diff options
Diffstat (limited to 'arch/mips/kernel/process.c')
| -rw-r--r-- | arch/mips/kernel/process.c | 649 |
1 files changed, 397 insertions, 252 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 4fe3d5715c4..0a1ec0f3bef 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -4,34 +4,36 @@ * for more details. * * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others. + * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) * Copyright (C) 1999, 2000 Silicon Graphics, Inc. * Copyright (C) 2004 Thiemo Seufer + * Copyright (C) 2013 Imagination Technologies Ltd. */ -#include <linux/config.h> #include <linux/errno.h> -#include <linux/module.h> #include <linux/sched.h> +#include <linux/tick.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/stddef.h> #include <linux/unistd.h> +#include <linux/export.h> #include <linux/ptrace.h> -#include <linux/slab.h> #include <linux/mman.h> #include <linux/personality.h> #include <linux/sys.h> #include <linux/user.h> -#include <linux/a.out.h> #include <linux/init.h> #include <linux/completion.h> +#include <linux/kallsyms.h> +#include <linux/random.h> -#include <asm/abi.h> +#include <asm/asm.h> #include <asm/bootinfo.h> #include <asm/cpu.h> #include <asm/dsp.h> #include <asm/fpu.h> +#include <asm/msa.h> #include <asm/pgtable.h> -#include <asm/system.h> #include <asm/mipsregs.h> #include <asm/processor.h> #include <asm/uaccess.h> @@ -39,92 +41,35 @@ #include <asm/elf.h> #include <asm/isadep.h> #include <asm/inst.h> +#include <asm/stacktrace.h> -/* - * The idle thread. There's no useful work to be done, so just try to conserve - * power and have a low exit latency (ie sit in a loop waiting for somebody to - * say that they'd like to reschedule) - */ -ATTRIB_NORET void cpu_idle(void) +#ifdef CONFIG_HOTPLUG_CPU +void arch_cpu_idle_dead(void) { - /* endless idle loop with no priority at all */ - while (1) { - while (!need_resched()) - if (cpu_wait) - (*cpu_wait)(); - schedule(); - } + /* What the heck is this check doing ? */ + if (!cpu_isset(smp_processor_id(), cpu_callin_map)) + play_dead(); } - -extern int do_signal(sigset_t *oldset, struct pt_regs *regs); -extern int do_signal32(sigset_t *oldset, struct pt_regs *regs); - -/* - * Native o32 and N64 ABI without DSP ASE - */ -extern int setup_frame(struct k_sigaction * ka, struct pt_regs *regs, - int signr, sigset_t *set); -extern int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs, - int signr, sigset_t *set, siginfo_t *info); - -struct mips_abi mips_abi = { - .do_signal = do_signal, -#ifdef CONFIG_TRAD_SIGNALS - .setup_frame = setup_frame, #endif - .setup_rt_frame = setup_rt_frame -}; - -#ifdef CONFIG_MIPS32_O32 -/* - * o32 compatibility on 64-bit kernels, without DSP ASE - */ -extern int setup_frame_32(struct k_sigaction * ka, struct pt_regs *regs, - int signr, sigset_t *set); -extern int setup_rt_frame_32(struct k_sigaction * ka, struct pt_regs *regs, - int signr, sigset_t *set, siginfo_t *info); - -struct mips_abi mips_abi_32 = { - .do_signal = do_signal32, - .setup_frame = setup_frame_32, - .setup_rt_frame = setup_rt_frame_32 -}; -#endif /* CONFIG_MIPS32_O32 */ - -#ifdef CONFIG_MIPS32_N32 -/* - * N32 on 64-bit kernels, without DSP ASE - */ -extern int setup_rt_frame_n32(struct k_sigaction * ka, struct pt_regs *regs, - int signr, sigset_t *set, siginfo_t *info); - -struct mips_abi mips_abi_n32 = { - .do_signal = do_signal, - .setup_rt_frame = setup_rt_frame_n32 -}; -#endif /* CONFIG_MIPS32_N32 */ asmlinkage void ret_from_fork(void); +asmlinkage void ret_from_kernel_thread(void); void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) { unsigned long status; /* New thread loses kernel privileges. */ - status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|KU_MASK); -#ifdef CONFIG_64BIT - status &= ~ST0_FR; - status |= (current->thread.mflags & MF_32BIT_REGS) ? 