显示当前函数的被调用图的同时,显示每个调用关系中的调用条件.

[houranled]

graph TD
    A(main) -->|condition...| C(FuncC)
    A -->|condition...| B(FuncB)
    B -->|condition...| D(FuncD)
    C -->|condition...| D
    D -.->|condition...| E[FuncD line 4300]
    F[condition and condition...] --> E

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[houranled]

condition的内容一般时候是隐藏,通过鼠标悬停、点击等方式查看。

[houranled]

`static int __ref kernel_init(void *unused)
{
int ret;

kernel_init_freeable();
/* need to finish all async __init code before freeing the memory */
async_synchronize_full();
kprobe_free_init_mem();
ftrace_free_init_mem();
free_initmem();
mark_readonly();

/*
 * Kernel mappings are now finalized - update the userspace page-table
 * to finalize PTI.
 */
pti_finalize();

system_state = SYSTEM_RUNNING;
numa_default_policy();

rcu_end_inkernel_boot();

do_sysctl_args();

if (ramdisk_execute_command) {
	ret = run_init_process(ramdisk_execute_command);
	if (!ret)
		return 0;
	pr_err("Failed to execute %s (error %d)\n",
	       ramdisk_execute_command, ret);
}

/*
 * We try each of these until one succeeds.
 *
 * The Bourne shell can be used instead of init if we are
 * trying to recover a really broken machine.
 */
if (execute_command) {
	ret = run_init_process(execute_command);
	if (!ret)
		return 0;
	panic("Requested init %s failed (error %d).",
	      execute_command, ret);
}

if (CONFIG_DEFAULT_INIT[0] != '\0') {
	ret = run_init_process(CONFIG_DEFAULT_INIT);
	if (ret)
		pr_err("Default init %s failed (error %d)\n",
		       CONFIG_DEFAULT_INIT, ret);
	else
		return 0;
}

if (!try_to_run_init_process("/sbin/init") ||
    !try_to_run_init_process("/etc/init") ||
    !try_to_run_init_process("/bin/init") ||
    !try_to_run_init_process("/bin/sh"))
	return 0;

panic("No working init found.  Try passing init= option to kernel. "
      "See Linux Documentation/admin-guide/init.rst for guidance.");//<====执行到此处的逻辑条件

}`

拿这个函数举例, 查看末尾代码行panic("No working init...的执行条件是:

(!ramdisk_execute_command || ( ret = run_init_process(ramdisk_execute_command) != 0)) && (!execute_command || (ret = run_init_process(execute_command) !=0)) && (CONFIG_DEFAULT_INIT[0] == '\0' || (ret = run_init_process(CONFIG_DEFAULT_INIT) =!0 )) && (try_to_run_init_process("/sbin/init") && try_to_run_init_process("/etc/init") && try_to_run_init_process("/bin/init") && try_to_run_init_process("/bin/sh") )

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注意,要考虑到: return exit 函数指针方式调用的情况.