diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sparc/kernel/process.c | |
download | op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/sparc/kernel/process.c')
-rw-r--r-- | arch/sparc/kernel/process.c | 746 |
1 files changed, 746 insertions, 0 deletions
diff --git a/arch/sparc/kernel/process.c b/arch/sparc/kernel/process.c new file mode 100644 index 0000000..143fe2f --- /dev/null +++ b/arch/sparc/kernel/process.c @@ -0,0 +1,746 @@ +/* $Id: process.c,v 1.161 2002/01/23 11:27:32 davem Exp $ + * linux/arch/sparc/kernel/process.c + * + * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) + * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) + */ + +/* + * This file handles the architecture-dependent parts of process handling.. + */ + +#include <stdarg.h> + +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/kallsyms.h> +#include <linux/mm.h> +#include <linux/stddef.h> +#include <linux/ptrace.h> +#include <linux/slab.h> +#include <linux/user.h> +#include <linux/a.out.h> +#include <linux/config.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/reboot.h> +#include <linux/delay.h> +#include <linux/pm.h> +#include <linux/init.h> + +#include <asm/auxio.h> +#include <asm/oplib.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/delay.h> +#include <asm/processor.h> +#include <asm/psr.h> +#include <asm/elf.h> +#include <asm/unistd.h> + +/* + * Power management idle function + * Set in pm platform drivers (apc.c and pmc.c) + */ +void (*pm_idle)(void); + +/* + * Power-off handler instantiation for pm.h compliance + * This is done via auxio, but could be used as a fallback + * handler when auxio is not present-- unused for now... + */ +void (*pm_power_off)(void); + +/* + * sysctl - toggle power-off restriction for serial console + * systems in machine_power_off() + */ +int scons_pwroff = 1; + +extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); + +struct task_struct *last_task_used_math = NULL; +struct thread_info *current_set[NR_CPUS]; + +/* + * default_idle is new in 2.5. XXX Review, currently stolen from sparc64. + */ +void default_idle(void) +{ +} + +#ifndef CONFIG_SMP + +#define SUN4C_FAULT_HIGH 100 + +/* + * the idle loop on a Sparc... ;) + */ +void cpu_idle(void) +{ + if (current->pid != 0) + goto out; + + /* endless idle loop with no priority at all */ + for (;;) { + if (ARCH_SUN4C_SUN4) { + static int count = HZ; + static unsigned long last_jiffies; + static unsigned long last_faults; + static unsigned long fps; + unsigned long now; + unsigned long faults; + unsigned long flags; + + extern unsigned long sun4c_kernel_faults; + extern void sun4c_grow_kernel_ring(void); + + local_irq_save(flags); + now = jiffies; + count -= (now - last_jiffies); + last_jiffies = now; + if (count < 0) { + count += HZ; + faults = sun4c_kernel_faults; + fps = (fps + (faults - last_faults)) >> 1; + last_faults = faults; +#if 0 + printk("kernel faults / second = %ld\n", fps); +#endif + if (fps >= SUN4C_FAULT_HIGH) { + sun4c_grow_kernel_ring(); + } + } + local_irq_restore(flags); + } + + while((!need_resched()) && pm_idle) { + (*pm_idle)(); + } + + schedule(); + check_pgt_cache(); + } +out: + return; +} + +#else + +/* This is being executed in task 0 'user space'. */ +void cpu_idle(void) +{ + /* endless idle loop with no priority at all */ + while(1) { + if(need_resched()) { + schedule(); + check_pgt_cache(); + } + barrier(); /* or else gcc optimizes... */ + } +} + +#endif + +extern char reboot_command []; + +extern void (*prom_palette)(int); + +/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ +void machine_halt(void) +{ + local_irq_enable(); + mdelay(8); + local_irq_disable(); + if (!serial_console && prom_palette) + prom_palette (1); + prom_halt(); + panic("Halt failed!"); +} + +EXPORT_SYMBOL(machine_halt); + +void machine_restart(char * cmd) +{ + char *p; + + local_irq_enable(); + mdelay(8); + local_irq_disable(); + + p = strchr (reboot_command, '\n'); + if (p) *p = 0; + if (!serial_console && prom_palette) + prom_palette (1); + if (cmd) + prom_reboot(cmd); + if (*reboot_command) + prom_reboot(reboot_command); + prom_feval ("reset"); + panic("Reboot failed!"); +} + +EXPORT_SYMBOL(machine_restart); + +void machine_power_off(void) +{ +#ifdef CONFIG_SUN_AUXIO + if (auxio_power_register && (!serial_console || scons_pwroff)) + *auxio_power_register |= AUXIO_POWER_OFF; +#endif + machine_halt(); +} + +EXPORT_SYMBOL(machine_power_off); + +static DEFINE_SPINLOCK(sparc_backtrace_lock); + +void __show_backtrace(unsigned long fp) +{ + struct reg_window *rw; + unsigned long flags; + int cpu = smp_processor_id(); + + spin_lock_irqsave(&sparc_backtrace_lock, flags); + + rw = (struct reg_window *)fp; + while(rw && (((unsigned long) rw) >= PAGE_OFFSET) && + !(((unsigned long) rw) & 0x7)) { + printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] " + "FP[%08lx] CALLER[%08lx]: ", cpu, + rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], + rw->ins[4], rw->ins[5], + rw->ins[6], + rw->ins[7]); + print_symbol("%s\n", rw->ins[7]); + rw = (struct reg_window *) rw->ins[6]; + } + spin_unlock_irqrestore(&sparc_backtrace_lock, flags); +} + +#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t") +#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t") +#define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp)) + +void show_backtrace(void) +{ + unsigned long fp; + + __SAVE; __SAVE; __SAVE; __SAVE; + __SAVE; __SAVE; __SAVE; __SAVE; + __RESTORE; __RESTORE; __RESTORE; __RESTORE; + __RESTORE; __RESTORE; __RESTORE; __RESTORE; + + __GET_FP(fp); + + __show_backtrace(fp); +} + +#ifdef CONFIG_SMP +void smp_show_backtrace_all_cpus(void) +{ + xc0((smpfunc_t) show_backtrace); + show_backtrace(); +} +#endif + +#if 0 +void show_stackframe(struct sparc_stackf *sf) +{ + unsigned long size; + unsigned long *stk; + int i; + + printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx " + "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n", + sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3], + sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]); + printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx " + "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n", + sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3], + sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc); + printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx " + "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n", + (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1], + sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5], + sf->xxargs[0]); + size = ((unsigned long)sf->fp) - ((unsigned long)sf); + size -= STACKFRAME_SZ; + stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ); + i = 0; + do { + printk("s%d: %08lx\n", i++, *stk++); + } while ((size -= sizeof(unsigned long))); +} +#endif + +void show_regs(struct pt_regs *r) +{ + struct reg_window *rw = (struct reg_window *) r->u_regs[14]; + + printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", + r->psr, r->pc, r->npc, r->y, print_tainted()); + print_symbol("PC: <%s>\n", r->pc); + printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", + r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], + r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); + printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", + r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], + r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); + print_symbol("RPC: <%s>\n", r->u_regs[15]); + + printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", + rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], + rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); + printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", + rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], + rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); +} + +/* + * The show_stack is an external API which we do not use ourselves. + * The oops is printed in die_if_kernel. + */ +void show_stack(struct task_struct *tsk, unsigned long *_ksp) +{ + unsigned long pc, fp; + unsigned long task_base; + struct reg_window *rw; + int count = 