Fix wchan implementation, based on earlier by from Atsushi Nemoto. (dc953df1) · Commits · 戴 / test

arch/mips/kernel/process.c

+77 −58

Original line number	Diff line number	Diff line
		@@ -211,22 +211,48 @@ long kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
		return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
		}

		struct mips_frame_info {
		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 },
		#endif
		/* kernel/timer.c */
		{ schedule_timeout, 1 },
		/* { nanosleep_restart, 1 }, */
		/* lib/rwsem-spinlock.c */
		{ __down_read, 1 },
		{ __down_write, 1 },
		};
		static struct mips_frame_info schedule_frame;
		static struct mips_frame_info schedule_timeout_frame;
		static struct mips_frame_info sleep_on_frame;
		static struct mips_frame_info sleep_on_timeout_frame;
		static struct mips_frame_info wait_for_completion_frame;

		static int mips_frame_info_initialized;
		static int __init get_frame_info(struct mips_frame_info info, void func)
		static int __init get_frame_info(struct mips_frame_info *info)
		{
		int i;
		void *func = info->func;
		union mips_instruction ip = (union mips_instruction )func;
		info->pc_offset = -1;
		info->frame_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 \|\|
		@@ -247,14 +273,16 @@ static int __init get_frame_info(struct mips_frame_info info, void func)
		/* sw / sd $ra, offset($sp) */
		if (ip->i_format.rt == 31) {
		if (info->pc_offset != -1)
		break;
		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)
		break;
		continue;
		//#endif
		info->frame_offset =
		ip->i_format.simmediate / sizeof(long);
		}
		@@ -272,13 +300,25 @@ static int __init get_frame_info(struct mips_frame_info info, void func)

		static int __init frame_info_init(void)
		{
		mips_frame_info_initialized =
		!get_frame_info(&schedule_frame, schedule) &&
		!get_frame_info(&schedule_timeout_frame, schedule_timeout) &&
		!get_frame_info(&sleep_on_frame, sleep_on) &&
		!get_frame_info(&sleep_on_timeout_frame, sleep_on_timeout) &&
		!get_frame_info(&wait_for_completion_frame, wait_for_completion);

		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;
		return 0;
		}

		@@ -303,60 +343,39 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
		/* get_wchan - a maintenance nightmare^W^Wpain in the ass ... */
		unsigned long get_wchan(struct task_struct *p)
		{
		unsigned long stack_page;
		unsigned long frame, pc;

		if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
		return 0;

		if (!mips_frame_info_initialized)
		stack_page = (unsigned long)p->thread_info;
		if (!stack_page \|\| !mips_frame_info_initialized)
		return 0;

		pc = thread_saved_pc(p);
		if (!in_sched_functions(pc))
		goto out;

		if (pc >= (unsigned long) sleep_on_timeout)
		goto schedule_timeout_caller;
		if (pc >= (unsigned long) sleep_on)
		goto schedule_caller;
		if (pc >= (unsigned long) interruptible_sleep_on_timeout)
		goto schedule_timeout_caller;
		if (pc >= (unsigned long)interruptible_sleep_on)
		goto schedule_caller;
		if (pc >= (unsigned long)wait_for_completion)
		goto schedule_caller;
		goto schedule_timeout_caller;

		schedule_caller:
		frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset];
		if (pc >= (unsigned long) sleep_on)
		pc = ((unsigned long *)frame)[sleep_on_frame.pc_offset];
		else
		pc = ((unsigned long *)frame)[wait_for_completion_frame.pc_offset];
		goto out;
		return pc;

		schedule_timeout_caller:
		/*
		* The schedule_timeout frame
		*/
		frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset];
		do {
		int i;

		/*
		* frame now points to sleep_on_timeout's frame
		*/
		pc = ((unsigned long *)frame)[schedule_timeout_frame.pc_offset];
		if (frame < stack_page \|\| frame > stack_page + THREAD_SIZE - 32)
		return 0;

		if (in_sched_functions(pc)) {
		/* schedule_timeout called by [interruptible_]sleep_on_timeout */
		frame = ((unsigned long *)frame)[schedule_timeout_frame.frame_offset];
		pc = ((unsigned long *)frame)[sleep_on_timeout_frame.pc_offset];
		for (i = ARRAY_SIZE(mfinfo) - 1; i >= 0; i--) {
		if (pc >= (unsigned long) mfinfo[i].func)
		break;
		}
		if (i < 0)
		break;

		out:

		#ifdef CONFIG_64BIT
		if (current->thread.mflags & MF_32BIT_REGS) /* Kludge for 32-bit ps */
		pc &= 0xffffffffUL;
		#endif
		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));

		return pc;
		}

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