* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2004 Thiemo Seufer
*/
-#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/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/elf.h>
#include <asm/isadep.h>
#include <asm/inst.h>
-#ifdef CONFIG_MIPS_MT_SMTC
-#include <asm/mipsmtregs.h>
-extern void smtc_idle_loop_hook(void);
-#endif /* CONFIG_MIPS_MT_SMTC */
+#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)
+void __noreturn cpu_idle(void)
{
+ int cpu;
+
+ /* CPU is going idle. */
+ cpu = smp_processor_id();
+
/* endless idle loop with no priority at all */
while (1) {
- while (!need_resched()) {
+ tick_nohz_stop_sched_tick(1);
+ while (!need_resched() && cpu_online(cpu)) {
#ifdef CONFIG_MIPS_MT_SMTC
+ extern void smtc_idle_loop_hook(void);
+
smtc_idle_loop_hook();
-#endif /* CONFIG_MIPS_MT_SMTC */
+#endif
if (cpu_wait)
(*cpu_wait)();
}
+#ifdef CONFIG_HOTPLUG_CPU
+ if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map) &&
+ (system_state == SYSTEM_RUNNING ||
+ system_state == SYSTEM_BOOTING))
+ play_dead();
+#endif
+ tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
-/*
- * Native o32 and N64 ABI without DSP ASE
- */
-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
- */
-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
- */
-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);
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);
+ status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
#ifdef CONFIG_64BIT
- status &= ~ST0_FR;
- status |= (current->thread.mflags & MF_32BIT_REGS) ? 0 : ST0_FR;
+ status |= test_thread_flag(TIF_32BIT_REGS) ? 0 : ST0_FR;
#endif
status |= KU_USER;
regs->cp0_status = status;
clear_used_math();
- lose_fpu();
+ clear_fpu_owner();
if (cpu_has_dsp)
__init_dsp();
regs->cp0_epc = pc;
{
}
-int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
+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;
- long childksp;
+ unsigned long childksp;
p->set_child_tid = p->clear_child_tid = NULL;
childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
/* set up new TSS. */
childregs = (struct pt_regs *) childksp - 1;
+ /* Put the stack after the struct pt_regs. */
+ childksp = (unsigned long) childregs;
*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;
*/
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
+#ifdef CONFIG_MIPS_MT_SMTC
/*
- * FPU affinity support is cleaner if we track the
- * user-visible CPU affinity from the very beginning.
- * The generic cpus_allowed mask will already have
- * been copied from the parent before copy_thread
- * is invoked.
+ * SMTC restores TCStatus after Status, and the CU bits
+ * are aliased there.
*/
- p->thread.user_cpus_allowed = p->cpus_allowed;
+ childregs->cp0_tcstatus &= ~(ST0_CU2|ST0_CU1);
+#endif
+ 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)
#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)
{
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));
/*
* Create a kernel thread
*/
-ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
+static void __noreturn kernel_thread_helper(void *arg, int (*fn)(void *))
{
do_exit(fn(arg));
}
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;
+ regs.cp0_status = (regs.cp0_status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
+ ((regs.cp0_status & (ST0_KUC | ST0_IEC)) << 2);
#else
regs.cp0_status |= ST0_EXL;
#endif
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
}
-static struct mips_frame_info {
- void *func;
- unsigned long func_size;
- int frame_size;
- int pc_offset;
-} *schedule_frame, mfinfo[64];
-static int mfinfo_num;
+/*
+ *
+ */
+struct mips_frame_info {
+ void *func;
+ unsigned long func_size;
+ int frame_size;
+ int pc_offset;
+};
-static int __init get_frame_info(struct mips_frame_info *info)
+static inline int is_ra_save_ins(union mips_instruction *ip)
{
- int i;
- void *func = info->func;
- union mips_instruction *ip = (union mips_instruction *)func;
+ /* 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;
+}
+
+static inline int is_jal_jalr_jr_ins(union mips_instruction *ip)
+{
+ 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;
+}
+
+static inline int is_sp_move_ins(union mips_instruction *ip)
+{
+ /* 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;
+ return 0;
+}
+
+static int get_frame_info(struct mips_frame_info *info)
+{
+ union mips_instruction *ip = info->func;
+ unsigned max_insns = info->func_size / sizeof(union mips_instruction);
+ unsigned i;
+
info->pc_offset = -1;
info->frame_size = 0;
