patch-2.3.99-pre8 linux/arch/s390/kernel/process.c

• Lines: 432
• Date: Fri May 12 11:41:45 2000
• Orig file: v2.3.99-pre7/linux/arch/s390/kernel/process.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre7/linux/arch/s390/kernel/process.c linux/arch/s390/kernel/process.c
@@ -0,0 +1,431 @@
+/*
+ *  arch/s390/kernel/process.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Schwidefsky ([email protected]),
+ *               Hartmut Penner ([email protected]),
+ *               Denis Joseph Barrow ([email protected],[email protected]),
+ *
+ *  Derived from "arch/i386/kernel/process.c"
+ *    Copyright (C) 1995, Linus Torvalds
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#define __KERNEL_SYSCALLS__
+#include <stdarg.h>
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/malloc.h>
+#include <linux/vmalloc.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/misc390.h>
+#include <asm/irq.h>
+
+spinlock_t semaphore_wake_lock = SPIN_LOCK_UNLOCKED;
+
+asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+
+/*
+ * The idle loop on a S390...
+ */
+
+static psw_t wait_psw;
+
+int cpu_idle(void *unused)
+{
+	/* endless idle loop with no priority at all */
+        init_idle();
+	current->priority = 0;
+	current->counter = -100;
+	wait_psw.mask = _WAIT_PSW_MASK;
+	wait_psw.addr = (unsigned long) &&idle_wakeup | 0x80000000L;
+	while(1) {
+                if (softirq_state[smp_processor_id()].active &
+		    softirq_state[smp_processor_id()].mask) {
+                        do_softirq();
+                        continue;
+                }
+                if (current->need_resched) {
+                        schedule();
+                        check_pgt_cache();
+                        continue;
+                }
+
+		/* load wait psw */
+		asm volatile (
+                        "lpsw %0"
+                        : : "m" (wait_psw) );
+idle_wakeup:
+	}
+}
+
+/*
+  As all the register will only be made displayable to the root
+  user ( via printk ) or checking if the uid of the user is 0 from
+  the /proc filesystem please god this will be secure enough DJB.
+  The lines are given one at a time so as not to chew stack space in
+  printk on a crash & also for the proc filesystem when you get
+  0 returned you know you've got all the lines
+ */
+
+int sprintf_regs(int line, char *buff, struct task_struct * task,
+		 struct thread_struct *thread, struct pt_regs * regs)
+{	
+	int linelen=0;
+	int regno,chaincnt;
+	u32 backchain,prev_backchain,endchain;
+
+	enum
+	{
+		sp_linefeed,
+		sp_psw,
+		sp_ksp,
+		sp_gprs,
+		sp_gprs1,
+		sp_gprs2,
+		sp_gprs3,
+		sp_gprs4,
+		sp_acrs,
+		sp_acrs1,
+		sp_acrs2,
+		sp_acrs3,
+		sp_acrs4,
+		sp_kern_backchain,
+		sp_kern_backchain1
+	};
+
+	if(task)
+		thread = &task->thread;
+	if(thread)
+		regs = thread->regs;
+	switch (line) {
+	case sp_linefeed:
+		linelen=sprintf(buff,"\n");
+		break;
+	case sp_psw:
+		if(regs)
+			linelen = sprintf(buff,"User PSW:    %08lx %08lx\n",
+					  (unsigned long) regs->psw.mask,
+					  (unsigned long) regs->psw.addr);
+		else
+			linelen = sprintf(buff,"pt_regs=NULL some info unavailable\n");
+		break;
+	case sp_ksp:
+		if (task)
+			linelen += sprintf(&buff[linelen],
+					   "task: %08x ", (addr_t)task);
+		if (thread)
+			linelen += sprintf(&buff[linelen],
+					   "thread: %08x ksp: %08x ",
+					   (addr_t)thread,(addr_t)thread->ksp);
+		if (regs)
+			linelen += sprintf(&buff[linelen],
+					   "pt_regs: %08x\n", (addr_t)regs);
+		break;
+	case sp_gprs:
+		if (regs)
+			linelen = sprintf(buff,"User GPRS:\n");
+		break;
+	case sp_gprs1 ... sp_gprs4:
+		if (regs) {
+			regno = (line-sp_gprs1)*4;
+			linelen = sprintf(buff,"%08x  %08x  %08x  %08x\n",
+					  regs->gprs[regno],
+					  regs->gprs[regno+1],
+					  regs->gprs[regno+2],
+					  regs->gprs[regno+3]);
+		}
+		break;
+	case sp_acrs:
+		if (regs)
