kmsan: print addresses in reports when possible

This is currently only possible for kmsan_check_memory()
google · Jun 7, 2018 · b047672 · b047672
1 parent 6bcacad
commit b047672
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Showing 3 changed files with 11 additions and 6 deletions.
diff --git a/mm/kmsan/kmsan.c b/mm/kmsan/kmsan.c
@@ -1043,7 +1043,7 @@ inline void *return_address(int arg)
 // |deep| is a dirty hack to skip an additional frame when calling
 // kmsan_report() from kmsan_copy_to_user().
 inline void kmsan_report(void *caller, depot_stack_handle_t origin,
-			int size, int off_first, int off_last, bool deep)
+			u64 address, int size, int off_first, int off_last, bool deep)
 {
 	unsigned long flags;
 	struct stack_trace trace;
@@ -1093,6 +1093,9 @@ inline void kmsan_report(void *caller, depot_stack_handle_t origin,
 		else
 			kmsan_pr_err("Bytes %d-%d of %d are uninitialized\n", off_first, off_last, size);
 	}
+	if (address) {
+		kmsan_pr_err("Memory access starts at %px\n", address);
+	}
 	kmsan_pr_err("==================================================================\n");
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
 	spin_unlock_irqrestore(&report_lock, flags);
@@ -1171,7 +1174,7 @@ void kmsan_internal_check_memory(const void *addr, size_t size)
 	for (i = 0; i < size; i++) {
 		if (!shadow[i]) {
 			if (prev_start != -1)
-				kmsan_report(_THIS_IP_, prev_origin, size, prev_start, i - 1, /*deep*/true);
+				kmsan_report(_THIS_IP_, prev_origin, addr, size, prev_start, i - 1, /*deep*/true);
 			prev_origin = 0;
 			prev_start = -1;
 			continue;
@@ -1184,13 +1187,13 @@ void kmsan_internal_check_memory(const void *addr, size_t size)
 			continue;
 		}
 		if (origin != prev_origin) {
-			kmsan_report(_THIS_IP_, prev_origin, size, prev_start, i - 1, /*deep*/true);
+			kmsan_report(_THIS_IP_, prev_origin, addr, size, prev_start, i - 1, /*deep*/true);
 			prev_origin = origin;
 			prev_start = i;
 		}
 	}
 	if (prev_origin) {
-		kmsan_report(_THIS_IP_, prev_origin, size, prev_start, size - 1, /*deep*/true);
+		kmsan_report(_THIS_IP_, prev_origin, addr, size, prev_start, size - 1, /*deep*/true);
 	}
 	LEAVE_RUNTIME(irq_flags);
 }

diff --git a/mm/kmsan/kmsan.h b/mm/kmsan/kmsan.h
@@ -93,7 +93,8 @@ depot_stack_handle_t kmsan_internal_chain_origin(depot_stack_handle_t id, bool f
 void do_kmsan_thread_create(struct task_struct *task);
 void kmsan_set_origin(u64 address, int size, u32 origin);
 inline void kmsan_report(void *caller, depot_stack_handle_t origin,
-			int size, int off_first, int off_last, bool deep);
+			u64 address, int size,
+			int off_first, int off_last, bool deep);
 
 int kmsan_alloc_meta_for_pages(struct page *page, unsigned int order,
 				gfp_t flags, int node);

diff --git a/mm/kmsan/kmsan_instr.c b/mm/kmsan/kmsan_instr.c
@@ -680,7 +680,8 @@ void __msan_warning_32(u32 origin)
 		return;
 	ENTER_RUNTIME(irq_flags);
 	caller = __builtin_return_address(0);
-	kmsan_report(caller, origin, /*size*/0, /*off_first*/0, /*off_last*/0, /*deep*/false);
+	kmsan_report(caller, origin, /*address*/0, /*size*/0,
+			/*off_first*/0, /*off_last*/0, /*deep*/false);
 	LEAVE_RUNTIME(irq_flags);
 }
 EXPORT_SYMBOL(__msan_warning_32);