Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 243 insertions, 0 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
new file mode 100644
index 000000000..99ef537e5
--- /dev/null
+++ b/arch/s390/kernel/process.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file handles the architecture dependent parts of process handling.
+ *
+ *    Copyright IBM Corp. 1999, 2009
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Hartmut Penner <hp@de.ibm.com>,
+ *		 Denis Joseph Barrow,
+ */
+
+#include <linux/elf-randomize.h>
+#include <linux/compiler.h>
+#include <linux/cpu.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/elfcore.h>
+#include <linux/smp.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/tick.h>
+#include <linux/personality.h>
+#include <linux/syscalls.h>
+#include <linux/compat.h>
+#include <linux/kprobes.h>
+#include <linux/random.h>
+#include <linux/export.h>
+#include <linux/init_task.h>
+#include <asm/cpu_mf.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/vtimer.h>
+#include <asm/exec.h>
+#include <asm/irq.h>
+#include <asm/nmi.h>
+#include <asm/smp.h>
+#include <asm/switch_to.h>
+#include <asm/runtime_instr.h>
+#include "entry.h"
+
+asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
+
+extern void kernel_thread_starter(void);
+
+void flush_thread(void)
+{
+}
+
+void arch_setup_new_exec(void)
+{
+	if (S390_lowcore.current_pid != current->pid) {
+		S390_lowcore.current_pid = current->pid;
+		if (test_facility(40))
+			lpp(&S390_lowcore.lpp);
+	}
+}
+
+void arch_release_task_struct(struct task_struct *tsk)
+{
+	runtime_instr_release(tsk);
+	guarded_storage_release(tsk);
+}
+
+int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+{
+	/*
+	 * Save the floating-point or vector register state of the current
+	 * task and set the CIF_FPU flag to lazy restore the FPU register
+	 * state when returning to user space.
+	 */
+	save_fpu_regs();
+
+	memcpy(dst, src, arch_task_struct_size);
+	dst->thread.fpu.regs = dst->thread.fpu.fprs;
+	return 0;
+}
+
+int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp,
+		    unsigned long arg, struct task_struct *p, unsigned long tls)
+{
+	struct fake_frame
+	{
+		struct stack_frame sf;
+		struct pt_regs childregs;
+	} *frame;
+
+	frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
+	p->thread.ksp = (unsigned long) frame;
+	/* Save access registers to new thread structure. */
+	save_access_regs(&p->thread.acrs[0]);
+	/* start new process with ar4 pointing to the correct address space */
+	p->thread.mm_segment = get_fs();
+	/* Don't copy debug registers */
+	memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
+	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
+	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
+	p->thread.per_flags = 0;
+	/* Initialize per thread user and system timer values */
+	p->thread.user_timer = 0;
+	p->thread.guest_timer = 0;
+	p->thread.system_timer = 0;
+	p->thread.hardirq_timer = 0;
+	p->thread.softirq_timer = 0;
+
+	frame->sf.back_chain = 0;
+	/* new return point is ret_from_fork */
+	frame->sf.gprs[8] = (unsigned long) ret_from_fork;
+	/* fake return stack for resume(), don't go back to schedule */
+	frame->sf.gprs[9] = (unsigned long) frame;
+
+	/* Store access registers to kernel stack of new process. */
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		/* kernel thread */
+		memset(&frame->childregs, 0, sizeof(struct pt_regs));
+		frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
+				PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
+		frame->childregs.psw.addr =
+				(unsigned long) kernel_thread_starter;
+		frame->childregs.gprs[9] = new_stackp; /* function */
+		frame->childregs.gprs[10] = arg;
+		frame->childregs.gprs[11] = (unsigned long) do_exit;
+		frame->childregs.orig_gpr2 = -1;
+
+		return 0;
+	}
+	frame->childregs = *current_pt_regs();
+	frame->childregs.gprs[2] = 0;	/* child returns 0 on fork. */
+	frame->childregs.flags = 0;
+	if (new_stackp)
+		frame->childregs.gprs[15] = new_stackp;
+
+	/* Don't copy runtime instrumentation info */
+	p->thread.ri_cb = NULL;
+	frame->childregs.psw.mask &= ~PSW_MASK_RI;
+	/* Don't copy guarded storage control block */
+	p->thread.gs_cb = NULL;
+	p->thread.gs_bc_cb = NULL;
+
+	/* Set a new TLS ?  */
+	if (clone_flags & CLONE_SETTLS) {
+		if (is_compat_task()) {
+			p->thread.acrs[0] = (unsigned int)tls;
+		} else {
+			p->thread.acrs[0] = (unsigned int)(tls >> 32);
+			p->thread.acrs[1] = (unsigned int)tls;
+		}
+	}
+	return 0;
+}
+
+asmlinkage void execve_tail(void)
+{
+	current->thread.fpu.fpc = 0;
+	asm volatile("sfpc %0" : : "d" (0));
+}
+
+/*
+ * fill in the FPU structure for a core dump.
+ */
+int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
+{
+	save_fpu_regs();
+	fpregs->fpc = current->thread.fpu.fpc;
+	fpregs->pad = 0;
+	if (MACHINE_HAS_VX)
+		convert_vx_to_fp((freg_t *)&fpregs->fprs,
+				 current->thread.fpu.vxrs);
+	else
+		memcpy(&fpregs->fprs, current->thread.fpu.fprs,
+		       sizeof(fpregs->fprs));
+	return 1;
+}
+EXPORT_SYMBOL(dump_fpu);
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	struct stack_frame *sf, *low, *high;
+	unsigned long return_address;
+	int count;
+
+	if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
+		return 0;
+
+	if (!try_get_task_stack(p))
+		return 0;
+
+	low = task_stack_page(p);
+	high = (struct stack_frame *) task_pt_regs(p);
+	sf = (struct stack_frame *) p->thread.ksp;
+	if (sf <= low || sf > high) {
+		return_address = 0;
+		goto out;
+	}
+	for (count = 0; count < 16; count++) {
+		sf = (struct stack_frame *) sf->back_chain;
+		if (sf <= low || sf > high) {
+			return_address = 0;
+			goto out;
+		}
+		return_address = sf->gprs[8];
+		if (!in_sched_functions(return_address))
+			goto out;
+	}
+out:
+	put_task_stack(p);
+	return return_address;
+}
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= get_random_int() & ~PAGE_MASK;
+	return sp & ~0xf;
+}
+
+static inline unsigned long brk_rnd(void)
+{
+	return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long ret;
+
+	ret = PAGE_ALIGN(mm->brk + brk_rnd());
+	return (ret > mm->brk) ? ret : mm->brk;
+}
+
+void set_fs_fixup(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	static bool warned;
+
+	set_fs(USER_DS);
+	if (warned)
+		return;
+	WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs->int_code);
+	show_registers(regs);
+	warned = true;
+}