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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | /* * Stack trace management functions * * Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> */ #include <linux/sched.h> #include <linux/sched/debug.h> #include <linux/sched/task_stack.h> #include <linux/stacktrace.h> #include <linux/export.h> #include <linux/uaccess.h> #include <asm/stacktrace.h> #include <asm/unwind.h> void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task, struct pt_regs *regs) { struct unwind_state state; unsigned long addr; if (regs && !consume_entry(cookie, regs->ip)) return; for (unwind_start(&state, task, regs, NULL); !unwind_done(&state); unwind_next_frame(&state)) { addr = unwind_get_return_address(&state); if (!addr || !consume_entry(cookie, addr)) break; } } int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task) { struct unwind_state state; struct pt_regs *regs; unsigned long addr; for (unwind_start(&state, task, NULL, NULL); !unwind_done(&state) && !unwind_error(&state); unwind_next_frame(&state)) { regs = unwind_get_entry_regs(&state, NULL); if (regs) { /* Success path for user tasks */ if (user_mode(regs)) return 0; /* * Kernel mode registers on the stack indicate an * in-kernel interrupt or exception (e.g., preemption * or a page fault), which can make frame pointers * unreliable. */ if (IS_ENABLED(CONFIG_FRAME_POINTER)) return -EINVAL; } addr = unwind_get_return_address(&state); /* * A NULL or invalid return address probably means there's some * generated code which __kernel_text_address() doesn't know * about. */ if (!addr) return -EINVAL; if (!consume_entry(cookie, addr)) return -EINVAL; } /* Check for stack corruption */ if (unwind_error(&state)) return -EINVAL; return 0; } /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ struct stack_frame_user { const void __user *next_fp; unsigned long ret_addr; }; static int copy_stack_frame(const struct stack_frame_user __user *fp, struct stack_frame_user *frame) { int ret; if (!__access_ok(fp, sizeof(*frame))) return 0; ret = 1; pagefault_disable(); if (__get_user(frame->next_fp, &fp->next_fp) || __get_user(frame->ret_addr, &fp->ret_addr)) ret = 0; pagefault_enable(); return ret; } void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, const struct pt_regs *regs) { const void __user *fp = (const void __user *)regs->bp; if (!consume_entry(cookie, regs->ip)) return; while (1) { struct stack_frame_user frame; frame.next_fp = NULL; frame.ret_addr = 0; if (!copy_stack_frame(fp, &frame)) break; if ((unsigned long)fp < regs->sp) break; if (!frame.ret_addr) break; if (!consume_entry(cookie, frame.ret_addr)) break; fp = frame.next_fp; } } |