2022-03-02 17:34:09

by andrey.konovalov

[permalink] [raw]
Subject: [PATCH mm 18/22] kasan: add comment about UACCESS regions to kasan_report

From: Andrey Konovalov <[email protected]>

Add a comment explaining why kasan_report() is the only reporting
function that uses user_access_save/restore().

Signed-off-by: Andrey Konovalov <[email protected]>
---
mm/kasan/report.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 7915af810815..08631d873204 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -430,6 +430,11 @@ void kasan_report_invalid_free(void *ptr, unsigned long ip)
end_report(&flags, ptr);
}

+/*
+ * kasan_report() is the only reporting function that uses
+ * user_access_save/restore(): kasan_report_invalid_free() cannot be called
+ * from a UACCESS region, and kasan_report_async() is not used on x86.
+ */
bool kasan_report(unsigned long addr, size_t size, bool is_write,
unsigned long ip)
{
--
2.25.1