0 : ST0_FR; -#endif + status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK); status |= KU_USER; regs->cp0_status = status; clear_used_math(); - lose_fpu(); - if (cpu_has_dsp) - __init_dsp(); + clear_fpu_owner(); + init_dsp(); + clear_thread_flag(TIF_MSA_CTX_LIVE); + disable_msa(); regs->cp0_epc = pc; regs->regs[29] = sp; - current_thread_info()->addr_limit = USER_DS; } void exit_thread(void) @@ -135,19 +80,21 @@ void flush_thread(void) { } -int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, - unsigned long unused, struct task_struct *p, struct pt_regs *regs) +int copy_thread(unsigned long clone_flags, unsigned long usp, + unsigned long arg, struct task_struct *p) { - struct thread_info *ti = p->thread_info; - struct pt_regs *childregs; - long childksp; + struct thread_info *ti = task_thread_info(p); + struct pt_regs *childregs, *regs = current_pt_regs(); + unsigned long childksp; p->set_child_tid = p->clear_child_tid = NULL; - childksp = (unsigned long)ti + THREAD_SIZE - 32; + childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; preempt_disable(); - if (is_fpu_owner()) + if (is_msa_enabled()) + save_msa(p); + else if (is_fpu_owner()) save_fp(p); if (cpu_has_dsp) @@ -157,27 +104,33 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, /* set up new TSS. */ childregs = (struct pt_regs *) childksp - 1; - *childregs = *regs; - childregs->regs[7] = 0; /* Clear error flag */ - -#if defined(CONFIG_BINFMT_IRIX) - if (current->personality != PER_LINUX) { - /* Under IRIX things are a little different. */ - childregs->regs[3] = 1; - regs->regs[3] = 0; - } -#endif - childregs->regs[2] = 0; /* Child gets zero as return value */ - regs->regs[2] = p->pid; - - if (childregs->cp0_status & ST0_CU0) { - childregs->regs[28] = (unsigned long) ti; - childregs->regs[29] = childksp; + /* Put the stack after the struct pt_regs. */ + childksp = (unsigned long) childregs; + p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); + if (unlikely(p->flags & PF_KTHREAD)) { + unsigned long status = p->thread.cp0_status; + memset(childregs, 0, sizeof(struct pt_regs)); ti->addr_limit = KERNEL_DS; - } else { - childregs->regs[29] = usp; - ti->addr_limit = USER_DS; + p->thread.reg16 = usp; /* fn */ + p->thread.reg17 = arg; + p->thread.reg29 = childksp; + p->thread.reg31 = (unsigned long) ret_from_kernel_thread; +#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) + status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | + ((status & (ST0_KUC | ST0_IEC)) << 2); +#else + status |= ST0_EXL; +#endif + childregs->cp0_status = status; + return 0; } + *childregs = *regs; + childregs->regs[7] = 0; /* Clear error flag */ + childregs->regs[2] = 0; /* Child gets zero as return value */ + if (usp) + childregs->regs[29] = usp; + ti->addr_limit = USER_DS; + p->thread.reg29 = (unsigned long) childregs; p->thread.reg31 = (unsigned long) ret_from_fork; @@ -185,10 +138,14 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, * New tasks lose permission to use the fpu. This accelerates context * switching for most programs since they don't use the fpu. */ - p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); + clear_tsk_thread_flag(p, TIF_USEDFPU); +#ifdef