From: Alexander Potapenko <glider@google.com>
Date: Wed, 7 May 2025 16:00:09 +0000 (+0200)
Subject: kmsan: fix usage of kmsan_enter_runtime() in kmsan_vmap_pages_range_noflush()
X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=8312ab31d362fcb6d68f1f2da4d1e89bc5d3f48c;p=linux-2.6-microblaze.git

kmsan: fix usage of kmsan_enter_runtime() in kmsan_vmap_pages_range_noflush()

Only enter the runtime to call __vmap_pages_range_noflush(), so that error
handling does not skip kmsan_leave_runtime().

This bug was spotted by CONFIG_WARN_CAPABILITY_ANALYSIS=y

Link: https://lkml.kernel.org/r/20250507160012.3311104-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: 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: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/kmsan/shadow.c b/mm/kmsan/shadow.c
index 6d32bfc18d6a..54f3c3c962f0 100644
--- a/mm/kmsan/shadow.c
+++ b/mm/kmsan/shadow.c
@@ -247,17 +247,19 @@ int kmsan_vmap_pages_range_noflush(unsigned long start, unsigned long end,
 	kmsan_enter_runtime();
 	mapped = __vmap_pages_range_noflush(shadow_start, shadow_end, prot,
 					    s_pages, page_shift);
+	kmsan_leave_runtime();
 	if (mapped) {
 		err = mapped;
 		goto ret;
 	}
+	kmsan_enter_runtime();
 	mapped = __vmap_pages_range_noflush(origin_start, origin_end, prot,
 					    o_pages, page_shift);
+	kmsan_leave_runtime();
 	if (mapped) {
 		err = mapped;
 		goto ret;
 	}
-	kmsan_leave_runtime();
 	flush_tlb_kernel_range(shadow_start, shadow_end);
 	flush_tlb_kernel_range(origin_start, origin_end);
 	flush_cache_vmap(shadow_start, shadow_end);