/* * arch/sh/kernel/process.c * * This file handles the architecture-dependent parts of process handling.. * * Copyright (C) 1995 Linus Torvalds * * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC * Copyright (C) 2002 - 2008 Paul Mundt * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include void show_regs(struct pt_regs * regs) { printk("\n"); printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm); printk("CPU : %d \t\t%s (%s %.*s)\n\n", smp_processor_id(), print_tainted(), init_utsname()->release, (int)strcspn(init_utsname()->version, " "), init_utsname()->version); print_symbol("PC is at %s\n", instruction_pointer(regs)); print_symbol("PR is at %s\n", regs->pr); printk("PC : %08lx SP : %08lx SR : %08lx ", regs->pc, regs->regs[15], regs->sr); #ifdef CONFIG_MMU printk("TEA : %08x\n", __raw_readl(MMU_TEA)); #else printk("\n"); #endif printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", regs->regs[0],regs->regs[1], regs->regs[2],regs->regs[3]); printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", regs->regs[4],regs->regs[5], regs->regs[6],regs->regs[7]); printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", regs->regs[8],regs->regs[9], regs->regs[10],regs->regs[11]); printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", regs->regs[12],regs->regs[13], regs->regs[14]); printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", regs->mach, regs->macl, regs->gbr, regs->pr); show_trace(NULL, (unsigned long *)regs->regs[15], regs); show_code(regs); } /* * Create a kernel thread */ __noreturn void kernel_thread_helper(void *arg, int (*fn)(void *)) { do_exit(fn(arg)); } /* Don't use this in BL=1(cli). Or else, CPU resets! */ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) { struct pt_regs regs; int pid; memset(®s, 0, sizeof(regs)); regs.regs[4] = (unsigned long)arg; regs.regs[5] = (unsigned long)fn; regs.pc = (unsigned long)kernel_thread_helper; regs.sr = SR_MD; #if defined(CONFIG_SH_FPU) regs.sr |= SR_FD; #endif /* Ok, create the new process.. */ pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); return pid; } EXPORT_SYMBOL(kernel_thread); void start_thread(struct pt_regs *regs, unsigned long new_pc, unsigned long new_sp) { regs->pr = 0; regs->sr = SR_FD; regs->pc = new_pc; regs->regs[15] = new_sp; free_thread_xstate(current); } EXPORT_SYMBOL(start_thread); /* * Free current thread data structures etc.. */ void exit_thread(void) { } void flush_thread(void) { struct task_struct *tsk = current; flush_ptrace_hw_breakpoint(tsk); #if defined(CONFIG_SH_FPU) /* Forget lazy FPU state */ clear_fpu(tsk, task_pt_regs(tsk)); clear_used_math(); #endif } void release_thread(struct task_struct *dead_task) { /* do nothing */ } /* Fill in the fpu structure for a core dump.. */ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) { int fpvalid = 0; #if defined(CONFIG_SH_FPU) struct task_struct *tsk = current; fpvalid = !!tsk_used_math(tsk); if (fpvalid) fpvalid = !fpregs_get(tsk, NULL, 0, sizeof(struct user_fpu_struct), fpu, NULL); #endif return fpvalid; } EXPORT_SYMBOL(dump_fpu); asmlinkage void ret_from_fork(void); int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long unused, struct task_struct *p, struct pt_regs *regs) { struct thread_info *ti = task_thread_info(p); struct pt_regs *childregs; #if defined(CONFIG_SH_DSP) struct task_struct *tsk = current; if (is_dsp_enabled(tsk)) { /* We can use the __save_dsp or just copy the struct: * __save_dsp(p); * p->thread.dsp_status.status |= SR_DSP */ p->thread.dsp_status = tsk->thread.dsp_status; } #endif childregs = task_pt_regs(p); *childregs = *regs; if (user_mode(regs)) { childregs->regs[15] = usp; ti->addr_limit = USER_DS; } else { childregs->regs[15] = (unsigned long)childregs; ti->addr_limit = KERNEL_DS; ti->status &= ~TS_USEDFPU; p->fpu_counter = 0; } if (clone_flags & CLONE_SETTLS) childregs->gbr = childregs->regs[0]; childregs->regs[0] = 0; /* Set return value for child */ p->thread.sp = (unsigned long) childregs; p->thread.pc = (unsigned long) ret_from_fork; memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); return 0; } /* * switch_to(x,y) should switch tasks from x to y. * */ __notrace_funcgraph struct task_struct * __switch_to(struct task_struct *prev, struct task_struct *next) { struct thread_struct *next_t = &next->thread; #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP) __stack_chk_guard = next->stack_canary; #endif unlazy_fpu(prev, task_pt_regs(prev)); /* we're going to use this soon, after a few expensive things */ if (next->fpu_counter > 5) prefetch(next_t->xstate); #ifdef CONFIG_MMU /* * Restore the kernel mode register * k7 (r7_bank1) */ asm volatile("ldc %0, r7_bank" : /* no output */ : "r" (task_thread_info(next))); #endif /* * If the task has used fpu the last 5 timeslices, just do a full * restore of the math state immediately to avoid the trap; the * chances of needing FPU soon are obviously high now */ if (next->fpu_counter > 5) __fpu_state_restore(); return prev; } asmlinkage int sys_fork(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs __regs) { #ifdef CONFIG_MMU struct pt_regs *regs = RELOC_HIDE(&__regs, 0); return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); #else /* fork almost works, enough to trick you into looking elsewhere :-( */ return -EINVAL; #endif } asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, unsigned long parent_tidptr, unsigned long child_tidptr, struct pt_regs __regs) { struct pt_regs *regs = RELOC_HIDE(&__regs, 0); if (!newsp) newsp = regs->regs[15]; return do_fork(clone_flags, newsp, regs, 0, (int __user *)parent_tidptr, (int __user *)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. */ asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs __regs) { struct pt_regs *regs = RELOC_HIDE(&__regs, 0); return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); } /* * sys_execve() executes a new program. */ asmlinkage int sys_execve(const char __user *ufilename, const char __user *const __user *uargv, const char __user *const __user *uenvp, unsigned long r7, struct pt_regs __regs) { struct pt_regs *regs = RELOC_HIDE(&__regs, 0); int error; char *filename; filename = getname(ufilename); error = PTR_ERR(filename); if (IS_ERR(filename)) goto out; error = do_execve(filename, uargv, uenvp, regs); putname(filename); out: return error; } unsigned long get_wchan(struct task_struct *p) { unsigned long pc; if (!p || p == current || p->state == TASK_RUNNING) return 0; /* * The same comment as on the Alpha applies here, too ... */ pc = thread_saved_pc(p); #ifdef CONFIG_FRAME_POINTER if (in_sched_functions(pc)) { unsigned long schedule_frame = (unsigned long)p->thread.sp; return ((unsigned long *)schedule_frame)[21]; } #endif return pc; }