Commit b65e4b56 authored by Alexander Potapenko's avatar Alexander Potapenko Committed by Andrew Morton
Browse files

kmsan: rework kmsan_in_runtime() handling in kmsan_report() 

kmsan_report() calls used to require entering/leaving the runtime around
them.  To simplify the things, drop this requirement and move calls to
kmsan_enter_runtime()/kmsan_leave_runtime() into kmsan_report().

Link: https://lkml.kernel.org/r/20250507160012.3311104-5-glider@google.com


Signed-off-by: default avatarAlexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e17c1f15

mm/kmsan/core.c

+0 −8
Original line number Diff line number Diff line
@@ -274,11 +274,9 @@ void kmsan_internal_check_memory(void *addr, size_t size, 
			 * bytes before, report them.

			 */

			if (cur_origin) {

				kmsan_enter_runtime();

				kmsan_report(cur_origin, addr, size,

					     cur_off_start, pos - 1, user_addr,

					     reason);

				kmsan_leave_runtime();

			}

			cur_origin = 0;

			cur_off_start = -1;
@@ -292,11 +290,9 @@ void kmsan_internal_check_memory(void *addr, size_t size, 
				 * poisoned bytes before, report them.

				 */

				if (cur_origin) {

					kmsan_enter_runtime();

					kmsan_report(cur_origin, addr, size,

						     cur_off_start, pos + i - 1,

						     user_addr, reason);

					kmsan_leave_runtime();

				}

				cur_origin = 0;

				cur_off_start = -1;
@@ -312,11 +308,9 @@ void kmsan_internal_check_memory(void *addr, size_t size, 
			 */

			if (cur_origin != new_origin) {

				if (cur_origin) {

					kmsan_enter_runtime();

					kmsan_report(cur_origin, addr, size,

						     cur_off_start, pos + i - 1,

						     user_addr, reason);

					kmsan_leave_runtime();

				}

				cur_origin = new_origin;

				cur_off_start = pos + i;
@@ -326,10 +320,8 @@ void kmsan_internal_check_memory(void *addr, size_t size, 
	}

	KMSAN_WARN_ON(pos != size);

	if (cur_origin) {

		kmsan_enter_runtime();

		kmsan_report(cur_origin, addr, size, cur_off_start, pos - 1,

			     user_addr, reason);

		kmsan_leave_runtime();

	}

}

mm/kmsan/instrumentation.c

+0 −4
Original line number Diff line number Diff line
@@ -312,13 +312,9 @@ EXPORT_SYMBOL(__msan_unpoison_alloca); 
void __msan_warning(u32 origin);

void __msan_warning(u32 origin)

{

	if (!kmsan_enabled || kmsan_in_runtime())

		return;

	kmsan_enter_runtime();

	kmsan_report(origin, /*address*/ NULL, /*size*/ 0,

		     /*off_first*/ 0, /*off_last*/ 0, /*user_addr*/ NULL,

		     REASON_ANY);

	kmsan_leave_runtime();

}

EXPORT_SYMBOL(__msan_warning);

mm/kmsan/report.c

+3 −3
Original line number Diff line number Diff line
@@ -157,14 +157,14 @@ void kmsan_report(depot_stack_handle_t origin, void *address, int size, 
	unsigned long ua_flags;

	bool is_uaf;



	if (!kmsan_enabled)

	if (!kmsan_enabled || kmsan_in_runtime())

		return;

	if (current->kmsan_ctx.depth)

		return;

	if (!origin)

		return;



	kmsan_disable_current();

	kmsan_enter_runtime();

	ua_flags = user_access_save();

	raw_spin_lock(&kmsan_report_lock);

	pr_err("=====================================================\n");
@@ -217,5 +217,5 @@ void kmsan_report(depot_stack_handle_t origin, void *address, int size, 
	if (panic_on_kmsan)

		panic("kmsan.panic set ...\n");

	user_access_restore(ua_flags);

	kmsan_enable_current();

	kmsan_leave_runtime();

}