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Diffstat (limited to 'arch/arm64/include/asm/stacktrace.h')
| -rw-r--r-- | arch/arm64/include/asm/stacktrace.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h new file mode 100644 index 000000000..eb29b1fe8 --- /dev/null +++ b/arch/arm64/include/asm/stacktrace.h @@ -0,0 +1,174 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 ARM Ltd. + */ +#ifndef __ASM_STACKTRACE_H +#define __ASM_STACKTRACE_H + +#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> + +enum stack_type { + STACK_TYPE_UNKNOWN, + STACK_TYPE_TASK, + STACK_TYPE_IRQ, + STACK_TYPE_OVERFLOW, + STACK_TYPE_SDEI_NORMAL, + STACK_TYPE_SDEI_CRITICAL, + __NR_STACK_TYPES +}; + +struct stack_info { + unsigned long low; + unsigned long high; + 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, + bool (*fn)(void *, unsigned long), void *data); +extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl); + +DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); + +static inline bool on_stack(unsigned long sp, unsigned long low, + unsigned long high, enum stack_type type, + struct stack_info *info) +{ + if (!low) + return false; + + if (sp < low || sp >= high) + return false; + + if (info) { + info->low = low; + info->high = high; + info->type = type; + } + return true; +} + +static inline bool on_irq_stack(unsigned long sp, + struct stack_info *info) +{ + unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr); + unsigned long high = low + IRQ_STACK_SIZE; + + return on_stack(sp, low, high, STACK_TYPE_IRQ, 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; + + return on_stack(sp, low, high, STACK_TYPE_TASK, info); +} + +#ifdef CONFIG_VMAP_STACK +DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack); + +static inline bool on_overflow_stack(unsigned long sp, + struct stack_info *info) +{ + unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack); + unsigned long high = low + OVERFLOW_STACK_SIZE; + + return on_stack(sp, low, high, STACK_TYPE_OVERFLOW, info); +} +#else +static inline bool on_overflow_stack(unsigned long sp, + struct stack_info *info) { return false; } +#endif + + +/* + * We can only safely access per-cpu stacks from current in a non-preemptible + * context. + */ +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()) + return false; + if (on_irq_stack(sp, info)) + return true; + if (on_overflow_stack(sp, info)) + return true; + if (on_sdei_stack(sp, info)) + return true; + + 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 */ |