+			linelen = sprintf(buff,"User ACRS:\n");
+		break;	
+        case sp_acrs1 ... sp_acrs4:
+		if (regs) {
+			regno = (line-sp_acrs1)*4;
+			linelen = sprintf(buff,"%08x  %08x  %08x  %08x\n",
+					  regs->acrs[regno],
+					  regs->acrs[regno+1],
+					  regs->acrs[regno+2],
+					  regs->acrs[regno+3]);
+		}
+		break;
+	case sp_kern_backchain:
+		if (thread && thread->ksp && regs)
+			linelen = sprintf(buff,"Kernel BackChain  CallChain    BackChain  CallChain\n");
+		break;
+	default:
+		if(thread && thread->ksp && regs) {
+			backchain = (thread->ksp & PSW_ADDR_MASK);
+			endchain = ((backchain & (-8192)) + 8192);
+			prev_backchain = backchain - 1;
+			line -= sp_kern_backchain1;
+			for (chaincnt = 0; ; chaincnt++) {
+				if ((backchain == 0) ||
+				    (backchain >= endchain) ||
+				    (chaincnt >= 8) || 
+				    (prev_backchain >= backchain))
+					break;
+				if ((chaincnt >> 1) == line) {
+					linelen += sprintf(&buff[linelen],"%s%08x   %08x     ",
+							 (chaincnt&1) ? "":"       ",
+							 backchain,*(u32 *)(backchain+56));
+				}
+				if ((chaincnt >> 1) > line)
+					break;
+				prev_backchain = backchain;
+				backchain = (*((u32 *)backchain)) & PSW_ADDR_MASK;
+			}
+			if (linelen)
+				linelen += sprintf(&buff[linelen],"\n");
+		}
+	}
+	return linelen;
+}
+
+
+void show_regs(struct task_struct *task, struct thread_struct *thread,
+	       struct pt_regs *regs)
+{
+	char buff[80];
+	int line;
+	
+	for (line = 0; sprintf_regs(line,buff,task,thread,regs); line++)
+		printk(buff);
+}
+
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
+{
+        int clone_arg = flags | CLONE_VM;
+        int retval;
+
+        __asm__ __volatile__(
+                "     sr    2,2\n"
+                "     lr    3,%1\n"
+                "     l     4,%6\n"     /* load kernel stack ptr of parent */
+                "     svc   %b2\n"                     /* Linux system call*/
+                "     cl    4,%6\n"    /* compare ksp's: child or parent ? */
+                "     je    0f\n"                          /* parent - jump*/
+                "     l     15,%6\n"            /* fix kernel stack pointer*/
+                "     ahi   15,%7\n"
+                "     xc    0(96,15),0(15)\n"           /* clear save area */
+                "     lr    2,%4\n"                        /* load argument*/
+                "     lr    14,%5\n"                      /* get fn-pointer*/
+                "     basr  14,14\n"                             /* call fn*/
+                "     svc   %b3\n"                     /* Linux system call*/
+                "0:   lr    %0,2"
+                : "=a" (retval)
+                : "d" (clone_arg), "i" (__NR_clone), "i" (__NR_exit),
+                  "d" (arg), "d" (fn), "i" (__LC_KERNEL_STACK) , "i" (-STACK_FRAME_OVERHEAD)
+                : "2", "3", "4" );
+        return retval;
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+}
+
+void flush_thread(void)
+{
+
+        current->used_math = 0;
+        current->flags &= ~PF_USEDFPU;
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp,
+        struct task_struct * p, struct pt_regs * regs)
+{
+        struct stack_frame
+          {
+            unsigned long back_chain;
+            unsigned long eos;
+            unsigned long glue1;
+            unsigned long glue2;
+            unsigned long scratch[2];
+            unsigned long gprs[10];    /* gprs 6 -15                       */
+            unsigned long fprs[4];     /* fpr 4 and 6                      */
+            unsigned long empty[4];
+#if CONFIG_REMOTE_DEBUG
+	    gdb_pt_regs childregs;
+#else
+            pt_regs childregs;
+#endif
+            __u32   pgm_old_ilc;       /* single step magic from entry.S */
+            __u32   pgm_svc_step;
+          } *frame;
+
+        frame = (struct stack_frame *) (2*PAGE_SIZE + (unsigned long) p) -1;
