--- /dev/null
+From df29a7440c4b5c65765c8f60396b3b13063e24e9 Mon Sep 17 00:00:00 2001
+From: Sven Schnelle <svens@linux.ibm.com>
+Date: Fri, 25 Jun 2021 15:02:08 +0200
+Subject: s390/signal: switch to using vdso for sigreturn and syscall restart
+
+From: Sven Schnelle <svens@linux.ibm.com>
+
+commit df29a7440c4b5c65765c8f60396b3b13063e24e9 upstream.
+
+with generic entry, there's a bug when it comes to restarting of signals.
+The failing sequence is:
+
+a) a signal is coming in, and no handler is registered, so the lower
+ part of arch_do_signal_or_restart() in arch/s390/kernel/signal.c
+ sets PIF_SYSCALL_RESTART.
+
+b) a second signal gets pending while the kernel is still in the exit
+ loop, and for that one, a handler exists.
+
+c) The first part of arch_do_signal_or_restart() is called. That part
+ calls handle_signal(), which sets up stack + registers for handling
+ the signal.
+
+d) __do_syscall() in arch/s390/kernel/syscall.c checks for
+ PIF_SYSCALL_RESTART right before leaving to userspace. If it is set,
+ it restart's the syscall. However, the registers are already setup
+ for handling a signal from c). The syscall is now restarted with the
+ wrong arguments.
+
+Change the code to:
+
+- use vdso for syscall_restart() instead of PIF_SYSCALL_RESTART because
+ we cannot rewind and go back to userspace on s390 because the system call
+ number might be encoded in the svc instruction.
+- for all other syscalls we rewind the PSW and return to userspace.
+
+Cc: <stable@kernel.org> # v5.12+ d57778feb987: s390/vdso: always enable vdso
+Cc: <stable@kernel.org> # v5.12+ 686341f2548b: s390/vdso64: add sigreturn,rt_sigreturn and restart_syscall
+Cc: <stable@kernel.org> # v5.12+ 43e1f76b0b69: s390/vdso: rename VDSO64_LBASE to VDSO_LBASE
+Cc: <stable@kernel.org> # v5.12+ 779df2248739: s390/vdso: add minimal compat vdso
+Cc: <stable@kernel.org> # v5.12+
+Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
+Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
+Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/s390/kernel/compat_signal.c | 13 +++----------
+ arch/s390/kernel/process.c | 6 ++++++
+ arch/s390/kernel/signal.c | 39 ++++++++++++++++++---------------------
+ arch/s390/kernel/syscall.c | 4 ++++
+ 4 files changed, 31 insertions(+), 31 deletions(-)
+
+--- a/arch/s390/kernel/compat_signal.c
++++ b/arch/s390/kernel/compat_signal.c
+@@ -28,6 +28,7 @@
+ #include <linux/uaccess.h>
+ #include <asm/lowcore.h>
+ #include <asm/switch_to.h>
++#include <asm/vdso.h>
+ #include "compat_linux.h"
+ #include "compat_ptrace.h"
+ #include "entry.h"
+@@ -118,7 +119,6 @@ static int restore_sigregs32(struct pt_r
+ fpregs_load((_s390_fp_regs *) &user_sregs.fpregs, ¤t->thread.fpu);
+
+ clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
+- clear_pt_regs_flag(regs, PIF_SYSCALL_RESTART);
+ return 0;
+ }
+
+@@ -304,11 +304,7 @@ static int setup_frame32(struct ksignal
+ restorer = (unsigned long __force)
+ ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
+ } else {
+- /* Signal frames without vectors registers are short ! */
+- __u16 __user *svc = (void __user *) frame + frame_size - 2;
+- if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
+- return -EFAULT;
+- restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
++ restorer = VDSO32_SYMBOL(current, sigreturn);
+ }
+
+ /* Set up registers for signal handler */
+@@ -371,10 +367,7 @@ static int setup_rt_frame32(struct ksign
+ restorer = (unsigned long __force)
+ ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
+ } else {
+- __u16 __user *svc = &frame->svc_insn;
+- if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
+- return -EFAULT;
+- restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
++ restorer = VDSO32_SYMBOL(current, rt_sigreturn);
+ }
+
+ /* Create siginfo on the signal stack */
+--- a/arch/s390/kernel/process.c
++++ b/arch/s390/kernel/process.c
+@@ -166,6 +166,12 @@ int copy_thread(unsigned long clone_flag
+ p->thread.acrs[1] = (unsigned int)tls;
+ }
+ }
++ /*
++ * s390 stores the svc return address in arch_data when calling
++ * sigreturn()/restart_syscall() via vdso. 1 means no valid address
++ * stored.
