+KBUILD_AFLAGS += -DBUILD_VDSO
+KBUILD_CFLAGS += -DBUILD_VDSO -DDISABLE_BRANCH_PROFILING
+
+KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
+KBUILD_AFLAGS_32 += -m31 -s
+
+KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
+KBUILD_CFLAGS_32 += -m31 -fPIC -shared -fno-common -fno-builtin
+
+LDFLAGS_vdso32.so.dbg += -fPIC -shared -nostdlib -soname=linux-vdso32.so.1 \
+ --hash-style=both --build-id=sha1 -melf_s390 -T
+
+$(targets:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
+$(targets:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
+
+obj-y += vdso32_wrapper.o
+CPPFLAGS_vdso32.lds += -P -C -U$(ARCH)
+
+# Disable gcov profiling, ubsan and kasan for VDSO code
+GCOV_PROFILE := n
+UBSAN_SANITIZE := n
+KASAN_SANITIZE := n
+
+# Force dependency (incbin is bad)
+$(obj)/vdso32_wrapper.o : $(obj)/vdso32.so
+
+$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) FORCE
+ $(call if_changed,ld)
+
+# strip rule for the .so file
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+ $(call if_changed,objcopy)
+
+$(obj-vdso32): %-32.o: %.S FORCE
+ $(call if_changed_dep,vdso32as)
+
+# actual build commands
+quiet_cmd_vdso32as = VDSO32A $@
+ cmd_vdso32as = $(CC) $(a_flags) -c -o $@ $<
+quiet_cmd_vdso32cc = VDSO32C $@
+ cmd_vdso32cc = $(CC) $(c_flags) -c -o $@ $<
+
+# install commands for the unstripped file
+quiet_cmd_vdso_install = INSTALL $@
+ cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
+
+vdso32.so: $(obj)/vdso32.so.dbg
+ @mkdir -p $(MODLIB)/vdso
+ $(call cmd,vdso_install)
+
+vdso_install: vdso32.so
+
+# Generate VDSO offsets using helper script
+gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
+quiet_cmd_vdsosym = VDSOSYM $@
+ cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
+
+include/generated/vdso32-offsets.h: $(obj)/vdso32.so.dbg FORCE
+ $(call if_changed,vdsosym)
diff --git a/arch/s390/kernel/vdso32/gen_vdso_offsets.sh b/arch/s390/kernel/vdso32/gen_vdso_offsets.sh
new file mode 100755
index 000000000000..9c4f951e227d
--- /dev/null
+++ b/arch/s390/kernel/vdso32/gen_vdso_offsets.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+#
+# Match symbols in the DSO that look like VDSO_*; produce a header file
+# of constant offsets into the shared object.
+#
+# Doing this inside the Makefile will break the $(filter-out) function,
+# causing Kbuild to rebuild the vdso-offsets header file every time.
+#
+# Inspired by arm64 version.
