linux/arch/x86/include/asm/unwind.h
Masami Hiramatsu f3a112c0c4 x86,rethook,kprobes: Replace kretprobe with rethook on x86
Replaces the kretprobe code with rethook on x86. With this patch,
kretprobe on x86 uses the rethook instead of kretprobe specific
trampoline code.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/164826163692.2455864.13745421016848209527.stgit@devnote2
2022-03-28 19:38:51 -07:00

155 lines
3.9 KiB
C

/* 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 */