CONFIG_MIPS_MT_FPAFF + clear_tsk_thread_flag(p, TIF_FPUBOUND); +#endif /* CONFIG_MIPS_MT_FPAFF */ + if (clone_flags & CLONE_SETTLS) ti->tp_value = regs->regs[7]; @@ -198,12 +155,18 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, /* Fill in the fpu structure for a core dump.. */ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) { - memcpy(r, ¤t->thread.fpu, sizeof(current->thread.fpu)); + int i; + + for (i = 0; i < NUM_FPU_REGS; i++) + memcpy(&r[i], ¤t->thread.fpu.fpr[i], sizeof(*r)); + + memcpy(&r[NUM_FPU_REGS], ¤t->thread.fpu.fcr31, + sizeof(current->thread.fpu.fcr31)); return 1; } -void dump_regs(elf_greg_t *gp, struct pt_regs *regs) +void elf_dump_regs(elf_greg_t *gp, struct pt_regs *regs) { int i; @@ -225,158 +188,259 @@ void dump_regs(elf_greg_t *gp, struct pt_regs *regs) #endif } -int dump_task_regs (struct task_struct *tsk, elf_gregset_t *regs) +int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) { - struct thread_info *ti = tsk->thread_info; - long ksp = (unsigned long)ti + THREAD_SIZE - 32; - dump_regs(&(*regs)[0], (struct pt_regs *) ksp - 1); + elf_dump_regs(*regs, task_pt_regs(tsk)); return 1; } -int dump_task_fpu (struct task_struct *t, elf_fpregset_t *fpr) +int dump_task_fpu(struct task_struct *t, elf_fpregset_t *fpr) { - memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu)); + int i; + + for (i = 0; i < NUM_FPU_REGS; i++) + memcpy(&fpr[i], &t->thread.fpu.fpr[i], sizeof(*fpr)); + + memcpy(&fpr[NUM_FPU_REGS], &t->thread.fpu.fcr31, + sizeof(t->thread.fpu.fcr31)); return 1; } -/* - * Create a kernel thread - */ -ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)) +#ifdef CONFIG_CC_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + +struct mips_frame_info { + void *func; + unsigned long func_size; + int frame_size; + int pc_offset; +}; + +#define J_TARGET(pc,target) \ + (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) + +static inline int is_ra_save_ins(union mips_instruction *ip) { - do_exit(fn(arg)); +#ifdef CONFIG_CPU_MICROMIPS + union mips_instruction mmi; + + /* + * swsp ra,offset + * swm16 reglist,offset(sp) + * swm32 reglist,offset(sp) + * sw32 ra,offset(sp) + * jradiussp - NOT SUPPORTED + * + * microMIPS is way more fun... + */ + if (mm_insn_16bit(ip->halfword[0])) { + mmi.word = (ip->halfword[0] << 16); + return ((mmi.mm16_r5_format.opcode == mm_swsp16_op && + mmi.mm16_r5_format.rt == 31) || + (mmi.mm16_m_format.opcode == mm_pool16c_op && + mmi.mm16_m_format.func == mm_swm16_op)); + } + else { + mmi.halfword[0] = ip->halfword[1]; + mmi.halfword[1] = ip->halfword[0]; + return ((mmi.mm_m_format.opcode == mm_pool32b_op && + mmi.mm_m_format.rd > 9 && + mmi.mm_m_format.base == 29 && + mmi.mm_m_format.func == mm_swm32_func) || + (mmi.i_format.opcode == mm_sw32_op && + mmi.i_format.rs == 29 && + mmi.i_format.rt == 31)); + } +#else + /* sw / sd $ra, offset($sp) */ + return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && + ip->i_format.rs == 29 && + ip->i_format.rt == 31; +#endif } -long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) +static inline int is_jump_ins(union mips_instruction *ip) { - struct pt_regs regs; +#ifdef CONFIG_CPU_MICROMIPS + /* + * jr16,jrc,jalr16,jalr16 + * jal + * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb + * jraddiusp - NOT SUPPORTED + * + * microMIPS is kind of more fun... + */ + union mips_instruction mmi; - memset(®s, 0, sizeof(regs)); + mmi.word = (ip->halfword[0] << 16); - regs.regs[4] = (unsigned long) arg; - regs.regs[5] = (unsigned