- 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;
- if (info->func_size && i >= info->func_size / 4)
+ 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_jal_jalr_jr_ins(ip))
break;
- if (
-#ifdef CONFIG_32BIT
- ip->i_format.opcode == addiu_op &&
-#endif
-#ifdef CONFIG_64BIT
- ip->i_format.opcode == daddiu_op &&
-#endif
- ip->i_format.rs == 29 &&
- ip->i_format.rt == 29) {
- /* addiu/daddiu sp,sp,-imm */
- if (info->frame_size)
- continue;
- info->frame_size = - ip->i_format.simmediate;
+ if (!info->frame_size) {
+ if (is_sp_move_ins(ip))
+ info->frame_size = - ip->i_format.simmediate;
+ continue;
}
-
- if (
-#ifdef CONFIG_32BIT
- ip->i_format.opcode == sw_op &&
-#endif
-#ifdef CONFIG_64BIT
- ip->i_format.opcode == sd_op &&
-#endif
- ip->i_format.rs == 29 &&
- ip->i_format.rt == 31) {
- /* sw / sd $ra, offset($sp) */
- if (info->pc_offset != -1)
- 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_size == 0) {
- if (func == schedule)
- printk("Can't analyze prologue code at %p\n", func);
- info->pc_offset = -1;
- info->frame_size = 0;
- }
-
- return 0;
+ 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;
+
static int __init frame_info_init(void)
{
- int i;
+ unsigned long size = 0;
#ifdef CONFIG_KALLSYMS
- char *modname;
- char namebuf[KSYM_NAME_LEN + 1];
- unsigned long start, size, ofs;
- extern char __sched_text_start[], __sched_text_end[];
- extern char __lock_text_start[], __lock_text_end[];
-
- start = (unsigned long)__sched_text_start;
- for (i = 0; i < ARRAY_SIZE(mfinfo); i++) {
- if (start == (unsigned long)schedule)
- schedule_frame = &mfinfo[i];
- if (!kallsyms_lookup(start, &size, &ofs, &modname, namebuf))
- break;
- mfinfo[i].func = (void *)(start + ofs);
- mfinfo[i].func_size = size;
- start += size - ofs;
- if (start >= (unsigned long)__lock_text_end)
- break;
- if (start == (unsigned long)__sched_text_end)
- start = (unsigned long)__lock_text_start;
- }
-#else
- mfinfo[0].func = schedule;
- schedule_frame = &mfinfo[0];
+ unsigned long ofs;
+
+ kallsyms_lookup_size_offset((unsigned long)schedule, &size, &ofs);
#endif
- for (i = 0; i < ARRAY_SIZE(mfinfo) && mfinfo[i].func; i++)
- get_frame_info(&mfinfo[i]);
+ schedule_mfi.func = schedule;
+ 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);
- mfinfo_num = i;
return 0;
}
/* New born processes are a special case */
if (t->reg31 == (unsigned long) ret_from_fork)
return t->reg31;
-
- if (!schedule_frame || 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
+/* 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 pc;
-#ifdef CONFIG_KALLSYMS
- unsigned long frame;
-#endif
+ struct mips_frame_info info;
+ unsigned long size, ofs;
+ int leaf;
+ extern void ret_from_irq(void);
+ extern void ret_from_exception(void);
+
+ stack_page = (unsigned long)task_stack_page(task);
+ if (!stack_page)
+ return 0;
- if (!p || p == current || p->state == TASK_RUNNING)
+ /*
+ * 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;
+ }
+ if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
return 0;
+ /*
+ * Return ra if an exception occured at the first instruction
+ */
+ if (unlikely(ofs == 0)) {
+ pc = *ra;
+ *ra = 0;
+ return pc;
+ }
- stack_page = (unsigned long)task_stack_page(p);
- if (!stack_page || !mfinfo_num)
+ info.func = (void *)(pc - ofs);
+ info.func_size = ofs; /* analyze from start to ofs */
+ leaf = get_frame_info(&info);
+ if (leaf < 0)
return 0;
- pc = thread_saved_pc(p);
+ if (*sp < stack_page ||
+ *sp + info.frame_size > stack_page + THREAD_SIZE - 32)
+ return 0;
+
+ 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;
+}
+#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
- if (!in_sched_functions(pc))
- return pc;
+ unsigned long sp;
+ unsigned long ra = 0;
+#endif
- frame = p->thread.reg29 + schedule_frame->frame_size;
- do {
- int i;
+ if (!task || task == current || task->state == TASK_RUNNING)
+ goto out;
+ if (!task_stack_page(task))
+ goto out;
- if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32)
- return 0;
+ pc = thread_saved_pc(task);
- for (i = mfinfo_num - 1; i >= 0; i--) {
- if (pc >= (unsigned long) mfinfo[i].func)
- break;
- }
- if (i < 0)
- break;
+#ifdef CONFIG_KALLSYMS
+ sp = task->thread.reg29 + schedule_mfi.frame_size;
- pc = ((unsigned long *)frame)[mfinfo[i].pc_offset];
- if (!mfinfo[i].frame_size)
- break;
- frame += mfinfo[i].frame_size;
- } while (in_sched_functions(pc));
+ 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;
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff