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136 lines
3.1 KiB
136 lines
3.1 KiB
/* |
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* Stack trace management functions |
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* |
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* Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <[email protected]> |
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*/ |
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#include <linux/sched.h> |
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#include <linux/sched/debug.h> |
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#include <linux/sched/task_stack.h> |
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#include <linux/stacktrace.h> |
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#include <linux/export.h> |
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#include <linux/uaccess.h> |
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#include <asm/stacktrace.h> |
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#include <asm/unwind.h> |
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void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, |
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struct task_struct *task, struct pt_regs *regs) |
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{ |
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struct unwind_state state; |
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unsigned long addr; |
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if (regs && !consume_entry(cookie, regs->ip)) |
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return; |
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for (unwind_start(&state, task, regs, NULL); !unwind_done(&state); |
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unwind_next_frame(&state)) { |
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addr = unwind_get_return_address(&state); |
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if (!addr || !consume_entry(cookie, addr)) |
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break; |
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} |
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} |
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/* |
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* This function returns an error if it detects any unreliable features of the |
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* stack. Otherwise it guarantees that the stack trace is reliable. |
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* |
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* If the task is not 'current', the caller *must* ensure the task is inactive. |
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*/ |
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int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, |
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void *cookie, struct task_struct *task) |
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{ |
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struct unwind_state state; |
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struct pt_regs *regs; |
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unsigned long addr; |
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for (unwind_start(&state, task, NULL, NULL); |
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!unwind_done(&state) && !unwind_error(&state); |
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unwind_next_frame(&state)) { |
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regs = unwind_get_entry_regs(&state, NULL); |
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if (regs) { |
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/* Success path for user tasks */ |
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if (user_mode(regs)) |
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return 0; |
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/* |
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* Kernel mode registers on the stack indicate an |
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* in-kernel interrupt or exception (e.g., preemption |
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* or a page fault), which can make frame pointers |
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* unreliable. |
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*/ |
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if (IS_ENABLED(CONFIG_FRAME_POINTER)) |
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return -EINVAL; |
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} |
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addr = unwind_get_return_address(&state); |
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/* |
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* A NULL or invalid return address probably means there's some |
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* generated code which __kernel_text_address() doesn't know |
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* about. |
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*/ |
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if (!addr) |
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return -EINVAL; |
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if (!consume_entry(cookie, addr)) |
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return -EINVAL; |
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} |
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/* Check for stack corruption */ |
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if (unwind_error(&state)) |
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return -EINVAL; |
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return 0; |
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} |
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/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ |
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struct stack_frame_user { |
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const void __user *next_fp; |
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unsigned long ret_addr; |
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}; |
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static int |
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copy_stack_frame(const struct stack_frame_user __user *fp, |
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struct stack_frame_user *frame) |
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{ |
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int ret; |
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if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE)) |
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return 0; |
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ret = 1; |
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pagefault_disable(); |
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if (__get_user(frame->next_fp, &fp->next_fp) || |
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__get_user(frame->ret_addr, &fp->ret_addr)) |
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ret = 0; |
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pagefault_enable(); |
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return ret; |
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} |
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void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, |
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const struct pt_regs *regs) |
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{ |
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const void __user *fp = (const void __user *)regs->bp; |
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if (!consume_entry(cookie, regs->ip)) |
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return; |
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while (1) { |
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struct stack_frame_user frame; |
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frame.next_fp = NULL; |
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frame.ret_addr = 0; |
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if (!copy_stack_frame(fp, &frame)) |
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break; |
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if ((unsigned long)fp < regs->sp) |
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break; |
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if (!frame.ret_addr) |
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break; |
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if (!consume_entry(cookie, frame.ret_addr)) |
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break; |
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fp = frame.next_fp; |
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} |
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} |
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