long) fn; - regs.cp0_epc = (unsigned long) kernel_thread_helper; - regs.cp0_status = read_c0_status(); -#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) - regs.cp0_status &= ~(ST0_KUP | ST0_IEC); - regs.cp0_status |= ST0_IEP; + if ((mmi.mm16_r5_format.opcode == mm_pool16c_op && + (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) || + ip->j_format.opcode == mm_jal32_op) + return 1; + if (ip->r_format.opcode != mm_pool32a_op || + ip->r_format.func != mm_pool32axf_op) + return 0; + return (((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op); #else - regs.cp0_status |= ST0_EXL; + if (ip->j_format.opcode == j_op) + return 1; + if (ip->j_format.opcode == jal_op) + return 1; + if (ip->r_format.opcode != spec_op) + return 0; + return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; #endif - - /* Ok, create the new process.. */ - return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } -static struct mips_frame_info { - void *func; - int omit_fp; /* compiled without fno-omit-frame-pointer */ - int frame_offset; - int pc_offset; -} schedule_frame, mfinfo[] = { - { schedule, 0 }, /* must be first */ - /* arch/mips/kernel/semaphore.c */ - { __down, 1 }, - { __down_interruptible, 1 }, - /* kernel/sched.c */ -#ifdef CONFIG_PREEMPT - { preempt_schedule, 0 }, -#endif - { wait_for_completion, 0 }, - { interruptible_sleep_on, 0 }, - { interruptible_sleep_on_timeout, 0 }, - { sleep_on, 0 }, - { sleep_on_timeout, 0 }, - { yield, 0 }, - { io_schedule, 0 }, - { io_schedule_timeout, 0 }, -#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) - { __preempt_spin_lock, 0 }, - { __preempt_write_lock, 0 }, +static inline int is_sp_move_ins(union mips_instruction *ip) +{ +#ifdef CONFIG_CPU_MICROMIPS + /* + * addiusp -imm + * addius5 sp,-imm + * addiu32 sp,sp,-imm + * jradiussp - NOT SUPPORTED + * + * microMIPS is not more fun... + */ + if (mm_insn_16bit(ip->halfword[0])) { + union mips_instruction mmi; + + mmi.word = (ip->halfword[0] << 16); + return ((mmi.mm16_r3_format.opcode == mm_pool16d_op && + mmi.mm16_r3_format.simmediate && mm_addiusp_func) || + (mmi.mm16_r5_format.opcode == mm_pool16d_op && + mmi.mm16_r5_format.rt == 29)); + } + return (ip->mm_i_format.opcode == mm_addiu32_op && + ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29); +#else + /* addiu/daddiu sp,sp,-imm */ + if (ip->i_format.rs != 29 || ip->i_format.rt != 29) + return 0; + if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) + return 1; #endif - /* kernel/timer.c */ - { schedule_timeout, 1 }, -/* { nanosleep_restart, 1 }, */ - /* lib/rwsem-spinlock.c */ - { __down_read, 1 }, - { __down_write, 1 }, -}; + return 0; +} -static int mips_frame_info_initialized; -static int __init get_frame_info(struct mips_frame_info *info) +static int get_frame_info(struct mips_frame_info *info) { - int i; - void *func = info->func; - union mips_instruction *ip = (union mips_instruction *)func; +#ifdef CONFIG_CPU_MICROMIPS + union mips_instruction *ip = (void *) (((char *) info->func) - 1); +#else + union mips_instruction *ip = info->func; +#endif + unsigned max_insns = info->func_size / sizeof(union mips_instruction); + unsigned i; + info->pc_offset = -1; - info->frame_offset = info->omit_fp ? 