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Diffstat (limited to 'arch/x86/include/asm/unwind.h')
| -rw-r--r-- | arch/x86/include/asm/unwind.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h new file mode 100644 index 000000000..7cede4dc2 --- /dev/null +++ b/arch/x86/include/asm/unwind.h @@ -0,0 +1,154 @@ +/* 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 */ |