kcsan: Refactor access_info initialization

In subsequent patches we'll want to split kcsan_report() into distinct
handlers for each report type. The largest bit of common work is
initializing the `access_info`, so let's factor this out into a helper,
and have the kcsan_report_*() functions pass the `aaccess_info` as a
parameter to kcsan_report().

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>

diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index 8bfa970..d8441be 100644 (file)
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -596,18 +596,10 @@ 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,
+static void kcsan_report(const struct access_info *ai, enum kcsan_value_change value_change,
                         enum kcsan_report_type type, struct other_info *other_info)
 {
        unsigned long flags = 0;
-       const struct access_info ai = {
-               .ptr            = ptr,
-               .size           = size,
-               .access_type    = access_type,
-               .task_pid       = in_task() ? task_pid_nr(current) : -1,
-               .cpu_id         = raw_smp_processor_id()
-       };
 
        kcsan_disable_current();
 
@@ -620,14 +612,14 @@ static void kcsan_report(const volatile void *ptr, size_t size, int access_type,
         */
        lockdep_off();
 
-       if (prepare_report(&flags, type, &ai, other_info)) {
+       if (prepare_report(&flags, type, ai, other_info)) {
                /*
                 * Never report if value_change is FALSE, only if we it is
                 * either TRUE or MAYBE. In case of MAYBE, further filtering may
                 * be done once we know the full stack trace in print_report().
                 */
                if (value_change != KCSAN_VALUE_CHANGE_FALSE)
-                       print_report(value_change, type, &ai, other_info);
+                       print_report(value_change, type, ai, other_info);
 
                release_report(&flags, other_info);
        }
@@ -636,22 +628,38 @@ static void kcsan_report(const volatile void *ptr, size_t size, int access_type,
        kcsan_enable_current();
 }
 
+static struct access_info prepare_access_info(const volatile void *ptr, size_t size,
+                                             int access_type)
+{
+       return (struct access_info) {
+               .ptr            = ptr,
+               .size           = size,
+               .access_type    = access_type,
+               .task_pid       = in_task() ? task_pid_nr(current) : -1,
+               .cpu_id         = raw_smp_processor_id()
+       };
+}
+
 void kcsan_report_set_info(const volatile void *ptr, size_t size, int access_type,
                           int watchpoint_idx)
 {
-       kcsan_report(ptr, size, access_type, KCSAN_VALUE_CHANGE_MAYBE,
-                    KCSAN_REPORT_CONSUMED_WATCHPOINT, &other_infos[watchpoint_idx]);
+       const struct access_info ai = prepare_access_info(ptr, size, access_type);
+
+       kcsan_report(&ai, KCSAN_VALUE_CHANGE_MAYBE, 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, &other_infos[watchpoint_idx]);
+       const struct access_info ai = prepare_access_info(ptr, size, access_type);
+
+       kcsan_report(&ai, value_change, 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, NULL);
+       const struct access_info ai = prepare_access_info(ptr, size, access_type);
+
+       kcsan_report(&ai, KCSAN_VALUE_CHANGE_TRUE, KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, NULL);
 }