0 : -1; - for (i = 0; i < 128; i++, ip++) { - /* if jal, jalr, jr, stop. */ - if (ip->j_format.opcode == jal_op || - (ip->r_format.opcode == spec_op && - (ip->r_format.func == jalr_op || - ip->r_format.func == jr_op))) - break; + info->frame_size = 0; - if ( -#ifdef CONFIG_32BIT - ip->i_format.opcode == sw_op && -#endif -#ifdef CONFIG_64BIT - ip->i_format.opcode == sd_op && + if (!ip) + goto err; + + if (max_insns == 0) + max_insns = 128U; /* unknown function size */ + max_insns = min(128U, max_insns); + + for (i = 0; i < max_insns; i++, ip++) { + + if (is_jump_ins(ip)) + break; + if (!info->frame_size) { + if (is_sp_move_ins(ip)) + { +#ifdef CONFIG_CPU_MICROMIPS + if (mm_insn_16bit(ip->halfword[0])) + { + unsigned short tmp; + + if (ip->halfword[0] & mm_addiusp_func) + { + tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2); + info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0)); + } else { + tmp = (ip->halfword[0] >> 1); + info->frame_size = -(signed short)(tmp & 0xf); + } + ip = (void *) &ip->halfword[1]; + ip--; + } else #endif - ip->i_format.rs == 29) - { - /* sw / sd $ra, offset($sp) */ - if (ip->i_format.rt == 31) { - if (info->pc_offset != -1) - continue; - info->pc_offset = - ip->i_format.simmediate / sizeof(long); - } - /* sw / sd $s8, offset($sp) */ - if (ip->i_format.rt == 30) { -//#if 0 /* gcc 3.4 does aggressive optimization... */ - if (info->frame_offset != -1) - continue; -//#endif - info->frame_offset = - ip->i_format.simmediate / sizeof(long); + info->frame_size = - ip->i_format.simmediate; } + continue; + } + if (info->pc_offset == -1 && is_ra_save_ins(ip)) { + info->pc_offset = + ip->i_format.simmediate / sizeof(long); + break; } } - if (info->pc_offset == -1 || info->frame_offset == -1) { - printk("Can't analyze prologue code at %p\n", func); - info->pc_offset = -1; - info->frame_offset = -1; - return -1; - } + if (info->frame_size && info->pc_offset >= 0) /* nested */ + return 0; + if (info->pc_offset < 0) /* leaf */ + return 1; + /* prologue seems boggus... */ +err: + return -1; +} + +static struct mips_frame_info schedule_mfi __read_mostly; + +#ifdef CONFIG_KALLSYMS +static unsigned long get___schedule_addr(void) +{ + return kallsyms_lookup_name("__schedule"); +} +#else +static unsigned long get___schedule_addr(void) +{ + union mips_instruction *ip = (void *)schedule; + int max_insns = 8; + int i; + for (i = 0; i < max_insns; i++, ip++) { + if (ip->j_format.opcode == j_op) + return J_TARGET(ip, ip->j_format.target); + } return 0; } +#endif static int __init frame_info_init(void) { - int i, found; - for (i = 0; i < ARRAY_SIZE(mfinfo); i++) - if (get_frame_info(&mfinfo[i])) - return -1; - schedule_frame = mfinfo[0]; - /* bubble sort */ - do { - struct mips_frame_info tmp; - found = 0; - for (i = 1; i < ARRAY_SIZE(mfinfo); i++) { - if (mfinfo[i-1].func > mfinfo[i].func) { - tmp = mfinfo[i]; - mfinfo[i] = mfinfo[i-1]; - mfinfo[i-1] = tmp; - found = 1; - } - } - } while (found); - mips_frame_info_initialized = 1; + unsigned long size = 0; +#ifdef CONFIG_KALLSYMS + unsigned long ofs; +#endif + unsigned long addr; + + addr = get___schedule_addr(); + if (!addr) + addr = (unsigned long)schedule; + +#ifdef CONFIG_KALLSYMS + kallsyms_lookup_size_offset(addr, &size, &ofs); +#endif + schedule_mfi.func = (void *)addr; + schedule_mfi.func_size = size; + + get_frame_info(&schedule_mfi); + + /* + * Without schedule() frame info, result given by + * thread_saved_pc() and get_wchan() are not reliable. + */ + if (schedule_mfi.pc_offset < 0) + printk("Can't analyze schedule() prologue at %p\n", schedule); + return 0; } @@ -392,50 +456,131 @@ unsigned long thread_saved_pc(struct task_struct *tsk) /* New born processes are a special case */ if (t->reg31 == (unsigned long) ret_from_fork) return