x86/unwind: Dump stack data on warnings (8b5e99f0) · Commits · 戴 / test

arch/x86/include/asm/unwind.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -12,7 +12,7 @@ struct unwind_state {
		struct task_struct *task;
		int graph_idx;
		#ifdef CONFIG_FRAME_POINTER
		unsigned long *bp;
		unsigned long bp, orig_sp;
		struct pt_regs *regs;
		#else
		unsigned long *sp;

arch/x86/kernel/unwind_frame.c

+38 −0

Original line number	Diff line number	Diff line
		@@ -6,6 +6,37 @@

		#define FRAME_HEADER_SIZE (sizeof(long) * 2)

		static void unwind_dump(struct unwind_state state, unsigned long sp)
		{
		static bool dumped_before = false;
		bool prev_zero, zero = false;
		unsigned long word;

		if (dumped_before)
		return;

		dumped_before = true;

		printk_deferred("unwind stack type:%d next_sp:%p mask:%lx graph_idx:%d\n",
		state->stack_info.type, state->stack_info.next_sp,
		state->stack_mask, state->graph_idx);

		for (sp = state->orig_sp; sp < state->stack_info.end; sp++) {
		word = READ_ONCE_NOCHECK(*sp);

		prev_zero = zero;
		zero = word == 0;

		if (zero) {
		if (!prev_zero)
		printk_deferred("%p: %016x ...\n", sp, 0);
		continue;
		}

		printk_deferred("%p: %016lx (%pB)\n", sp, word, (void *)word);
		}
		}

		unsigned long unwind_get_return_address(struct unwind_state *state)
		{
		unsigned long addr;
		@@ -25,6 +56,7 @@ unsigned long unwind_get_return_address(struct unwind_state *state)
		"WARNING: unrecognized kernel stack return address %p at %p in %s:%d\n",
		(void *)addr, addr_p, state->task->comm,
		state->task->pid);
		unwind_dump(state, addr_p);
		return 0;
		}

		@@ -74,6 +106,7 @@ static bool update_stack_state(struct unwind_state state, void addr,
		size_t len)
		{
		struct stack_info *info = &state->stack_info;
		enum stack_type orig_type = info->type;

		/*
		* If addr isn't on the current stack, switch to the next one.
		@@ -87,6 +120,9 @@ static bool update_stack_state(struct unwind_state state, void addr,
		&state->stack_mask))
		return false;

		if (!state->orig_sp \|\| info->type != orig_type)
		state->orig_sp = addr;

		return true;
		}

		@@ -185,11 +221,13 @@ bad_address:
		"WARNING: kernel stack regs at %p in %s:%d has bad 'bp' value %p\n",
		state->regs, state->task->comm,
		state->task->pid, next_frame);
		unwind_dump(state, (unsigned long *)state->regs);
		} else {
		printk_deferred_once(KERN_WARNING
		"WARNING: kernel stack frame pointer at %p in %s:%d has bad value %p\n",
		state->bp, state->task->comm,
		state->task->pid, next_frame);
		unwind_dump(state, state->bp);
		}
		the_end:
		state->stack_info.type = STACK_TYPE_UNKNOWN;

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