#include <asm/elf.h>
#include <asm/isadep.h>
#include <asm/inst.h>
+#include <asm/stacktrace.h>
#ifdef CONFIG_MIPS_MT_SMTC
#include <asm/mipsmtregs.h>
extern void smtc_idle_loop_hook(void);
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;
#endif
/* Ok, create the new process.. */
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
+ return do_fork(flags | CLONE_VM | CLONE_UNTRACED | CLONE_KTHREAD,
+ 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;
+ }
+
+ info.func = (void *)(pc - ofs);
+ info.func_size = ofs; /* analyze from start to ofs */
+ leaf = get_frame_info(&info);
+ if (leaf < 0)
return 0;
- stack_page = (unsigned long)task_stack_page(p);
- if (!stack_page || !mfinfo_num)
+ if (*sp < stack_page ||
+ *sp + info.frame_size > stack_page + THREAD_SIZE - 32)
return 0;
- pc = thread_saved_pc(p);
+ 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;
}
-
git://git.onelab.eu / linux-2.6.git / blobdiff