kcsan: Refactor passing watchpoint/other_info

The `watchpoint_idx` argument to kcsan_report() isn't meaningful for
races which were not detected by a watchpoint, and it would be clearer
if callers passed the other_info directly so that a NULL value can be
passed in this case.

Given that callers manipulate their watchpoints before passing the index
into kcsan_report_*(), and given we index the `other_infos` array using
this before we sanity-check it, the subsequent sanity check isn't all
that useful.

Let's remove the `watchpoint_idx` sanity check, and move the job of
finding the `other_info` out of kcsan_report().

Other than the removal of the check, there should be no functional
change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Mark Rutland 2021-04-14 13:28:19 +02:00 committed by Paul E. McKenney
parent 793c2579be
commit 95f7524d7f

View file

@ -600,7 +600,7 @@ static noinline bool prepare_report(unsigned long *flags,
static void kcsan_report(const volatile void *ptr, size_t size, int access_type,
enum kcsan_value_change value_change,
enum kcsan_report_type type, int watchpoint_idx)
enum kcsan_report_type type, struct other_info *other_info)
{
unsigned long flags = 0;
const struct access_info ai = {
@ -610,12 +610,8 @@ static void kcsan_report(const volatile void *ptr, size_t size, int access_type,
.task_pid = in_task() ? task_pid_nr(current) : -1,
.cpu_id = raw_smp_processor_id()
};
struct other_info *other_info = type == KCSAN_REPORT_RACE_UNKNOWN_ORIGIN
? NULL : &other_infos[watchpoint_idx];
kcsan_disable_current();
if (WARN_ON(watchpoint_idx < 0 || watchpoint_idx >= ARRAY_SIZE(other_infos)))
goto out;
/*
* Because we may generate reports when we're in scheduler code, the use
@ -642,7 +638,6 @@ static void kcsan_report(const volatile void *ptr, size_t size, int access_type,
}
lockdep_on();
out:
kcsan_enable_current();
}
@ -650,18 +645,18 @@ void kcsan_report_set_info(const volatile void *ptr, size_t size, int access_typ
int watchpoint_idx)
{
kcsan_report(ptr, size, access_type, KCSAN_VALUE_CHANGE_MAYBE,
KCSAN_REPORT_CONSUMED_WATCHPOINT, watchpoint_idx);
KCSAN_REPORT_CONSUMED_WATCHPOINT, &other_infos[watchpoint_idx]);
}
void kcsan_report_known_origin(const volatile void *ptr, size_t size, int access_type,
enum kcsan_value_change value_change, int watchpoint_idx)
{
kcsan_report(ptr, size, access_type, value_change,
KCSAN_REPORT_RACE_SIGNAL, watchpoint_idx);
KCSAN_REPORT_RACE_SIGNAL, &other_infos[watchpoint_idx]);
}
void kcsan_report_unknown_origin(const volatile void *ptr, size_t size, int access_type)
{
kcsan_report(ptr, size, access_type, KCSAN_VALUE_CHANGE_TRUE,
KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, 0);
KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, NULL);
}