+#
+
+LC_ALL=C
+sed -n 's/\([0-9a-f]*\) . __kernel_compat_\(.*\)/\#define vdso32_offset_\2\t0x\1/p'
diff --git a/arch/s390/kernel/vdso32/note.S b/arch/s390/kernel/vdso32/note.S
new file mode 100644
index 000000000000..db19d0680a0a
--- /dev/null
+++ b/arch/s390/kernel/vdso32/note.S
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/uts.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+ELFNOTE_START(Linux, 0, "a")
+ .long LINUX_VERSION_CODE
+ELFNOTE_END
diff --git a/arch/s390/kernel/vdso32/vdso32.lds.S b/arch/s390/kernel/vdso32/vdso32.lds.S
new file mode 100644
index 000000000000..bff50b6acd6d
--- /dev/null
+++ b/arch/s390/kernel/vdso32/vdso32.lds.S
@@ -0,0 +1,141 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This is the infamous ld script for the 64 bits vdso
+ * library
+ */
+
+#include <asm/page.h>
+#include <asm/vdso.h>
+
+OUTPUT_FORMAT("elf32-s390", "elf32-s390", "elf32-s390")
+OUTPUT_ARCH(s390:31-bit)
+ENTRY(_start)
+
+SECTIONS
+{
+ PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
+#ifdef CONFIG_TIME_NS
+ PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
+#endif
+ . = VDSO_LBASE + SIZEOF_HEADERS;
+
+ .hash : { *(.hash) } :text
+ .gnu.hash : { *(.gnu.hash) }
+ .dynsym : { *(.dynsym) }
+ .dynstr : { *(.dynstr) }
+ .gnu.version : { *(.gnu.version) }
+ .gnu.version_d : { *(.gnu.version_d) }
+ .gnu.version_r : { *(.gnu.version_r) }
+
+ .note : { *(.note.*) } :text :note
+
+ . = ALIGN(16);
+ .text : {
+ *(.text .stub .text.* .gnu.linkonce.t.*)
+ } :text
+ PROVIDE(__etext = .);
+ PROVIDE(_etext = .);
+ PROVIDE(etext = .);
+
+ /*
+ * Other stuff is appended to the text segment:
+ */
+ .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
+ .rodata1 : { *(.rodata1) }
+
+ .dynamic : { *(.dynamic) } :text :dynamic
+
+ .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
+ .eh_frame : { KEEP (*(.eh_frame)) } :text
+ .gcc_except_table : { *(.gcc_except_table .gcc_except_table.*) }
+
+ .rela.dyn ALIGN(8) : { *(.rela.dyn) }
+ .got ALIGN(8) : { *(.got .toc) }
+
+ _end = .;
+ PROVIDE(end = .);
+
+ /*
+ * Stabs debugging sections are here too.
+ */
+ .stab 0 : { *(.stab) }
+ .stabstr 0 : { *(.stabstr) }
+ .stab.excl 0 : { *(.stab.excl) }
+ .stab.exclstr 0 : { *(.stab.exclstr) }
+ .stab.index 0 : { *(.stab.index) }
+ .stab.indexstr 0 : { *(.stab.indexstr) }
+ .comment 0 : { *(.comment) }
+
+ /*
+ * DWARF debug sections.
+ * Symbols in the DWARF debugging sections are relative to the
+ * beginning of the section so we begin them at 0.
+ */
+ /* DWARF 1 */
+ .debug 0 : { *(.debug) }
+ .line 0 : { *(.line) }
+ /* GNU DWARF 1 extensions */
+ .debug_srcinfo 0 : { *(.debug_srcinfo) }
+ .debug_sfnames 0 : { *(.debug_sfnames) }
+ /* DWARF 1.1 and DWARF 2 */
+ .debug_aranges 0 : { *(.debug_aranges) }
+ .debug_pubnames 0 : { *(.debug_pubnames) }
+ /* DWARF 2 */
+ .debug_info 0 : { *(.debug_info .gnu.linkonce.wi.*) }
+ .debug_abbrev 0 : { *(.debug_abbrev) }
+ .debug_line 0 : { *(.debug_line) }
+ .debug_frame 0 : { *(.debug_frame) }
+ .debug_str 0 : { *(.debug_str) }
+ .debug_loc 0 : { *(.debug_loc) }
+ .debug_macinfo 0 : { *(.debug_macinfo) }
+ /* SGI/MIPS DWARF 2 extensions */
+ .debug_weaknames 0 : { *(.debug_weaknames) }
+ .debug_funcnames 0 : { *(.debug_funcnames) }
+ .debug_typenames 0 : { *(.debug_typenames) }
+ .debug_varnames 0 : { *(.debug_varnames) }
+ /* DWARF 3 */
+ .debug_pubtypes 0 : { *(.debug_pubtypes) }
+ .debug_ranges 0 : { *(.debug_ranges) }
+ .gnu.attributes 0 : { KEEP (*(.gnu.attributes)) }
+
+ /DISCARD/ : {
+ *(.note.GNU-stack)
+ *(.branch_lt)
+ *(.data .data.* .gnu.linkonce.d.* .sdata*)
+ *(.bss .sbss .dynbss .dynsbss)
+ }
+}
+
+/*
+ * Very old versions of ld do not recognize this name token; use the constant.