t->reg31; - - if (schedule_frame.pc_offset < 0) + if (schedule_mfi.pc_offset < 0) return 0; - return ((unsigned long *)t->reg29)[schedule_frame.pc_offset]; + return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; } -/* get_wchan - a maintenance nightmare^W^Wpain in the ass ... */ -unsigned long get_wchan(struct task_struct *p) + +#ifdef CONFIG_KALLSYMS +/* generic stack unwinding function */ +unsigned long notrace unwind_stack_by_address(unsigned long stack_page, + unsigned long *sp, + unsigned long pc, + unsigned long *ra) { - unsigned long stack_page; - unsigned long frame, pc; + struct mips_frame_info info; + unsigned long size, ofs; + int leaf; + extern void ret_from_irq(void); + extern void ret_from_exception(void); - if (!p || p == current || p->state == TASK_RUNNING) + if (!stack_page) return 0; - stack_page = (unsigned long)p->thread_info; - if (!stack_page || !mips_frame_info_initialized) + /* + * If we reached the bottom of interrupt context, + * return saved pc in pt_regs. + */ + if (pc == (unsigned long)ret_from_irq || + pc == (unsigned long)ret_from_exception) { + struct pt_regs *regs; + if (*sp >= stack_page && + *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { + regs = (struct pt_regs *)*sp; + pc = regs->cp0_epc; + if (__kernel_text_address(pc)) { + *sp = regs->regs[29]; + *ra = regs->regs[31]; + return pc; + } + } return 0; - - pc = thread_saved_pc(p); - if (!in_sched_functions(pc)) + } + if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) + return 0; + /* + * Return ra if an exception occurred at the first instruction + */ + if (unlikely(ofs == 0)) { + pc = *ra; + *ra = 0; return pc; + } - frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset]; - do { - int i; + info.func = (void *)(pc - ofs); + info.func_size = ofs; /* analyze from start to ofs */ + leaf = get_frame_info(&info); + if (leaf < 0) + return 0; - if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32) - return 0; + if (*sp < stack_page || + *sp + info.frame_size > stack_page + THREAD_SIZE - 32) + return 0; - for (i = ARRAY_SIZE(mfinfo) - 1; i >= 0; i--) { - if (pc >= (unsigned long) mfinfo[i].func) - break; - } - if (i < 0) - break; + if (leaf) + /* + * For some extreme cases, get_frame_info() can + * consider wrongly a nested function as a leaf + * one. In that cases avoid to return always the + * same value. + */ + pc = pc != *ra ? *ra : 0; + else + pc = ((unsigned long *)(*sp))[info.pc_offset]; + + *sp += info.frame_size; + *ra = 0; + return __kernel_text_address(pc) ? pc : 0; +} +EXPORT_SYMBOL(unwind_stack_by_address); - if (mfinfo[i].omit_fp) - break; - pc = ((unsigned long *)frame)[mfinfo[i].pc_offset]; - frame = ((unsigned long *)frame)[mfinfo[i].frame_offset]; - } while (in_sched_functions(pc)); +/* used by show_backtrace() */ +unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, + unsigned long pc, unsigned long *ra) +{ + unsigned long stack_page = (unsigned long)task_stack_page(task); + return unwind_stack_by_address(stack_page, sp, pc, ra); +} +#endif + +/* + * get_wchan - a maintenance nightmare^W^Wpain in the ass ... + */ +unsigned long get_wchan(struct task_struct *task) +{ + unsigned long pc = 0; +#ifdef CONFIG_KALLSYMS + unsigned long sp; + unsigned long ra = 0; +#endif + + if (!task || task == current || task->state == TASK_RUNNING) + goto out; + if (!task_stack_page(task)) + 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; } -EXPORT_SYMBOL(get_wchan); +/* + * 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; +} |