99 lines
3.1 KiB
C
99 lines
3.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Return hooking with list-based shadow stack.
|
|
*/
|
|
#ifndef _LINUX_RETHOOK_H
|
|
#define _LINUX_RETHOOK_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/objpool.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/llist.h>
|
|
#include <linux/rcupdate.h>
|
|
|
|
struct rethook_node;
|
|
|
|
typedef void (*rethook_handler_t) (struct rethook_node *, void *, unsigned long, struct pt_regs *);
|
|
|
|
/**
|
|
* struct rethook - The rethook management data structure.
|
|
* @data: The user-defined data storage.
|
|
* @handler: The user-defined return hook handler.
|
|
* @pool: The pool of struct rethook_node.
|
|
* @ref: The reference counter.
|
|
* @rcu: The rcu_head for deferred freeing.
|
|
*
|
|
* Don't embed to another data structure, because this is a self-destructive
|
|
* data structure when all rethook_node are freed.
|
|
*/
|
|
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
|