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Diffstat (limited to 'arch/mips/kernel/process.c')
-rw-r--r--arch/mips/kernel/process.c132
1 files changed, 50 insertions, 82 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index b160ea30de0..2613a0dd4b8 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -273,13 +273,15 @@ long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 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 inline int is_ra_save_ins(union mips_instruction *ip)
{
@@ -348,45 +350,30 @@ 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
+ unsigned long ofs;
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];
+
+ kallsyms_lookup((unsigned long)schedule, &size, &ofs, &modname, namebuf);
#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_frame->pc_offset < 0)
+ if (schedule_mfi.pc_offset < 0)
printk("Can't analyze schedule() prologue at %p\n", schedule);
- mfinfo_num = i;
return 0;
}
@@ -402,58 +389,11 @@ 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 || 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)
-{
- unsigned long stack_page;
- unsigned long pc;
-#ifdef CONFIG_KALLSYMS
- unsigned long frame;
-#endif
-
- if (!p || p == current || p->state == TASK_RUNNING)
- return 0;
-
- stack_page = (unsigned long)task_stack_page(p);
- if (!stack_page || !mfinfo_num)
- return 0;
-
- pc = thread_saved_pc(p);
-#ifdef CONFIG_KALLSYMS
- if (!in_sched_functions(pc))
- return pc;
-
- frame = p->thread.reg29 + schedule_frame->frame_size;
- do {
- int i;
-
- if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32)
- return 0;
-
- for (i = mfinfo_num - 1; i >= 0; i--) {
- if (pc >= (unsigned long) mfinfo[i].func)
- break;
- }
- if (i < 0)
- break;
-
- if (mfinfo[i].pc_offset < 0)
- break;
- pc = ((unsigned long *)frame)[mfinfo[i].pc_offset];
- if (!mfinfo[i].frame_size)
- break;
- frame += mfinfo[i].frame_size;
- } while (in_sched_functions(pc));
-#endif
-
- return pc;
-}
#ifdef CONFIG_KALLSYMS
/* used by show_backtrace() */
@@ -504,3 +444,31 @@ unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
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
+ unsigned long sp;
+#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, 0);
+#endif
+
+out:
+ return pc;
+}