init android origin source code

1 files changed, 354 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/arch/s390/kernel/process.c b/ANDROID_3.4.5/arch/s390/kernel/process.c
new file mode 100644
index 00000000..60055cef
--- /dev/null
+++ b/ANDROID_3.4.5/arch/s390/kernel/process.c
@@ -0,0 +1,354 @@
+/*
+ * 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/compiler.h>
+#include <linux/cpu.h>
+#include <linux/sched.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/module.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/irq.h>
+#include <asm/timer.h>
+#include <asm/nmi.h>
+#include <asm/smp.h>
+#include <asm/switch_to.h>
+#include "entry.h"
+
+asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
+
+/*
+ * Return saved PC of a blocked thread. used in kernel/sched.
+ * resume in entry.S does not create a new stack frame, it
+ * just stores the registers %r6-%r15 to the frame given by
+ * schedule. We want to return the address of the caller of
+ * schedule, so we have to walk the backchain one time to
+ * find the frame schedule() store its return address.
+ */
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+	struct stack_frame *sf, *low, *high;
+
+	if (!tsk || !task_stack_page(tsk))
+		return 0;
+	low = task_stack_page(tsk);
+	high = (struct stack_frame *) task_pt_regs(tsk);
+	sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
+	if (sf <= low || sf > high)
+		return 0;
+	sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
+	if (sf <= low || sf > high)
+		return 0;
+	return sf->gprs[8];
+}
+
+/*
+ * The idle loop on a S390...
+ */
+static void default_idle(void)
+{
+	if (cpu_is_offline(smp_processor_id()))
+		cpu_die();
+	local_irq_disable();
+	if (need_resched()) {
+		local_irq_enable();
+		return;
+	}
+	local_mcck_disable();
+	if (test_thread_flag(TIF_MCCK_PENDING)) {
+		local_mcck_enable();
+		local_irq_enable();
+		return;
+	}
+	/* Halt the cpu and keep track of cpu time accounting. */
+	vtime_stop_cpu();
+}
+
+void cpu_idle(void)
+{
+	for (;;) {
+		tick_nohz_idle_enter();
+		rcu_idle_enter();
+		while (!need_resched() && !test_thread_flag(TIF_MCCK_PENDING))
+			default_idle();
+		rcu_idle_exit();
+		tick_nohz_idle_exit();
+		if (test_thread_flag(TIF_MCCK_PENDING))
+			s390_handle_mcck();
+		schedule_preempt_disabled();
+	}
+}
+
+extern void __kprobes kernel_thread_starter(void);
+
+asm(
+	".section .kprobes.text, \"ax\"\n"
+	".global kernel_thread_starter\n"
+	"kernel_thread_starter:\n"
+	"    la    2,0(10)\n"
+	"    basr  14,9\n"
+	"    la    2,0\n"
+	"    br    11\n"
+	".previous\n");
+
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
+{
+	struct pt_regs regs;
+
+	memset(&regs, 0, sizeof(regs));
+	regs.psw.mask = psw_kernel_bits |
+		PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
+	regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
+	regs.gprs[9] = (unsigned long) fn;
+	regs.gprs[10] = (unsigned long) arg;
+	regs.gprs[11] = (unsigned long) do_exit;
+	regs.orig_gpr2 = -1;
+
+	/* Ok, create the new process.. */
+	return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
+		       0, &regs, 0, NULL, NULL);
+}
+EXPORT_SYMBOL(kernel_thread);
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+}
+
+void flush_thread(void)
+{
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
+		unsigned long unused,
+		struct task_struct *p, struct pt_regs *regs)
+{
+	struct thread_info *ti;
+	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;
+	/* Store access registers to kernel stack of new process. */
+	frame->childregs = *regs;
+	frame->childregs.gprs[2] = 0;	/* child returns 0 on fork. */
+	frame->childregs.gprs[15] = new_stackp;
+	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;
+
+	/* Save access registers to new thread structure. */
+	save_access_regs(&p->thread.acrs[0]);
+
+#ifndef CONFIG_64BIT
+	/*
+	 * save fprs to current->thread.fp_regs to merge them with
+	 * the emulated registers and then copy the result to the child.
