535 lines
13 KiB
C
535 lines
13 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
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* Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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* Copyright (C) 2004 Thiemo Seufer
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* Copyright (C) 2013 Imagination Technologies Ltd.
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*/
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/tick.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/export.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/personality.h>
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#include <linux/sys.h>
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#include <linux/init.h>
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#include <linux/completion.h>
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#include <linux/kallsyms.h>
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#include <linux/random.h>
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#include <asm/asm.h>
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#include <asm/bootinfo.h>
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#include <asm/cpu.h>
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#include <asm/dsp.h>
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#include <asm/fpu.h>
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#include <asm/msa.h>
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#include <asm/pgtable.h>
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#include <asm/mipsregs.h>
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#include <asm/processor.h>
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#include <asm/reg.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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#include <asm/elf.h>
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#include <asm/isadep.h>
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#include <asm/inst.h>
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#include <asm/stacktrace.h>
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#ifdef CONFIG_HOTPLUG_CPU
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void arch_cpu_idle_dead(void)
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{
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/* What the heck is this check doing ? */
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if (!cpu_isset(smp_processor_id(), cpu_callin_map))
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play_dead();
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}
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#endif
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asmlinkage void ret_from_fork(void);
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asmlinkage void ret_from_kernel_thread(void);
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void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
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{
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unsigned long status;
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/* New thread loses kernel privileges. */
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status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
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status |= KU_USER;
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regs->cp0_status = status;
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clear_used_math();
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clear_fpu_owner();
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init_dsp();
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clear_thread_flag(TIF_USEDMSA);
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clear_thread_flag(TIF_MSA_CTX_LIVE);
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disable_msa();
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regs->cp0_epc = pc;
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regs->regs[29] = sp;
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}
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void exit_thread(void)
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{
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}
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void flush_thread(void)
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{
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}
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int copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long arg, struct task_struct *p)
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{
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struct thread_info *ti = task_thread_info(p);
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struct pt_regs *childregs, *regs = current_pt_regs();
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unsigned long childksp;
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p->set_child_tid = p->clear_child_tid = NULL;
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childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
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preempt_disable();
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if (is_msa_enabled())
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save_msa(p);
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else if (is_fpu_owner())
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save_fp(p);
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if (cpu_has_dsp)
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save_dsp(p);
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preempt_enable();
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/* set up new TSS. */
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childregs = (struct pt_regs *) childksp - 1;
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/* Put the stack after the struct pt_regs. */
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childksp = (unsigned long) childregs;
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p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
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if (unlikely(p->flags & PF_KTHREAD)) {
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unsigned long status = p->thread.cp0_status;
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memset(childregs, 0, sizeof(struct pt_regs));
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ti->addr_limit = KERNEL_DS;
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p->thread.reg16 = usp; /* fn */
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p->thread.reg17 = arg;
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p->thread.reg29 = childksp;
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p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
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#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
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status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
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((status & (ST0_KUC | ST0_IEC)) << 2);
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#else
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status |= ST0_EXL;
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#endif
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childregs->cp0_status = status;
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return 0;
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}
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*childregs = *regs;
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childregs->regs[7] = 0; /* Clear error flag */
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childregs->regs[2] = 0; /* Child gets zero as return value */
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if (usp)
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childregs->regs[29] = usp;
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ti->addr_limit = USER_DS;
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p->thread.reg29 = (unsigned long) childregs;
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p->thread.reg31 = (unsigned long) ret_from_fork;
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/*
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* New tasks lose permission to use the fpu. This accelerates context
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* switching for most programs since they don't use the fpu.
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*/
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childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
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clear_tsk_thread_flag(p, TIF_USEDFPU);
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clear_tsk_thread_flag(p, TIF_USEDMSA);
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clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE);
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#ifdef CONFIG_MIPS_MT_FPAFF
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clear_tsk_thread_flag(p, TIF_FPUBOUND);
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#endif /* CONFIG_MIPS_MT_FPAFF */
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if (clone_flags & CLONE_SETTLS)
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ti->tp_value = regs->regs[7];
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return 0;
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}
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#ifdef CONFIG_CC_STACKPROTECTOR
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#include <linux/stackprotector.h>
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unsigned long __stack_chk_guard __read_mostly;
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EXPORT_SYMBOL(__stack_chk_guard);
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#endif
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struct mips_frame_info {
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void *func;
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unsigned long func_size;
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int frame_size;
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int pc_offset;
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};
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#define J_TARGET(pc,target) \
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(((unsigned long)(pc) & 0xf0000000) | ((target) << 2))
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static inline int is_ra_save_ins(union mips_instruction *ip)
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{
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#ifdef CONFIG_CPU_MICROMIPS
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union mips_instruction mmi;
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/*
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* swsp ra,offset
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* swm16 reglist,offset(sp)
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* swm32 reglist,offset(sp)
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* sw32 ra,offset(sp)
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* jradiussp - NOT SUPPORTED
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*
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* microMIPS is way more fun...
