[tip: locking/urgent] kcsan: Refactor access_info initialization

From: tip-bot2 for Mark Rutland
Date: Wed Jun 30 2021 - 09:53:12 EST


The following commit has been merged into the locking/urgent branch of tip:

Commit-ID: 39b2e763f2defe326e960daefb7fe6acbb2a95b1
Gitweb: https://git.kernel.org/tip/39b2e763f2defe326e960daefb7fe6acbb2a95b1
Author: Mark Rutland <mark.rutland@xxxxxxx>
AuthorDate: Wed, 14 Apr 2021 13:28:21 +02:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Tue, 18 May 2021 10:58:15 -07:00

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@xxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/kcsan/report.c | 42 +++++++++++++++++++++++++-----------------
1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index 8bfa970..d8441be 100644
--- 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);
}