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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131/* * 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 intcopy_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; }}