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*/
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if (mm_insn_16bit(ip->halfword[0])) {
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mmi.word = (ip->halfword[0] << 16);
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return ((mmi.mm16_r5_format.opcode == mm_swsp16_op &&
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mmi.mm16_r5_format.rt == 31) ||
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(mmi.mm16_m_format.opcode == mm_pool16c_op &&
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mmi.mm16_m_format.func == mm_swm16_op));
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}
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else {
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mmi.halfword[0] = ip->halfword[1];
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mmi.halfword[1] = ip->halfword[0];
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return ((mmi.mm_m_format.opcode == mm_pool32b_op &&
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mmi.mm_m_format.rd > 9 &&
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mmi.mm_m_format.base == 29 &&
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mmi.mm_m_format.func == mm_swm32_func) ||
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(mmi.i_format.opcode == mm_sw32_op &&
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mmi.i_format.rs == 29 &&
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mmi.i_format.rt == 31));
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}
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#else
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/* sw / sd $ra, offset($sp) */
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return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
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ip->i_format.rs == 29 &&
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ip->i_format.rt == 31;
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#endif
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}
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static inline int is_jump_ins(union mips_instruction *ip)
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{
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#ifdef CONFIG_CPU_MICROMIPS
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/*
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* jr16,jrc,jalr16,jalr16
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* jal
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* jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb
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* jraddiusp - NOT SUPPORTED
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*
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* microMIPS is kind of more fun...
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*/
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union mips_instruction mmi;
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mmi.word = (ip->halfword[0] << 16);
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if ((mmi.mm16_r5_format.opcode == mm_pool16c_op &&
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(mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) ||
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ip->j_format.opcode == mm_jal32_op)
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return 1;
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if (ip->r_format.opcode != mm_pool32a_op ||
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ip->r_format.func != mm_pool32axf_op)
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return 0;
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return (((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op);
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#else
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if (ip->j_format.opcode == j_op)
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return 1;
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if (ip->j_format.opcode == jal_op)
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return 1;
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if (ip->r_format.opcode != spec_op)
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return 0;
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return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
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#endif
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}
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static inline int is_sp_move_ins(union mips_instruction *ip)
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{
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#ifdef CONFIG_CPU_MICROMIPS
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/*
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* addiusp -imm
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* addius5 sp,-imm
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* addiu32 sp,sp,-imm
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* jradiussp - NOT SUPPORTED
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*
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* microMIPS is not more fun...
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*/
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if (mm_insn_16bit(ip->halfword[0])) {
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union mips_instruction mmi;
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mmi.word = (ip->halfword[0] << 16);
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return ((mmi.mm16_r3_format.opcode == mm_pool16d_op &&
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mmi.mm16_r3_format.simmediate && mm_addiusp_func) ||
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(mmi.mm16_r5_format.opcode == mm_pool16d_op &&
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mmi.mm16_r5_format.rt == 29));
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}
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return (ip->mm_i_format.opcode == mm_addiu32_op &&
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ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29);
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#else
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/* addiu/daddiu sp,sp,-imm */
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if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
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return 0;
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if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
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return 1;
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#endif
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return 0;
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}
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static int get_frame_info(struct mips_frame_info *info)
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{
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#ifdef CONFIG_CPU_MICROMIPS
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union mips_instruction *ip = (void *) (((char *) info->func) - 1);
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#else
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union mips_instruction *ip = info->func;
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#endif
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unsigned max_insns = info->func_size / sizeof(union mips_instruction);
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unsigned i;
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info->pc_offset = -1;
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info->frame_size = 0;
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if (!ip)
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goto err;
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if (max_insns == 0)
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max_insns = 128U; /* unknown function size */
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max_insns = min(128U, max_insns);
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for (i = 0; i < max_insns; i++, ip++) {
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if (is_jump_ins(ip))
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break;
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if (!info->frame_size) {
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if (is_sp_move_ins(ip))
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{
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#ifdef CONFIG_CPU_MICROMIPS
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if (mm_insn_16bit(ip->halfword[0]))
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{
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unsigned short tmp;
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if (ip->halfword[0] & mm_addiusp_func)
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{
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tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2);
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info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0));
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} else {
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tmp = (ip->halfword[0] >> 1);
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info->frame_size = -(signed short)(tmp & 0xf);
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}
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ip = (void *) &ip->halfword[1];
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ip--;
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} else
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#endif
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info->frame_size = - ip->i_format.simmediate;
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}
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continue;
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}
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if (info->pc_offset == -1 && is_ra_save_ins(ip)) {
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info->pc_offset =
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ip->i_format.simmediate / sizeof(long);
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break;
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}
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}
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if (info->frame_size && info->pc_offset >= 0) /* nested */
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return 0;
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if (info->pc_offset < 0) /* leaf */
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return 1;
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/* prologue seems boggus... */
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err:
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return -1;
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}
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static struct mips_frame_info schedule_mfi __read_mostly;
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#ifdef CONFIG_KALLSYMS
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static unsigned long get___schedule_addr(void)
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{
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return kallsyms_lookup_name("__schedule");
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}
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#else
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static unsigned long get___schedule_addr(void)
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{
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union mips_instruction *ip = (void *)schedule;
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int max_insns = 8;
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int i;
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for (i = 0; i < max_insns; i++, ip++) {
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if (ip->j_format.opcode == j_op)
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return J_TARGET(ip, ip->j_format.target);
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}
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return 0;
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}
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#endif
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static int __init frame_info_init(void)
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{
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unsigned long size = 0;
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#ifdef CONFIG_KALLSYMS
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unsigned long ofs;
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#endif
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unsigned long addr;
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addr = get___schedule_addr();
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if (!addr)
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addr = (unsigned long)schedule;
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#ifdef CONFIG_KALLSYMS
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kallsyms_lookup_size_offset(addr, &size, &ofs);
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#endif
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schedule_mfi.func = (void *)addr;
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schedule_mfi.func_size = size;
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get_frame_info(&schedule_mfi);
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/*
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* Without schedule() frame info, result given by
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* thread_saved_pc() and get_wchan() are not reliable.
