The following commit has been merged into the locking/urgent branch of tip: Commit-ID: 95f7524d7f0c6fddbc24fb623d61b7d508626f41 Gitweb: https://git.kernel.org/tip/95f7524d7f0c6fddbc24fb623d61b7d508626f41 Author: Mark Rutland <mark.rutland@xxxxxxx> AuthorDate: Wed, 14 Apr 2021 13:28:19 +02:00 Committer: Paul E. McKenney <paulmck@xxxxxxxxxx> CommitterDate: Tue, 18 May 2021 10:58:14 -07:00 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@xxxxxxx> Signed-off-by: Marco Elver <elver@xxxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- kernel/kcsan/report.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c index 5232bf2..88225f6 100644 --- a/kernel/kcsan/report.c +++ b/kernel/kcsan/report.c @@ -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); }