++ */
++ p->restart_block.arch_data = 1;
+ return 0;
+ }
+
+--- a/arch/s390/kernel/signal.c
++++ b/arch/s390/kernel/signal.c
+@@ -32,6 +32,7 @@
+ #include <linux/uaccess.h>
+ #include <asm/lowcore.h>
+ #include <asm/switch_to.h>
++#include <asm/vdso.h>
+ #include "entry.h"
+
+ /*
+@@ -171,7 +172,6 @@ static int restore_sigregs(struct pt_reg
+ fpregs_load(&user_sregs.fpregs, ¤t->thread.fpu);
+
+ clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
+- clear_pt_regs_flag(regs, PIF_SYSCALL_RESTART);
+ return 0;
+ }
+
+@@ -334,15 +334,10 @@ static int setup_frame(int sig, struct k
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+- if (ka->sa.sa_flags & SA_RESTORER) {
++ if (ka->sa.sa_flags & SA_RESTORER)
+ restorer = (unsigned long) ka->sa.sa_restorer;
+- } else {
+- /* Signal frame without vector registers are short ! */
+- __u16 __user *svc = (void __user *) frame + frame_size - 2;
+- if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
+- return -EFAULT;
+- restorer = (unsigned long) svc;
+- }
++ else
++ restorer = VDSO64_SYMBOL(current, sigreturn);
+
+ /* Set up registers for signal handler */
+ regs->gprs[14] = restorer;
+@@ -397,14 +392,10 @@ static int setup_rt_frame(struct ksignal
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+- if (ksig->ka.sa.sa_flags & SA_RESTORER) {
++ if (ksig->ka.sa.sa_flags & SA_RESTORER)
+ restorer = (unsigned long) ksig->ka.sa.sa_restorer;
+- } else {
+- __u16 __user *svc = &frame->svc_insn;
+- if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
+- return -EFAULT;
+- restorer = (unsigned long) svc;
+- }
++ else
++ restorer = VDSO64_SYMBOL(current, rt_sigreturn);
+
+ /* Create siginfo on the signal stack */
+ if (copy_siginfo_to_user(&frame->info, &ksig->info))
+@@ -501,7 +492,7 @@ void arch_do_signal_or_restart(struct pt
+ }
+ /* No longer in a system call */
+ clear_pt_regs_flag(regs, PIF_SYSCALL);
+- clear_pt_regs_flag(regs, PIF_SYSCALL_RESTART);
++
+ rseq_signal_deliver(&ksig, regs);
+ if (is_compat_task())
+ handle_signal32(&ksig, oldset, regs);
+@@ -517,14 +508,20 @@ void arch_do_signal_or_restart(struct pt
+ switch (regs->gprs[2]) {
+ case -ERESTART_RESTARTBLOCK:
+ /* Restart with sys_restart_syscall */
+- regs->int_code = __NR_restart_syscall;
+- fallthrough;
++ regs->gprs[2] = regs->orig_gpr2;
++ current->restart_block.arch_data = regs->psw.addr;
++ if (is_compat_task())
++ regs->psw.addr = VDSO32_SYMBOL(current, restart_syscall);
++ else
++ regs->psw.addr = VDSO64_SYMBOL(current, restart_syscall);
++ if (test_thread_flag(TIF_SINGLE_STEP))
++ clear_thread_flag(TIF_PER_TRAP);
++ break;
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+- /* Restart system call with magic TIF bit. */
+ regs->gprs[2] = regs->orig_gpr2;
+- set_pt_regs_flag(regs, PIF_SYSCALL_RESTART);
++ regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
+ if (test_thread_flag(TIF_SINGLE_STEP))
+ clear_thread_flag(TIF_PER_TRAP);
+ break;
+--- a/arch/s390/kernel/syscall.c