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*/
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if (schedule_mfi.pc_offset < 0)
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printk("Can't analyze schedule() prologue at %p\n", schedule);
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return 0;
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}
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arch_initcall(frame_info_init);
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/*
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* Return saved PC of a blocked thread.
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*/
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unsigned long thread_saved_pc(struct task_struct *tsk)
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{
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struct thread_struct *t = &tsk->thread;
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/* New born processes are a special case */
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if (t->reg31 == (unsigned long) ret_from_fork)
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return t->reg31;
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if (schedule_mfi.pc_offset < 0)
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return 0;
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return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset];
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}
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#ifdef CONFIG_KALLSYMS
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/* generic stack unwinding function */
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unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
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unsigned long *sp,
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unsigned long pc,
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unsigned long *ra)
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{
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struct mips_frame_info info;
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unsigned long size, ofs;
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int leaf;
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extern void ret_from_irq(void);
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extern void ret_from_exception(void);
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if (!stack_page)
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return 0;
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/*
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* If we reached the bottom of interrupt context,
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* return saved pc in pt_regs.
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*/
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if (pc == (unsigned long)ret_from_irq ||
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pc == (unsigned long)ret_from_exception) {
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struct pt_regs *regs;
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if (*sp >= stack_page &&
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*sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) {
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regs = (struct pt_regs *)*sp;
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pc = regs->cp0_epc;
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if (__kernel_text_address(pc)) {
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*sp = regs->regs[29];
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*ra = regs->regs[31];
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return pc;
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}
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}
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return 0;
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}
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if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
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return 0;
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/*
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* Return ra if an exception occurred at the first instruction
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*/
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if (unlikely(ofs == 0)) {
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pc = *ra;
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*ra = 0;
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return pc;
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}
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info.func = (void *)(pc - ofs);
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info.func_size = ofs; /* analyze from start to ofs */
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leaf = get_frame_info(&info);
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if (leaf < 0)
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return 0;
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if (*sp < stack_page ||
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*sp + info.frame_size > stack_page + THREAD_SIZE - 32)
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return 0;
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if (leaf)
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/*
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* For some extreme cases, get_frame_info() can
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* consider wrongly a nested function as a leaf
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* one. In that cases avoid to return always the
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* same value.
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*/
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pc = pc != *ra ? *ra : 0;
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else
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pc = ((unsigned long *)(*sp))[info.pc_offset];
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*sp += info.frame_size;
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*ra = 0;
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return __kernel_text_address(pc) ? pc : 0;
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}
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EXPORT_SYMBOL(unwind_stack_by_address);
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/* used by show_backtrace() */
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unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
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unsigned long pc, unsigned long *ra)
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{
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unsigned long stack_page = (unsigned long)task_stack_page(task);
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return unwind_stack_by_address(stack_page, sp, pc, ra);
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}
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#endif
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/*
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* get_wchan - a maintenance nightmare^W^Wpain in the ass ...
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*/
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unsigned long get_wchan(struct task_struct *task)
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{
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unsigned long pc = 0;
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#ifdef CONFIG_KALLSYMS
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unsigned long sp;
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unsigned long ra = 0;
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#endif
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if (!task || task == current || task->state == TASK_RUNNING)
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goto out;
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if (!task_stack_page(task))
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goto out;
|
|
|
|
pc = thread_saved_pc(task);
|
|
|
|
#ifdef CONFIG_KALLSYMS
|
|
sp = task->thread.reg29 + schedule_mfi.frame_size;
|
|
|
|
while (in_sched_functions(pc))
|
|
pc = unwind_stack(task, &sp, pc, &ra);
|
|
#endif
|
|
|
|
out:
|
|
return pc;
|
|
}
|
|
|
|
/*
|
|
* Don't forget that the stack pointer must be aligned on a 8 bytes
|
|
* boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
|
|
*/
|
|
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 & ALMASK;
|
|
}
|