cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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unwind.h (3982B)

      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
     14struct 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
     42void __unwind_start(struct unwind_state *state, struct task_struct *task,
     43		    struct pt_regs *regs, unsigned long *first_frame);
     44bool unwind_next_frame(struct unwind_state *state);
     45unsigned long unwind_get_return_address(struct unwind_state *state);
     46unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
     47
     48static inline bool unwind_done(struct unwind_state *state)
     49{
     50	return state->stack_info.type == STACK_TYPE_UNKNOWN;
     51}
     52
     53static inline bool unwind_error(struct unwind_state *state)
     54{
     55	return state->error;
     56}
     57
     58static inline
     59void 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 */
     71static 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
     88static 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
     96void unwind_init(void);
     97void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
     98			void *orc, size_t orc_size);
     99#else
    100static inline void unwind_init(void) {}
    101static inline
    102void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
    103			void *orc, size_t orc_size) {}
    104#endif
    105
    106static inline
    107unsigned 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. */
    119static inline
    120unsigned 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
    145static 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 */