++++ b/arch/s390/kernel/syscall.c
+@@ -121,6 +121,10 @@ void do_syscall(struct pt_regs *regs)
+
+ regs->gprs[2] = nr;
+
++ if (nr == __NR_restart_syscall && !(current->restart_block.arch_data & 1)) {
++ regs->psw.addr = current->restart_block.arch_data;
++ current->restart_block.arch_data = 1;
++ }
+ nr = syscall_enter_from_user_mode_work(regs, nr);
+
+ /*
--- /dev/null
+From 779df2248739b6308c03b354c99e4c352141e3bc Mon Sep 17 00:00:00 2001
+From: Sven Schnelle <svens@linux.ibm.com>
+Date: Fri, 25 Jun 2021 14:50:08 +0200
+Subject: s390/vdso: add minimal compat vdso
+
+From: Sven Schnelle <svens@linux.ibm.com>
+
+commit 779df2248739b6308c03b354c99e4c352141e3bc upstream.
+
+Add a small vdso for 31 bit compat application that provides
+trampolines for calls to sigreturn,rt_sigreturn,syscall_restart.
+This is requird for moving these syscalls away from the signal
+frame to the vdso. Note that this patch effectively disables
+CONFIG_COMPAT when using clang to compile the kernel. clang
+doesn't support 31 bit mode.
+
+We want to redirect sigreturn and restart_syscall to the vdso. However,
+the kernel cannot parse the ELF vdso file, so we need to generate header
+files which contain the offsets of the syscall instructions in the vdso
+page.
+
+Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
+Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
+Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/s390/Kconfig | 1
+ arch/s390/Makefile | 13 ++
+ arch/s390/include/asm/elf.h | 2
+ arch/s390/include/asm/vdso.h | 27 +++--
+ arch/s390/include/asm/vdso/gettimeofday.h | 1
+ arch/s390/kernel/Makefile | 1
+ arch/s390/kernel/vdso.c | 50 ++++++---
+ arch/s390/kernel/vdso32/.gitignore | 2
+ arch/s390/kernel/vdso32/Makefile | 75 ++++++++++++++
+ arch/s390/kernel/vdso32/gen_vdso_offsets.sh | 15 ++
+ arch/s390/kernel/vdso32/note.S | 13 ++
+ arch/s390/kernel/vdso32/vdso32.lds.S | 141 ++++++++++++++++++++++++++++
+ arch/s390/kernel/vdso32/vdso32_wrapper.S | 15 ++
+ arch/s390/kernel/vdso32/vdso_user_wrapper.S | 21 ++++
+ arch/s390/kernel/vdso64/Makefile | 8 +
+ arch/s390/kernel/vdso64/gen_vdso_offsets.sh | 15 ++
+ 16 files changed, 373 insertions(+), 27 deletions(-)
+ create mode 100644 arch/s390/kernel/vdso32/.gitignore
+ create mode 100644 arch/s390/kernel/vdso32/Makefile
+ create mode 100755 arch/s390/kernel/vdso32/gen_vdso_offsets.sh
+ create mode 100644 arch/s390/kernel/vdso32/note.S
+ create mode 100644 arch/s390/kernel/vdso32/vdso32.lds.S
+ create mode 100644 arch/s390/kernel/vdso32/vdso32_wrapper.S
+ create mode 100644 arch/s390/kernel/vdso32/vdso_user_wrapper.S
+ create mode 100755 arch/s390/kernel/vdso64/gen_vdso_offsets.sh
+
+--- a/arch/s390/Kconfig
++++ b/arch/s390/Kconfig
+@@ -438,6 +438,7 @@ 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
+--- a/arch/s390/Makefile
++++ b/arch/s390/Makefile
+@@ -165,6 +165,19 @@ 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) \