+ */
+#define PT_GNU_EH_FRAME 0x6474e550
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+ text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
+ dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
+ note PT_NOTE FLAGS(4); /* PF_R */
+ eh_frame_hdr PT_GNU_EH_FRAME;
+}
+
+/*
+ * This controls what symbols we export from the DSO.
+ */
+VERSION
+{
+ VDSO_VERSION_STRING {
+ global:
+ /*
+ * Has to be there for the kernel to find
+ */
+ __kernel_compat_restart_syscall;
+ __kernel_compat_rt_sigreturn;
+ __kernel_compat_sigreturn;
+ local: *;
+ };
+}
diff --git a/arch/s390/kernel/vdso32/vdso32_wrapper.S b/arch/s390/kernel/vdso32/vdso32_wrapper.S
new file mode 100644
index 000000000000..de2fb930471a
--- /dev/null
+++ b/arch/s390/kernel/vdso32/vdso32_wrapper.S
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/page.h>
+
+ __PAGE_ALIGNED_DATA
+
+ .globl vdso32_start, vdso32_end
+ .balign PAGE_SIZE
+vdso32_start:
+ .incbin "arch/s390/kernel/vdso32/vdso32.so"
+ .balign PAGE_SIZE
+vdso32_end:
+
+ .previous
diff --git a/arch/s390/kernel/vdso32/vdso_user_wrapper.S b/arch/s390/kernel/vdso32/vdso_user_wrapper.S
new file mode 100644
index 000000000000..3f42f27f978c
--- /dev/null
+++ b/arch/s390/kernel/vdso32/vdso_user_wrapper.S
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <asm/unistd.h>
+#include <asm/dwarf.h>
+
+.macro vdso_syscall func,syscall
+ .globl __kernel_compat_\func
+ .type __kernel_compat_\func,@function
+ .align 8
+__kernel_compat_\func:
+ CFI_STARTPROC
+ svc \syscall
+ /* Make sure we notice when a syscall returns, which shouldn't happen */
+ .word 0
+ CFI_ENDPROC
+ .size __kernel_compat_\func,.-__kernel_compat_\func
+.endm
+
+vdso_syscall restart_syscall,__NR_restart_syscall
+vdso_syscall sigreturn,__NR_sigreturn
+vdso_syscall rt_sigreturn,__NR_rt_sigreturn
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
index a6e0fb6b91d6..2a2092ce19f1 100644
--- a/arch/s390/kernel/vdso64/Makefile
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -74,3 +74,11 @@ vdso64.so: $(obj)/vdso64.so.dbg
$(call cmd,vdso_install)
vdso_install: vdso64.so
+
+# Generate VDSO offsets using helper script
+gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
+quiet_cmd_vdsosym = VDSOSYM $@
+ cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
+
+include/generated/vdso64-offsets.h: $(obj)/vdso64.so.dbg FORCE
+ $(call if_changed,vdsosym)
diff --git a/arch/s390/kernel/vdso64/gen_vdso_offsets.sh b/arch/s390/kernel/vdso64/gen_vdso_offsets.sh
new file mode 100755
index 000000000000..37f05cb38dad
--- /dev/null
+++ b/arch/s390/kernel/vdso64/gen_vdso_offsets.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+#
+# Match symbols in the DSO that look like VDSO_*; produce a header file
+# of constant offsets into the shared object.
+#
+# Doing this inside the Makefile will break the $(filter-out) function,
+# causing Kbuild to rebuild the vdso-offsets header file every time.
+#
+# Inspired by arm64 version.
+#
+
+LC_ALL=C
+sed -n 's/\([0-9a-f]*\) . __kernel_\(.*\)/\#define vdso64_offset_\2\t0x\1/p'