[linux-2.6-block.git] / arch / x86 / include / asm / unwind.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_UNWIND_H
#define _ASM_X86_UNWIND_H

#include <linux/sched.h>
#include <linux/ftrace.h>
#include <linux/rethook.h>
#include <asm/ptrace.h>
#include <asm/stacktrace.h>

#define IRET_FRAME_OFFSET (offsetof(struct pt_regs, ip))
#define IRET_FRAME_SIZE   (sizeof(struct pt_regs) - IRET_FRAME_OFFSET)

struct unwind_state {
	struct stack_info stack_info;
	unsigned long stack_mask;
	struct task_struct *task;
	int graph_idx;
#if defined(CONFIG_RETHOOK)
	struct llist_node *kr_cur;
#endif
	bool error;
#if defined(CONFIG_UNWINDER_ORC)
	bool signal, full_regs;
	unsigned long sp, bp, ip;
	struct pt_regs *regs, *prev_regs;
#elif defined(CONFIG_UNWINDER_FRAME_POINTER)
	bool got_irq;
	unsigned long *bp, *orig_sp, ip;
	/*
	 * If non-NULL: The current frame is incomplete and doesn't contain a
	 * valid BP. When looking for the next frame, use this instead of the
	 * non-existent saved BP.
	 */
	unsigned long *next_bp;
	struct pt_regs *regs;
#else
	unsigned long *sp;
#endif
};

void __unwind_start(struct unwind_state *state, struct task_struct *task,
		    struct pt_regs *regs, unsigned long *first_frame);
bool unwind_next_frame(struct unwind_state *state);
unsigned long unwind_get_return_address(struct unwind_state *state);
unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);

static inline bool unwind_done(struct unwind_state *state)
{
	return state->stack_info.type == STACK_TYPE_UNKNOWN;
}

static inline bool unwind_error(struct unwind_state *state)
{
	return state->error;
}

static inline
void unwind_start(struct unwind_state *state, struct task_struct *task,
		  struct pt_regs *regs, unsigned long *first_frame)
{
	first_frame = first_frame ? : get_stack_pointer(task, regs);

	__unwind_start(state, task, regs, first_frame);
}

#if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER)
/*
 * If 'partial' returns true, only the iret frame registers are valid.
 */
static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
						    bool *partial)
{
	if (unwind_done(state))
		return NULL;

	if (partial) {
#ifdef CONFIG_UNWINDER_ORC
		*partial = !state->full_regs;
#else
		*partial = false;
#endif
	}

	return state->regs;
}
#else
static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
						    bool *partial)
{
	return NULL;
}
#endif

#ifdef CONFIG_UNWINDER_ORC
void unwind_init(void);
void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
			void *orc, size_t orc_size);
#else
static inline void unwind_init(void) {}
static inline
void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
			void *orc, size_t orc_size) {}
#endif

static inline
unsigned long unwind_recover_rethook(struct unwind_state *state,
				     unsigned long addr, unsigned long *addr_p)
{
#ifdef CONFIG_RETHOOK
	if (is_rethook_trampoline(addr))
		return rethook_find_ret_addr(state->task, (unsigned long)addr_p,
					     &state->kr_cur);
#endif
	return addr;
}

/* Recover the return address modified by rethook and ftrace_graph. */
static inline
unsigned long unwind_recover_ret_addr(struct unwind_state *state,
				     unsigned long addr, unsigned long *addr_p)
{
	unsigned long ret;

	ret = ftrace_graph_ret_addr(state->task, &state->graph_idx,
				    addr, addr_p);
	return unwind_recover_rethook(state, ret, addr_p);
}

/*
 * This disables KASAN checking when reading a value from another task's stack,
 * since the other task could be running on another CPU and could have poisoned
 * the stack in the meantime.
 */
#define READ_ONCE_TASK_STACK(task, x)			\
({							\
	unsigned long val;				\
	if (task == current)				\
		val = READ_ONCE(x);			\
	else						\
		val = READ_ONCE_NOCHECK(x);		\
	val;						\
})

static inline bool task_on_another_cpu(struct task_struct *task)
{
#ifdef CONFIG_SMP
	return task != current && task->on_cpu;
#else
	return false;
#endif
}