0; + + if (tsk != NULL) + task_base = (unsigned long) tsk->thread_info; + else + task_base = (unsigned long) current_thread_info(); + + fp = (unsigned long) _ksp; + do { + /* Bogus frame pointer? */ + if (fp < (task_base + sizeof(struct thread_info)) || + fp >= (task_base + (PAGE_SIZE << 1))) + break; + rw = (struct reg_window *) fp; + pc = rw->ins[7]; + printk("[%08lx : ", pc); + print_symbol("%s ] ", pc); + fp = rw->ins[6]; + } while (++count < 16); + printk("\n"); +} + +/* + * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. + */ +unsigned long thread_saved_pc(struct task_struct *tsk) +{ + return tsk->thread_info->kpc; +} + +/* + * Free current thread data structures etc.. + */ +void exit_thread(void) +{ +#ifndef CONFIG_SMP + if(last_task_used_math == current) { +#else + if(current_thread_info()->flags & _TIF_USEDFPU) { +#endif + /* Keep process from leaving FPU in a bogon state. */ + put_psr(get_psr() | PSR_EF); + fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, + ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); +#ifndef CONFIG_SMP + last_task_used_math = NULL; +#else + current_thread_info()->flags &= ~_TIF_USEDFPU; +#endif + } +} + +void flush_thread(void) +{ + current_thread_info()->w_saved = 0; + + /* No new signal delivery by default */ + current->thread.new_signal = 0; +#ifndef CONFIG_SMP + if(last_task_used_math == current) { +#else + if(current_thread_info()->flags & _TIF_USEDFPU) { +#endif + /* Clean the fpu. */ + put_psr(get_psr() | PSR_EF); + fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, + ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); +#ifndef CONFIG_SMP + last_task_used_math = NULL; +#else + current_thread_info()->flags &= ~_TIF_USEDFPU; +#endif + } + + /* Now, this task is no longer a kernel thread. */ + current->thread.current_ds = USER_DS; + if (current->thread.flags & SPARC_FLAG_KTHREAD) { + current->thread.flags &= ~SPARC_FLAG_KTHREAD; + + /* We must fixup kregs as well. */ + /* XXX This was not fixed for ti for a while, worked. Unused? */ + current->thread.kregs = (struct pt_regs *) + ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ)); + } +} + +static __inline__ struct sparc_stackf __user * +clone_stackframe(struct sparc_stackf __user *dst, + struct sparc_stackf __user *src) +{ + unsigned long size, fp; + struct sparc_stackf *tmp; + struct sparc_stackf __user *sp; + + if (get_user(tmp, &src->fp)) + return NULL; + + fp = (unsigned long) tmp; + size = (fp - ((unsigned long) src)); + fp = (unsigned long) dst; + sp = (struct sparc_stackf __user *)(fp - size); + + /* do_fork() grabs the parent semaphore, we must release it + * temporarily so we can build the child clone stack frame + * without deadlocking. + */ + if (__copy_user(sp, src, size)) + sp = NULL; + else if (put_user(fp, &sp->fp)) + sp = NULL; + + return sp; +} + +asmlinkage int sparc_do_fork(unsigned long clone_flags, + unsigned long stack_start, + struct pt_regs *regs, + unsigned long stack_size) +{ + unsigned long parent_tid_ptr, child_tid_ptr; + + parent_tid_ptr = regs->u_regs[UREG_I2]; + child_tid_ptr = regs->u_regs[UREG_I4]; + + return do_fork(clone_flags, stack_start, + regs, stack_size, + (int __user *) parent_tid_ptr, + (int __user *) child_tid_ptr); +} + +/* Copy a Sparc thread. The fork() return value conventions + * under SunOS are nothing short of bletcherous: + * Parent --> %o0 == childs pid, %o1 == 0 + * Child --> %o0 == parents pid, %o1 == 1 + * + * NOTE: We have a separate fork kpsr/kwim because + * the parent could change these values between + * sys_fork invocation and when we reach here + * if the parent should sleep while trying to + * allocate the task_struct and kernel stack in + * do_fork(). + * XXX See comment above sys_vfork in sparc64. todo. + */ +extern void ret_from_fork(void); + +int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, + unsigned long unused, + struct task_struct *p, struct pt_regs *regs) +{ + struct thread_info *ti = p->thread_info; + struct pt_regs *childregs; + char *new_stack; + +#ifndef CONFIG_SMP + if(last_task_used_math == current) { +#else + if(current_thread_info()->flags & _TIF_USEDFPU) { +#endif + put_psr(get_psr() | PSR_EF); + fpsave(&p->thread.float_regs[0], &p->thread.fsr, + &p->thread.fpqueue[0], &p->thread.fpqdepth); +#ifdef CONFIG_SMP + current_thread_info()->flags &= ~_TIF_USEDFPU; +#endif + } + + /* + * p->thread_info new_stack childregs + * ! ! ! {if(PSR_PS) } + * V V (stk.fr.) V (pt_regs) { (stk.fr.) } + * +----- - - - - - ------+===========+============={+==========}+ + */ + new_stack = (char*)ti + THREAD_SIZE; + if (regs->psr & PSR_PS) + new_stack -= STACKFRAME_SZ; + new_stack -= STACKFRAME_SZ + TRACEREG_SZ; + memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); + childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); + + /* + * A new process must start with interrupts closed in 2.5, + * because this is how Mingo's scheduler works (see schedule_tail + * and finish_arch_switch). If we do not do it, a timer interrupt hits + * before we unlock, attempts to re-take the rq->lock, and then we die. + * Thus, kpsr|=PSR_PIL. + */ + ti->ksp = (unsigned long) new_stack; + ti->kpc = (((unsigned long) ret_from_fork) - 0x8); + ti->kpsr = current->thread.fork_kpsr | PSR_PIL; + ti->kwim = current->thread.fork_kwim; + + if(regs->psr & PSR_PS) { + extern struct pt_regs fake_swapper_regs; + + p->thread.kregs = &fake_swapper_regs; + new_stack += STACKFRAME_SZ + TRACEREG_SZ; + childregs->u_regs[UREG_FP] = (unsigned long) new_stack; + p->thread.flags |= SPARC_FLAG_KTHREAD; + p->thread.current_ds = KERNEL_DS; + memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ); + childregs->u_regs[UREG_G6] = (unsigned long) ti; + } else { + p->thread.kregs = childregs; + childregs->u_regs[UREG_FP] = sp; + p->thread.flags &= ~SPARC_FLAG_KTHREAD; + p->thread.current_ds = USER_DS; + + if (sp != regs->u_regs[UREG_FP]) { + struct sparc_stackf __user *childstack; + struct sparc_stackf __user *parentstack; + + /* + * This is a clone() call with supplied user stack. + * Set some valid stack frames to give to the child. + */ + childstack = (struct sparc_stackf __user *) + (sp & ~0x7UL); + parentstack = (struct sparc_stackf __user *) + regs->u_regs[UREG_FP]; + +#if 0 + printk("clone: parent stack:\n"); + show_stackframe(parentstack); +#endif + + childstack = clone_stackframe(childstack, parentstack); + if (!childstack) + return -EFAULT; + +#if 0 + printk("clone: child stack:\n"); + show_stackframe(childstack); +#endif + + childregs->u_regs[UREG_FP] = (unsigned long)childstack; + } + } + +#ifdef CONFIG_SMP + /* FPU must be disabled on SMP. */ + childregs->psr &= ~PSR_EF; +#endif + + /* Set the return value for the child. */ + childregs->u_regs[UREG_I0] = current->pid; + childregs->u_regs[UREG_I1] = 1; + + /* Set the return value for the parent. */ + regs->u_regs[UREG_I1] = 0; + + if (clone_flags & CLONE_SETTLS) + childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; + + return 0; +} + +/* + * fill in the user structure for a core dump.. + */ +void dump_thread(struct pt_regs * regs, struct user * dump) +{ + unsigned long first_stack_page; + + dump->magic = SUNOS_CORE_MAGIC; + dump->len = sizeof(struct user); + dump->regs.psr = regs->psr; + dump->regs.pc = regs->pc; + dump->regs.npc = regs->npc; + dump->regs.y = regs->y; + /* fuck me plenty */ + memcpy(&dump->regs.regs[0], ®s->u_regs[1], (sizeof(unsigned long) * 15)); + dump->uexec = current->thread.core_exec; + dump->u_tsize = (((unsigned long) current->mm->end_code) - + ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1); + dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))); + dump->u_dsize -= dump->u_tsize; + dump->u_dsize &= ~(PAGE_SIZE - 1); + first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1)); + dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1); + memcpy(&dump->fpu.fpstatus.fregs.regs[0], ¤t->thread.float_regs[0], (sizeof(unsigned long) * 32)); + dump->fpu.fpstatus.fsr = current->thread.fsr; + dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0; + dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth; + memcpy(&dump->fpu.fpstatus.fpq[0], ¤t->thread.fpqueue[0], + ((sizeof(unsigned