include/linux/rethook.h

Source file repositories/reference/linux-study-clean/include/linux/rethook.h

File Facts

System
Linux kernel
Corpus path
include/linux/rethook.h
Extension
.h
Size
3223 bytes
Lines
99
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct rethook {
	void			*data;
	/*
	 * To avoid sparse warnings, this uses a raw function pointer with
	 * __rcu, instead of rethook_handler_t. But this must be same as
	 * rethook_handler_t.
	 */
	void (__rcu *handler) (struct rethook_node *, void *, unsigned long, struct pt_regs *);
	struct objpool_head	pool;
	struct rcu_head		rcu;
};

/**
 * struct rethook_node - The rethook shadow-stack entry node.
 * @rcu: The rcu_head for deferred freeing.
 * @llist: The llist, linked to a struct task_struct::rethooks.
 * @rethook: The pointer to the struct rethook.
 * @ret_addr: The storage for the real return address.
 * @frame: The storage for the frame pointer.
 *
 * You can embed this to your extended data structure to store any data
 * on each entry of the shadow stack.
 */
struct rethook_node {
	struct rcu_head		rcu;
	struct llist_node	llist;
	struct rethook		*rethook;
	unsigned long		ret_addr;
	unsigned long		frame;
};

struct rethook *rethook_alloc(void *data, rethook_handler_t handler, int size, int num);
void rethook_stop(struct rethook *rh);
void rethook_free(struct rethook *rh);
struct rethook_node *rethook_try_get(struct rethook *rh);
void rethook_recycle(struct rethook_node *node);
void rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mcount);
unsigned long rethook_find_ret_addr(struct task_struct *tsk, unsigned long frame,
				    struct llist_node **cur);

/* Arch dependent code must implement arch_* and trampoline code */
void arch_rethook_prepare(struct rethook_node *node, struct pt_regs *regs, bool mcount);
void arch_rethook_trampoline(void);

/**
 * is_rethook_trampoline() - Check whether the address is rethook trampoline
 * @addr: The address to be checked
 *
 * Return true if the @addr is the rethook trampoline address.
 */
static inline bool is_rethook_trampoline(unsigned long addr)
{
	return addr == (unsigned long)dereference_symbol_descriptor(arch_rethook_trampoline);
}

/* If the architecture needs to fixup the return address, implement it. */
void arch_rethook_fixup_return(struct pt_regs *regs,
			       unsigned long correct_ret_addr);

/* Generic trampoline handler, arch code must prepare asm stub */
unsigned long rethook_trampoline_handler(struct pt_regs *regs,
					 unsigned long frame);

#ifdef CONFIG_RETHOOK
void rethook_flush_task(struct task_struct *tk);
#else
#define rethook_flush_task(tsk)	do { } while (0)
#endif

#endif

Annotation

Implementation Notes