[PATCH 4/5] iov_iter: Use generic instrumented.h

[Marco Elver <elver@google.com>]

This replaces the kasan instrumentation with generic instrumentation,
implicitly adding KCSAN instrumentation support.

For KASAN no functional change is intended.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
---
 lib/iov_iter.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index fb29c02c6a3c..f06f6f1dd686 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -8,6 +8,7 @@
 #include <linux/splice.h>
 #include <net/checksum.h>
 #include <linux/scatterlist.h>
+#include <linux/instrumented.h>
 
 #define PIPE_PARANOIA /* for now */
 
@@ -137,20 +138,26 @@
 
 static int copyout(void __user *to, const void *from, size_t n)
 {
+	size_t res = n;
+
 	if (access_ok(to, n)) {
-		kasan_check_read(from, n);
-		n = raw_copy_to_user(to, from, n);
+		instrument_copy_to_user_pre(from, n);
+		res = raw_copy_to_user(to, from, n);
+		instrument_copy_to_user_post(from, n, res);
 	}
-	return n;
+	return res;
 }
 
 static int copyin(void *to, const void __user *from, size_t n)
 {
+	size_t res = n;
+
 	if (access_ok(from, n)) {
-		kasan_check_write(to, n);
-		n = raw_copy_from_user(to, from, n);
+		instrument_copy_from_user_pre(to, n);
+		res = raw_copy_from_user(to, from, n);
+		instrument_copy_from_user_post(to, n, res);
 	}
-	return n;
+	return res;
 }
 
 static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
@@ -638,11 +645,14 @@ EXPORT_SYMBOL(_copy_to_iter);
 #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
 static int copyout_mcsafe(void __user *to, const void *from, size_t n)
 {
+	size_t res = n;
+
 	if (access_ok(to, n)) {
-		kasan_check_read(from, n);
-		n = copy_to_user_mcsafe((__force void *) to, from, n);
+		instrument_copy_to_user_pre(from, n);
+		res = copy_to_user_mcsafe((__force void *) to, from, n);
+		instrument_copy_to_user_post(from, n, res);
 	}
-	return n;
+	return res;
 }
 
 static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
-- 
2.25.0.341.g760bfbb309-goog