+        frame = (struct stack_frame *) (((unsigned long) frame)&-8L);
+        p->thread.regs = &frame->childregs;
+        p->thread.ksp = (unsigned long) frame;
+        frame->childregs = *regs;
+        frame->childregs.gprs[15] = new_stackp;
+        frame->eos = 0;
+
+        /* new return point is ret_from_sys_call */
+        frame->gprs[8] = ((unsigned long) &ret_from_fork) | 0x80000000;
+
+        /* fake return stack for resume(), don't go back to schedule */
+        frame->gprs[9]  = (unsigned long) frame;
+	frame->pgm_svc_step = 0; /* Nope we aren't single stepping an svc */
+        /* save fprs, if used in last task */
+	save_fp_regs(&p->thread.fp_regs);
+        p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _SEGMENT_TABLE;
+        p->thread.fs = USER_DS;
+        /* Don't copy debug registers */
+        memset(&p->thread.per_info,0,sizeof(p->thread.per_info));
+        return 0;
+}
+
+asmlinkage int sys_fork(struct pt_regs regs)
+{
+        int ret;
+
+        lock_kernel();
+        ret = do_fork(SIGCHLD, regs.gprs[15], &regs);
+        unlock_kernel();
+        return ret;
+}
+
+asmlinkage int sys_clone(struct pt_regs regs)
+{
+        unsigned long clone_flags;
+        unsigned long newsp;
+        int ret;
+
+        lock_kernel();
+        clone_flags = regs.gprs[3];
+        newsp = regs.gprs[2];
+        if (!newsp)
+                newsp = regs.gprs[15];
+        ret = do_fork(clone_flags, newsp, &regs);
+        unlock_kernel();
+        return ret;
+}
+
+/*
+ * 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.
+ */
+asmlinkage int sys_vfork(struct pt_regs regs)
+{
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
+                       regs.gprs[15], &regs);
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(struct pt_regs regs)
+{
+        int error;
+        char * filename;
+
+        filename = getname((char *) regs.orig_gpr2);
+        error = PTR_ERR(filename);
+        if (IS_ERR(filename))
+                goto out;
+        error = do_execve(filename, (char **) regs.gprs[3], (char **) regs.gprs[4], &regs);
+	if (error == 0)
+		current->flags &= ~PF_DTRACE;
+        putname(filename);
+out:
+        return error;
+}
+
+
+/*
+ * fill in the FPU structure for a core dump.
+ */
+int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
+{
+	save_fp_regs(fpregs);
+	return 1;
+}
+
+/*
+ * fill in the user structure for a core dump..
+ */
+void dump_thread(struct pt_regs * regs, struct user * dump)
+{
+
+/* changed the size calculations - should hopefully work better. lbt */
+	dump->magic = CMAGIC;
+	dump->start_code = 0;
+	dump->start_stack = regs->gprs[15] & ~(PAGE_SIZE - 1);
+	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
+	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
+	dump->u_dsize -= dump->u_tsize;
+	dump->u_ssize = 0;
+	if (dump->start_stack < TASK_SIZE)
+		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
+	memcpy(&dump->regs.gprs[0],regs,sizeof(s390_regs));
+	dump_fpu (regs, &dump->regs.fp_regs);
+	memcpy(&dump->regs.per_info,&current->thread.per_info,sizeof(per_struct));
+}
+
+/*
+ * These bracket the sleeping functions..
+ */
+extern void scheduling_functions_start_here(void);
+extern void scheduling_functions_end_here(void);
+#define first_sched	((unsigned long) scheduling_functions_start_here)
+#define last_sched	((unsigned long) scheduling_functions_end_here)
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	unsigned long r14, r15;
+	unsigned long stack_page;
+	int count = 0;
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+	stack_page = (unsigned long) p;
+	r15 = p->thread.ksp;
+	do {
+		r14 = *(unsigned long *) (r15+56);
+		if (r14 < first_sched || r14 >= last_sched)
+			return r14;
+		r15 = *(unsigned long *) (r15+60);
+	} while (count++ < 16);
+	return 0;
+}
+#undef last_sched
+#undef first_sched
+