Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 242 insertions, 0 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
new file mode 100644
index 000000000..42af4b3aa
--- /dev/null
+++ b/arch/s390/kernel/process.c
@@ -0,0 +1,242 @@
+// 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 <linux/entry-common.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/stacktrace.h>
+#include <asm/switch_to.h>
+#include <asm/runtime_instr.h>
+#include <asm/unwind.h>
+#include "entry.h"
+
+void ret_from_fork(void) asm("ret_from_fork");
+
+void __ret_from_fork(struct task_struct *prev, struct pt_regs *regs)
+{
+	void (*func)(void *arg);
+
+	schedule_tail(prev);
+
+	if (!user_mode(regs)) {
+		/* Kernel thread */
+		func = (void *)regs->gprs[9];
+		func((void *)regs->gprs[10]);
+	}
+	clear_pt_regs_flag(regs, PIF_SYSCALL);
+	syscall_exit_to_user_mode(regs);
+}
+
+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;
+
+	/*
+	 * Don't transfer over the runtime instrumentation or the guarded
+	 * storage control block pointers. These fields are cleared here instead
+	 * of in copy_thread() to avoid premature freeing of associated memory
+	 * on fork() failure. Wait to clear the RI flag because ->stack still
+	 * refers to the source thread.
+	 */
+	dst->thread.ri_cb = NULL;
+	dst->thread.gs_cb = NULL;
+	dst->thread.gs_bc_cb = NULL;
+
+	return 0;
+}
+
+int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
+{
+	unsigned long clone_flags = args->flags;
+	unsigned long new_stackp = args->stack;
+	unsigned long tls = args->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 */
+	/* 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;
+	p->thread.last_break = 1;
+
+	frame->sf.back_chain = 0;
+	frame->sf.gprs[5] = (unsigned long)frame + sizeof(struct stack_frame);
+	frame->sf.gprs[6] = (unsigned long)p;
+	/* 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(args->fn)) {
+		/* 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)__ret_from_fork;
+		frame->childregs.gprs[9] = (unsigned long)args->fn;
+		frame->childregs.gprs[10] = (unsigned long)args->fn_arg;
+		frame->childregs.orig_gpr2 = -1;
+		frame->childregs.last_break = 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;
+	/*
+	 * Clear the runtime instrumentation flag after the above childregs
+	 * copy. The CB pointer was already cleared in arch_dup_task_struct().
+	 */
+	frame->childregs.psw.mask &= ~PSW_MASK_RI;
+
+	/* 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;
+		}
+	}
+	/*
+	 * 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;
+}
+
+void execve_tail(void)
+{
+	current->thread.fpu.fpc = 0;
+	asm volatile("sfpc %0" : : "d" (0));
+}
+
+unsigned long __get_wchan(struct task_struct *p)
+{
+	struct unwind_state state;
+	unsigned long ip = 0;
+
+	if (!task_stack_page(p))
+		return 0;
+
+	if (!try_get_task_stack(p))
+		return 0;
+
+	unwind_for_each_frame(&state, p, NULL, 0) {
+		if (state.stack_info.type != STACK_TYPE_TASK) {
+			ip = 0;
+			break;
+		}
+
+		ip = unwind_get_return_address(&state);
+		if (!ip)
+			break;
+
+		if (!in_sched_functions(ip))
+			break;
+	}
+
+	put_task_stack(p);
+	return ip;
+}
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= prandom_u32_max(PAGE_SIZE);
+	return sp & ~0xf;
+}
+
+static inline unsigned long brk_rnd(void)
+{
+	return (get_random_u16() & 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;
+}