[MIPS] Rewrite get_wchan and its helper functions using kallsyms_lookup.
Implement get_wchan() and frame_info_init() using kallsyms_lookup().
This fixes problem with static sched/lock functions and mfinfo[]
maintenance issue. If CONFIG_KALLSYMS was disabled, get_wchan() just
returns thread_saved_pc() value.
Also unwind stackframe based on "addiu sp,-imm" analysis instead of
frame pointer. This fixes problem with functions compiled without
-fomit-frame-pointer.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Atsushi Nemoto
Ralf Baechle
Родитель
1bdfd0d963
Коммит
6307751989
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@ -25,6 +25,7 @@
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#include <linux/a.out.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 <asm/abi.h>
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#include <asm/bootinfo.h>
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@ -272,46 +273,19 @@ long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
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static struct mips_frame_info {
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void *func;
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int omit_fp; /* compiled without fno-omit-frame-pointer */
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int frame_offset;
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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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} schedule_frame, mfinfo[] = {
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{ schedule, 0 }, /* must be first */
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/* arch/mips/kernel/semaphore.c */
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{ __down, 1 },
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{ __down_interruptible, 1 },
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/* kernel/sched.c */
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#ifdef CONFIG_PREEMPT
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{ preempt_schedule, 0 },
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#endif
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{ wait_for_completion, 0 },
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{ interruptible_sleep_on, 0 },
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{ interruptible_sleep_on_timeout, 0 },
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{ sleep_on, 0 },
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{ sleep_on_timeout, 0 },
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{ yield, 0 },
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{ io_schedule, 0 },
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{ io_schedule_timeout, 0 },
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#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
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{ __preempt_spin_lock, 0 },
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{ __preempt_write_lock, 0 },
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#endif
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/* kernel/timer.c */
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{ schedule_timeout, 1 },
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/* { nanosleep_restart, 1 }, */
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/* lib/rwsem-spinlock.c */
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{ __down_read, 1 },
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{ __down_write, 1 },
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};
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} *schedule_frame, mfinfo[64];
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static int mfinfo_num;
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static int mips_frame_info_initialized;
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static int __init get_frame_info(struct mips_frame_info *info)
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{
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int i;
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void *func = info->func;
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union mips_instruction *ip = (union mips_instruction *)func;
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info->pc_offset = -1;
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info->frame_offset = info->omit_fp ? 0 : -1;
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info->frame_size = 0;
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for (i = 0; i < 128; i++, ip++) {
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/* if jal, jalr, jr, stop. */
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if (ip->j_format.opcode == jal_op ||
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@ -320,6 +294,23 @@ static int __init get_frame_info(struct mips_frame_info *info)
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ip->r_format.func == jr_op)))
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break;
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if (info->func_size && i >= info->func_size / 4)
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break;
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if (
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#ifdef CONFIG_32BIT
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ip->i_format.opcode == addiu_op &&
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#endif
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#ifdef CONFIG_64BIT
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ip->i_format.opcode == daddiu_op &&
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#endif
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ip->i_format.rs == 29 &&
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ip->i_format.rt == 29) {
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/* addiu/daddiu sp,sp,-imm */
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if (info->frame_size)
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continue;
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info->frame_size = - ip->i_format.simmediate;
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}
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if (
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#ifdef CONFIG_32BIT
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ip->i_format.opcode == sw_op &&
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@ -327,31 +318,20 @@ static int __init get_frame_info(struct mips_frame_info *info)
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#ifdef CONFIG_64BIT
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ip->i_format.opcode == sd_op &&
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#endif
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ip->i_format.rs == 29)
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{
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ip->i_format.rs == 29 &&
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ip->i_format.rt == 31) {
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/* sw / sd $ra, offset($sp) */
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if (ip->i_format.rt == 31) {
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if (info->pc_offset != -1)
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continue;
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info->pc_offset =
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ip->i_format.simmediate / sizeof(long);
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}
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/* sw / sd $s8, offset($sp) */
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if (ip->i_format.rt == 30) {
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//#if 0 /* gcc 3.4 does aggressive optimization... */
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if (info->frame_offset != -1)
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continue;
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//#endif
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info->frame_offset =
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ip->i_format.simmediate / sizeof(long);
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}
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if (info->pc_offset != -1)
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continue;
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info->pc_offset =
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ip->i_format.simmediate / sizeof(long);
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}
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}
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if (info->pc_offset == -1 || info->frame_offset == -1) {
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printk("Can't analyze prologue code at %p\n", func);