+	 */
+	save_fp_regs(&current->thread.fp_regs);
+	memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
+	       sizeof(s390_fp_regs));
+	/* Set a new TLS ?  */
+	if (clone_flags & CLONE_SETTLS)
+		p->thread.acrs[0] = regs->gprs[6];
+#else /* CONFIG_64BIT */
+	/* Save the fpu registers to new thread structure. */
+	save_fp_regs(&p->thread.fp_regs);
+	/* Set a new TLS ?  */
+	if (clone_flags & CLONE_SETTLS) {
+		if (is_compat_task()) {
+			p->thread.acrs[0] = (unsigned int) regs->gprs[6];
+		} else {
+			p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
+			p->thread.acrs[1] = (unsigned int) regs->gprs[6];
+		}
+	}
+#endif /* CONFIG_64BIT */
+	/* 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);
+	clear_tsk_thread_flag(p, TIF_PER_TRAP);
+	/* Initialize per thread user and system timer values */
+	ti = task_thread_info(p);
+	ti->user_timer = 0;
+	ti->system_timer = 0;
+	return 0;
+}
+
+SYSCALL_DEFINE0(fork)
+{
+	struct pt_regs *regs = task_pt_regs(current);
+	return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
+}
+
+SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags,
+		int __user *, parent_tidptr, int __user *, child_tidptr)
+{
+	struct pt_regs *regs = task_pt_regs(current);
+
+	if (!newsp)
+		newsp = regs->gprs[15];
+	return do_fork(clone_flags, newsp, regs, 0,
+		       parent_tidptr, child_tidptr);
+}
+
+/*
+ * This is trivial, and on the face of it looks like it
+ * could equally well be done in user mode.
+ *
+ * Not so, for quite unobvious reasons - register pressure.
+ * In user mode vfork() cannot have a stack frame, and if
+ * done by calling the "clone()" system call directly, you
+ * do not have enough call-clobbered registers to hold all
+ * the information you need.
+ */
+SYSCALL_DEFINE0(vfork)
+{
+	struct pt_regs *regs = task_pt_regs(current);
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
+		       regs->gprs[15], regs, 0, NULL, NULL);
+}
+
+asmlinkage void execve_tail(void)
+{
+	current->thread.fp_regs.fpc = 0;
+	if (MACHINE_HAS_IEEE)
+		asm volatile("sfpc %0,%0" : : "d" (0));
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+SYSCALL_DEFINE3(execve, const char __user *, name,
+		const char __user *const __user *, argv,
+		const char __user *const __user *, envp)
+{
+	struct pt_regs *regs = task_pt_regs(current);
+	char *filename;
+	long rc;
+
+	filename = getname(name);
+	rc = PTR_ERR(filename);
+	if (IS_ERR(filename))
+		return rc;
+	rc = do_execve(filename, argv, envp, regs);
+	if (rc)
+		goto out;
+	execve_tail();
+	rc = regs->gprs[2];
+out:
+	putname(filename);
+	return rc;
+}
+
+/*
+ * fill in the FPU structure for a core dump.
+ */
+int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
+{
+#ifndef CONFIG_64BIT
+	/*
+	 * save fprs to current->thread.fp_regs to merge them with
+	 * the emulated registers and then copy the result to the dump.
+	 */
+	save_fp_regs(&current->thread.fp_regs);
+	memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
+#else /* CONFIG_64BIT */
+	save_fp_regs(fpregs);
+#endif /* CONFIG_64BIT */
+	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;
+	low = task_stack_page(p);
+	high = (struct stack_frame *) task_pt_regs(p);
+	sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
+	if (sf <= low || sf > high)
+		return 0;
+	for (count = 0; count < 16; count++) {
+		sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
+		if (sf <= low || sf > high)
+			return 0;
+		return_address = sf->gprs[8] & PSW_ADDR_INSN;
+		if (!in_sched_functions(return_address))
+			return return_address;
+	}
+	return 0;
+}
+
+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)
+{
+	/* 8MB for 32bit, 1GB for 64bit */
+	if (is_32bit_task())
+		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
+	else
+		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
+
+	if (ret < mm->brk)
+		return mm->brk;
+	return ret;
+}
+
+unsigned long randomize_et_dyn(unsigned long base)
+{
+	unsigned long ret = PAGE_ALIGN(base + brk_rnd());
+
+	if (!(current->flags & PF_RANDOMIZE))
+		return base;
+	if (ret < base)
+		return base;
+	return ret;
+}