kernel/trace/trace_kprobe.c

Source file repositories/reference/linux-study-clean/kernel/trace/trace_kprobe.c

File Facts

System
Linux kernel
Corpus path
kernel/trace/trace_kprobe.c
Extension
.c
Size
54901 bytes
Lines
2216
Domain
Core OS
Bucket
Scheduler, Processes, Timers, Sync, And Syscalls
Inferred role
Core OS: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct file_operations kprobe_events_ops = {
	.owner          = THIS_MODULE,
	.open           = probes_open,
	.read           = seq_read,
	.llseek         = seq_lseek,
	.release        = seq_release,
	.write		= probes_write,
};

static unsigned long trace_kprobe_missed(struct trace_kprobe *tk)
{
	return trace_kprobe_is_return(tk) ?
		tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
}

/* Probes profiling interfaces */
static int probes_profile_seq_show(struct seq_file *m, void *v)
{
	struct dyn_event *ev = v;
	struct trace_kprobe *tk;
	unsigned long nmissed;

	if (!is_trace_kprobe(ev))
		return 0;

	tk = to_trace_kprobe(ev);
	nmissed = trace_kprobe_missed(tk);
	seq_printf(m, "  %-44s %15lu %15lu\n",
		   trace_probe_name(&tk->tp),
		   trace_kprobe_nhit(tk),
		   nmissed);

	return 0;
}

static const struct seq_operations profile_seq_op = {
	.start  = dyn_event_seq_start,
	.next   = dyn_event_seq_next,
	.stop   = dyn_event_seq_stop,
	.show   = probes_profile_seq_show
};

static int profile_open(struct inode *inode, struct file *file)
{
	int ret;

	ret = security_locked_down(LOCKDOWN_TRACEFS);
	if (ret)
		return ret;

	return seq_open(file, &profile_seq_op);
}

static const struct file_operations kprobe_profile_ops = {
	.owner          = THIS_MODULE,
	.open           = profile_open,
	.read           = seq_read,
	.llseek         = seq_lseek,
	.release        = seq_release,
};

/* Note that we don't verify it, since the code does not come from user space */
static int
process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
		   void *dest, void *base)
{
	struct pt_regs *regs = rec;
	unsigned long val;
	int ret;

retry:
	/* 1st stage: get value from context */
	switch (code->op) {
	case FETCH_OP_REG:
		val = regs_get_register(regs, code->param);
		break;
	case FETCH_OP_STACK:
		val = regs_get_kernel_stack_nth(regs, code->param);
		break;
	case FETCH_OP_STACKP:
		val = kernel_stack_pointer(regs);
		break;
	case FETCH_OP_RETVAL:
		val = regs_return_value(regs);
		break;
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
	case FETCH_OP_ARG:
		val = regs_get_kernel_argument(regs, code->param);
		break;
	case FETCH_OP_EDATA:

Annotation

Implementation Notes