#endif /* _ASM_X86_UNWIND_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _ASM_X86_UNWIND_H
	3	#define _ASM_X86_UNWIND_H
	4
	5	#include <linux/sched.h>
	6	#include <linux/ftrace.h>
	7	#include <linux/rethook.h>
	8	#include <asm/ptrace.h>
	9	#include <asm/stacktrace.h>
	10
	11	#define IRET_FRAME_OFFSET (offsetof(struct pt_regs, ip))
	12	#define IRET_FRAME_SIZE (sizeof(struct pt_regs) - IRET_FRAME_OFFSET)
	13
	14	struct unwind_state {
	15	struct stack_info stack_info;
	16	unsigned long stack_mask;
	17	struct task_struct *task;
	18	int graph_idx;
	19	#if defined(CONFIG_RETHOOK)
	20	struct llist_node *kr_cur;
	21	#endif
	22	bool error;
	23	#if defined(CONFIG_UNWINDER_ORC)
	24	bool signal, full_regs;
	25	unsigned long sp, bp, ip;
	26	struct pt_regs regs, prev_regs;
	27	#elif defined(CONFIG_UNWINDER_FRAME_POINTER)
	28	bool got_irq;
	29	unsigned long bp, orig_sp, ip;
	30	/*
	31	* If non-NULL: The current frame is incomplete and doesn't contain a
	32	* valid BP. When looking for the next frame, use this instead of the
	33	* non-existent saved BP.
	34	*/
	35	unsigned long *next_bp;
	36	struct pt_regs *regs;
	37	#else
	38	unsigned long *sp;
	39	#endif
	40	};
	41
	42	void __unwind_start(struct unwind_state state, struct task_struct task,
	43	struct pt_regs regs, unsigned long first_frame);
	44	bool unwind_next_frame(struct unwind_state *state);
	45	unsigned long unwind_get_return_address(struct unwind_state *state);
	46	unsigned long unwind_get_return_address_ptr(struct unwind_state state);
	47
	48	static inline bool unwind_done(struct unwind_state *state)
	49	{
	50	return state->stack_info.type == STACK_TYPE_UNKNOWN;
	51	}
	52
	53	static inline bool unwind_error(struct unwind_state *state)
	54	{
	55	return state->error;
	56	}
	57
	58	static inline
	59	void unwind_start(struct unwind_state state, struct task_struct task,
	60	struct pt_regs regs, unsigned long first_frame)
	61	{
	62	first_frame = first_frame ? : get_stack_pointer(task, regs);
	63
	64	__unwind_start(state, task, regs, first_frame);
	65	}
	66
	67	#if defined(CONFIG_UNWINDER_ORC) \|\| defined(CONFIG_UNWINDER_FRAME_POINTER)
	68	/*
	69	* If 'partial' returns true, only the iret frame registers are valid.
	70	*/
	71	static inline struct pt_regs unwind_get_entry_regs(struct unwind_state state,
	72	bool *partial)
	73	{
	74	if (unwind_done(state))
	75	return NULL;
	76
	77	if (partial) {
	78	#ifdef CONFIG_UNWINDER_ORC
	79	*partial = !state->full_regs;
	80	#else
	81	*partial = false;
	82	#endif
	83	}
	84
	85	return state->regs;
	86	}
	87	#else
	88	static inline struct pt_regs unwind_get_entry_regs(struct unwind_state state,
	89	bool *partial)
	90	{
	91	return NULL;
	92	}
	93	#endif
	94
	95	#ifdef CONFIG_UNWINDER_ORC
	96	void unwind_init(void);
	97	void unwind_module_init(struct module mod, void orc_ip, size_t orc_ip_size,
	98	void *orc, size_t orc_size);
	99	#else
	100	static inline void unwind_init(void) {}
	101	static inline
	102	void unwind_module_init(struct module mod, void orc_ip, size_t orc_ip_size,
	103	void *orc, size_t orc_size) {}
	104	#endif
	105
	106	static inline
	107	unsigned long unwind_recover_rethook(struct unwind_state *state,
	108	unsigned long addr, unsigned long *addr_p)
	109	{
	110	#ifdef CONFIG_RETHOOK
	111	if (is_rethook_trampoline(addr))
	112	return rethook_find_ret_addr(state->task, (unsigned long)addr_p,
	113	&state->kr_cur);
	114	#endif
	115	return addr;
	116	}
	117
	118	/* Recover the return address modified by rethook and ftrace_graph. */
	119	static inline
	120	unsigned long unwind_recover_ret_addr(struct unwind_state *state,
	121	unsigned long addr, unsigned long *addr_p)
	122	{
	123	unsigned long ret;
	124
	125	ret = ftrace_graph_ret_addr(state->task, &state->graph_idx,
	126	addr, addr_p);
	127	return unwind_recover_rethook(state, ret, addr_p);
	128	}
	129
	130	/*
	131	* This disables KASAN checking when reading a value from another task's stack,
	132	* since the other task could be running on another CPU and could have poisoned
	133	* the stack in the meantime.
	134	*/
	135	#define READ_ONCE_TASK_STACK(task, x) \
	136	({ \
	137	unsigned long val; \
	138	if (task == current) \
	139	val = READ_ONCE(x); \
	140	else \
	141	val = READ_ONCE_NOCHECK(x); \
	142	val; \
	143	})
	144
	145	static inline bool task_on_another_cpu(struct task_struct *task)
	146	{
	147	#ifdef CONFIG_SMP
	148	return task != current && task->on_cpu;
	149	#else
	150	return false;
	151	#endif
	152	}
	153
	154	#endif /* _ASM_X86_UNWIND_H */