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if (info->pc_offset == -1 || info->frame_size == 0) {
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if (func == schedule)
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printk("Can't analyze prologue code at %p\n", func);
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info->pc_offset = -1;
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info->frame_offset = -1;
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return -1;
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info->frame_size = 0;
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}
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return 0;
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@ -359,25 +339,36 @@ static int __init get_frame_info(struct mips_frame_info *info)
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static int __init frame_info_init(void)
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{
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int i, found;
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for (i = 0; i < ARRAY_SIZE(mfinfo); i++)
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if (get_frame_info(&mfinfo[i]))
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return -1;
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schedule_frame = mfinfo[0];
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/* bubble sort */
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do {
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struct mips_frame_info tmp;
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found = 0;
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for (i = 1; i < ARRAY_SIZE(mfinfo); i++) {
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if (mfinfo[i-1].func > mfinfo[i].func) {
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tmp = mfinfo[i];
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mfinfo[i] = mfinfo[i-1];
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mfinfo[i-1] = tmp;
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found = 1;
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}
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}
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} while (found);
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mips_frame_info_initialized = 1;
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int i;
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#ifdef CONFIG_KALLSYMS
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char *modname;
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char namebuf[KSYM_NAME_LEN + 1];
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unsigned long start, size, ofs;
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extern char __sched_text_start[], __sched_text_end[];
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extern char __lock_text_start[], __lock_text_end[];
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start = (unsigned long)__sched_text_start;
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for (i = 0; i < ARRAY_SIZE(mfinfo); i++) {
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if (start == (unsigned long)schedule)
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schedule_frame = &mfinfo[i];
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if (!kallsyms_lookup(start, &size, &ofs, &modname, namebuf))
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break;
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mfinfo[i].func = (void *)(start + ofs);
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mfinfo[i].func_size = size;
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start += size - ofs;
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if (start >= (unsigned long)__lock_text_end)
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break;
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if (start == (unsigned long)__sched_text_end)
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start = (unsigned long)__lock_text_start;
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}
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#else
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mfinfo[0].func = schedule;
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schedule_frame = &mfinfo[0];
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#endif
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for (i = 0; i < ARRAY_SIZE(mfinfo) && mfinfo[i].func; i++)
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get_frame_info(&mfinfo[i]);
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mfinfo_num = i;
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return 0;
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}
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@ -394,47 +385,52 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
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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_frame.pc_offset < 0)
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if (!schedule_frame || schedule_frame->pc_offset < 0)
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return 0;
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return ((unsigned long *)t->reg29)[schedule_frame.pc_offset];
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return ((unsigned long *)t->reg29)[schedule_frame->pc_offset];
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}
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/* get_wchan - a maintenance nightmare^W^Wpain in the ass ... */
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unsigned long get_wchan(struct task_struct *p)
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{
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unsigned long stack_page;
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unsigned long frame, pc;
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unsigned long pc;
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#ifdef CONFIG_KALLSYMS
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unsigned long frame;
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#endif
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if (!p || p == current || p->state == TASK_RUNNING)
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return 0;
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stack_page = (unsigned long)task_stack_page(p);
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if (!stack_page || !mips_frame_info_initialized)
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if (!stack_page || !mfinfo_num)
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return 0;
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pc = thread_saved_pc(p);
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#ifdef CONFIG_KALLSYMS
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if (!in_sched_functions(pc))
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return pc;
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frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset];
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frame = p->thread.reg29 + schedule_frame->frame_size;
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do {
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int i;
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if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32)
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return 0;
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for (i = ARRAY_SIZE(mfinfo) - 1; i >= 0; i--) {
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for (i = mfinfo_num - 1; i >= 0; i--) {
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if (pc >= (unsigned long) mfinfo[i].func)
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break;
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}
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if (i < 0)
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break;
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if (mfinfo[i].omit_fp)
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break;
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pc = ((unsigned long *)frame)[mfinfo[i].pc_offset];
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frame = ((unsigned long *)frame)[mfinfo[i].frame_offset];
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if (!mfinfo[i].frame_size)
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break;
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frame += mfinfo[i].frame_size;
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} while (in_sched_functions(pc));
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#endif
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return pc;
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}
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