++ $(build)=arch/s390/kernel/vdso32 include/generated/vdso32-offsets.h)
++endif
+
+ # Don't use tabs in echo arguments
+ define archhelp
+--- a/arch/s390/include/asm/elf.h
++++ b/arch/s390/include/asm/elf.h
+@@ -144,8 +144,6 @@ typedef s390_compat_regs compat_elf_greg
+ #include <linux/sched/mm.h> /* for task_struct */
+ #include <asm/mmu_context.h>
+
+-#include <asm/vdso.h>
+-
+ /*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+--- a/arch/s390/include/asm/vdso.h
++++ b/arch/s390/include/asm/vdso.h
+@@ -4,18 +4,31 @@
+
+ #include <vdso/datapage.h>
+
+-/* Default link address for the vDSO */
+-#define VDSO_LBASE 0
+-
+-#define __VVAR_PAGES 2
+-
+-#define VDSO_VERSION_STRING LINUX_2.6.29
+-
+ #ifndef __ASSEMBLY__
+
++#include <generated/vdso64-offsets.h>
++#ifdef CONFIG_COMPAT
++#include <generated/vdso32-offsets.h>
++#endif
++
++#define VDSO64_SYMBOL(tsk, name) ((tsk)->mm->context.vdso_base + (vdso64_offset_##name))
++#ifdef CONFIG_COMPAT
++#define VDSO32_SYMBOL(tsk, name) ((tsk)->mm->context.vdso_base + (vdso32_offset_##name))
++#else
++#define VDSO32_SYMBOL(tsk, name) (-1UL)
++#endif
++
+ extern struct vdso_data *vdso_data;
+
+ int vdso_getcpu_init(void);
+
+ #endif /* __ASSEMBLY__ */
++
++/* Default link address for the vDSO */
++#define VDSO_LBASE 0
++
++#define __VVAR_PAGES 2
++
++#define VDSO_VERSION_STRING LINUX_2.6.29
++
+ #endif /* __S390_VDSO_H__ */
+--- a/arch/s390/include/asm/vdso/gettimeofday.h
++++ b/arch/s390/include/asm/vdso/gettimeofday.h
+@@ -8,7 +8,6 @@
+
+ #include <asm/timex.h>
+ #include <asm/unistd.h>
+-#include <asm/vdso.h>
+ #include <linux/compiler.h>
+
+ #define vdso_calc_delta __arch_vdso_calc_delta
+--- a/arch/s390/kernel/Makefile
++++ b/arch/s390/kernel/Makefile
+@@ -78,3 +78,4 @@ obj-$(findstring y, $(CONFIG_PROTECTED_V
+
+ # vdso
+ obj-y += vdso64/
++obj-$(CONFIG_COMPAT) += vdso32/
+--- 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_ma
+ .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 l
+ {
+ 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 l
+ 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");
+-
+- 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;
++ 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;
++}
++
++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);
+--- /dev/null
++++ b/arch/s390/kernel/vdso32/.gitignore
+@@ -0,0 +1,2 @@
++# SPDX-License-Identifier: GPL-2.0-only
++vdso32.lds
+--- /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)
+--- /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'
+--- /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
+--- /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: *;
++ };
++}
+--- /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
+--- /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
+--- 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)
+--- /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'
projects / thirdparty / kernel / stable-queue.git / commitdiff
