| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 ARM Ltd. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 15 | */ |
| 16 | #ifndef __ASM_STACKTRACE_H |
| 17 | #define __ASM_STACKTRACE_H |
| 18 | |
| 19 | #include <linux/percpu.h> |
| 20 | #include <linux/sched.h> |
| 21 | #include <linux/sched/task_stack.h> |
| 22 | |
| 23 | #include <asm/memory.h> |
| 24 | #include <asm/ptrace.h> |
| 25 | #include <asm/sdei.h> |
| 26 | |
| 27 | struct stackframe { |
| 28 | unsigned long fp; |
| 29 | unsigned long pc; |
| 30 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 31 | int graph; |
| 32 | #endif |
| 33 | }; |
| 34 | |
| 35 | enum stack_type { |
| 36 | STACK_TYPE_UNKNOWN, |
| 37 | STACK_TYPE_TASK, |
| 38 | STACK_TYPE_IRQ, |
| 39 | STACK_TYPE_OVERFLOW, |
| 40 | STACK_TYPE_SDEI_NORMAL, |
| 41 | STACK_TYPE_SDEI_CRITICAL, |
| 42 | }; |
| 43 | |
| 44 | struct stack_info { |
| 45 | unsigned long low; |
| 46 | unsigned long high; |
| 47 | enum stack_type type; |
| 48 | }; |
| 49 | |
| 50 | extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); |
| 51 | extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame, |
| 52 | int (*fn)(struct stackframe *, void *), void *data); |
| 53 | extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk); |
| 54 | |
| 55 | DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); |
| 56 | |
| 57 | static inline bool on_irq_stack(unsigned long sp, |
| 58 | struct stack_info *info) |
| 59 | { |
| 60 | unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr); |
| 61 | unsigned long high = low + IRQ_STACK_SIZE; |
| 62 | |
| 63 | if (!low) |
| 64 | return false; |
| 65 | |
| 66 | if (sp < low || sp >= high) |
| 67 | return false; |
| 68 | |
| 69 | if (info) { |
| 70 | info->low = low; |
| 71 | info->high = high; |
| 72 | info->type = STACK_TYPE_IRQ; |
| 73 | } |
| 74 | |
| 75 | return true; |
| 76 | } |
| 77 | |
| 78 | static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp, |
| 79 | struct stack_info *info) |
| 80 | { |
| 81 | unsigned long low = (unsigned long)task_stack_page(tsk); |
| 82 | unsigned long high = low + THREAD_SIZE; |
| 83 | |
| 84 | if (sp < low || sp >= high) |
| 85 | return false; |
| 86 | |
| 87 | if (info) { |
| 88 | info->low = low; |
| 89 | info->high = high; |
| 90 | info->type = STACK_TYPE_TASK; |
| 91 | } |
| 92 | |
| 93 | return true; |
| 94 | } |
| 95 | |
| 96 | #ifdef CONFIG_VMAP_STACK |
| 97 | DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack); |
| 98 | |
| 99 | static inline bool on_overflow_stack(unsigned long sp, |
| 100 | struct stack_info *info) |
| 101 | { |
| 102 | unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack); |
| 103 | unsigned long high = low + OVERFLOW_STACK_SIZE; |
| 104 | |
| 105 | if (sp < low || sp >= high) |
| 106 | return false; |
| 107 | |
| 108 | if (info) { |
| 109 | info->low = low; |
| 110 | info->high = high; |
| 111 | info->type = STACK_TYPE_OVERFLOW; |
| 112 | } |
| 113 | |
| 114 | return true; |
| 115 | } |
| 116 | #else |
| 117 | static inline bool on_overflow_stack(unsigned long sp, |
| 118 | struct stack_info *info) { return false; } |
| 119 | #endif |
| 120 | |
| 121 | |
| 122 | /* |
| 123 | * We can only safely access per-cpu stacks from current in a non-preemptible |
| 124 | * context. |
| 125 | */ |
| 126 | static inline bool on_accessible_stack(struct task_struct *tsk, |
| 127 | unsigned long sp, |
| 128 | struct stack_info *info) |
| 129 | { |
| 130 | if (on_task_stack(tsk, sp, info)) |
| 131 | return true; |
| 132 | if (tsk != current || preemptible()) |
| 133 | return false; |
| 134 | if (on_irq_stack(sp, info)) |
| 135 | return true; |
| 136 | if (on_overflow_stack(sp, info)) |
| 137 | return true; |
| 138 | if (on_sdei_stack(sp, info)) |
| 139 | return true; |
| 140 | |
| 141 | return false; |
| 142 | } |
| 143 | |
| 144 | #endif /* __ASM_STACKTRACE_H */ |