diff options
Diffstat (limited to 'arch/arm64/include/asm/stacktrace.h')
| -rw-r--r-- | arch/arm64/include/asm/stacktrace.h | 78 |
1 files changed, 65 insertions, 13 deletions
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index df45af931459..4d9b1f48dc39 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -8,19 +8,12 @@ #include <linux/percpu.h> #include <linux/sched.h> #include <linux/sched/task_stack.h> +#include <linux/types.h> #include <asm/memory.h> #include <asm/ptrace.h> #include <asm/sdei.h> -struct stackframe { - unsigned long fp; - unsigned long pc; -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - int graph; -#endif -}; - enum stack_type { STACK_TYPE_UNKNOWN, STACK_TYPE_TASK, @@ -28,6 +21,7 @@ enum stack_type { STACK_TYPE_OVERFLOW, STACK_TYPE_SDEI_NORMAL, STACK_TYPE_SDEI_CRITICAL, + __NR_STACK_TYPES }; struct stack_info { @@ -36,6 +30,37 @@ struct stack_info { enum stack_type type; }; +/* + * A snapshot of a frame record or fp/lr register values, along with some + * accounting information necessary for robust unwinding. + * + * @fp: The fp value in the frame record (or the real fp) + * @pc: The fp value in the frame record (or the real lr) + * + * @stacks_done: Stacks which have been entirely unwound, for which it is no + * longer valid to unwind to. + * + * @prev_fp: The fp that pointed to this frame record, or a synthetic value + * of 0. This is used to ensure that within a stack, each + * subsequent frame record is at an increasing address. + * @prev_type: The type of stack this frame record was on, or a synthetic + * value of STACK_TYPE_UNKNOWN. This is used to detect a + * transition from one stack to another. + * + * @graph: When FUNCTION_GRAPH_TRACER is selected, holds the index of a + * replacement lr value in the ftrace graph stack. + */ +struct stackframe { + unsigned long fp; + unsigned long pc; + DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES); + unsigned long prev_fp; + enum stack_type prev_type; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + int graph; +#endif +}; + extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame, int (*fn)(struct stackframe *, void *), void *data); @@ -64,8 +89,9 @@ static inline bool on_irq_stack(unsigned long sp, return true; } -static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp, - struct stack_info *info) +static inline bool on_task_stack(const struct task_struct *tsk, + unsigned long sp, + struct stack_info *info) { unsigned long low = (unsigned long)task_stack_page(tsk); unsigned long high = low + THREAD_SIZE; @@ -112,10 +138,13 @@ static inline bool on_overflow_stack(unsigned long sp, * We can only safely access per-cpu stacks from current in a non-preemptible * context. */ -static inline bool on_accessible_stack(struct task_struct *tsk, - unsigned long sp, - struct stack_info *info) +static inline bool on_accessible_stack(const struct task_struct *tsk, + unsigned long sp, + struct stack_info *info) { + if (info) + info->type = STACK_TYPE_UNKNOWN; + if (on_task_stack(tsk, sp, info)) return true; if (tsk != current || preemptible()) @@ -130,4 +159,27 @@ static inline bool on_accessible_stack(struct task_struct *tsk, return false; } +static inline void start_backtrace(struct stackframe *frame, + unsigned long fp, unsigned long pc) +{ + frame->fp = fp; + frame->pc = pc; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + frame->graph = 0; +#endif + + /* + * Prime the first unwind. + * + * In unwind_frame() we'll check that the FP points to a valid stack, + * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be + * treated as a transition to whichever stack that happens to be. The + * prev_fp value won't be used, but we set it to 0 such that it is + * definitely not an accessible stack address. + */ + bitmap_zero(frame->stacks_done, __NR_STACK_TYPES); + frame->prev_fp = 0; + frame->prev_type = STACK_TYPE_UNKNOWN; +} + #endif /* __ASM_STACKTRACE_H */ |