/*
* Entry point from instrumented code.
* This is called once per basic-block/edge.
*/
void notrace __sanitizer_cov_trace_pc(void)
{
struct task_struct *t;
enum kcov_mode mode;
t = current;
/*
* We are interested in code coverage as a function of a syscall inputs,
* so we ignore code executed in interrupts.
* The checks for whether we are in an interrupt are open-coded, because
* 1. We can't use in_interrupt() here, since it also returns true
* when we are inside local_bh_disable() section.
* 2. We don't want to use (in_irq() | in_serving_softirq() | in_nmi()),
* since that leads to slower generated code (three separate tests,
* one for each of the flags).
*/
if (!t || (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET
| NMI_MASK)))
return;
mode = READ_ONCE(t->kcov_mode);
if (mode == KCOV_MODE_TRACE) {
unsigned long *area;
unsigned long pos;
unsigned long ip = _RET_IP_;
#ifdef CONFIG_RANDOMIZE_BASE
ip -= kaslr_offset();
#endif
/*
* There is some code that runs in interrupts but for which
* in_interrupt() returns false (e.g. preempt_schedule_irq()).
* READ_ONCE()/barrier() effectively provides load-acquire wrt
* interrupts, there are paired barrier()/WRITE_ONCE() in
* kcov_ioctl_locked().
*/
barrier();
area = t->kcov_area;
/* The first word is number of subsequent PCs. */
pos = READ_ONCE(area[0]) + 1;
if (likely(pos < t->kcov_size)) {
area[pos] = ip;
WRITE_ONCE(area[0], pos);
}
}
}
/*
* Entry point from instrumented code.
* This is called once per basic-block/edge.
*/
void notrace __sanitizer_cov_trace_pc(void)
{
struct task_struct *t;
enum kcov_mode mode;
t = current;
/*
* We are interested in code coverage as a function of a syscall inputs,
* so we ignore code executed in interrupts.
*/
if (!t || !in_task())
return;
mode = READ_ONCE(t->kcov_mode);
if (mode == KCOV_MODE_TRACE) {
unsigned long *area;
unsigned long pos;
unsigned long ip = _RET_IP_;
#ifdef CONFIG_RANDOMIZE_BASE
ip -= kaslr_offset();
#endif
/*
* There is some code that runs in interrupts but for which
* in_interrupt() returns false (e.g. preempt_schedule_irq()).
* READ_ONCE()/barrier() effectively provides load-acquire wrt
* interrupts, there are paired barrier()/WRITE_ONCE() in
* kcov_ioctl_locked().
*/
barrier();
area = t->kcov_area;
/* The first word is number of subsequent PCs. */
pos = READ_ONCE(area[0]) + 1;
if (likely(pos < t->kcov_size)) {
area[pos] = ip;
WRITE_ONCE(area[0], pos);
}
}
}