long) * 2) * 16)); + dump->sigcode = 0; +} + +/* + * fill in the fpu structure for a core dump. + */ +int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) +{ + if (used_math()) { + memset(fpregs, 0, sizeof(*fpregs)); + fpregs->pr_q_entrysize = 8; + return 1; + } +#ifdef CONFIG_SMP + if (current_thread_info()->flags & _TIF_USEDFPU) { + put_psr(get_psr() | PSR_EF); + fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, + ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); + if (regs != NULL) { + regs->psr &= ~(PSR_EF); + current_thread_info()->flags &= ~(_TIF_USEDFPU); + } + } +#else + if (current == last_task_used_math) { + put_psr(get_psr() | PSR_EF); + fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, + ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); + if (regs != NULL) { + regs->psr &= ~(PSR_EF); + last_task_used_math = NULL; + } + } +#endif + memcpy(&fpregs->pr_fr.pr_regs[0], + ¤t->thread.float_regs[0], + (sizeof(unsigned long) * 32)); + fpregs->pr_fsr = current->thread.fsr; + fpregs->pr_qcnt = current->thread.fpqdepth; + fpregs->pr_q_entrysize = 8; + fpregs->pr_en = 1; + if(fpregs->pr_qcnt != 0) { + memcpy(&fpregs->pr_q[0], + ¤t->thread.fpqueue[0], + sizeof(struct fpq) * fpregs->pr_qcnt); + } + /* Zero out the rest. */ + memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, + sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); + return 1; +} + +/* + * sparc_execve() executes a new program after the asm stub has set + * things up for us. This should basically do what I want it to. + */ +asmlinkage int sparc_execve(struct pt_regs *regs) +{ + int error, base = 0; + char *filename; + + /* Check for indirect call. */ + if(regs->u_regs[UREG_G1] == 0) + base = 1; + + filename = getname((char __user *)regs->u_regs[base + UREG_I0]); + error = PTR_ERR(filename); + if(IS_ERR(filename)) + goto out; + error = do_execve(filename, + (char __user * __user *)regs->u_regs[base + UREG_I1], + (char __user * __user *)regs->u_regs[base + UREG_I2], + regs); + putname(filename); + if (error == 0) { + task_lock(current); + current->ptrace &= ~PT_DTRACE; + task_unlock(current); + } +out: + return error; +} + +/* + * This is the mechanism for creating a new kernel thread. + * + * NOTE! Only a kernel-only process(ie the swapper or direct descendants + * who haven't done an "execve()") should use this: it will work within + * a system call from a "real" process, but the process memory space will + * not be free'd until both the parent and the child have exited. + */ +pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) +{ + long retval; + + __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */ + "mov %5, %%g3\n\t" /* and arg. */ + "mov %1, %%g1\n\t" + "mov %2, %%o0\n\t" /* Clone flags. */ + "mov 0, %%o1\n\t" /* usp arg == 0 */ + "t 0x10\n\t" /* Linux/Sparc clone(). */ + "cmp %%o1, 0\n\t" + "be 1f\n\t" /* The parent, just return. */ + " nop\n\t" /* Delay slot. */ + "jmpl %%g2, %%o7\n\t" /* Call the function. */ + " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */ + "mov %3, %%g1\n\t" + "t 0x10\n\t" /* Linux/Sparc exit(). */ + /* Notreached by child. */ + "1: mov %%o0, %0\n\t" : + "=r" (retval) : + "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), + "i" (__NR_exit), "r" (fn), "r" (arg) : + "g1", "g2", "g3", "o0", "o1", "memory", "cc"); + return retval; +} + +unsigned long get_wchan(struct task_struct *task) +{ + unsigned long pc, fp, bias = 0; + unsigned long task_base = (unsigned long) task; + unsigned long ret = 0; + struct reg_window *rw; + int count = 0; + + if (!task || task == current || + task->state == TASK_RUNNING) + goto out; + + fp = task->thread_info->ksp + bias; + do { + /* Bogus frame pointer? */ + if (fp < (task_base + sizeof(struct thread_info)) || + fp >= (task_base + (2 * PAGE_SIZE))) + break; + rw = (struct reg_window *) fp; + pc = rw->ins[7]; + if (!in_sched_functions(pc)) { + ret = pc; + goto out; + } + fp = rw->ins[6] + bias; + } while (++count < 16); + +out: + return ret; +} + |